tag:theconversation.com,2011:/au/topics/quantum-physics-259/articlesQuantum physics – The Conversation2024-03-26T17:01:56Ztag:theconversation.com,2011:article/2262572024-03-26T17:01:56Z2024-03-26T17:01:56ZHow long before quantum computers can benefit society? That’s Google’s US$5 million question<figure><img src="https://images.theconversation.com/files/583117/original/file-20240320-26-rmpub2.jpg?ixlib=rb-1.1.0&rect=5%2C0%2C3828%2C2160&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption"></span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-illustration/quantum-computer-black-background-3d-render-1571871052">Bartlomiej K. Wroblewski / Shutterstock</a></span></figcaption></figure><p>Google and the XPrize Foundation have launched a competition worth US$5 million (£4 million) to develop <a href="https://blog.google/technology/research/google-gesda-and-xprize-launch-new-competition-in-quantum-applications/">real-world applications for quantum computers</a> that benefit society – by speeding up progress on one of the UN Sustainable Development Goals, for example. The principles of quantum physics suggest quantum computers could perform very fast calculations on particular problems, so this competition may expand the range of applications where they have an advantage over conventional computers.</p>
<p>In our everyday lives, the way nature works can generally be described by what we call <a href="https://en.wikipedia.org/wiki/Classical_physics#:%7E:text=Classical%20physical%20concepts%20are%20often,of%20quantum%20mechanics%20and%20relativity.">classical physics</a>. But nature behaves very differently at tiny quantum scales – below the size of an atom. </p>
<p>The race to harness quantum technology can be viewed as a new industrial revolution, progressing from devices that use the properties of classical physics to those utilising the <a href="https://www.energy.gov/science/doe-explainsquantum-mechanics#:%7E:text=Quantum%20mechanics%20is%20the%20field,%E2%80%9Cwave%2Dparticle%20duality.%E2%80%9D">weird and wonderful properties of quantum mechanics</a>. Scientists have spent decades trying to develop new technologies by harnessing these properties. </p>
<p>Given how often we are told that <a href="https://projects.research-and-innovation.ec.europa.eu/en/horizon-magazine/quantum-technologies">quantum technologies</a> will revolutionise our everyday lives, you may be surprised that we still have to search for practical applications by offering a prize. However, while there are numerous examples of success using quantum properties for enhanced precision in sensing and timing, there has been a surprising lack of progress in the development of quantum computers that outdo their classical predecessors.</p>
<p>The main bottleneck holding up this development is that the software – using <a href="https://www.nature.com/articles/npjqi201523">quantum algorithms</a> –
needs to demonstrate an advantage over computers based on classical physics. This is commonly known as <a href="https://theconversation.com/what-is-quantum-advantage-a-quantum-computing-scientist-explains-an-approaching-milestone-marking-the-arrival-of-extremely-powerful-computers-213306">“quantum advantage”</a>.</p>
<p>A crucial way quantum computing differs from classical computing is in using a property known as <a href="https://spectrum.ieee.org/what-is-quantum-entanglement">“entanglement”</a>. Classical computing <a href="https://web.stanford.edu/class/cs101/bits-bytes.html">uses “bits”</a> to represent information. These bits consist of ones and zeros, and everything a computer does comprises strings of these ones and zeros. But quantum computing allows these bits to be in a <a href="https://azure.microsoft.com/en-gb/resources/cloud-computing-dictionary/what-is-a-qubit">“superposition” of ones and zeros</a>. In other words, it is as if these ones and zeros occur simultaneously in the quantum bit, or qubit.</p>
<p>It is this property which allows computational tasks to be performed all at once. Hence the belief that quantum computing can offer a significant advantage over classical computing, as it is able to perform many computing tasks at the same time. </p>
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<a href="https://theconversation.com/what-is-quantum-advantage-a-quantum-computing-scientist-explains-an-approaching-milestone-marking-the-arrival-of-extremely-powerful-computers-213306">What is quantum advantage? A quantum computing scientist explains an approaching milestone marking the arrival of extremely powerful computers</a>
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<h2>Notable quantum algorithms</h2>
<p>While performing many tasks simultaneously should lead to a performance increase over classical computers, putting this into practice has proven more difficult than theory would suggest. There are actually only a few notable quantum algorithms which can perform their tasks better than those using classical physics.</p>
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<p>The most notable are the <a href="https://www.st-andrews.ac.uk/physics/quvis/simulations_html5/sims/cryptography-bb84/Quantum_Cryptography.html">BB84 protocol</a>, developed in 1984, and <a href="https://www.nature.com/articles/s41598-021-95973-w">Shor’s algorithm</a>, developed in 1994, both of which use entanglement to outperform classical algorithms on particular tasks. </p>
<p>The BB84 protocol is a cryptographic protocol – a system for ensuring secure, private communication between two or more parties which is considered more secure than comparable classical algorithms.</p>
<p>Shor’s algorithm uses entanglement to demonstrate how current <a href="https://www.rand.org/pubs/commentary/2023/09/when-a-quantum-computer-is-able-to-break-our-encryption.html#:%7E:text=One%20of%20the%20most%20important,secure%20internet%20traffic%20against%20interception.">classical encryption protocols can be broken</a>, because they are based on the factorisation of very large numbers. <a href="https://ieeexplore.ieee.org/document/365700">There is also evidence</a> that it can perform certain calculations faster than similar algorithms designed for conventional computers. </p>
<p>Despite the superiority of these two algorithms over conventional ones, few advantageous quantum algorithms have followed. However, researchers have not given up trying to develop them. Currently, there are a couple of main directions in research.</p>
<h2>Potential quantum benefits</h2>
<p>The first is to use quantum mechanics to assist in what are called <a href="https://arxiv.org/abs/2312.02279">large-scale optimisation tasks</a>. Optimisation – finding the best or most effective way to solve a particular task – is vital in everyday life, from ensuring traffic flow runs effectively, to managing operational procedures in factory pipelines, to streaming services deciding what to recommend to each user. It seems clear that quantum computers could help with these problems.</p>
<p>If we could reduce the computational time required to perform the optimisation, it could save energy, reducing the carbon footprint of the many computers currently performing these tasks around the world and the data centres supporting them.</p>
<p>Another development that could offer wide-reaching benefits is to use quantum computation to simulate systems, such as combinations of atoms, that behave according to quantum mechanics. Understanding and predicting how quantum systems work in practice could, for example, lead to better drug design and medical treatments. </p>
<p>Quantum systems could also lead to improved electronic devices. As computer chips get smaller, quantum effects take hold, potentially reducing the devices’s performance. A better fundamental understanding of quantum mechanics could help avoid this.</p>
<p>While there has been significant investment in building quantum computers, there has been less focus on ensuring they will directly benefit the public. However, that now appears to be changing.</p>
<p>Whether we will all have quantum computers in our homes within the next 20 years remains doubtful. But, given the current financial commitment to making quantum computation a practical reality, it seems that society is finally in a better position to make use of them. What precise form will this take? There’s US$5 million dollars on the line to find out.</p><img src="https://counter.theconversation.com/content/226257/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Adam Lowe does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Quantum computing has huge promise from a technical perspective, but the practical benefits are less clear.Adam Lowe, Lecturer, School of Computer Science and Digital Technologies, Aston UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2243722024-03-03T19:19:44Z2024-03-03T19:19:44ZGravity experiments on the kitchen table: why a tiny, tiny measurement may be a big leap forward for physics<figure><img src="https://images.theconversation.com/files/579074/original/file-20240301-30-ecsdm7.jpg?ixlib=rb-1.1.0&rect=3%2C16%2C2131%2C1536&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-illustration/string-theory-physical-processes-quantum-entanglement-733672807">Shutterstock</a></span></figcaption></figure><p>Just over a week ago, European physicists <a href="https://www.science.org/doi/10.1126/sciadv.adk2949">announced</a> they had measured the strength of gravity on the smallest scale ever. </p>
<p>In a clever tabletop experiment, researchers at Leiden University in the Netherlands, the University of Southampton in the UK, and the Institute for Photonics and Nanotechnologies in Italy measured a force of around 30 attonewtons on a particle with just under half a milligram of mass. An attonewton is a billionth of a billionth of a newton, the standard unit of force.</p>
<p>The researchers <a href="https://www.eurekalert.org/news-releases/1035222">say</a> the work could “unlock more secrets about the universe’s very fabric” and may be an important step toward the next big revolution in physics. </p>
<p>But why is that? It’s not just the result: it’s the method, and what it says about a path forward for a branch of science critics say may be trapped in a loop of <a href="https://www.prospectmagazine.co.uk/ideas/technology/38913/is-particle-physics-at-a-dead-end">rising costs and diminishing returns</a>.</p>
<h2>Gravity</h2>
<p>From a physicist’s point of view, gravity is an extremely weak force. This might seem like an odd thing to say. It doesn’t feel weak when you’re trying to get out of bed in the morning!</p>
<p>Still, compared with the other forces that we know about – such as the electromagnetic force that is responsible for binding atoms together and for generating light, and the strong nuclear force that binds the cores of atoms – gravity exerts a relatively weak attraction between objects. </p>
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<a href="https://theconversation.com/explainer-standard-model-of-particle-physics-2539">Explainer: Standard Model of Particle Physics</a>
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<p>And on smaller scales, the effects of gravity get weaker and weaker.</p>
<p>It’s easy to see the effects of gravity for objects the size of a star or planet, but it is much harder to detect gravitational effects for small, light objects.</p>
<h2>The need to test gravity</h2>
<p>Despite the difficulty, physicists really want to test gravity at small scales. This is because it could help resolve a century-old mystery in current physics.</p>
<p>Physics is dominated by two extremely successful theories. </p>
<p>The first is general relativity, which describes gravity and spacetime at large scales. The second is quantum mechanics, which is a theory of particles and fields – the basic building blocks of matter – at small scales. </p>
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Read more:
<a href="https://theconversation.com/approaching-zero-super-chilled-mirrors-edge-towards-the-borders-of-gravity-and-quantum-physics-162785">Approaching zero: super-chilled mirrors edge towards the borders of gravity and quantum physics</a>
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<p>These two theories are in some ways contradictory, and physicists don’t understand what happens in situations where both should apply. One goal of modern physics is to combine general relativity and quantum mechanics into a theory of “quantum gravity”. </p>
<p>One example of a situation where quantum gravity is needed is to fully understand black holes. These are predicted by general relativity – and we have observed huge ones in space – but tiny black holes may also arise at the quantum scale. </p>
<p>At present, however, we don’t know how to bring general relativity and quantum mechanics together to give an account of how gravity, and thus black holes, work in the quantum realm.</p>
<h2>New theories and new data</h2>
<p>A number of approaches to a potential theory of quantum gravity have been developed, including <a href="https://theconversation.com/explainer-string-theory-2983">string theory</a>, <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5567241/">loop quantum gravity</a> and <a href="https://link.springer.com/article/10.1007/s41114-019-0023-1">causal set theory</a>.</p>
<p>However, these approaches are entirely theoretical. We currently don’t have any way to test them via experiments.</p>
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<p>To empirically test these theories, we’d need a way to measure gravity at very small scales where quantum effects dominate.</p>
<p>Until recently, performing such tests was out of reach. It seemed we would need very large pieces of equipment: even bigger than the world’s largest particle accelerator, the Large Hadron Collider, which sends high-energy particles zooming around a 27-kilometre loop before smashing them together. </p>
<h2>Tabletop experiments</h2>
<p>This is why the recent small-scale measurement of gravity is so important.</p>
<p>The experiment conducted jointly between the Netherlands and the UK is a “tabletop” experiment. It didn’t require massive machinery.</p>
<p>The experiment works by floating a particle in a magnetic field and then swinging a weight past it to see how it “wiggles” in response.</p>
<p>This is analogous to the way one planet “wiggles” when it swings past another.</p>
<p>By levitating the particle with magnets, it can be isolated from many of the influences that make detecting weak gravitational influences so hard.</p>
<p>The beauty of tabletop experiments like this is they don’t cost billions of dollars, which removes one of the main barriers to conducting small-scale gravity experiments, and potentially to making progress in physics. (The latest proposal for a bigger successor to the Large Hadron Collider would <a href="https://www.nature.com/articles/d41586-024-00353-9">cost US$17 billion</a>.)</p>
<h2>Work to do</h2>
<p>Tabletop experiments are very promising, but there is still work to do.</p>
<p>The recent experiment comes close to the quantum domain, but doesn’t quite get there. The masses and forces involved will need to be even smaller, to find out how gravity acts at this scale. </p>
<p>We also need to be prepared for the possibility that it may not be possible to push tabletop experiments this far.</p>
<p>There may yet be some technological limitation that prevents us from conducting experiments of gravity at quantum scales, pushing us back toward building bigger colliders.</p>
<h2>Back to the theories</h2>
<p>It’s also worth noting some of the theories of quantum gravity that might be tested using tabletop experiments are very radical.</p>
<p>Some theories, such as loop quantum gravity, suggest <a href="https://theconversation.com/time-might-not-exist-according-to-physicists-and-philosophers-but-thats-okay-181268">space and time may disappear</a> at very small scales or high energies. If that’s right, it may not be possible to carry out experiments at these scales.</p>
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Read more:
<a href="https://theconversation.com/explainer-string-theory-2983">Explainer: String theory</a>
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<p>After all, experiments as we know them are the kind of thing that happen at a particular place, across a particular interval of time. If theories like this are correct, we may need to rethink the very nature of experimentation so we can make sense of it in situations where space and time are absent.</p>
<p>On the other hand, the very fact we can perform straightforward experiments involving gravity at small scales may suggest that space and time are present after all.</p>
<p>Which will prove true? The best way to find out is to keep going with tabletop experiments, and to push them as far as they can go.</p><img src="https://counter.theconversation.com/content/224372/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Sam Baron receives funding from the Australian Research Council.</span></em></p>A new measurement of gravity at small scales hints at an alternative to billion-dollar experiments for the future of physics.Sam Baron, Associate Professor, Philosophy of Science, The University of MelbourneLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2133062023-11-17T13:29:43Z2023-11-17T13:29:43ZWhat is quantum advantage? A quantum computing scientist explains an approaching milestone marking the arrival of extremely powerful computers<figure><img src="https://images.theconversation.com/files/559476/original/file-20231114-21-dv3rca.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C5731%2C3829&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">IBM's quantum computer got President Joe Biden's attention.</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/president-joe-biden-looks-at-quantum-computer-as-he-tours-news-photo/1243772280">Mandel Ngan/AFP via Getty Images</a></span></figcaption></figure><p>Quantum advantage is the milestone the field of quantum computing is fervently working toward, where a quantum computer can solve problems that are beyond the reach of the most powerful non-quantum, or classical, computers. </p>
<p>Quantum refers to the scale of atoms and molecules where the laws of physics as we experience them break down and a different, counterintuitive set of laws apply. Quantum computers take advantage of these strange behaviors to solve problems.</p>
<p>There are some types of problems that are <a href="https://theconversation.com/limits-to-computing-a-computer-scientist-explains-why-even-in-the-age-of-ai-some-problems-are-just-too-difficult-191930">impractical for classical computers to solve</a>, such as cracking state-of-the-art encryption algorithms. Research in recent decades has shown that quantum computers have the potential to solve some of these problems. If a quantum computer can be built that actually does solve one of these problems, it will have demonstrated quantum advantage.</p>
<p>I am <a href="https://scholar.google.com/citations?user=2J2t64gAAAAJ&hl=en">a physicist</a> who studies quantum information processing and the control of quantum systems. I believe that this frontier of scientific and technological innovation not only promises groundbreaking advances in computation but also represents a broader surge in quantum technology, including significant advancements in quantum cryptography and quantum sensing.</p>
<h2>The source of quantum computing’s power</h2>
<p>Central to quantum computing is the quantum bit, or <a href="https://quantumatlas.umd.edu/entry/qubit/">qubit</a>. Unlike classical bits, which can only be in states of 0 or 1, a qubit can be in any state that is some combination of 0 and 1. This state of neither just 1 or just 0 is known as a <a href="https://quantumatlas.umd.edu/entry/superposition/">quantum superposition</a>. With every additional qubit, the number of states that can be represented by the qubits doubles. </p>
<p>This property is often mistaken for the source of the power of quantum computing. Instead, it comes down to an intricate interplay of superposition, <a href="https://encyclopedia2.thefreedictionary.com/Quantum+Interference">interference</a> and <a href="https://theconversation.com/nobel-winning-quantum-weirdness-undergirds-an-emerging-high-tech-industry-promising-better-ways-of-encrypting-communications-and-imaging-your-body-191929">entanglement</a>.</p>
<p>Interference involves manipulating qubits so that their states combine constructively during computations to amplify correct solutions and destructively to suppress the wrong answers. Constructive interference is what happens when the peaks of two waves – like sound waves or ocean waves – combine to create a higher peak. Destructive interference is what happens when a wave peak and a wave trough combine and cancel each other out. Quantum algorithms, which are few and difficult to devise, set up a sequence of interference patterns that yield the correct answer to a problem.</p>
<p>Entanglement establishes a uniquely quantum correlation between qubits: The state of one cannot be described independently of the others, no matter how far apart the qubits are. This is what Albert Einstein famously dismissed as “spooky action at a distance.” Entanglement’s collective behavior, orchestrated through a quantum computer, enables computational speed-ups that are beyond the reach of classical computers.</p>
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<figcaption><span class="caption">The ones and zeros – and everything in between – of quantum computing.</span></figcaption>
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<h2>Applications of quantum computing</h2>
<p>Quantum computing has a range of potential uses where it can outperform classical computers. In cryptography, quantum computers pose both an opportunity and a challenge. Most famously, they have the <a href="https://theconversation.com/is-quantum-computing-a-cybersecurity-threat-107411">potential to decipher current encryption algorithms</a>, such as the widely used <a href="https://www.britannica.com/topic/RSA-encryption">RSA scheme</a>. </p>
<p>One consequence of this is that today’s encryption protocols need to be reengineered to be resistant to future quantum attacks. This recognition has led to the burgeoning field of <a href="https://www.nist.gov/programs-projects/post-quantum-cryptography">post-quantum cryptography</a>. After a long process, the National Institute of Standards and Technology recently selected four quantum-resistant algorithms and has begun the process of readying them so that organizations around the world can use them in their encryption technology.</p>
<p>In addition, quantum computing can dramatically speed up quantum simulation: the ability to predict the outcome of experiments operating in the quantum realm. Famed physicist Richard Feynman <a href="https://doi.org/10.1007/BF02650179">envisioned this possibility</a> more than 40 years ago. Quantum simulation offers the potential for considerable advancements in chemistry and materials science, aiding in areas such as the intricate modeling of molecular structures for drug discovery and enabling the discovery or creation of materials with novel properties. </p>
<p>Another use of quantum information technology is <a href="https://doi.org/10.1103/RevModPhys.89.035002">quantum sensing</a>: detecting and measuring physical properties like electromagnetic energy, gravity, pressure and temperature with greater sensitivity and precision than non-quantum instruments. Quantum sensing has myriad applications in fields such as <a href="https://www.azoquantum.com/Article.aspx?ArticleID=444">environmental monitoring</a>, <a href="https://doi.org/10.1038/s41586-021-04315-3">geological exploration</a>, <a href="https://doi.org/10.1038/s42254-023-00558-3">medical imaging</a> and <a href="https://www.defenseone.com/ideas/2022/06/quantum-sensorsunlike-quantum-computersare-already-here/368634/">surveillance</a>.</p>
<p>Initiatives such as the development of a quantum internet that interconnects quantum computers are crucial steps toward bridging the quantum and classical computing worlds. This network could be secured using quantum cryptographic protocols such as quantum key distribution, which enables ultra-secure communication channels that are protected against computational attacks – including those using quantum computers.</p>
<p>Despite a growing application suite for quantum computing, developing new algorithms that make full use of the quantum advantage – in particular <a href="https://journals.aps.org/prxquantum/pdf/10.1103/PRXQuantum.3.030101">in machine learning</a> – remains a critical area of ongoing research.</p>
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<span class="caption">A prototype quantum sensor developed by MIT researchers can detect any frequency of electromagnetic waves.</span>
<span class="attribution"><a class="source" href="https://news.mit.edu/2022/quantum-sensor-frequency-0621">Guoqing Wang</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc-nd/4.0/">CC BY-NC-ND</a></span>
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<h2>Staying coherent and overcoming errors</h2>
<p>The quantum computing field faces significant hurdles in hardware and software development. Quantum computers are highly sensitive to any unintentional interactions with their environments. This leads to the phenomenon of decoherence, where qubits rapidly degrade to the 0 or 1 states of classical bits. </p>
<p>Building large-scale quantum computing systems capable of delivering on the promise of quantum speed-ups requires overcoming decoherence. The key is developing effective methods of suppressing and correcting quantum errors, <a href="http://www.cambridge.org/9780521897877">an area my own research is focused on</a>.</p>
<p>In navigating these challenges, numerous quantum hardware and software startups have emerged alongside well-established technology industry players like Google and IBM. This industry interest, combined with significant investment from governments worldwide, underscores a collective recognition of quantum technology’s transformative potential. These initiatives foster a rich ecosystem where academia and industry collaborate, accelerating progress in the field.</p>
<h2>Quantum advantage coming into view</h2>
<p>Quantum computing may one day be as disruptive as the arrival of <a href="https://memberservices.theconversation.com/newsletters/?nl=ai">generative AI</a>. Currently, the development of quantum computing technology is at a crucial juncture. On the one hand, the field has already shown early signs of having achieved a narrowly specialized quantum advantage. <a href="https://www.nature.com/articles/s41586-019-1666-5">Researchers at Google</a> and later a <a href="https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.127.180501">team of researchers in China</a> demonstrated quantum advantage <a href="https://doi.org/10.1038/s41534-023-00703-x">for generating a list of random numbers</a> with certain properties. My research team demonstrated a quantum speed-up <a href="https://doi.org/10.1103/PhysRevLett.130.210602">for a random number guessing game</a>.</p>
<p>On the other hand, there is a tangible risk of entering a “quantum winter,” a period of reduced investment if practical results fail to materialize in the near term.</p>
<p>While the technology industry is working to deliver quantum advantage in products and services in the near term, academic research remains focused on investigating the fundamental principles underpinning this new science and technology. This ongoing basic research, fueled by enthusiastic cadres of new and bright students of the type I encounter almost every day, ensures that the field will continue to progress.</p><img src="https://counter.theconversation.com/content/213306/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Daniel Lidar receives funding from the NSF, DARPA, ARO, and DOE.</span></em></p>Several companies have made quantum computers, but these early models have yet to demonstrate quantum advantage: the ability to outstrip ordinary supercomputers.Daniel Lidar, Professor of Electrical Engineering, Chemistry, and Physics & Astronomy, University of Southern CaliforniaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2056282023-10-17T19:03:53Z2023-10-17T19:03:53ZNew technique uses near-miss particle physics to peer into quantum world − two physicists explain how they are measuring wobbling tau particles<figure><img src="https://images.theconversation.com/files/532985/original/file-20230620-21-sf8wvl.jpg?ixlib=rb-1.1.0&rect=464%2C501%2C4206%2C3241&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The Large Hadron Collider at CERN can be used to study many kinds of fundamental particles, including mysterious and rare tau particles.</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/abstract-neon-circles-digital-fractal-black-royalty-free-image/1191907046?phrase=particle+physics&adppopup=true">Oxygen/Moment via Getty Images</a></span></figcaption></figure><p>One way physicists seek clues to unravel the mysteries of the universe is by smashing matter together and inspecting the debris. But these types of destructive experiments, while incredibly informative, have limits. </p>
<p>We are two scientists who <a href="https://www.colorado.edu/physics/dennis-perepelitsa">study nuclear</a> and <a href="https://www.phy.cam.ac.uk/staff/dr-jesse-liu">particle physics</a> using CERN’s Large Hadron Collider near Geneva, Switzerland. Working with an international group of nuclear and particle physicists, our team realized that hidden in the data from previous studies was a remarkable and innovative experiment. </p>
<p>In a new paper published in Physical Review Letters, we developed a new method with our colleagues for measuring <a href="https://doi.org/10.1103/PhysRevLett.131.151802">how fast a particle called the tau wobbles</a>.</p>
<p>Our novel approach looks at the times incoming particles in the accelerator whiz by each other rather than the times they smash together in head-on collisions. Surprisingly, this approach enables far more accurate measurements of the tau particle’s wobble than previous techniques. This is the first time in nearly 20 years scientists have measured this wobble, known as the <a href="https://doi.org/10.1088/1742-6596/912/1/012001">tau magnetic moment</a>, and it may help illuminate tantalizing cracks <a href="https://theconversation.com/the-standard-model-of-particle-physics-may-be-broken-an-expert-explains-182081">emerging in the known laws of physics</a>.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/531776/original/file-20230613-26-1ofchy.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A diagram showing a particle wobbling off of a vertical axis." src="https://images.theconversation.com/files/531776/original/file-20230613-26-1ofchy.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/531776/original/file-20230613-26-1ofchy.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=319&fit=crop&dpr=1 600w, https://images.theconversation.com/files/531776/original/file-20230613-26-1ofchy.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=319&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/531776/original/file-20230613-26-1ofchy.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=319&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/531776/original/file-20230613-26-1ofchy.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=401&fit=crop&dpr=1 754w, https://images.theconversation.com/files/531776/original/file-20230613-26-1ofchy.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=401&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/531776/original/file-20230613-26-1ofchy.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=401&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Electrons, muons and taus all wobble in a magnetic field like a spinning top. Measuring the wobbling speed can provide clues into quantum physics.</span>
<span class="attribution"><span class="source">Jesse Liu</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<h2>Why measure a wobble?</h2>
<p>Electrons, the building blocks of atoms, have two heavier cousins called the <a href="https://www.britannica.com/science/subatomic-particle/Charged-leptons-electron-muon-tau">muon and the tau</a>. Taus are the heaviest in this family of three and the most mysterious, as they exist only for minuscule amounts of time.</p>
<p>Interestingly, when you place an electron, muon or tau inside a magnetic field, these particles wobble in a manner similar to how a spinning top wobbles on a table. This wobble is called a particle’s magnetic moment. It is possible to predict how fast these particles should wobble using the <a href="https://home.cern/science/physics/standard-model">Standard Model of particle physics</a> – scientists’ best theory of how particles interact.</p>
<p>Since the 1940s, physicists have been interested in measuring magnetic moments to reveal intriguing <a href="https://doi.org/10.1103/PhysRev.74.250">effects in the quantum world</a>. According to quantum physics, clouds of particles and antiparticles are constantly <a href="https://www.symmetrymagazine.org/article/july-2009/virtual-particles">popping in and out of existence</a>. These fleeting fluctuations slightly alter how fast electrons, muons and taus wobble inside a magnetic field. By measuring this wobble very precisely, physicists can peer into this cloud to uncover possible hints of undiscovered particles. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/531789/original/file-20230613-15-4hjd2s.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A chart showing the basic particles." src="https://images.theconversation.com/files/531789/original/file-20230613-15-4hjd2s.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/531789/original/file-20230613-15-4hjd2s.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=574&fit=crop&dpr=1 600w, https://images.theconversation.com/files/531789/original/file-20230613-15-4hjd2s.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=574&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/531789/original/file-20230613-15-4hjd2s.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=574&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/531789/original/file-20230613-15-4hjd2s.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=722&fit=crop&dpr=1 754w, https://images.theconversation.com/files/531789/original/file-20230613-15-4hjd2s.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=722&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/531789/original/file-20230613-15-4hjd2s.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=722&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Electrons, muons and taus are three closely related particles in the Standard Model of particle physics – scientists’ current best description of the fundamental laws of nature.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:Standard_Model_of_Elementary_Particles.svg#/media/File:Standard_Model_of_Elementary_Particles.svg">MissMJ, Cush/Wikimedia Commons</a></span>
</figcaption>
</figure>
<h2>Testing electrons, muons and taus</h2>
<p>In 1948, theoretical physicist Julian Schwinger first calculated how the quantum cloud <a href="https://doi.org/10.1103/PhysRev.73.416">alters the electron’s magnetic moment</a>. Since then, experimental physicists have measured the speed of the electron’s wobble to an extraordinary <a href="https://doi.org/10.1038/s41586-020-2964-7">13 decimal places</a>. </p>
<p>The heavier the particle, the more its wobble will change because of undiscovered new particles lurking in its quantum cloud. Since electrons are so light, this limits their sensitivity to new particles.</p>
<p>Muons and taus are much heavier but also far shorter-lived than electrons. While muons exist only for mere microseconds, scientists at Fermilab near Chicago measured the muon’s magnetic moment to <a href="https://news.fnal.gov/2021/04/first-results-from-fermilabs-muon-g-2-experiment-strengthen-evidence-of-new-physics/">10 decimal places</a> in 2021. They found that muons wobbled noticeably faster than Standard Model predictions, suggesting unknown particles may be appearing in the muon’s quantum cloud.</p>
<p>Taus are the heaviest particle of the family – 17 times more massive than a muon and 3,500 times heavier than an electron. This makes them much more <a href="https://doi.org/10.1103/PhysRevD.64.035003">sensitive to potentially undiscovered particles</a> in the quantum clouds. But taus are also the hardest to see, since they live for just a millionth of the time a muon exists.</p>
<p>To date, the best measurement of the tau’s magnetic moment was made in 2004 using <a href="https://home.cern/science/accelerators/large-electron-positron-collider">a now-retired electron collider</a> at CERN. Though an incredible scientific feat, after multiple years of collecting data that experiment could measure the speed of the tau’s wobble to only <a href="https://doi.org/10.1140/epjc/s2004-01852-y">two decimal places</a>. Unfortunately, to test the Standard Model, physicists would need a measurement <a href="https://doi.org/10.1142/S0217732307022694">10 times as precise</a>.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/531773/original/file-20230613-29-zwf5pp.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Diagram showing two particles nearly colliding." src="https://images.theconversation.com/files/531773/original/file-20230613-29-zwf5pp.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/531773/original/file-20230613-29-zwf5pp.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=319&fit=crop&dpr=1 600w, https://images.theconversation.com/files/531773/original/file-20230613-29-zwf5pp.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=319&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/531773/original/file-20230613-29-zwf5pp.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=319&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/531773/original/file-20230613-29-zwf5pp.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=401&fit=crop&dpr=1 754w, https://images.theconversation.com/files/531773/original/file-20230613-29-zwf5pp.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=401&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/531773/original/file-20230613-29-zwf5pp.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=401&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Instead of colliding two nuclei head-on to create tau particles, two lead ions can whiz past each other in a near miss and still produce taus.</span>
<span class="attribution"><span class="source">Jesse Liu</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<h2>Lead ions for near-miss physics</h2>
<p>Since the 2004 measurement of the tau’s magenetic moment, physicists have been seeking new ways to measure the tau wobble.</p>
<p>The Large Hadron Collider usually smashes the nuclei of two atoms together – that is why it is called a collider. These head-on collisions create a <a href="https://cds.cern.ch/record/2841509">fireworks display of debris</a> that can include taus, but the noisy conditions preclude careful measurements of the tau’s magnetic moment.</p>
<p>From 2015 to 2018, there was an experiment at CERN that was designed primarily to allow nuclear physicists to study <a href="https://home.cern/science/physics/heavy-ions-and-quark-gluon-plasma">exotic hot matter</a> created in head-on collisions. The particles used in this experiment were lead nuclei that had been stripped of their electrons – called lead ions. Lead ions are electrically charged and produce <a href="https://doi.org/10.1038/nphys4208">strong electromagnetic fields</a>. </p>
<p>The electromagnetic fields of lead ions contain particles of light called photons. When two lead ions collide, their photons can also collide and convert all their energy into a single pair of particles. It was these photon collisions that scientists used to <a href="https://doi.org/10.1103/PhysRevLett.121.212301">measure muons</a>.</p>
<p>These lead ion experiments ended in 2018, but it wasn’t until 2019 that one of us, Jesse Liu, teamed up with particle physicist Lydia Beresford in Oxford, England, and realized the data from the same lead ion experiments could potentially be used to do something new: measure the tau’s magnetic moment. </p>
<p><a href="https://doi.org/10.1103/PhysRevD.102.113008">This discovery was a total surprise</a>. It goes like this: Lead ions are so small that they often miss each other in collision experiments. But occasionally, the ions pass very close to each other without touching. When this happens, their accompanying photons can still smash together while the ions continue flying on their merry way. </p>
<p>These photon collisions can create a variety of particles – like the muons in the previous experiment, and also taus. But without the chaotic fireworks produced by head-on collisions, these near-miss events are far quieter and ideal for measuring traits of the elusive tau.</p>
<p>Much to our excitement, when the team looked back at data from 2018, indeed these lead ion near misses were creating tau particles. There was a new experiment hidden in plain sight!</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/532999/original/file-20230620-8426-na9es5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A long tube in an underground tunnel." src="https://images.theconversation.com/files/532999/original/file-20230620-8426-na9es5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/532999/original/file-20230620-8426-na9es5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=399&fit=crop&dpr=1 600w, https://images.theconversation.com/files/532999/original/file-20230620-8426-na9es5.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=399&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/532999/original/file-20230620-8426-na9es5.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=399&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/532999/original/file-20230620-8426-na9es5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=502&fit=crop&dpr=1 754w, https://images.theconversation.com/files/532999/original/file-20230620-8426-na9es5.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=502&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/532999/original/file-20230620-8426-na9es5.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=502&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The Large Hadron Collider accelerates particles to incredibly high speeds before trying to smash particles together, but not all attempts result in successful collisions.</span>
<span class="attribution"><a class="source" href="http://cds.cern.ch/record/1211045">Maximilien Brice/CERN</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<h2>First measurement of tau wobble in two decades</h2>
<p>In April 2022, the CERN team announced that we had found <a href="https://atlas.cern/updates/briefing/observation-taupair-heavy-ions">direct evidence of tau particles created</a> during lead ion near misses. Using that data, the team was also able to measure the tau magnetic moment – the first time such a measurement had been done since 2004. The final results were published on Oct. 12, 2023.</p>
<p>This landmark result measured the tau wobble to two decimal places. Much to our astonishment, this method tied the previous best measurement using only one month of data recorded in 2018.</p>
<p>After no experimental progress for nearly 20 years, this result opens an entirely new and important path toward the tenfold improvement in precision needed to test Standard Model predictions. Excitingly, more data is on the horizon. </p>
<p>The Large Hadron Collider just restarted <a href="https://home.cern/news/news/experiments/lhc-lead-ion-collision-run-starts">lead ion data collection on Sept. 28, 2023</a>, after routine maintenance and upgrades. Our team plans to quadruple the sample size of lead ion near-miss data by 2025. This increase in data will double the accuracy of the measurement of the tau magnetic moment, and improvements to analysis methods may go even further.</p>
<p>Tau particles are one of physicists’ best windows to the enigmatic quantum world, and we are excited for surprises that upcoming results may reveal about the fundamental nature of the universe.</p><img src="https://counter.theconversation.com/content/205628/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Jesse Liu is supported by a Junior Research Fellowship at Trinity College, University of Cambridge. </span></em></p><p class="fine-print"><em><span>Dennis V. Perepelitsa receives research funding from the U.S. Department of Energy, Office of Science.</span></em></p>Physicists uncovered a new experiment hidden in old data from the Large Hadron Collider. Using this innovative approach, the team has unlocked an entirely new way to study quantum physics.Jesse Liu, Research Fellow in Physics, University of CambridgeDennis V. Perepelitsa, Associate Professor of Physics, University of Colorado BoulderLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2104282023-08-04T12:29:16Z2023-08-04T12:29:16ZBefore he developed the atomic bomb, J. Robert Oppenheimer’s early work revolutionized the field of quantum chemistry – and his theory is still used today<figure><img src="https://images.theconversation.com/files/541027/original/file-20230803-25-pvmco1.jpg?ixlib=rb-1.1.0&rect=0%2C7%2C2615%2C2031&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">J. Robert Oppenheimer is responsible for a fundamental idea in the field of quantum chemistry. </span> <span class="attribution"><a class="source" href="https://newsroom.ap.org/detail/87e22879387a45cb8083993acdcbe034?ext=true">AP Photo/John Rooney</a></span></figcaption></figure><p>The release of the film “<a href="https://www.oppenheimermovie.com/">Oppenheimer</a>,” in July 2023, has renewed interest in the enigmatic scientist J. Robert Oppenheimer’s life. While Oppenheimer will always be recognized as the <a href="https://ahf.nuclearmuseum.org/ahf/profile/j-robert-oppenheimer/">father of the atomic bomb</a>, his early contributions to <a href="https://www.livescience.com/33816-quantum-mechanics-explanation.html">quantum mechanics</a> form the bedrock of modern <a href="https://www.sciencedirect.com/topics/chemistry/quantum-chemistry">quantum chemistry</a>. His work still informs how scientists think about the structure of molecules today.</p>
<p>Early on in the film, preeminent scientific figures of the time, including Nobel laureates <a href="https://www.nobelprize.org/prizes/physics/1932/heisenberg/facts/">Werner Heisenberg</a> and <a href="https://www.nobelprize.org/prizes/physics/1939/lawrence/biographical/">Ernest Lawrence</a>, compliment the young Oppenheimer on his groundbreaking work on molecules. As a <a href="https://scholar.google.com/citations?hl=en&pli=1&user=df8z7MQAAAAJ">physical chemist</a>, Oppenheimer’s work on molecular quantum mechanics plays a major role in both my teaching and my research. </p>
<h2>The Born-Oppenheimer approximation</h2>
<p>In 1927, Oppenheimer published a paper called “<a href="https://doi.org/10.1142/9789812795762_0001">On the Quantum Theory of Molecules</a>” with his research adviser <a href="https://www.nobelprize.org/prizes/physics/1954/born/biographical/">Max Born</a>. This paper outlined what is commonly referred to as the Born-Oppenheimer approximation. While the name credits both Oppenheimer and his adviser, most historians recognize that the theory is mostly Oppenheimer’s work.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/541044/original/file-20230803-23-t9qc82.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A black-and-white old photo of two men wearing jackets and ties. The one on the right is younger and looking down, in the backround is a blackboard with equations written on it." src="https://images.theconversation.com/files/541044/original/file-20230803-23-t9qc82.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/541044/original/file-20230803-23-t9qc82.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=489&fit=crop&dpr=1 600w, https://images.theconversation.com/files/541044/original/file-20230803-23-t9qc82.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=489&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/541044/original/file-20230803-23-t9qc82.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=489&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/541044/original/file-20230803-23-t9qc82.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=614&fit=crop&dpr=1 754w, https://images.theconversation.com/files/541044/original/file-20230803-23-t9qc82.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=614&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/541044/original/file-20230803-23-t9qc82.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=614&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">J. Robert Oppenheimer, on the right, in 1947, speaking to mathematician Oswald Veblen at the Princeton Institute for Advance Study.</span>
<span class="attribution"><a class="source" href="https://newsroom.ap.org/detail/PrincetonOppenheimer1947/cda75d90e0fe4924be9217d9399b34c0/photo?Query=oppenheimer&mediaType=photo&sortBy=&dateRange=Anytime&totalCount=535&currentItemNo=33&vs=true">AP/Anonymous</a></span>
</figcaption>
</figure>
<p>The Born-Oppenheimer approximation offers a way to simplify the complex problem of describing molecules at the atomic level.</p>
<p>Imagine you want to calculate the optimum molecular structure, chemical bonding patterns and physical properties of a molecule using <a href="https://www.britannica.com/science/quantum-mechanics-physics">quantum mechanics</a>. You would start by defining the position and motion of all the atomic nuclei and electrons and calculating the important charge attractions and repulsions occurring between these particles in the <a href="https://chem.libretexts.org/Bookshelves/Physical_and_Theoretical_Chemistry_Textbook_Maps/Physical_Chemistry_(LibreTexts)/09%3A_Chemical_Bonding_in_Diatomic_Molecules/9.02%3A_The_H_Prototypical_Species">molecule</a>. </p>
<p>Calculating the properties of molecules gets even more complicated at the quantum level, where particles have wavelike properties and scientists can’t pinpoint their exact position. Instead, particles like electrons must be described by a <a href="https://www.britannica.com/science/wave-function">wave function</a>. A wave function describes the electron’s probability of being in a certain region of space. Determining this wave function and the corresponding energies of the molecule is what is known as solving the <a href="https://chem.libretexts.org/Bookshelves/Physical_and_Theoretical_Chemistry_Textbook_Maps/Thermodynamics_and_Chemical_Equilibrium_(Ellgen)/18%3A_Quantum_Mechanics_and_Molecular_Energy_Levels/18.04%3A_The_Schrodinger_Equation_for_a_Molecule">molecular Schrödinger equation</a>. </p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/AR23uxZruhE?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Solving the Schrödinger equation lets scientists calculate the properties of a molecule.</span></figcaption>
</figure>
<p>Unfortunately, this equation <a href="https://doi.org/10.1134/S1063779622010038">cannot be solved exactly</a> for even the <a href="https://chem.libretexts.org/Bookshelves/Physical_and_Theoretical_Chemistry_Textbook_Maps/Physical_Chemistry_(LibreTexts)/09%3A_Chemical_Bonding_in_Diatomic_Molecules/9.02%3A_The_H_Prototypical_Species">simplest possible molecule, H₂⁺</a>, which consists of three particles: two hydrogen nuclei (or protons) and one electron. </p>
<p>Oppenheimer’s approach provided a means to obtain an approximate solution. He observed that atomic nuclei are significantly heavier than electrons, with a single proton being nearly 2,000 times more massive than an electron. This means nuclei move much slower than electrons, so scientists can think of them as stationary objects while solving the Schrödinger equation solely for the electrons. </p>
<p>This method reduces the complexity of the calculation and enables scientists to <a href="https://chem.libretexts.org/Bookshelves/Physical_and_Theoretical_Chemistry_Textbook_Maps/Book%3A_Quantum_States_of_Atoms_and_Molecules_(Zielinksi_et_al)/10%3A_Theories_of_Electronic_Molecular_Structure/10.01%3A_The_Born-Oppenheimer_Approximation">determine the molecule’s wave function</a> with relative ease. </p>
<p>This approximation may seem like a minor adjustment, but the Born-Oppenheimer approximation goes far beyond just simplifying quantum mechanics calculations on molecules. It actually shapes how chemists view molecules and chemical reactions. </p>
<p>When scientists visualize molecules, we usually think of them as a set of fixed nuclei with shared electrons that move between nuclei.
In chemistry class, students typically build “<a href="https://doi.org/10.1021/ed048p407">ball-and-stick</a>” models consisting of rigid nuclei (balls) sharing electrons through a bonding framework (sticks). These models are a direct consequence of the <a href="https://doi.org/10.1007/s002149900049">Born-Oppenheimer approximation</a>.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/540016/original/file-20230728-24473-tdzlqu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Three images, one on the left showing simple chemistry annotation of a hexagonal benzene ring of C for carbon connected to H for hydrogen. The second image shows the same shape, but with spheres to represent the atoms and sticks to represent bonds." src="https://images.theconversation.com/files/540016/original/file-20230728-24473-tdzlqu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/540016/original/file-20230728-24473-tdzlqu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=184&fit=crop&dpr=1 600w, https://images.theconversation.com/files/540016/original/file-20230728-24473-tdzlqu.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=184&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/540016/original/file-20230728-24473-tdzlqu.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=184&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/540016/original/file-20230728-24473-tdzlqu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=231&fit=crop&dpr=1 754w, https://images.theconversation.com/files/540016/original/file-20230728-24473-tdzlqu.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=231&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/540016/original/file-20230728-24473-tdzlqu.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=231&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The ball-and-stick model shows nuclei represented by spheres – or balls – with shared electron bonds represented by sticks. This image shows the structure of a benzene molecule.</span>
<span class="attribution"><span class="source">Aaron Harrison</span></span>
</figcaption>
</figure>
<p>The Born-Oppenheimer approximation also influenced how scientists think about chemical reactions. During a chemical reaction, atomic nuclei are not stationary; they rearrange and move. Electron interactions guide the nuclei’s movements by forming an <a href="https://chem.libretexts.org/Courses/University_of_California_Davis/UCD_Chem_107B%3A_Physical_Chemistry_for_Life_Scientists/Chapters/2%3A_Chemical_Kinetics/2.06%3A_Potential_Energy_Surfaces/">energy surface</a>, which the nuclei can move on throughout the reaction. In this way, electrons drive the molecule’s progression through a chemical reaction. Oppenheimer demonstrated that the way electrons behave is the essence of chemistry as a science.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/540907/original/file-20230802-25-b7ng1i.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A diagram showing a graph of a chemical reaction, with a molecule arranged one way at the beginning, and another way at the end." src="https://images.theconversation.com/files/540907/original/file-20230802-25-b7ng1i.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/540907/original/file-20230802-25-b7ng1i.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=381&fit=crop&dpr=1 600w, https://images.theconversation.com/files/540907/original/file-20230802-25-b7ng1i.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=381&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/540907/original/file-20230802-25-b7ng1i.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=381&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/540907/original/file-20230802-25-b7ng1i.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=478&fit=crop&dpr=1 754w, https://images.theconversation.com/files/540907/original/file-20230802-25-b7ng1i.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=478&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/540907/original/file-20230802-25-b7ng1i.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=478&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Molecules can change structure during a chemical reaction.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:Rxn_coordinate_diagram.JPG">Chem540grp1f08/Wikimedia Commons</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<h2>Computational quantum chemistry</h2>
<p>In the century since the publication of the Born-Oppenheimer approximation, scientists have vastly improved their ability to calculate the chemical structure and reactivity of molecules.</p>
<p>This field, known as computational quantum chemistry, has grown exponentially with the widespread availability of faster, more powerful high-end computational resources. Currently, chemists use computational quantum chemistry for various applications ranging from discovering novel <a href="https://doi.org/10.1016/j.cplett.2021.138723">pharmaceuticals</a> to designing better <a href="https://doi.org/10.1039/D0TC03709E">photovoltaics</a> before ever trying to produce them in the lab. At the core of much of this field of research is the Born-Oppenheimer approximation. </p>
<p>Despite its many uses, the Born-Oppenheimer approximation <a href="https://elliptigon.com/when-born-oppenheimer-fails/">isn’t perfect</a>. For example, the approximation often breaks down in light-driven chemical reactions, such as in the chemical reaction that <a href="https://doi.org/10.1038/nchem.894">allows animals to see light</a>. Chemists are <a href="https://doi.org/10.1098/rsta.2020.0375">investigating workarounds</a> for these cases. Nevertheless, the application of quantum chemistry made possible by the Born-Oppenheimer approximation will continue to expand and improve. </p>
<p>In the future, a new era of <a href="https://www.scientificamerican.com/article/how-quantum-computing-could-remake-chemistry/">quantum computers</a> could make computational quantum chemistry even more robust by performing faster computations on increasingly large molecular systems.</p><img src="https://counter.theconversation.com/content/210428/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Aaron W. Harrison does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Remember building model molecules with balls and sticks in chemistry class? You have J. Robert Oppenheimer to thank for that, as a quantum chemist explains.Aaron W. Harrison, Assistant Professor of Chemistry, Austin CollegeLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2049952023-05-15T12:33:56Z2023-05-15T12:33:56ZQuantum physics proposes a new way to study biology – and the results could revolutionize our understanding of how life works<figure><img src="https://images.theconversation.com/files/525487/original/file-20230510-21-cnx7u8.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C1999%2C1499&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Looking at life at the atomic scale offers a more comprehensive understanding of the macroscopic world.</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/colorful-model-of-helix-dna-strand-royalty-free-image/157531306">theasis/E+ via Getty Images</a></span></figcaption></figure><p>Imagine using your cellphone to control the activity of your own cells to treat injuries and disease. It sounds like something from the imagination of an overly optimistic science fiction writer. But this may one day be a possibility through the emerging field of quantum biology.</p>
<p>Over the past few decades, scientists have made incredible progress in understanding and manipulating biological systems at increasingly small scales, from <a href="https://theconversation.com/when-researchers-dont-have-the-proteins-they-need-they-can-get-ai-to-hallucinate-new-structures-173209">protein folding</a> to <a href="https://www.genome.gov/genetics-glossary/Genetic-Engineering">genetic engineering</a>. And yet, the extent to which quantum effects influence living systems remains barely understood.</p>
<p>Quantum effects are phenomena that occur between atoms and molecules that can’t be explained by classical physics. It has been known for more than a century that the rules of classical mechanics, like Newton’s laws of motion, <a href="https://iopscience.iop.org/book/mono/978-0-7503-1206-6/chapter/bk978-0-7503-1206-6ch1">break down at atomic scales</a>. Instead, tiny objects behave according to a different set of laws known as <a href="https://www.britannica.com/science/quantum-mechanics-physics">quantum mechanics</a>. </p>
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<iframe width="440" height="260" src="https://www.youtube.com/embed/7kb1VT0J3DE?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Quantum mechanics describes the properties of atoms and molecules.</span></figcaption>
</figure>
<p>For humans, who can only perceive the macroscopic world, or what’s visible to the naked eye, quantum mechanics can seem counterintuitive and somewhat magical. Things you might not expect happen in the quantum world, like <a href="https://theconversation.com/we-did-a-breakthrough-speed-test-in-quantum-tunnelling-and-heres-why-thats-exciting-113761">electrons “tunneling” through</a> tiny energy barriers and appearing on the other side unscathed, or being in two different places at the same time in a <a href="https://scienceexchange.caltech.edu/topics/quantum-science-explained/quantum-superposition">phenomenon called superposition</a>.</p>
<p>I am trained as a <a href="https://scholar.google.com/citations?user=1aqtpo8AAAAJ&hl=en">quantum engineer</a>. Research in quantum mechanics is usually geared toward technology. However, and somewhat surprisingly, there is increasing evidence that nature – an engineer with billions of years of practice – has learned how to <a href="https://royalsociety.org/grants-schemes-awards/book-prizes/science-book-prize/2015/life-on-the-edge/">use quantum mechanics to function optimally</a>. If this is indeed true, it means that our understanding of biology is radically incomplete. It also means that we could possibly control physiological processes by using the quantum properties of biological matter.</p>
<h2>Quantumness in biology is probably real</h2>
<p>Researchers can manipulate quantum phenomena to build better technology. In fact, you already live in a <a href="https://uwaterloo.ca/institute-for-quantum-computing/quantum-101/quantum-applications-today">quantum-powered world</a>: from laser pointers to GPS, magnetic resonance imaging and the transistors in your computer – all these technologies rely on quantum effects.</p>
<p>In general, quantum effects only manifest at very small length and mass scales, or when temperatures approach absolute zero. This is because quantum objects like atoms and molecules <a href="https://www.theatlantic.com/science/archive/2018/10/beyond-weird-decoherence-quantum-weirdness-schrodingers-cat/573448/">lose their “quantumness”</a> when they uncontrollably interact with each other and their environment. In other words, a macroscopic collection of quantum objects is better described by the laws of classical mechanics. Everything that starts quantum dies classical. For example, an electron can be manipulated to be in two places at the same time, but it will end up in only one place after a short while – exactly what would be expected classically.</p>
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<figcaption><span class="caption">Electrons can be in two places at the same time, but will end up in one location eventually.</span></figcaption>
</figure>
<p>In a complicated, noisy biological system, it is thus expected that most quantum effects will rapidly disappear, washed out in what the physicist Erwin Schrödinger called the “<a href="https://doi.org/10.1017/CBO9781139644129">warm, wet environment of the cell</a>.” To most physicists, the fact that the living world operates at elevated temperatures and in complex environments implies that biology can be adequately and fully described by classical physics: no funky barrier crossing, no being in multiple locations simultaneously.</p>
<p>Chemists, however, have for a long time begged to differ. Research on basic chemical reactions at room temperature unambiguously shows that <a href="https://doi.org/10.1063/5.0006547">processes occurring within biomolecules</a> like proteins and genetic material are the result of quantum effects. Importantly, such nanoscopic, short-lived quantum effects are consistent with driving some macroscopic physiological processes that biologists have measured in living cells and organisms. Research suggests that quantum effects influence biological functions, including <a href="https://doi.org/10.1146/annurev-biochem-051710-133623">regulating enzyme activity</a>, <a href="https://doi.org/10.1146/annurev-biophys-032116-094545">sensing magnetic fields</a>, <a href="https://doi.org/10.1038/srep38543">cell metabolism</a> and <a href="https://doi.org/10.1038/s41570-019-0087-1">electron transport in biomolecules</a>.</p>
<h2>How to study quantum biology</h2>
<p>The tantalizing possibility that subtle quantum effects can tweak biological processes presents both an exciting frontier and a challenge to scientists. Studying quantum mechanical effects in biology requires tools that can measure the short time scales, small length scales and subtle differences in quantum states that give rise to physiological changes – all integrated within a traditional wet lab environment.</p>
<p><a href="http://www.claricedaiello.com">In my work</a>, I build instruments to study and control the quantum properties of small things like electrons. In the same way that electrons have mass and charge, they also have a <a href="https://www.britannica.com/science/spin-atomic-physics">quantum property called spin</a>. Spin defines how the electrons interact with a magnetic field, in the same way that charge defines how electrons interact with an electric field. The quantum experiments I have been building <a href="https://doi.org/10.1038/ncomms2375">since graduate school</a>, and now in my own lab, aim to apply tailored magnetic fields to change the spins of particular electrons.</p>
<p>Research has demonstrated that many physiological processes are influenced by weak magnetic fields. These processes include <a href="https://doi.org/10.1126/sciadv.aau7201">stem cell development</a> and <a href="https://doi.org/10.1021/nn502923s">maturation</a>, <a href="https://doi.org/10.1371/journal.pone.0054775">cell proliferation rates</a>, <a href="https://doi.org/10.1021/acscentsci.8b00008">genetic material repair</a> and <a href="https://doi.org/10.1371/journal.pone.0179340">countless others</a>. These physiological responses to magnetic fields are consistent with chemical reactions that depend on the spin of particular electrons within molecules. Applying a weak magnetic field to change electron spins can thus effectively control a chemical reaction’s final products, with important physiological consequences.</p>
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<iframe width="440" height="260" src="https://www.youtube.com/embed/0SPD2r0xV8k?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Birds use quantum effects in navigation.</span></figcaption>
</figure>
<p>Currently, a lack of understanding of how such processes work at the nanoscale level prevents researchers from determining exactly what strength and frequency of magnetic fields cause specific chemical reactions in cells. Current cellphone, wearable and miniaturization technologies are already sufficient to produce <a href="https://doi.org/10.14814%2Fphy2.15189">tailored, weak magnetic fields that change physiology</a>, both for good and for bad. The missing piece of the puzzle is, hence, a “deterministic codebook” of how to map quantum causes to physiological outcomes.</p>
<p>In the future, fine-tuning nature’s quantum properties could enable researchers to develop therapeutic devices that are noninvasive, remotely controlled and accessible with a mobile phone. Electromagnetic treatments could potentially be used to prevent and treat disease, such as <a href="https://doi.org/10.1038/s41416-020-01136-5">brain tumors</a>, as well as in biomanufacturing, such as <a href="https://doi.org/10.1016/j.biomaterials.2022.121658">increasing lab-grown meat production</a>.</p>
<h2>A whole new way of doing science</h2>
<p>Quantum biology is one of the most interdisciplinary fields to ever emerge. How do you build community and train scientists to work in this area? </p>
<p>Since the pandemic, my lab at the University of California, Los Angeles and the University of Surrey’s Quantum Biology Doctoral Training Centre have organized <a href="https://groups.google.com/u/1/g/bigquantumbiologymeetings">Big Quantum Biology meetings</a> to provide an informal weekly forum for researchers to meet and share their expertise in fields like mainstream quantum physics, biophysics, medicine, chemistry and biology.</p>
<p>Research with potentially transformative implications for biology, medicine and the physical sciences will require working within an equally transformative model of collaboration. Working in one unified lab would allow scientists from disciplines that take very different approaches to research to conduct experiments that meet the breadth of quantum biology from the quantum to the molecular, the cellular and the organismal.</p>
<p>The existence of quantum biology as a discipline implies that traditional understanding of life processes is incomplete. Further research will lead to new insights into the age-old question of what life is, how it can be controlled and how to learn with nature to build better quantum technologies.</p><img src="https://counter.theconversation.com/content/204995/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Clarice D. Aiello receives funding from NSF, ONR, IDOR Foundation, Faggin Foundation, Templeton Foundation. </span></em></p>Studying the brief and tiny quantum effects that drive living systems could one day lead to new approaches to treatments and technologies.Clarice D. Aiello, Quantum Biology Tech (QuBiT) Lab, Assistant Professor of Electrical and Computer Engineering, University of California, Los AngelesLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1977122023-01-17T00:16:42Z2023-01-17T00:16:42ZPhysicists have used entanglement to ‘stretch’ the uncertainty principle, improving quantum measurements<figure><img src="https://images.theconversation.com/files/504370/original/file-20230113-14-rc7nuw.jpeg?ixlib=rb-1.1.0&rect=0%2C0%2C7000%2C4191&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Shutterstock</span></span></figcaption></figure><p>Almost a century ago, German physicist Werner Heisenberg realised the laws of quantum mechanics placed some fundamental limits on how accurately we can measure certain properties of microscopic objects. </p>
<p>However, the laws of quantum mechanics can also offer ways to make measurements more accurate than would otherwise be possible.</p>
<p>In new research <a href="https://www.nature.com/articles/s41567-022-01875-7">published in Nature Physics</a>, we have outlined a way to achieve more accurate measurements of microscopic objects using quantum computers. This could prove useful in a huge range of next-generation technologies, including biomedical sensing, laser ranging and quantum communications. </p>
<p>We were also able to push beyond the limits of a variation of Heisenberg’s “uncertainty principle” in certain circumstances, suggesting different uncertainty principles may be necessary in different scenarios.</p>
<h2>Quantum uncertainties</h2>
<p>If you want to examine the properties of a large everyday object like a car, it’s a simple process. </p>
<p>For example, a car has a well-defined position, colour and speed. You can measure them one after another or all at once with no issues. Measuring the position of your car will not change its colour or speed.</p>
<p>However, this becomes much trickier if you’re trying to examine microscopic quantum objects like electrons or photons (which are tiny little particles of light). </p>
<p>Certain properties of quantum objects are connected to each other. Measuring one property can influence another property. </p>
<hr>
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<em>
<strong>
Read more:
<a href="https://theconversation.com/explainer-heisenbergs-uncertainty-principle-7512">Explainer: Heisenberg’s Uncertainty Principle</a>
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</em>
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<p>For example, measuring the position of an electron will affect its speed and vice versa. </p>
<p>These properties are called “conjugate” properties. </p>
<p>The link between these properties is a direct manifestation of Heisenberg’s uncertainty principle. It is not possible to simultaneously measure two conjugate properties of a quantum object to whatever degree of accuracy you like: the more you know about one, the less you know about the other.</p>
<p>While the uncertainty principle imposes a limit on how accurate some measurements can be, reaching that limit in practice can be very challenging. However, measuring quantum objects in the greatest amount of detail possible is important for advancing fundamental science as well as developing new technologies. </p>
<h2>Entangled objects</h2>
<p>In our new research, we designed a way to determine conjugate properties of quantum objects more accurately. Our collaborators were then able to carry out this measurement in various labs around the world.</p>
<p>The new technique revolves around a strange quirk of quantum systems, known as entanglement. When two objects are entangled, we can measure them more accurately than if they weren’t entangled.</p>
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<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/what-is-quantum-entanglement-a-physicist-explains-the-science-of-einsteins-spooky-action-at-a-distance-191927">What is quantum entanglement? A physicist explains the science of Einstein’s ‘spooky action at a distance’</a>
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<p>We realised we could use quantum computers, which can precisely control the state of quantum objects, to create two identical quantum objects and entangle them. By measuring the entangled objects together, we could determine their properties more precisely than if they were measured individually. </p>
<p>Measuring the two entangled identical quantum objects reduces the noise in the measurement, making it more accurate.</p>
<h2>A less noisy future</h2>
<p>In theory, it is also possible to entangle and measure three or more quantum systems to achieve even better precision. However, we haven’t been able to make this work experimentally as yet. </p>
<p>The results of measuring three identical entangled objects together were very noisy. However, as quantum computers improve and become more accurate, it may be possible to faithfully measure three copies of a quantum system simultaneously in the future.</p>
<figure class="align-center ">
<img alt="An elaborate cooling rig for a quantum computer, against a black background." src="https://images.theconversation.com/files/504371/original/file-20230113-20-t7ufet.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/504371/original/file-20230113-20-t7ufet.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=338&fit=crop&dpr=1 600w, https://images.theconversation.com/files/504371/original/file-20230113-20-t7ufet.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=338&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/504371/original/file-20230113-20-t7ufet.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=338&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/504371/original/file-20230113-20-t7ufet.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=424&fit=crop&dpr=1 754w, https://images.theconversation.com/files/504371/original/file-20230113-20-t7ufet.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=424&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/504371/original/file-20230113-20-t7ufet.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=424&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Quantum computers of the future may be less noisy.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<p>One of the key strengths of this work is that a quantum enhancement can still be observed in very noisy scenarios. This bodes well for future practical applications, such as in biomedical measurements, which will inevitably occur in noisy real-world environments.</p>
<h2>What about the uncertainty principle?</h2>
<p>This research also has implications for the aforementioned uncertainty principle. </p>
<p>One interpretation of the uncertainty principle is that it is impossible to measure conjugate properties of quantum objects with unlimited accuracy. But another interpretation is that measuring one conjugate property of a quantum object must necessarily disturb the second conjugate property by some minimum amount. </p>
<p>In this research, we were able to violate an uncertainty principle based on the second interpretation. This suggests that, depending on what physical setting is considered, different uncertainty principles may be necessary for different scenarios. </p>
<h2>A global collaboration</h2>
<p>We tested our theory on a total of 19 different quantum computers, which used three different quantum computing technologies: superconductors, trapped ions and photonics. These devices are located across Europe and America and can be accessed via the internet, allowing researchers from across the globe to connect and carry out important research.</p>
<p>We carried out the study with colleagues at the ARC Centre of Excellence for Quantum Computation and Communication Technology (CQC2T), in collaboration with researchers from the Institute of Materials Research and Engineering at A*STAR in Singapore, the University of Jena, the University of Innsbruck, Macquarie University and Amazon Web Services.</p><img src="https://counter.theconversation.com/content/197712/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>The authors do not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Examining microscopic quantum objects is exceedingly tricky, because their properties are connected to each other. But there could be a new method to measure them as accurately as possible.Lorcan Conlon, PhD student, Quantum Science & Technology, Australian National UniversitySyed Assad, Research Associate, Quantum Science & Technology, Australian National UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1896742022-10-31T18:35:43Z2022-10-31T18:35:43ZWhat quantum technology means for Canada’s future<figure><img src="https://images.theconversation.com/files/492191/original/file-20221027-23824-csb3yk.png?ixlib=rb-1.1.0&rect=23%2C23%2C3970%2C2622&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">A look inside the quantum computing process. Quantum technology is a $142 billion opportunity that could employ 229,000 Canadians by 2040.</span> <span class="attribution"><span class="source">(Photonic)</span>, <span class="license">Author provided</span></span></figcaption></figure><p>Canada is a world leader in developing quantum technologies and is well-positioned to secure its place in the emerging quantum industry. </p>
<p><a href="https://qt.eu/discover-quantum/quantum-technologies-in-a-nutshell/">Quantum technologies</a> are new and emerging technologies based on the unique properties of <a href="https://scholar.harvard.edu/files/david-morin/files/waves_quantum.pdf">quantum mechanics</a> — the science that deals with the physical properties of nature on an atomic and subatomic level.</p>
<p>In the future, we’ll see quantum technology transforming computing, communications, cryptography and much more. They will be incredibly powerful, offering capabilities that reach beyond today’s technologies. </p>
<p>The potential impact of these technologies on the Canadian economy will be transformative: the <a href="https://policyoptions.irpp.org/magazines/august-2021/how-to-ensure-canadas-quantum-computing-strategy-is-a-success/">National Research Council of Canada</a> has identified quantum technology as a $142 billion opportunity that could employ 229,000 Canadians by 2040.</p>
<p>Canada could gain far-reaching economic and social benefits from the rapidly developing quantum industry, but it must act now to secure them — before someone else delivers the first large-scale quantum computer, which will likely be sooner than expected.</p>
<h2>Quantum technology is the future</h2>
<p>Quantum computing is a <a href="https://theconversation.com/in-the-future-everyone-might-use-quantum-computers-112063">rapidly-developing type of quantum technology</a> that combines concepts from quantum physics with classical computation. The result is quantum computers, which can accomplish tasks that classical computers can’t.</p>
<p>While quantum computers will be revolutionary, they will also introduce new problems by breaking the public key cryptography that secures today’s internet and corporate networks. <a href="https://doi.org/10.1038/nature23461">Public key cryptography</a> is a method of encrypting data with pairs of keys. Anyone with a public key can encrypt a message, but only those holding the matching private key can decrypt it. </p>
<p>The keys are generated by computers running complex mathematical problems that can’t be broken by today’s most powerful computers, but can be broken by quantum computers. Data intercepted and stored today <a href="https://www.factbasedinsight.com/quantum-crypto-trust-me-ive-come-to-save-the-world">is already vulnerable to this future threat</a>. </p>
<p>This presents an opportunity for Canada to invest in new technologies to secure communications, starting with “post-quantum” encryption algorithms, then layering on
<a href="https://www.techtarget.com/searchsecurity/definition/quantum-key-distribution-QKD">quantum key distribution</a>, a type of provably secure quantum encryption based on quantum mechanics. </p>
<p>To use quantum key distribution over vast distances, we’ll need to develop <a href="https://doi.org/10.1088/1367-2630/abfa63">satellite-based quantum repeaters</a> that function similarly to repeaters in today’s telecommunications fibre networks. They allow quantum signal transmission over long distances. <a href="https://www.asc-csa.gc.ca/eng/satellites/qeyssat.asp">Canadian researchers are well on their way to developing them</a>.</p>
<p>Unless we defend our cybersecurity infrastructure now, the advent of a quantum computer could be the information-security equivalent of the nuclear bomb: almost no information or computing systems would be secure against a future quantum attack. Canada needs to seize the opportunity to lead the world in building, deploying and exporting technology to enable the global quantum internet and protect itself.</p>
<h2>Preparing for the future</h2>
<p>Truly predicting the impact of <a href="https://hbr.org/2021/07/quantum-computing-is-coming-what-can-it-do">large-scale quantum computers</a> is as hard as predicting the changes that followed the commercialization of semiconductor physics. </p>
<p>When the crown jewel of semiconductor microchip technology — transistors — were first commercialized, they were expected to be most helpful in the development of hearing aids. They drove a <a href="https://www.semiconductors.org/semiconductors-101/what-is-a-semiconductor/">computation and communications revolution</a>; <a href="https://www.bbc.com/future/bespoke/made-on-earth/how-the-chip-changed-everything/">today we find the physics of semiconductors inside everything</a> from laptops and phones to cars and medical devices.</p>
<p>Once large-scale quantum physics is commercialized, it will similarly impact almost every field, industry and aspect of our lives. Scientists and engineers will be able to solve all sorts of problems with quantum computers, including simulating and designing drug targets, making better batteries and <a href="https://www.bcg.com/publications/2020/quantum-advantage-fighting-climate-change">creating more efficient ways to produce green hydrogen and synthetic gas</a>.</p>
<h2>Maintaining the lead</h2>
<p>To maintain its leadership, Canada needs to move beyond research and development and accelerate a quantum ecosystem that includes a strong talent pipeline, businesses supported by supply chains and governments and industry involvement. There are a few things Canada can do to drive this leadership: </p>
<p><strong>Continue to fund quantum research:</strong> Canada has <a href="https://www.univcan.ca/media-room/media-releases/how-canadian-universities-are-propelling-us-towards-a-quantum-future/">more than a dozen quantum research institutes and labs</a>, including my <a href="https://www.sfu.ca/physics/siliconquantum/">Silicon Quantum Technologies Lab</a> at Simon Fraser University. The Canadian government has invested more than $1 billion since 2005 in quantum research and will likely announce a national quantum strategy soon. Canada must continue funding quantum research or risk losing its talent base and current competitive advantage.</p>
<p><strong>Build our talent pipeline with more open immigration</strong>: Even though quantum experts are trained in every major university in Canada, the demand for them is <a href="https://thebusinesscouncil.ca/publication/closing-the-quantum-computing-skills-gap-could-make-all-the-difference-in-tackling-climate-change/">three times the number of new graduates</a>. Canada needs the kind of <a href="https://www.ictc-ctic.ca/wp-content/uploads/2012/06/ICTC_IEP_SA_National_EN_03-12.pdf">fast-track immigration programs that fuelled the telecom boom in the 1990s</a>.</p>
<figure class="align-center ">
<img alt="Someone wearing a mask and protective goggles holding a computer microchip in front of their face" src="https://images.theconversation.com/files/492194/original/file-20221027-24414-egb33q.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/492194/original/file-20221027-24414-egb33q.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/492194/original/file-20221027-24414-egb33q.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/492194/original/file-20221027-24414-egb33q.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/492194/original/file-20221027-24414-egb33q.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/492194/original/file-20221027-24414-egb33q.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/492194/original/file-20221027-24414-egb33q.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Transistors are one of the building blocks of modern electronic technology, including computer chips.</span>
<span class="attribution"><span class="source">(Shutterstock)</span></span>
</figcaption>
</figure>
<p><strong>Be our own best customers</strong>: Canadian companies are leading the way, but they need support. <a href="https://www.quantumindustrycanada.ca/">Quantum Industry Canada</a> boasts of more than 30 member companies. Vancouver is home to <a href="https://www.dwavesys.com/company/about-d-wave/">the pioneering D-Wave</a> and <a href="https://photonic.com/about-photonic/">Photonic Inc.</a>, the company I founded to commercialize silicon quantum technologies. More than <a href="https://www.mckinsey.com/%7E/media/mckinsey/featured%20insights/the%20rise%20of%20quantum%20computing/quantum%20technology%20monitor/2021/mckinsey-quantum-technology-monitor-202109.pdf">$650 million was invested in Canadian startups between 2001 and 2021</a>. On a per capita basis, this is far beyond the $2.1 billion invested in U.S. companies over the same period.</p>
<p>What early quantum companies need most is customers: early, major procurement contracts, or <a href="https://www.darpa.mil/about-us/what-darpa-does">DARPA-like moonshot contracts</a>. Without these contracts, the entire Canadian quantum industry will slip away into other jurisdictions that focus investment and procurement on domestic bidders, like what is happening in <a href="https://doi.org/10.1088/2058-9565/ab042d">the European Union</a> and <a href="https://www.whitehouse.gov/briefing-room/statements-releases/2022/05/04/fact-sheet-president-biden-announces-two-presidential-directives-advancing-quantum-technologies/">the U.S.</a></p>
<h2>Learning from the past</h2>
<p>Canada has an opportunity to break out of its pattern of inventing transformative technology, but not reaping the rewards. This is what happened with the invention of the transistor.</p>
<p>The <a href="https://hackaday.com/2018/12/11/julius-lilienfeld-and-the-first-transistor/">first transistor patent was actually filed in Canada</a> by Canadian-Hungarian physicist Julius Edgar Lilienfeld, 20 years before the Bell Labs demonstration. Canada was also one of the places where <a href="https://www.bce.ca/about-bce/history/timeline">Alexander Graham Bell</a> worked to develop and patent the telephone. </p>
<p>Despite this, the transistor was commercialized in the U.S. and led to the country’s <a href="https://www.ibisworld.com/industry-statistics/market-size/semiconductor-circuit-manufacturing-united-states">US$63 billion semiconductor industry</a>. Bell commercialized the telephone through <a href="https://www.nytimes.com/interactive/2016/02/12/technology/att-history.html">The Bell Telephone Company, which eventually became AT&T</a>.</p>
<p>Canada is poised to make even greater contributions to quantum technology. Much existing technology has been invented here in Canada — including quantum cryptography, <a href="https://sciencebusiness.net/news/canada-lays-groundwork-become-powerhouse-quantum-technology">which was co-invented by University of Montreal professor Gilles Brassard</a>. Instead of repeating its past mistakes, Canada should act now to secure the success of the quantum technology industry.</p><img src="https://counter.theconversation.com/content/189674/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Stephanie Simmons is the founder and Chief Quantum Officer at Photonic Inc. She is an Associate Professor, Canada Research Chair, and CIFAR Fellow, based out of the Department of Physics at Simon Fraser University (SFU). </span></em></p>Canada is well positioned to gain far-reaching economic and social benefits from the rapidly developing quantum industry, but it must act now to secure its success.Stephanie Simmons, Associate Professor, SFU and Tier 2 Canada Research Chair in Silicon Quantum Technologies, Simon Fraser UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1916982022-10-10T13:20:06Z2022-10-10T13:20:06ZThe magic of touch: how deafblind people taught us to ‘see’ the world differently during COVID<figure><img src="https://images.theconversation.com/files/488856/original/file-20221009-58320-oy1rpz.jpg?ixlib=rb-1.1.0&rect=16%2C139%2C5447%2C3276&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/silhouette-hand-behind-glass-foreground-276478628">Toeizuza Thailand/Shutterstock</a></span></figcaption></figure><blockquote>
<p>As someone who is severely deaf and completely blind, I felt overnight I had lost a third sense, my sense of touch. To make matters worse, people around me faded away – voices had become so quiet that there was an eerie soundlessness all around. Nothing was making sense any more.</p>
</blockquote>
<p>Issy McGrath has <a href="https://medlineplus.gov/genetics/condition/usher-syndrome/#:%7E:text=Usher%20syndrome%20type%20II%20is,to%20hear%20high%2Dfrequency%20sounds.">type 2 Usher syndrome</a>. Completely blind and severely deaf, she has a passion for music and plays the flute. Using a combination of touch, smell and keen imagination – her “inner eye” – Issy says she frequently senses things that are beyond the grasp of sight: the “almost solid” nature of the winter air in the morning, or the enchanting atmosphere of a frozen landscape.</p>
<hr>
<iframe id="noa-web-audio-player" style="border: none" src="https://embed-player.newsoveraudio.com/v4?key=x84olp&id=https://theconversation.com/the-magic-of-touch-how-deafblind-people-taught-us-to-see-the-world-differently-during-covid-191698&bgColor=F5F5F5&color=D8352A&playColor=D8352A" width="100%" height="110px"></iframe>
<p><em>You can listen to more articles from The Conversation, narrated by Noa, <a href="https://theconversation.com/us/topics/audio-narrated-99682">here</a>.</em></p>
<hr>
<p>For Issy and many others like her, the COVID pandemic had a devastating effect on day-to-day life. “Two-metre social distancing felt like the world had turned its back on me,” she recalls. “It was too far for me to reach out and touch everything around me. Yet it’s mainly through touch that I get a sense of what a person is like.”</p>
<p>A retired teacher living in Glasgow, Scotland, Issy speaks poignantly about her COVID struggles in an <a href="https://touch-post-covid.gla.ac.uk/index.php/example-data/">audio diary</a> that was part of my <a href="https://touch-post-covid.gla.ac.uk/">research</a> into the experiences of deafblind people during the pandemic:</p>
<blockquote>
<p>As I approach my garden gate, feeling around for the latch to open it, a thought occurs to me. There is a pandemic sweeping the world and maybe I will catch the virus from this wooden fence. Maybe it’s on the latch I have just touched. I shake my hands to free myself from these thoughts. I make my way back to my house and wash my hands thoroughly, trying to free my mind of these fearful imaginings.</p>
</blockquote>
<h2>‘You can feel the energy of things’</h2>
<p>As a filmmaker, I am constantly questioning how and what we see – and what we <em>don’t</em> see. This has led me to work closely with deafblind communities around the UK, to understand how their view of the world differs from everyone else’s – in an ocularcentric society that privileges vision over all other senses.</p>
<p>Perceiving through touch takes time. By methodically stroking different surfaces, deafblind people build up a mental image not only of a person or object, but their place in the surrounding room or landscape. Deafblind people’s hands and skin are, I think, unusually sensitive to different levels of rigidity, to the feeling of different textures, and to slight differences in movement or temperature.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/488854/original/file-20221009-45436-nyr7ga.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/488854/original/file-20221009-45436-nyr7ga.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=338&fit=crop&dpr=1 600w, https://images.theconversation.com/files/488854/original/file-20221009-45436-nyr7ga.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=338&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/488854/original/file-20221009-45436-nyr7ga.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=338&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/488854/original/file-20221009-45436-nyr7ga.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=424&fit=crop&dpr=1 754w, https://images.theconversation.com/files/488854/original/file-20221009-45436-nyr7ga.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=424&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/488854/original/file-20221009-45436-nyr7ga.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=424&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">John Whitfield, a key member of the research project: ‘You are desperate to get information but it’s very tiring.’</span>
<span class="attribution"><span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>John Whitfield, a training officer at <a href="https://dbscotland.org.uk/what-we-do/">Deafblind Scotland</a>, has been severely deaf since birth and now has only 5% of his vision left. He describes how much concentration is required to understand the world around him and keep up with conversations. “Sometimes that is very, very tiring,” he admits.</p>
<blockquote>
<p>Because you are so conscious of the restriction on your hearing and vision, your brain has to compensate – and your body is having to compensate too by getting information in whatever way it can. My sense of smell is heightened, for example. You are just desperate to get as much information from the environment as you possibly can, so you will use any method.</p>
</blockquote>
<p>For Roger Wilson-Hindr, who lives with his vision-impaired wife in a small village in the Midlands of England, touching means more than just receiving sensory input or holding on to information. He says every tactile interaction is a chance to form a new relationship, adding that “touch and physical contact take on greater significance if your eyes and ears are badly damaged like mine”.</p>
<p>Corneal scars and glaucoma suffered during childhood limit what Roger can perceive – he is able to see colour but with little definition. Trees, one of his favourite things, appear as a golden or green mass.</p>
<hr>
<figure class="align-right ">
<img alt="" src="https://images.theconversation.com/files/288776/original/file-20190820-170910-8bv1s7.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/288776/original/file-20190820-170910-8bv1s7.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/288776/original/file-20190820-170910-8bv1s7.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/288776/original/file-20190820-170910-8bv1s7.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/288776/original/file-20190820-170910-8bv1s7.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/288776/original/file-20190820-170910-8bv1s7.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/288776/original/file-20190820-170910-8bv1s7.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=754&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
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<p><strong><em>This story is part of Conversation Insights</em></strong>
<br><em>The Insights team generates <a href="https://theconversation.com/uk/topics/insights-series-71218">long-form journalism</a> and is working with academics from different backgrounds who have been engaged in projects to tackle societal and scientific challenges.</em></p>
<hr>
<p>But when gardening, he can still “feel” the seasons through the bendability, texture and direction of the stems and branches. He says there is a “magic” to touch – “you can feel the energy of things” – and that it’s not always just about making up for a lack of vision. Deafblind people’s tactile world contains much joy.</p>
<p>Imagine, then, the impact for Roger and all other blind and deafblind people when COVID transformed the meaning of touch and proximity to others – from a life-enricher to a potential life threat. As Issy puts it:</p>
<blockquote>
<p>Social distancing meant the world both passed me by and left me constantly conflicted. Do I allow people into my space so that I can interact and make sense of the world, risking catching the virus? Or do I ask people to respect the two-metre social distance rule, and allow a creeping sense of isolation to overwhelm my emotional wellbeing?</p>
</blockquote>
<h2>The importance of touch</h2>
<p>There are two common misconceptions about deafblind people: that they require continuous assistance and are not easy to communicate with. During our research, we heard how these perceptions contribute to their exclusion from wider society and can have a damaging effect on their confidence. This was all made worse by the pandemic, as Issy explains:</p>
<blockquote>
<p>Holding someone’s hand provides me with so much information – to feel the fabric of someone’s clothing means I can get a real sense of their being. Suddenly [with the onset of COVID], to be so far away from the scent of their perfume or the texture of their hair … it was all gone. Even with the relaxing of social-distancing, the joy I had in reaching out to touch and link arms with other people has become subdued and cautious, as I warily navigate my world through my sense of touch.</p>
</blockquote>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/rzKyw7cTdao?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Issy McGrath talks about her struggles during the pandemic. Film by Azadeh Emadi.</span></figcaption>
</figure>
<p>When we think about touch, we usually think of hands and fingertips. But Roger highlights that, for deafblind people, “touch uses all aspects of our body – from the top of our head to feel the sunlight, to our feet for feeling where we are on the street”. Indeed, all of our interviewees emphasised the importance of touching with their feet – helping them to scan and perceive the environment while walking, to recognise the characteristics of different spaces and create a mental map.</p>
<p>As the first lockdown was easing, Issy recalls being reduced to tears in the middle of a street in her suddenly unfamiliar Glasgow neighbourhood. With cafés and restaurants expanding outside and altering the usual pedestrian layout, she found herself continually bumping into unexpected obstacles and people. As well as the frustration of having to create a new internal map of the area, she worried that people might become annoyed because of her lack of social distancing.</p>
<p>At the same time, she also felt a new threat from people invading her personal space:</p>
<blockquote>
<p>I remember standing outside a supermarket, waiting for my husband, when someone tapped me abruptly on my shoulder and asked where the nearest car park was. Realising he had touched me was a shock and made me feel so uncomfortable. I asked if he was socially distancing and he replied that he had been trying to attract my attention for ages. Until that moment I was totally unaware he was there.</p>
</blockquote>
<h2>Conversations with a quantum physicist</h2>
<p>Before the pandemic took a grip of the world, much of my research was focused on pixels. In particular, how these tiny areas of illumination join forces to create an uninterrupted experience of film without ever revealing themselves – each undergoing a different rate of change depending on the codes they receive.</p>
<p>This led to some fascinating conversations with a quantum physicist, Daniele Faccio from my university’s physics department, about how new technology might reveal hitherto imperceptible light phenomena. His team were using <a href="https://www.nature.com/articles/s41566-020-0697-7">single-photon cameras</a> that can detect light waves as particles and thus “freeze” light in motion, taking photographs of a light pulse or video of light as it moves through a room.</p>
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Read more:
<a href="https://theconversation.com/disabled-people-are-already-cutting-back-on-costs-more-than-others-for-many-the-150-cost-of-living-payment-wont-do-much-to-help-191022">Disabled people are already cutting back on costs more than others – for many, the £150 cost of living payment won't do much to help</a>
</strong>
</em>
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<p>As a videomaker, I found this technology fascinating – and I wondered if we could pool our knowledge to help blind people “watch” moving images by translating them into a tactile experience. In other words, develop a platform that could work as a form of “video Braille”. </p>
<p>In 2019, we began experimenting with ultrasound technology to focus soundwaves and create pressure spots that could be felt on someone’s hands. In this way, we hoped we could turn pixels from moving images into a range of tactile experiences linked to a film’s content (e.g. facial expressions, emotions, movement). The tactile sensations could include different temperatures, pressures and movements on the palm of each hand.</p>
<p>Then the pandemic intervened, our project was put on hold, and time slowed to a frustrating crawl. A saving grace, though, was my growing understanding of the way deafblind people take such care to understand their surroundings, never rushing the process of learning about a new situation. This helped me to slowly accept and learn from this extraordinary period, rather than trying to escape it.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/r8zBgoM_i0Y?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Film of Issy McGrath in her kitchen by Azadeh Emadi.</span></figcaption>
</figure>
<p>Once lockdown ended, I tried to convey this by filming <a href="https://touch-post-covid.gla.ac.uk/index.php/touchscreen/#purple">Issy in her kitchen</a> as she made a cup of tea and arranged a vase of purple flowers. What to sighted viewers might look like “fumbling and stumbling” (as Issy calls it) is actually her way of learning and knowing. We see her gently touching the flowers, smelling their scent, imagining their forms as she measures their length, cuts and carefully arranges them into a vase. She is taking as much time as her touch needs:</p>
<blockquote>
<p>Although the way I move around might look to you like a struggle, it’s not. I am putting my hand out to reach and touch things, pick things up, make sense of what’s in front of me, because that is the way I interact with my world. I am drawing up a map in my mind of what’s out there. So instead of thinking I am struggling, let me fumble and stumble – that is all information for me. The reward I get is that I will be, and am, a much more autonomous and resilient deafblind person.</p>
</blockquote>
<h2>A tool to help deafblind people</h2>
<p>The insights offered by Issy and our other deafblind collaborators during the early days of COVID made us determined to <a href="https://www.mdpi.com/1424-8220/22/19/7136">develop a tool</a> that could help give them some independence in navigating the newly opened-up spaces after lockdown. This shifted our attention from developing a video Braille tool to one that could accurately locate the people and objects around them. </p>
<p>The synergy we’d already found between arts and quantum physics resulted in our idea for a new “spatial awareness” tool. Over a series of workshops starting in June 2021, Issy and John helped our research team to understand how deafblind people imagine, memorise and map a space both with and without touch – and thus what they needed from our device.</p>
<p>The prototype consisted of two elements: a portable radar and wearable feedback devices (a headband and an armband). “I am going to be honest and say I felt like the borg from Star Wars,” recalls Issy, our first tester. “But wow, it was fascinating.”</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/488857/original/file-20221009-57478-mwbb1c.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Deafblind man pointing out man in front of him" src="https://images.theconversation.com/files/488857/original/file-20221009-57478-mwbb1c.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/488857/original/file-20221009-57478-mwbb1c.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=382&fit=crop&dpr=1 600w, https://images.theconversation.com/files/488857/original/file-20221009-57478-mwbb1c.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=382&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/488857/original/file-20221009-57478-mwbb1c.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=382&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/488857/original/file-20221009-57478-mwbb1c.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=480&fit=crop&dpr=1 754w, https://images.theconversation.com/files/488857/original/file-20221009-57478-mwbb1c.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=480&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/488857/original/file-20221009-57478-mwbb1c.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=480&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">John Whitfield tests the prototype device to help deafblind people sense others around them.</span>
<span class="attribution"><span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>The radar would scan the space up to six metres in front and to each side of the tester, tracking people as they came into range and moved about. This information was turned into vibrations of different intensity using tiny <a href="https://www.nfpmotor.com/products-coin-vibration-motors.html">coin vibration motors</a> in the headband and armband, which activated depending on the distance and direction of the detected person.</p>
<p>In our first test in a large theatre room at the University of Glasgow, Issy – having turned off her hearing aids to avoid getting any other environmental clues – was asked to indicate the direction of a person entering the near-space in front of her based on the vibrations she felt in the headband.</p>
<p>Most of the time, without hesitation, she correctly indicated where they were standing. It was an emotional moment for her, and all of us, when we told her about the accuracy of her answers. For the first time since she went completely blind, she was sensing where people were without relying on touch:</p>
<blockquote>
<p>Goodness, it would be so nice to walk up the road with this technology. Along with Yang my guide dog, I’d have a device that can tell me much more about the space around me and what’s happening – you know, how many people are in front of me, to the side, where are they? Am I walking right into a big crowd?</p>
</blockquote>
<p>In our second test, Issy used both the headband (to indicate the person’s direction) and armband (for their proximity) – but struggled to correctly detect how far away a person was. After a few trials, we realised the coin vibrations motors were too close together for her to differentiate the signals, and that the forearm location was also confusing. It would be better to combine the two sets of information (distance and direction) into one headband, and use the intensity of vibrations to indicate how far away the person was.</p>
<p>After further trials, we <a href="https://www.mdpi.com/1424-8220/22/19/7136">refined the tool</a> enough to be implemented into a cap. From the outset, our participants had stressed the importance of creating wearable technology that could blend in with everyday clothing if it was to be of true benefit to users such as Issy:</p>
<blockquote>
<p>The fact that it could give me an extra sense of my surroundings is fascinating. I actually just wanted to say to the guys: ‘Do you fancy going up Great Western Road with it now?’</p>
</blockquote>
<h2>‘A magic that reveals the joy in the world’</h2>
<p>In May 2022, I was giving Issy a tour of our <a href="https://www.cca-glasgow.com/whats-on/collection/touchscreen-rethinking-perception-through-sight-and-skin">TouchScreen event</a> at the Centre for Contemporary Arts in Glasgow. She was immediately drawn to a video installation called <a href="https://www.wolfgangweileder.com/other/trees_video_installation.html">Trees, by Wolfgang Weileder</a>. The video shows trees in different locations being cut down.</p>
<p>While standing in front of the large screen, she said she could sense the trees in the video via her cane. The sound frequencies from the audio were travelling from the speakers through the ground – she was thrilled because she felt included in the experience of the artwork.</p>
<p>As we stood there, I shifted my attention from seeing to feeling with my feet – and I could sense the vibrations too. This new layer of experience had been imperceptible to me a moment ago, yet now I felt physically related to the trees as they were being cut down. I also became aware of the ground connecting me with Issy. The sound was touching us both.</p>
<figure>
<iframe src="https://player.vimeo.com/video/340255071" width="500" height="281" frameborder="0" webkitallowfullscreen="" mozallowfullscreen="" allowfullscreen=""></iframe>
<figcaption><span class="caption">Trees by Wolfgang Weileder.</span></figcaption>
</figure>
<p>Favouring vision over other senses means we risk missing out on a host of rich experiences and connections – not least with people like Issy, Roger, John and other differently-abled people.</p>
<p>So the ambition of our <a href="https://touch-post-covid.gla.ac.uk/">ongoing research</a> – combining deeper understanding of the needs of deafblind people with cutting-edge quantum technology – is not only to enable deafblind people to play a bigger role in society. We also want to use their unique understanding of the world to enrich everyone else’s.</p>
<p>There could be more research into technology that enables them to communicate more independently. For example, by looking at how mmWaves (the type of radio waves used in airport security scanners) could be used to recognise hand gestures and touch-based communication beyond sign-language. </p>
<p>Certainly, there is more for us all to learn about the value of touch in the aftermath of the pandemic. If our eyesight is about knowing through a safe distance, touch is about forming intimate relations and becoming entangled with the surrounding world. As Issy says:</p>
<blockquote>
<p>You know, as somebody who has lost their eyesight, I was just too busy trying to get on with things. You don’t stop for two minutes and think: ‘Well actually, I hadn’t thought … how much I rely on touch and how much it means to me. How much it helps me to visualise the world.’</p>
</blockquote>
<p>For John, touch is a “holistic way of feeling” through the body. For Issy it is about “imagination” and knowing through “fumbling and stumbling”. For Roger, touch is like “magic” that reveals the joy in the world.</p>
<p>It is sad that it has taken a pandemic to bring greater understanding of the significance of touch – and in particular, touch deprivation – in our daily lives. But perhaps the disconnectedness we all experienced has also evoked greater empathy for the struggles deafblind people have been experiencing throughout history, such as isolation, lack of effective communication and exclusion from society.</p>
<p>It’s time we embraced their unique insights and learn about the way they “see” and feel the world. Or as Issy puts it:</p>
<blockquote>
<p>I always say to people, ‘You come into my space for two minutes and I’ll show you the way, in my world and my deafblind culture. The way I interact and connect with my space. Walk with me and I’ll show you the way – not through your eyes … but by connecting with me and my hands through touch.</p>
</blockquote>
<p><em>This article is part of an Insights series developed with <a href="https://www.ukri.org/about-us/">UK Research and Innovation</a> (UKRI) to explore the wider implications of research carried out during the COVID pandemic. <a href="https://touch-post-covid.gla.ac.uk/">Touch Post-COVID-19</a> is a UKRI-funded <a href="https://touch-post-covid.gla.ac.uk/index.php/team/">interdisciplinary research project</a> based at the University of Glasgow.</em></p>
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<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/313478/original/file-20200204-41481-1n8vco4.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/313478/original/file-20200204-41481-1n8vco4.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=112&fit=crop&dpr=1 600w, https://images.theconversation.com/files/313478/original/file-20200204-41481-1n8vco4.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=112&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/313478/original/file-20200204-41481-1n8vco4.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=112&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/313478/original/file-20200204-41481-1n8vco4.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=140&fit=crop&dpr=1 754w, https://images.theconversation.com/files/313478/original/file-20200204-41481-1n8vco4.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=140&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/313478/original/file-20200204-41481-1n8vco4.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=140&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<p class="fine-print"><em><span>Azadeh Emadi does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>A cultural collaboration with deafblind people led to the development of a high-tech device to help navigate their world post-lockdownAzadeh Emadi, Lecturer in Screen Production, School of Culture & Creative Arts, University of GlasgowLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1919292022-10-07T13:34:23Z2022-10-07T13:34:23ZNobel-winning quantum weirdness undergirds an emerging high-tech industry, promising better ways of encrypting communications and imaging your body<figure><img src="https://images.theconversation.com/files/488631/original/file-20221006-14-mzyckh.jpg?ixlib=rb-1.1.0&rect=0%2C8%2C3000%2C2384&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Devices like this experimental apparatus can produce pairs of photons that are linked, or 'entangled'.</span> <span class="attribution"><a class="source" href="https://www.ornl.gov/news/researchers-reach-quantum-networking-milestone-real-world-environment">Carlos Jones/ORNL, U.S. Dept. of Energy</a></span></figcaption></figure><p>Unhackable communications devices, high-precision GPS and high-resolution medical imaging all have something in common. These technologies – some under development and some already on the market all rely on the non-intuitive quantum phenomenon of <a href="https://theconversation.com/what-is-quantum-entanglement-a-physicist-explains-the-science-of-einsteins-spooky-action-at-a-distance-191927">entanglement</a>.</p>
<p>Two quantum particles, like pairs of atoms or photons, can become entangled. That means a property of one particle is linked to a property of the other, and a change to one particle instantly affects the other particle, regardless of how far apart they are. This correlation is a key resource in quantum information technologies. </p>
<p>For the most part, quantum entanglement is still a subject of physics research, but it’s also a component of commercially available technologies, and it plays a starring role in the emerging <a href="https://www.google.com/search?hl=en&as_q=list+of+quantum+information+processing+market+research+reports&as_epq=&as_oq=&as_eq=&as_nlo=&as_nhi=&lr=&cr=&as_qdr=all&as_sitesearch=&as_occt=any&safe=images&as_filetype=&tbs=">quantum information processing industry</a>.</p>
<h2>Pioneers</h2>
<p>The <a href="https://theconversation.com/nobel-prize-physicists-share-prize-for-insights-into-the-spooky-world-of-quantum-mechanics-191884">2022 Nobel Prize in Physics</a> recognized the profound legacy of <a href="https://www.nobelprize.org/prizes/physics/2022/aspect/facts/">Alain Aspect</a> of France, <a href="https://www.nobelprize.org/prizes/physics/2022/clauser/facts/">John F. Clauser</a> of the U.S. and Austrian <a href="https://www.nobelprize.org/prizes/physics/2022/zeilinger/facts/">Anton Zeilinger</a>’s experimental work with quantum entanglement, which has personally touched me since the start of my graduate school career as <a href="https://scholar.google.com/citations?hl=en&user=WTPrTLUAAAAJ&view_op=list_works&sortby=pubdate">a physicist</a>. Anton Zeilinger was a mentor of my Ph.D. mentor, <a href="https://physics.illinois.edu/people/directory/profile/kwiat">Paul Kwiat</a>, which heavily influenced my dissertation on experimentally understanding decoherence in photonic entanglement. </p>
<p><a href="https://www.theatlantic.com/science/archive/2018/10/beyond-weird-decoherence-quantum-weirdness-schrodingers-cat/573448/">Decoherence</a> occurs when the environment interacts with a quantum object – in this case a photon – to knock it out of the quantum state of superposition. In <a href="https://scienceexchange.caltech.edu/topics/quantum-science-explained/quantum-superposition">superposition</a>, a quantum object is isolated from the environment and exists in a strange blend of two opposite states at the same time, like a coin toss landing as both heads and tails. Superposition is necessary for two or more quantum objects to become entangled.</p>
<h2>Entanglement goes the distance</h2>
<p>Quantum entanglement is a critical element of quantum information processing, and photonic entanglement of the type pioneered by the Nobel laureates is crucial for transmitting quantum information. Quantum entanglement can be used to build large-scale quantum communications networks.</p>
<p>On a path toward long-distance quantum networks, Jian-Wei Pan, one of Zeilinger’s former students, and colleagues demonstrated entanglement distribution to two locations separated by 764 miles (1,203 km) on Earth <a href="https://doi.org/10.1126/science.aan3211">via satellite transmission</a>. However, direct transmission rates of quantum information are limited due to <a href="https://doi.org/10.1038/ncomms15043">loss</a>, meaning too many photons get absorbed by matter in transit so not enough reach the destination. </p>
<p>Entanglement is critical for solving this roadblock, through the nascent technology of quantum repeaters. An important milestone for early quantum repeaters, called entanglement swapping, <a href="https://link.aps.org/doi/10.1103/PhysRevLett.80.3891">was demonstrated</a> by Zeilinger and colleagues in 1998. Entanglement swapping links one each of two pairs of entangled photons, thereby entangling the two initially independent photons, which can be far apart from each other.</p>
<h2>Quantum protection</h2>
<p>Perhaps the most well known quantum communications application is Quantum Key Distribution (QKD), which allows someone to securely distribute encryption keys. If those keys are stored properly, they will be secure, even from future powerful, code-breaking quantum computers. </p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/UiJiXNEm-Go?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">How quantum encryption keeps secrets safe.</span></figcaption>
</figure>
<p>While the first proposal for QKD did not explicitly require entanglement, an entanglement-based version was subsequently <a href="https://link.aps.org/doi/10.1103/PhysRevLett.67.661">proposed</a>. Shortly after this proposal came the first demonstration of the technique, through the air over a short distance on a <a href="https://doi.org/10.1007/BF00191318">table-top</a>. The first demonstrations of entangement-based QKD were published by research groups led by <a href="https://doi.org/10.1103/PhysRevLett.84.4729">Zeilinger</a>, <a href="https://doi.org/10.1103/PhysRevLett.84.4737">Kwiat</a> and <a href="https://doi.org/10.1103/PhysRevLett.84.4733">Nicolas Gisin</a> were published in the same issue of Physical Review Letters in May 2000.</p>
<p>These entanglement-based distributed keys can be used to dramatically improve the security of communications. A first important demonstration along these lines was from the Zeilinger group, which conducted a <a href="https://doi.org/10.1364/OPEX.12.003865">bank wire transfer in Vienna, Austria, in 2004</a>. In this case, the two halves of the QKD system were located at the headquarters of a large bank and the Vienna City Hall. The optical fibers that carried the photons were installed in the Vienna sewer system and spanned nine-tenths of a mile (1.45 km).</p>
<h2>Entanglement for sale</h2>
<p>Today, there are a handful of companies that have commercialized quantum key distribution technology, including my group’s collaborator <a href="https://qubitekk.com/">Qubitekk</a>, which focuses on an entanglement-based approach to QKD. With a more recent commercial Qubitekk system, my colleagues and I demonstrated <a href="https://doi.org/10.1038/s41598-022-16090-w">secure smart grid communications</a> in Chattanooga, Tennessee.</p>
<p>Quantum communications, computing and sensing technologies are of <a href="https://idstch.com/technology/photonics/entangled-photon-sources-is-critical-technology-for-secure-communications-systems/">great interest to the military and intelligence communities</a>. Quantum entanglement also promises to boost medical imaging through <a href="https://doi.org/10.1038/srep37714">optical sensing</a> and high-resolution <a href="https://news.engineering.arizona.edu/news/quantum-entanglement-offers-unprecedented-precision-gps-imaging-and-beyond">radio frequency detection</a>, which could also improve GPS positioning. There’s even a company gearing up to <a href="https://www.techrepublic.com/article/quantum-entanglement-as-a-service-the-key-technology-for-unbreakable-networks/">offer entanglement-as-a-service</a> by providing customers with network access to entangled qubits for secure communications.</p>
<p>There are many other quantum applications that have been proposed and have yet to be invented that will be enabled by future entangled quantum networks. Quantum computers will perhaps have the most direct impact on society by enabling direct simulation of problems that do not scale well on conventional digital computers. In general, quantum computers produce complex entangled networks when they are operating. These computers could have huge impacts on society, ranging from reducing energy consumption to developing personally tailored medicine. </p>
<p>Finally, entangled quantum sensor networks promise the capability to measure theorized phenomena, such as dark matter, that cannot be seen with today’s conventional technology. The strangeness of quantum mechanics, elucidated through decades of fundamental experimental and theoretical work, has given rise to a new burgeoning global quantum industry.</p><img src="https://counter.theconversation.com/content/191929/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Nicholas Peters receives funding from The United States Department of Energy (DOE) Office of Science Advanced Scientific Computing Research program and DOE's Office of Cybersecurity, Energy Security and Emergency Response. He is affiliated with Oak Ridge National Laboratory. </span></em></p>Quantum entanglement is the stuff of sci-fi, advanced physics research and, increasingly, technology used by governments, banks and the military.Nicholas Peters, Joint Faculty, University of TennesseeLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1870142022-07-25T20:01:55Z2022-07-25T20:01:55ZThis Australian experiment is on the hunt for an elusive particle that could help unlock the mystery of dark matter<figure><img src="https://images.theconversation.com/files/475787/original/file-20220725-22-e2kyjx.jpeg?ixlib=rb-1.1.0&rect=150%2C25%2C5440%2C4166&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Shutterstock</span></span></figcaption></figure><p>Australian scientists are making strides towards solving one of the greatest mysteries of the universe: the nature of invisible “dark matter”.</p>
<p>The ORGAN Experiment, Australia’s first major dark matter detector, recently completed a search for a hypothetical particle called an axion – a popular candidate among theories that try to explain dark matter.</p>
<p>ORGAN has placed new limits on the possible characteristics of axions and thus helped narrow the search for them. But before we get ahead of ourselves …</p>
<h2>Let’s start with a story</h2>
<p>About 14 billion years ago, all the little pieces of matter – the fundamental particles that would later become you, the planet and the galaxy – were compressed into one very dense, hot region.</p>
<p>Then the Big Bang happened and everything flew apart. The particles combined into atoms, which eventually clumped together to make stars, which exploded and created all kinds of exotic matter. </p>
<p>After a few billion years came Earth, which was eventually crawling with little things called humans. Cool story, right? Turns out it’s not the whole story; it’s not even half.</p>
<p>People, planets, stars and galaxies are all made of “regular matter”. But we know regular matter makes up just one-sixth of all the matter in the universe. </p>
<p>The rest is made of what we call “dark matter”. Its name tells you almost everything we know about it. It doesn’t emit light (so we call it “dark”) and it has mass (so we call it “matter”).</p>
<h2>If it’s invisible, how do we know it’s there?</h2>
<p>When we observe the way things move in space, we find time and again that we can’t explain our observations if we consider only what we can see. </p>
<p>Spinning galaxies are a great example. Most galaxies spin at speeds that can’t be explained by the gravitational pull from visible matter alone. </p>
<p>So there must be dark matter in these galaxies, providing extra gravity and allowing them to spin faster – without parts being flung off into space. We think dark matter literally holds galaxies together.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/475806/original/file-20220725-19-1mwcwz.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Cluster of galaxies displayed in hues of pink and purple against a black cosmic background." src="https://images.theconversation.com/files/475806/original/file-20220725-19-1mwcwz.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/475806/original/file-20220725-19-1mwcwz.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=434&fit=crop&dpr=1 600w, https://images.theconversation.com/files/475806/original/file-20220725-19-1mwcwz.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=434&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/475806/original/file-20220725-19-1mwcwz.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=434&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/475806/original/file-20220725-19-1mwcwz.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=545&fit=crop&dpr=1 754w, https://images.theconversation.com/files/475806/original/file-20220725-19-1mwcwz.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=545&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/475806/original/file-20220725-19-1mwcwz.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=545&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The ‘Bullet Cluster’ is a massive cluster of galaxies which has been interpreted as being strong evidence for the existence of dark matter.</span>
<span class="attribution"><a class="source" href="https://science.nasa.gov/matter-bullet-cluster">NASA</a></span>
</figcaption>
</figure>
<p>So there must be an enormous amount of dark matter in the universe, pulling on all the things we can see. It’s passing through you, too, like some kind of cosmic ghost. You just can’t feel it.</p>
<h2>How could we detect it?</h2>
<p>Many scientists believe dark matter could be composed of hypothetical particles called axions. Axions were originally proposed as part of a solution to another major problem in particle physics called the “strong CP problem” (which we could write a whole article about). </p>
<p>Anyway, after the axion was proposed, scientists realised the particle could also make up dark matter under certain conditions. That’s because axions are expected to have very weak interactions with regular matter, but still have some mass: the two conditions needed for dark matter.</p>
<p>So how do you go about searching for axions? </p>
<p>Well, since dark matter is thought to be all around us, we can build detectors right here on Earth. And, luckily, the theory that predicts axions also predicts that axions can convert into photons (particles of light) under the right conditions.</p>
<p>This is good news, because we’re great at detecting photons. And this is exactly what ORGAN does. It engineers the correct conditions for axion–photon conversion and looks for weak photon signals – little flashes of light generated by dark matter passing through the detector. </p>
<p>This kind of experiment is called an axion haloscope and was first proposed in the <a href="https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.51.1415">1980s</a>. There are a few in the world today, each one slightly different in important ways.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/475807/original/file-20220725-24-v7qdc9.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/475807/original/file-20220725-24-v7qdc9.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/475807/original/file-20220725-24-v7qdc9.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/475807/original/file-20220725-24-v7qdc9.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/475807/original/file-20220725-24-v7qdc9.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/475807/original/file-20220725-24-v7qdc9.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/475807/original/file-20220725-24-v7qdc9.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/475807/original/file-20220725-24-v7qdc9.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The ORGAN Experiment’s main detector. A small copper cylinder called a ‘resonant cavity’ traps photons generated during dark matter conversion. The cylinder is bolted to a ‘dilution refrigerator’ which cools the experiment to very low temperatures.</span>
<span class="attribution"><span class="license">Author provided</span></span>
</figcaption>
</figure>
<h2>Shining a light on dark matter</h2>
<p>An axion is believed to convert into a photon in the presence of a strong magnetic field. In a typical haloscope, we generate this magnetic field using a big electromagnet called a “superconducting solenoid”.</p>
<p>Inside the magnetic field we place one or several hollow chambers of metal, which are meant to trap the photons and cause them to bounce around inside, making them easier to detect.</p>
<p>However, there is one hiccup. Everything that has a temperature constantly emits small random flashes of light (which is why thermal imaging cameras work). These random emissions, or “noise”, make it harder to detect the faint dark matter signals we’re looking for. </p>
<p>To work around this, we’ve placed our resonator in a “dilution refrigerator”. This fancy fridge cools the experiment to cryogenic temperatures, about −273°C, which greatly reduces the noise. </p>
<p>The colder the experiment is, the better we can “listen” for faint photons produced during dark matter conversion.</p>
<h2>Targeting mass regions</h2>
<p>An axion of a certain mass will convert into a photon of a certain frequency, or colour. But since the mass of axions is unknown, experiments must target their search to different regions, focusing on those where dark matter is considered more likely to exist.</p>
<p>If no dark matter signal is found, then either the experiment is not sensitive enough to hear the signal above the noise, or there’s no dark matter in the corresponding axion mass region. </p>
<p>When this happens, we set an “exclusion limit” – which is just a way of saying “we didn’t find any dark matter in this mass range, to this level of sensitivity”. This tells the rest of the dark matter research community to direct their searches elsewhere.</p>
<p>ORGAN is the most sensitive experiment in its targeted frequency range. Its recent run detected no dark matter signals. This result has set an important exclusion limit on the possible characteristics <a href="https://www.science.org/doi/10.1126/sciadv.abq3765">of axions</a>.</p>
<p>This is the first phase of a multi-year plan to search for axions. We’re currently preparing the next experiment, which will be more sensitive and target a new, as-yet-unexplored mass range. </p>
<h2>But why does dark matter matter?</h2>
<p>Well, for one, we know from history that when we invest in fundamental physics, we end up developing important technologies. For instance, all modern computing relies on our understanding of quantum mechanics.</p>
<p>We never would have discovered electricity, or radio waves, if we didn’t pursue things that, at the time, appeared to be strange physical phenomena beyond our understanding. Dark matter is the same.</p>
<p>Consider everything humans have accomplished by understanding just one-sixth of the matter in the universe – and imagine what we could do if we unlocked the rest.</p>
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Read more:
<a href="https://theconversation.com/the-search-for-dark-matter-gets-a-speed-boost-from-quantum-technology-153604">The search for dark matter gets a speed boost from quantum technology</a>
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<img src="https://counter.theconversation.com/content/187014/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Ben McAllister works for The University of Western Australia. The work referenced in this article is funded by the Australian Research Council.</span></em></p>Regular matter makes up just one-sixth of all the matter in the universe. What would it mean to finally understand what makes up the rest?Ben McAllister, Research Fellow, Department of Physics, The University of Western AustraliaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1826222022-05-25T13:24:45Z2022-05-25T13:24:45ZQuantum physics offers insights about leadership in the 21st century<figure><img src="https://images.theconversation.com/files/463267/original/file-20220516-23-5mwuzq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Shutterstock</span></span></figcaption></figure><p>It may seem strange to look to the discipline of quantum physics for lessons that will help to create future-fit leaders. But science has a lot to offer us. </p>
<p>Like scientists, business leaders need to be able to manage rapid change and ambiguity in a non-linear, multi-disciplinary and networked environment. But, for the most part, businesses find themselves trapped in processes that draw on the paradigm of certainty and predictability. This approach is analogous to the Newtonian physics developed in the 1600’s.</p>
<p>The ambiguity that business leaders operate in is encapsulated in mathematical models developed by the advances in Quantum Physics developed in the early 1900’s. These advances culminated in massive progression in technology. And they can accommodate the complexity and uncertainty archetypes found in nature – and now by extension human behaviour. </p>
<p>These mathematical models allow for improved scenario and forecasting. They are therefore very useful in <a href="https://www.adamhall.solutions/blog/2021/4/5/how-quantum-physics-relates-to-businessnbsp-leadership">vastly improving decision-making</a>, as pointed out by the author Adam C. Hall.</p>
<h2>Quantum physics and quantum organisations</h2>
<p>Throughout history, scholars have tried to make sense of human behaviour and, by extension, leadership attributes by studying natural phenomena. </p>
<p><a href="https://ideas.repec.org/h/spr/sprchp/978-981-16-7849-3_13.html">According</a> to complexity economist Brian Arthur and physicist Geoffrey West human social systems function optimally as complex adaptive systems – or quantum systems. </p>
<p>The newly developed field of quantum leadership maps the human, conscious equivalents onto the 12 systems that define complex adaptive systems or quantum organisations. These are: self-awareness; vision and value led; spontaneity; holism; field-independence; humility; ability to reframe; asking fundamental questions; celebration of diversity; positive use of adversity; compassion; a sense of vocation (purpose).</p>
<p>Quantum leadership is essentially <a href="https://www.quantumleadershipactivism.org/eng/resources/3/quantum-leadership/">a new management approach</a> that integrates the most effective attributes of traditional leadership with recent advances in both quantum physics and neuroscience. It is a model that allows for greater responsiveness. It draws on our innate ability to recognise, adapt and respond to uncertainty and complexity.</p>
<p>My academic work has been in nanophysics. This is an study where the laws of physics become governed by quantum physics as opposed to the rigid and deterministic Newtonian approach. </p>
<p>When entering the corporate world my interest was piqued on how leaders should respond to complexity, ambiguity and non-liniearity. This complimentarity extended my curiosity. In turn this led me to navigate several disciplines dealing with complex systems.</p>
<p>Quantum Mechanics has been confirmed by <a href="https://www.livescience.com/33816-quantum-mechanics-explanation.html">scientific evidence</a>. The <a href="https://courses.lumenlearning.com/physics/chapter/27-3-youngs-double-slit-experiment/">most popularly cited</a> experiment was the <a href="https://www.nobelprize.org/prizes/physics/1929/broglie/facts/">Nobel winning</a> theoretical development by Louis-Victor Pierre Raymond de Broglie explaining the wave-particle duality of light illustrated by the double <a href="https://www.britannica.com/science/light/Youngs-double-slit-experiment">slit experiment of Thomas Young</a>. This showed that the outcome of any potential event is multi-fold and dependent on the vantage point of the observer. </p>
<p>This doesn’t imply the correctness or incorrectness of any outcome. It just highlights how vantage point can – and does – influence behaviour and decision-making.</p>
<p>To come to grips with the vast change precipitated by the fourth industrial revolution businesses have to acknowledge that outcomes are vantage point dependent and random. This industrial revolution provides the potential to precipitate fundamental and positive changes in the way in which societies and work are organised.</p>
<p>Disruptive technologies such as mobile banking, practices such as remote working, and dramatic changes in consumer behaviour are inevitably rousing leadership from a linear mindset as they uncover non-linear opportunities. </p>
<p>The imperative of developing leaders that can deal with pervasive disruptions has being recognized by leading business schools. Examples include <a href="https://www.insead.edu/executive-education/insead-online-programmes?CampaignId=GGL_Search_A&SiteId=GGL&CampaignName=EMEA-ZA%5BEN%5D_GGL-Brand%5BGEN%5D-Online_MT-Exact&AdId=ONLINE&device=c&term=insead%20executive%20education%20online_(e)&gclid=CjwKCAjw7IeUBhBbEiwADhiEMacdFezsAzm0s7hgR1U5KT6ZpM7wViUOsngeRMN-BdjDgiKSRAk71hoCmcsQAvD_BwE">INSEAD’s programme in Executive Education</a>. One course covers developing effective strategies and learning how to innovate in a disruptive, uncertain world.</p>
<h2>Defining the quantum leader</h2>
<p>The concept of a quantum leader is gaining <a href="https://www.amazon.com/Quantum-Leader-Revolution-Business-Thinking/dp/1633882411">traction in behavioural studies</a>. </p>
<p>Quantum leaders, like the systems they have to manage, are poised at ‘the edge of chaos.’ They thrive on the potential latent in uncertainty. They are also:</p>
<ul>
<li><p>vision and value led</p></li>
<li><p>adapt quickly, </p></li>
<li><p>are unafraid to play with the boundaries and reinvent the rules, and </p></li>
<li><p>celebrate diversity. </p></li>
</ul>
<p>In this way, they are precipitating a radical break from the past.</p>
<p>Practically, quantum leadership is informed by quantum thinking and guided by the defining principles of quantum physics. Quantum leaders think ahead by formulating many scenarios for what the future might hold, encourage questions and experiments, and thrive on uncertainty.</p>
<p>Quantum leaders are guided by the same principles that inform complex adaptive systems. They can also operate effectively outside the direct control of formal systems. They have the ability to reframe challenges and issues within the context of the environment. And develop new approaches through relationships.</p>
<p>In short, they are curious, adaptable and tolerant of ambiguity and uncertainty.</p>
<p>The charismatic and forceful leader like the iconic <a href="https://www.nytimes.com/2019/07/02/obituaries/lee-iacocca-dead.html">Lee Iacocca led Chrysler </a> to the company to great heights. Yet <a href="https://qz.com/work/1658240/how-lee-iacocca-who-bashed-the-japanese-is-being-remembered-in-japan/">he failed to anticipate</a> the dominance of Japanese automotive manufacturers. Lionised leaders who consult only as a matter of form but impose what they believed to be their superior way of thinking are the antithesis of what a quantum leaders represents. </p>
<p>The ingrained categorisation or divide between ‘hard, such as Physics’ and ‘soft, the Humanities in general’ sciences is self limiting. It creates unnecessary chasms between creativity and innovation. The quantum management paradigm recognises that analytics, design, creativity and human behaviour has to be integrated into the mindsets of future leaders. </p>
<h2>Where to from here?</h2>
<p>The World Economic Forum <a href="https://www.weforum.org/agenda/2020/01/reskilling-revolution-jobs-future-skills/">estimates</a> that digital transformation will transform a third of all jobs globally within the next decade. In addition billions of people will require reskilling. This trend will hit developing nations particularly hard. They have limited access to technology, remain locked into traditional teaching methods, and still practice top-down models of management.</p>
<p>In seeking solutions to this scenario, intellectuals across all disciplines need to come together to explore a more agile, multi-disciplinary approach to social and business management. Drawing on quantum theory concepts, we need to create a different way of looking at probability and possibility in the business world.</p>
<p>Business schools need to develop a new kind of business leader that can consider all possible outcomes. They need to be adaptable enough to function in a world in which outcomes may well be counter-intuitive. This is the way of the future.</p><img src="https://counter.theconversation.com/content/182622/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Randall Carolissen does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Quantum leaders are curious, adaptable and tolerant of ambiguity and uncertainty.Randall Carolissen, Dean Johannesburg Business School, University of JohannesburgLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1716082021-12-07T14:58:31Z2021-12-07T14:58:31ZQuantum entanglement: what it is, and why physicists want to harness it<figure><img src="https://images.theconversation.com/files/434373/original/file-20211129-25-djd15g.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Two particles are said to be entangled when one cannot be perfectly described without information about the other being included.</span> <span class="attribution"><span class="source">Shutterstock/ezphoto</span></span></figcaption></figure><p>“Quantum entanglement” is one of several plot devices that crops up in modern sci-fi movies. Fans of the <a href="https://www.wired.co.uk/article/marvel-movies-science">Marvel superhero movies</a>, for instance, will be familiar with the idea of different time lines merging and intersecting, or characters’ destinies becoming intertwined through seemingly magical means.</p>
<p>But “quantum entanglement” isn’t just a sci-fi buzzword. It’s a very real, perplexing and useful phenomenon. “Entanglement” is one aspect of the broader collection of ideas in physics known as quantum mechanics, which is a theory that describes the behaviour of nature at the atomic, and even subatomic, level.</p>
<p>Understanding and harnessing entanglement is key to creating many cutting-edge technologies. These include quantum computers, which can solve certain problems far faster than ordinary computers, and quantum communication devices, which would allow us to communicate with one another without the slightest possibility of a eavesdropper listening in.</p>
<p>But what exactly <em>is</em> quantum entanglement? Two particles in quantum mechanics are said to be <em>entangled</em> when one of the particles cannot be perfectly described without including all of the information about the other one: the particles are “connected” in such a way that they are not independent of one another. While this sort of idea may seem to make sense at first glance, it is a difficult concept to grasp – and physicists are still learning more about it.</p>
<h2>Quantum dice</h2>
<p>Suppose that I give you and your friend, Thandi, each a small, opaque black box. Each box contains an ordinary six-sided die. You are both told to lightly shake your boxes to jumble the dice around. Then you part ways. Thandi goes home to one South African city, Cape Town; you return to another, Durban. You don’t communicate with each other during the process. When you get home, you each open your box and look at the upward-facing number on your die. </p>
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<span class="attribution"><span class="source">Shutterstock</span></span>
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<p>Ordinarily, there would be no correlation between the numbers you and Thandi see. She would be equally likely to observe any number between 1 and 6, as would you; importantly, the number she sees on her die would have no bearing whatsoever on the number you see on yours. </p>
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Read more:
<a href="https://theconversation.com/is-reality-a-game-of-quantum-mirrors-a-new-theory-suggests-it-might-be-162936">Is reality a game of quantum mirrors? A new theory suggests it might be</a>
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<p>This is unsurprising – indeed, it’s how the world normally works. However, if we could make this example “quantum”, it could behave quite differently. Suppose that I now tell Thandi and you to first lightly tap your boxes together, before then separately shaking them and heading your separate ways. </p>
<p>In a quantum mechanics analogy, this action of tapping the boxes against one another would enchant the dice and link – or entangle – them in a mysterious fashion: once you each arrive home, open your boxes and look at the numbers, your number and Thandi’s are guaranteed to be perfectly correlated. If you see a ‘4’ in Durban, you know that Thandi in Cape Town is guaranteed to measure a ‘4’ on her die too; if you happen to see a ‘6’, so will she.</p>
<p>In this analogy, the dice represent individual particles (like atoms or particles of light called photons) and the magic act of tapping the boxes together physically is what entangles them, so that measuring one die gives us information about the other.</p>
<h2>Making better entanglement</h2>
<p>As far as we know, there’s no magical box-tapping action to enchant a pair of dice or other objects on our human, macroscopic scale (if there were, we would be able to experience quantum mechanics in our everyday life and it would probably not be such a foreign, perplexing concept). For now, scientists have to be content with using things on the microscopic level, where it is much easier to observe quantum effects, like charged atoms called ions or special superconducting devices called <a href="https://www.youtube.com/watch?v=9MFPvrjHgF0">transmons</a>.</p>
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Read more:
<a href="https://theconversation.com/explainer-what-is-quantum-machine-learning-and-how-can-it-help-us-114627">Explainer: what is quantum machine learning and how can it help us?</a>
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<p>This is the kind of work carried out in the University of the Witwatersrand’s <a href="https://structured-light.org/">Structured Light Laboratory</a>, in South Africa. Instead of ions or transmons, however, researchers in the lab use particles of light, called photons, to better understand quantum mechanics and its implications. We are interested in using the quantum nature of light for a variety of purposes: from designing efficient communication systems which are completely unhackable by a malevolent third party, to creating methods of imaging sensitive biological samples without damaging them. </p>
<p>Studies like this often require us to start with specially created states of entangled photons. But it’s not as simple as putting two dice in separate boxes and tapping them together. The processes used to create entangled photons in a real laboratory are constrained by many experimental variables. These include the shape of laser beams used in experiments and the sizes of small crystals where the entangled photons are created. These can give subpar outputs – or unideal states – that require researchers to selectively throw away some measurements once an experiment is done. This is not an optimal situation: photons are discarded and so energy is wasted.</p>
<p>A group of researchers from the lab, myself among them, recently took a step towards solving this problem. In <a href="https://onlinelibrary.wiley.com/doi/10.1002/qute.202100066">a journal article</a>, we mathematically calculated what the optimal laser shape needs to be in order to, as best as possible, create the entangled state that an experimenter would want to start their experiment with. The method proposes changing the input laser beam shape at the beginning of an experiment to maximise the entangled photon creation process later in the experiment. This will mean more photons available to perform your experiment the way you want to, and fewer stray ones.</p>
<p>Improving the efficiency of the entanglement creation and manipulation process, using techniques such as the one proposed, will be important to optimise the efficiency of a number of other quantum technologies, like quantum cryptography systems and the other technologies already mentioned. This is especially important as the fourth industrial revolution moves ahead globally and technologies with quantum mechanics at their cores undoubtedly <a href="https://www.weforum.org/agenda/2019/10/quantum-computers-next-frontier-classical-google-ibm-nasa-supremacy">become more commonplace</a>.</p><img src="https://counter.theconversation.com/content/171608/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Nicholas Bornman receives funding from the CSIR Scarce Skills Programme.</span></em></p>The quantum nature of light can be harnessed for a variety of purposes.Nicholas Bornman, Ph.D. student, University of the WitwatersrandLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1645822021-07-19T17:08:15Z2021-07-19T17:08:15ZCan consciousness be explained by quantum physics? My research takes us a step closer to finding out<figure><img src="https://images.theconversation.com/files/411896/original/file-20210719-25-191cj1c.jpeg?ixlib=rb-1.1.0&rect=197%2C188%2C5604%2C3799&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Some scientists believe consciousness is generated by quantum processes, but the theory is yet to be empirically tested.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-illustration/human-brain-capabilities-conceptual-vision-326869622">vitstudio/Shutterstock</a></span></figcaption></figure><p>One of the most important open questions in science is how our consciousness is established. In the 1990s, <a href="https://www.nobelprize.org/prizes/physics/2020/penrose/facts/">long before winning</a> the 2020 Nobel Prize in Physics for his prediction of black holes, physicist Roger Penrose teamed up with anaesthesiologist Stuart Hameroff to propose an ambitious answer. </p>
<p><a href="https://royalsocietypublishing.org/doi/10.1098/rsta.1998.0254">They claimed</a> that the brain’s neuronal system forms an intricate network and that the consciousness this produces should obey the rules of <a href="https://www.sciencedirect.com/topics/chemistry/quantum-mechanics">quantum mechanics</a> – the theory that determines how tiny particles like electrons move around. This, they argue, could explain the mysterious complexity of human consciousness.</p>
<p>Penrose and Hameroff were met with incredulity. Quantum mechanical laws are usually only found to apply at <a href="https://www.nature.com/articles/166887a0">very low temperatures</a>. Quantum computers, for example, currently operate at around <a href="https://www.newscientist.com/article/2240539-quantum-computer-chips-demonstrated-at-the-highest-temperatures-ever/">-272°C</a>. At higher temperatures, classical mechanics takes over. Since our body works at room temperature, you would expect it to be governed by the classical laws of physics. For this reason, the quantum consciousness theory has been <a href="http://www.bbc.com/earth/story/20170215-the-strange-link-between-the-human-mind-and-quantum-physics?">dismissed outright</a> by many scientists – though others are <a href="https://plato.stanford.edu/entries/qt-consciousness/">persuaded supporters</a>.</p>
<p>Instead of entering into this debate, I decided to join forces with colleagues from China, led by Professor Xian-Min Jin at Shanghai Jiaotong University, to test some of the principles underpinning the quantum theory of consciousness. </p>
<p>In <a href="https://www.nature.com/articles/s41566-021-00845-4">our new paper</a>, we’ve investigated how quantum particles could move in a complex structure like the brain – but in a lab setting. If our findings can one day be compared with activity measured in the brain, we may come one step closer to validating or dismissing Penrose and Hameroff’s <a href="https://plato.stanford.edu/entries/qt-consciousness/">controversial theory</a>.</p>
<h2>Brains and fractals</h2>
<p>Our brains are composed of cells called neurons, and their combined activity is believed to generate consciousness. Each neuron contains <a href="https://psych.athabascau.ca/html/Psych402/Biotutorials/1/microtubules.shtml">microtubules</a>, which transport substances to different parts of the cell. The Penrose-Hameroff theory of quantum consciousness argues that microtubules are structured in a <a href="https://theconversation.com/explainer-what-are-fractals-10865">fractal pattern</a> which would enable quantum processes to occur.</p>
<p>Fractals are structures that are neither two-dimensional nor three-dimensional, but are instead some fractional value in between. In mathematics, fractals emerge as <a href="https://www.youtube.com/watch?v=NGMRB4O922I&ab_channel=Numberphile">beautiful patterns</a> that repeat themselves infinitely, generating what is seemingly impossible: a structure that has a finite area, but an infinite perimeter.</p>
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Read more:
<a href="https://theconversation.com/explainer-what-are-fractals-10865">Explainer: what are fractals?</a>
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<p>This might sound impossible to visualise, but fractals actually occur frequently <a href="https://theconversation.com/fractal-patterns-in-nature-and-art-are-aesthetically-pleasing-and-stress-reducing-73255">in nature</a>. If you look closely at the florets <a href="https://theconversation.com/why-do-cauliflowers-look-so-odd-weve-cracked-the-maths-behind-their-fractal-shape-164121">of a cauliflower</a> or the branches <a href="https://theconversation.com/fractal-patterns-in-nature-and-art-are-aesthetically-pleasing-and-stress-reducing-73255">of a fern</a>, you’ll see that they’re both made up of the same basic shape repeating itself over and over again, but at smaller and smaller scales. That’s a key characteristic of fractals.</p>
<p>The same happens if you look inside your own body: the structure of <a href="https://www.sciencedirect.com/science/article/pii/S1474667016387791">your lungs</a>, for instance, is fractal, as are the <a href="https://www.sciencedirect.com/science/article/abs/pii/S0960077904005867">blood vessels</a> in your circulatory system. Fractals also feature in the enchanting repeating artworks of <a href="http://www.pxleyes.com/blog/2010/06/recursion-the-art-and-ideas-behind-m-c-eschers-drawings/">MC Escher</a> and <a href="https://www.discovermagazine.com/the-sciences/pollocks-fractals">Jackson Pollock</a>, and they’ve been used for decades in technology, such as in the <a href="https://antenna-theory.com/antennas/fractal.php">design of antennas</a>. These are all examples of classical fractals – fractals that abide by the laws of classical physics rather than quantum physics. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/411888/original/file-20210719-23-8ojaav.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A fractal Escher artwork" src="https://images.theconversation.com/files/411888/original/file-20210719-23-8ojaav.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/411888/original/file-20210719-23-8ojaav.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/411888/original/file-20210719-23-8ojaav.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/411888/original/file-20210719-23-8ojaav.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/411888/original/file-20210719-23-8ojaav.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/411888/original/file-20210719-23-8ojaav.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/411888/original/file-20210719-23-8ojaav.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">This extension of Escher’s Circle Limit III shows its fractal, repeating nature.</span>
<span class="attribution"><a class="source" href="https://www.deviantart.com/vladimir-bulatov/art/M-C-Escher-Circle-Limit-III-in-a-rectangle-281848653">Vladimir-Bulatov/Deviantart</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc-sa/4.0/">CC BY-NC-SA</a></span>
</figcaption>
</figure>
<p>It’s easy to see why fractals have been used to explain the complexity of human consciousness. Because they’re infinitely intricate, allowing complexity to emerge from simple repeated patterns, they could be the structures that support the mysterious depths of our minds. </p>
<p>But if this is the case, it could only be happening on the quantum level, with tiny particles moving in fractal patterns within the brain’s neurons. That’s why Penrose and Hameroff’s proposal is called a theory of “quantum consciousness”. </p>
<h2>Quantum consciousness</h2>
<p>We’re not yet able to measure the behaviour of quantum fractals in the brain – if they exist at all. But advanced technology means we can now measure quantum fractals in the lab. In <a href="https://www.nature.com/articles/s41567-018-0328-0/">recent research</a> involving a <a href="http://hoffman.physics.harvard.edu/research/STMintro.php">scanning tunnelling microscope</a> (STM), my colleagues at Utrecht and I carefully arranged electrons in a fractal pattern, creating a quantum fractal. </p>
<p>When we then measured the wave function of the electrons, which describes their quantum state, we found that they too lived at the fractal dimension dictated by the physical pattern we’d made. In this case, the pattern we used on the quantum scale was the <a href="https://www.britannica.com/science/Sierpinski-gasket">Sierpiński triangle</a>, which is a shape that’s somewhere between one-dimensional and two-dimensional.</p>
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<p>This was an exciting finding, but STM techniques cannot probe how quantum particles move – which would tell us more about how quantum processes might occur in the brain. So in <a href="https://www.nature.com/articles/s41566-021-00845-4">our latest research</a>, my colleagues at Shanghai Jiaotong University and I went one step further. Using state-of-the-art photonics experiments, we were able to reveal the quantum motion that takes place within fractals in unprecedented detail. </p>
<p>We achieved this by <a href="https://www.thoughtco.com/what-is-a-photon-definition-and-properties-2699039">injecting photons</a> (particles of light) into an artificial chip that was painstakingly engineered into a tiny Sierpiński triangle. We injected photons at the tip of the triangle and watched how they spread throughout its fractal structure in a process called <a href="https://www.sciencedirect.com/topics/physics-and-astronomy/quantum-transport">quantum transport</a>. We then repeated this experiment on two different fractal structures, both shaped as squares rather than triangles. And in each of these structures we conducted hundreds of experiments.</p>
<figure class="align-center ">
<img alt="A repeating square fractal" src="https://images.theconversation.com/files/411920/original/file-20210719-13-1j3nr.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/411920/original/file-20210719-13-1j3nr.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/411920/original/file-20210719-13-1j3nr.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/411920/original/file-20210719-13-1j3nr.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/411920/original/file-20210719-13-1j3nr.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/411920/original/file-20210719-13-1j3nr.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/411920/original/file-20210719-13-1j3nr.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=754&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">We also conducted experiments on a square-shaped fractal called the Sierpiński carpet.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:Sierpinski_carpet_5.svg">Johannes Rössel/wikimedia</a></span>
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<p>Our observations from these experiments reveal that quantum fractals actually behave in a different way to classical ones. Specifically, we found that the spread of light across a fractal is governed by different laws in the quantum case compared to the classical case.</p>
<p>This new knowledge of quantum fractals could provide the foundations for scientists to experimentally test the theory of quantum consciousness. If quantum measurements are one day taken from the human brain, they could be compared against our results to definitely decide whether consciousness is a classical or a quantum phenomenon.</p>
<p>Our work could also have profound implications across scientific fields. By investigating quantum transport in our artificially designed fractal structures, we may have taken the first tiny steps towards the unification of physics, mathematics and biology, which could greatly enrich our understanding of the world around us as well as the world that exists in our heads.</p><img src="https://counter.theconversation.com/content/164582/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Cristiane de Morais Smith receives funding from NWO. </span></em></p>New experiments could help scientists settle the longstanding debate about whether consciousness is generated by quantum activity.Cristiane de Morais Smith, Professor, Theoretical Physics, Utrecht UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1625142021-07-02T03:55:33Z2021-07-02T03:55:33ZCurious Kids: is light a wave or a particle?<figure><img src="https://images.theconversation.com/files/409433/original/file-20210702-28-qga4sb.jpeg?ixlib=rb-1.1.0&rect=294%2C210%2C5237%2C3522&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Shutterstock</span></span></figcaption></figure><blockquote>
<p>Is light a wave or particle? — Ishan, age 15, Dubai</p>
</blockquote>
<p><a href="https://theconversation.com/au/topics/curious-kids-36782"><img src="https://images.theconversation.com/files/291898/original/file-20190911-190031-enlxbk.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=90&fit=crop&dpr=1" width="100%"></a></p>
<p>Hi Ishan! Thanks for your great question. </p>
<p>Light can be described both as a wave and as a particle. There are two experiments in particular that have revealed the dual nature of light.</p>
<p>When we’re thinking of light as being made of of particles, these particles are called “photons”. Photons have no mass, and each one carries a specific amount of energy. Meanwhile, when we think about light propagating as waves, these are waves of electromagnetic radiation. Other examples of electromagnetic radiation include X-rays and ultraviolet radiation.</p>
<p>It’s worth remembering light — regardless of whether it’s behaving like a wave or particles — will always travel at roughly 300,000 kilometres per second. The speed of light as it travels through space (or another vacuum) is the fastest phenomenon in the universe, as far as we know.</p>
<h2>The double-slit experiment</h2>
<p>Imagine you have a bucket of tennis balls. Two metres in front of you is a solid panel with two holes in it. A metre behind that panel is a wall. You dip each ball in red paint and throw it at one hole, and then the other. A successful throw will leave a red mark on the wall behind, leaving a specific pattern of roundish dots.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/406382/original/file-20210615-2626-1e4orym.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/406382/original/file-20210615-2626-1e4orym.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/406382/original/file-20210615-2626-1e4orym.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=547&fit=crop&dpr=1 600w, https://images.theconversation.com/files/406382/original/file-20210615-2626-1e4orym.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=547&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/406382/original/file-20210615-2626-1e4orym.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=547&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/406382/original/file-20210615-2626-1e4orym.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=688&fit=crop&dpr=1 754w, https://images.theconversation.com/files/406382/original/file-20210615-2626-1e4orym.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=688&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/406382/original/file-20210615-2626-1e4orym.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=688&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Throw balls at a wall and, if your aim is good, you’ll get a pattern of dots.</span>
<span class="attribution"><span class="source">Provided by author</span></span>
</figcaption>
</figure>
<p>Now, suppose you shoot a single beam of light at the same panel with holes in it, on the same trajectory as the tennis balls. If light is a beam of particles, or in other words a beam of photons, you would expect to see a similar pattern to that made by the tennis balls where the light particles strike the wall. </p>
<p>That, however, isn’t what you see. Instead, you see a complex pattern of stripes. Why? </p>
<p>This is because light, in this situation, acts like a wave. When we shoot a beam of light through the holes, it breaks into two beams. The two resulting waves then interfere with each other to become either stronger (constructive interference) or weaker (destructive interference). </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/406386/original/file-20210615-3832-wx5ufp.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/406386/original/file-20210615-3832-wx5ufp.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/406386/original/file-20210615-3832-wx5ufp.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=526&fit=crop&dpr=1 600w, https://images.theconversation.com/files/406386/original/file-20210615-3832-wx5ufp.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=526&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/406386/original/file-20210615-3832-wx5ufp.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=526&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/406386/original/file-20210615-3832-wx5ufp.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=661&fit=crop&dpr=1 754w, https://images.theconversation.com/files/406386/original/file-20210615-3832-wx5ufp.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=661&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/406386/original/file-20210615-3832-wx5ufp.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=661&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">A single wave of light breaks into two, generating what’s called an ‘interference pattern’.</span>
<span class="attribution"><span class="source">Provided by author</span></span>
</figcaption>
</figure>
<p>The waves create a lattice pattern, which results in a series of stripes on the wall. In the above image, the stripes are larger and brighter at places where the waves join. The gaps between the stripes are the result of destructive interference, and the stripes are the result of constructive interference. </p>
<h2>The photoelectric effect</h2>
<p>The above experiment shows light behaving as a wave. But Albert Einstein showed us we can also describe light as being made up of individual particles of energy: photons. This is necessary to account for something called the “photoelectric effect”. </p>
<p>When you shoot light at a sheet of metal, the metal emits electrons: particles that are electrically charged. This is the photoelectric effect. </p>
<p>Prior to Einstein, scientists tried to explain the photoelectric effect by assuming light only takes the form of a wave. To understand their reasoning, imagine ripples in a pond. The ripples have peaks where the wave rises up, and troughs where it dips down.</p>
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<em>
<strong>
Read more:
<a href="https://theconversation.com/curious-kids-how-do-ripples-form-and-why-do-they-spread-out-across-the-water-120308">Curious Kids: how do ripples form and why do they spread out across the water?</a>
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<p>Now imagine there’s also a boat in the pond with Lego soldiers aboard. As the ripples reach the boat, they have the potential to throw the soldiers off. The more energy the ripples carry, the greater the force with which the soldiers will be thrown off. </p>
<p>And since each ripple can potentially throw off a soldier, the more ripples that reach the boat within a certain time limit, the more soldiers we can expect will be thrown off during that time.</p>
<p>Light waves also have peaks and troughs and therefore ripple in a similar manner. In the wave theory of light, these oscillations are linked to two properties of light: intensity and frequency.</p>
<p>Simply put, the <em>frequency</em> of a light wave is the number of peaks that pass a point in space in a given period (like when a certain number of ripples strike the boat within a specific time). The <em>intensity</em> corresponds to the energy of the wave (like the energy carried by each ripple in our pond). </p>
<p>Scientists in the 19th century pictured electrons on a sheet of metal as behaving similarly to the Lego soldiers on our raft. When light strikes the metal, the ripples should throw the electrons off. </p>
<p>The greater the intensity (the energy of the ripples) the faster the electrons will fly off, they thought. The higher the frequency within a specific time period, the greater the number of electrons that will get thrown off during that time — right?</p>
<p>What we actually see is the complete opposite! It’s the frequency of the light hitting the metal which determines the speed of the electrons as they shoot off. Meanwhile the intensity of the light, or how much energy it carries, actually determines the number of electrons flying away.</p>
<h2>Einstein’s explanation</h2>
<p>Einstein had a great explanation for this peculiar observation. He hypothesised light is made of particles, and is in fact not a wave. He then linked the intensity of light to the <em>number of photons</em> in a beam, and the frequency of light to <em>how much energy each photon carries</em>. </p>
<p>When more photons are shot at the metal (greater intensity), there are more collisions between the photons and electrons, so a greater number of electrons are emitted. Thus, the intensity of the light determines the <em>number</em> of electrons emitted, rather than the speed with which they fly off. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/406384/original/file-20210615-3808-18xdab1.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/406384/original/file-20210615-3808-18xdab1.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/406384/original/file-20210615-3808-18xdab1.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=208&fit=crop&dpr=1 600w, https://images.theconversation.com/files/406384/original/file-20210615-3808-18xdab1.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=208&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/406384/original/file-20210615-3808-18xdab1.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=208&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/406384/original/file-20210615-3808-18xdab1.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=261&fit=crop&dpr=1 754w, https://images.theconversation.com/files/406384/original/file-20210615-3808-18xdab1.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=261&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/406384/original/file-20210615-3808-18xdab1.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=261&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Increase the intensity of light, and therefore the number of photons bombarding a sheet of metal, and you’ll also see a greater number of electrons being shot off.</span>
<span class="attribution"><span class="source">Provided by author</span></span>
</figcaption>
</figure>
<p>When light’s frequency is increased and each photon carries more energy, then each electron also takes more energy from the collision — and will therefore fly off with more speed. </p>
<p>This explanation earned Einstein a Nobel Prize in 1921. </p>
<h2>Wave or particle?</h2>
<p>Considering all of the above, one question remains: is light a wave that sometimes looks like a particle, or a particle that sometimes looks like a wave? There is disagreement about this.</p>
<p>My money is on light being a wave that displays particle-like properties under certain conditions. But this remains a controversial issue — one that takes us into the exciting realm of quantum mechanics. I encourage you to dig deeper and make up your own mind! </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/curious-kids-why-is-the-sky-blue-and-where-does-it-start-81165">Curious Kids: Why is the sky blue and where does it start?</a>
</strong>
</em>
</p>
<hr>
<img src="https://counter.theconversation.com/content/162514/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Sam Baron receives funding from the Australian Research Council.</span></em></p>Einstein was awarded a Nobel prize for his explanation for how light can be described as being made up of individual particles of energy under certain conditions.Sam Baron, Associate professor, Australian Catholic UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1466382021-02-22T14:20:23Z2021-02-22T14:20:23ZCan the laws of physics disprove God?<figure><img src="https://images.theconversation.com/files/368289/original/file-20201109-23-s91zxo.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C4493%2C1994&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Could God travel faster than the speed of light?</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/wooden-cross-over-abstract-sky-background-1312105874">robert_s/Shutterstock</a></span></figcaption></figure><p><em>I still believed in God (I am now an atheist) when I heard the following question at a seminar, first posed by Einstein, and was stunned by its elegance and depth: ‘If there is a God who created the entire universe and ALL of its laws of physics, does God follow God’s own laws? Or can God supersede his own laws, such as travelling faster than the speed of light and thus being able to be in two different places at the same time?’ Could the answer help us prove whether or not God exists or is this where scientific empiricism and religious faith intersect, with NO true answer?</em> David Frost, 67, Los Angeles. </p>
<p>I was in lockdown when I received this question and was instantly intrigued. It’s no wonder about the timing – tragic events, such as pandemics, often cause us to question the existence of God: if there is a merciful God, why is a catastrophe like this happening? So the idea that God might be “bound” by the laws of physics – which also govern chemistry and biology and thus the limits of medical science – was an interesting one to explore.</p>
<p>If God wasn’t able to break the laws of physics, she arguably wouldn’t be as powerful as you’d expect a supreme being to be. But if she could, why haven’t we seen any evidence of the laws of physics ever being broken in the universe? </p>
<hr>
<figure class="align-right ">
<img alt="" src="https://images.theconversation.com/files/313328/original/file-20200203-41485-1foofme.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/313328/original/file-20200203-41485-1foofme.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/313328/original/file-20200203-41485-1foofme.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/313328/original/file-20200203-41485-1foofme.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/313328/original/file-20200203-41485-1foofme.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/313328/original/file-20200203-41485-1foofme.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/313328/original/file-20200203-41485-1foofme.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=754&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption"></span>
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<p><strong><em>This article is part of <a href="https://theconversation.com/uk/topics/lifes-big-questions-80040?utm_source=TCUK&utm_medium=linkback&utm_campaign=TCUKengagement&utm_content=LifesBigQuestionsUK">Life’s Big Questions</a></em></strong>
<br><em>The Conversation’s new series, co-published with BBC Future, seeks to answer our readers’ nagging questions about life, love, death and the universe. We work with professional researchers who have dedicated their lives to uncovering new perspectives on the questions that shape our lives.</em></p>
<hr>
<p>To tackle the question, let’s break it down a bit. First, can God travel faster than light? Let’s just take the question at face value. Light travels at an approximate speed of 3 x 10<sup>5</sup> kilometres every second, or 186,000 miles per second. We learn at school that nothing can travel faster than the speed of light – not even the USS Enterprise in Star Trek when its dilithium crystals are set to max. </p>
<p>But is it true? A few years ago, a group of physicists posited that particles called tachyons <a href="https://www.scientificamerican.com/article/what-is-known-about-tachy/">travelled above light speed</a>. Fortunately, their existence as real particles is deemed highly unlikely. If they they did exist, they would have an imaginary mass and the fabric of space and time would become distorted – leading to violations of causality (and possibly a headache for God). </p>
<p>It seems, so far, that no object has been observed that can travel faster than the speed of light. This in itself does not say anything at all about God. It merely reinforces the knowledge that light travels very fast indeed. </p>
<p>Things get a bit more interesting when you consider how far light has travelled since the beginning. Assuming a traditional big bang cosmology and a light speed of 3 x 10<sup>5</sup> km/s, then we can calculate that light has travelled roughly 10<sup>23</sup> km in the 13.8 billion years of the universe’s existence. Or rather, the observable universe’s existence. </p>
<p>The universe is expanding at a rate of approximately 70km/s per Mpc (1 Mpc = 1 Megaparsec ~ 3 x 10<sup>19</sup> km), so current estimates suggest that the distance to the edge of the universe is 46 billion light years. As time goes on, the volume of space increases, and light has to travel for longer to reach us. </p>
<p>There is a lot more universe out there than we can view, but the most distant object that we have seen is a galaxy, GN-z11, <a href="https://www.nasa.gov/feature/goddard/2016/hubble-team-breaks-cosmic-distance-record/">observed by the Hubble Space Telescope</a>. This is approximately 10<sup>23</sup> km or 13.4 billion light years away, meaning that it has taken 13.4 billion years for light from the galaxy to reach us. But when the light “set off”, the galaxy was only about 3 billion light years away from our galaxy, the Milky Way. </p>
<p>We cannot observe or see across the entirety of the universe that has grown since the big bang because insufficient time has passed for light from the first fractions of a second to reach us. Some argue that we therefore cannot be sure whether the laws of physics <a href="https://www.edge.org/response-detail/27129">could be broken in other cosmic regions</a> – perhaps they are just local, accidental laws. And that leads us on to something even bigger than the universe.</p>
<h2>The multiverse</h2>
<p>Many cosmologists believe that the universe may be part of a more extended cosmos, <a href="https://theconversation.com/the-theory-of-parallel-universes-is-not-just-maths-it-is-science-that-can-be-tested-46497">a multiverse</a>, where many different universes co-exist but don’t interact. The idea of the multiverse is backed by the <a href="http://www.ctc.cam.ac.uk/outreach/origins/inflation_zero.php">theory of inflation</a> – the idea that the universe expanded hugely before it was 10<sup>-32</sup> seconds old. Inflation is an important theory because it can explain why the universe has the shape and structure that we see around us. </p>
<p>But if inflation could happen once, why not many times? We know from experiments that quantum fluctuations can give rise to pairs of particles suddenly coming into existance, only to disappear moments later. And if such fluctuations can produce particles, why not entire atoms or universes? It’s <a href="https://cds.cern.ch/record/485381/files/0101507.pdf">been suggested that</a>, during the period of chaotic inflation, not everything was happening at the same rate – quantum fluctuations in the expansion could have produced bubbles that blew up to become universes in their own right.</p>
<figure class="align-center ">
<img alt="Pictures of bubbles containing universes." src="https://images.theconversation.com/files/368343/original/file-20201109-20-1wfq4b6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/368343/original/file-20201109-20-1wfq4b6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/368343/original/file-20201109-20-1wfq4b6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/368343/original/file-20201109-20-1wfq4b6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/368343/original/file-20201109-20-1wfq4b6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/368343/original/file-20201109-20-1wfq4b6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/368343/original/file-20201109-20-1wfq4b6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=754&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Are we living in a bubble universe?</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-illustration/universe-bubbles-140483161">Juergen Faelchle/Shutterstock</a></span>
</figcaption>
</figure>
<p>But how does God fit into the multiverse? One headache for cosmologists has been the fact that our universe seems <a href="https://plato.stanford.edu/entries/fine-tuning/">fine-tuned for life to exist</a>. The fundamental particles created in the big bang had the correct properties to enable the formation of hydrogen and deuterium – substances which produced the first stars. </p>
<p>The physical laws governing nuclear reactions in these stars then produced the stuff that life’s made of – carbon, nitrogen and oxygen. So how come all the physical laws and parameters in the universe happen to have the values that allowed stars, planets and ultimately life to develop? </p>
<p>Some argue it’s just a lucky coincidence. Others say we shouldn’t be surprised to see biofriendly physical laws – they after all produced us, so what else would we see? Some theists, however, argue it points <a href="https://rintintin.colorado.edu/%7Evancecd/phil201/Collins.pdf">to the existence of a God</a> creating favourable conditions.</p>
<p>But God isn’t a valid scientific explanation. The theory of the multiverse, instead, solves the mystery because it allows different universes to have different physical laws. So it’s not surprising that we should happen to see ourselves in one of the few universes that could support life. Of course, you can’t disprove the idea that a God may have created the multiverse.</p>
<p>This is all very hypothetical, and one of the biggest criticisms of theories of the multiverse is that because there seem to have been no interactions between our universe and other universes, then the notion of the multiverse cannot be directly tested. </p>
<h2>Quantum weirdness</h2>
<p>Now let’s consider whether God can be in more than one place at the same time. Much of the science and technology we use in space science is based on the counter-intuitive theory of the tiny world of atoms and particles known as quantum mechanics.</p>
<p>The theory enables something called <a href="https://theconversation.com/physicists-prove-quantum-spookiness-and-start-chasing-schrodingers-cat-48190">quantum entanglement</a>: spookily connected particles. If two particles are entangled, you automatically manipulate its partner when you manipulate it, even if they are very far apart and without the two interacting. There are better descriptions of entanglement than the one I give here – but this is simple enough that I can follow it. </p>
<p>Imagine a particle that decays into two sub-particles, A and B. The properties of the sub-particles must add up to the properties of the original particle – this is the principle of conservation. For example, all particles have a quantum property called “spin” – roughly, they move as if they were tiny compass needles. If the original particle has a “spin” of zero, one of the two sub-particles must have a positive spin and the other a negative spin, which means that each of A and B has a 50% chance of having a positive or a negative spin. (According to quantum mechanics, particles are by definition in a mix of different states until you actually measure them.)</p>
<p>The properties of A and B are not independent of each other – they are entangled – even if located in separate laboratories on separate planets. So if you measure the spin of A and you find it to be positive. Imagine a friend measured the spin of B at exactly the same time that you measured A. In order for the principle of conservation to work, she must find the spin of B to be negative. </p>
<p>But – and this is where things become murky – like sub-particle A, B had a 50:50 chance of being positive, so its spin state “became” negative at the time that the spin state of A was measured as positive. In other words, information about spin state was transferred between the two sub-particles instantly. Such transfer of quantum information apparently happens faster than the speed of light. Given that Einstein himself described quantum entanglement as “spooky action at a distance”, I think all of us can be forgiven for finding this a rather bizarre effect. </p>
<p>So there is something faster than the speed of light after all: quantum information. This doesn’t prove or disprove God, but it can help us think of God in physical terms – maybe as a shower of entangled particles, transferring quantum information back and forth, and so occupying many places at the same time? Even many universes at the same time? </p>
<figure class="align-center ">
<img alt="Artist's concept of entangled particles." src="https://images.theconversation.com/files/368345/original/file-20201109-23-npi3o5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/368345/original/file-20201109-23-npi3o5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=350&fit=crop&dpr=1 600w, https://images.theconversation.com/files/368345/original/file-20201109-23-npi3o5.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=350&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/368345/original/file-20201109-23-npi3o5.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=350&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/368345/original/file-20201109-23-npi3o5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=440&fit=crop&dpr=1 754w, https://images.theconversation.com/files/368345/original/file-20201109-23-npi3o5.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=440&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/368345/original/file-20201109-23-npi3o5.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=440&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Spooky action.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-illustration/particle-quantum-entanglement-correlation-mechanics-3d-1457191784">Jurik Peter/Shutterstock</a></span>
</figcaption>
</figure>
<p>I have this image of God keeping galaxy-sized plates spinning while juggling planet-sized balls – tossing bits of information from one teetering universe to another, to keep everything in motion. Fortunately, God can multitask – keeping the fabric of space and time in operation. All that is required is a little faith.</p>
<p>Has this essay come close to answering the questions posed? I suspect not: if you believe in God (as I do), then the idea of God being bound by the laws of physics is nonsense, because God can do everything, even travel faster than light. If you don’t believe in God, then the question is equally nonsensical, because there isn’t a God and nothing can travel faster than light. Perhaps the question is really one for agnostics, who don’t know whether there is a God.</p>
<p>This is indeed where science and religion differ. Science requires proof, religious belief requires faith. Scientists don’t try to prove or disprove God’s existence because they know there isn’t an experiment that can ever detect God. And if you believe in God, it doesn’t matter what scientists discover about the universe – any cosmos can be thought of as being consistent with God.</p>
<p>Our views of God, physics or anything else ultimately depends on perspective. But let’s end with a quotation from a truly authoritative source. No, it isn’t the bible. Nor is it a cosmology textbook. It’s from <a href="https://www.goodreads.com/book/show/34517.Reaper_Man">Reaper Man</a> by Terry Pratchett:</p>
<p>“Light thinks it travels faster than anything but it is wrong. No matter how fast light travels, it finds the darkness has always got there first, and is waiting for it.” </p>
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<p><em>To get all of life’s big answers, join the hundreds of thousands of people who value evidence-based news by <a href="https://theconversation.com/uk/newsletters/the-daily-newsletter-2?utm_source=TCUK&utm_medium=linkback&utm_campaign=TCUKengagement&utm_content=LifesBigQuestionsUK"><strong>subscribing to our newsletter</strong></a>. You can send us your big questions by email at <a href="mailto:bigquestions@theconversation.com">bigquestions@theconversation.com</a> and we’ll try to get a researcher or expert on the case.</em></p>
<p><em>More <a href="https://theconversation.com/uk/topics/lifes-big-questions-80040?utm_source=TCUK&utm_medium=linkback&utm_campaign=TCUKengagement&utm_content=LifesBigQuestionsUK">Life’s Big Questions</a>:</em></p>
<ul>
<li><p><em><a href="https://theconversation.com/happiness-is-feeling-content-more-important-than-purpose-and-goals-131503?utm_source=TCUK&utm_medium=linkback&utm_campaign=TCUKengagement&utm_content=LifesBigQuestionsUK">Happiness: is contentment more important than purpose and goals?</a></em></p></li>
<li><p><em><a href="https://theconversation.com/could-we-live-in-a-world-without-rules-128664?utm_source=TCUK&utm_medium=linkback&utm_campaign=TCUKengagement&utm_content=LifesBigQuestionsUK">Could we live in a world without rules?</a></em></p></li>
<li><p><em><a href="https://theconversation.com/death-can-our-final-moment-be-euphoric-129648?utm_source=TCUK&utm_medium=linkback&utm_campaign=TCUKengagement&utm_content=LifesBigQuestionsUK">Death: can our final moment be euphoric?</a></em></p></li>
<li><p><em><a href="https://theconversation.com/are-humans-still-part-of-nature-or-is-it-now-just-our-dominion-128790?utm_source=TCUK&utm_medium=linkback&utm_campaign=TCUKengagement&utm_content=LifesBigQuestionsUK">Nature: have humans now evolved beyond the natural world, and do we still need it?</a></em></p></li>
<li><p><em><a href="https://theconversation.com/love-is-it-just-a-fleeting-high-fuelled-by-brain-chemicals-129201?utm_source=TCUK&utm_medium=linkback&utm_campaign=TCUKengagement&utm_content=LifesBigQuestionsUK">Love: is it just a fleeting high fuelled by brain chemicals?</a></em></p></li>
</ul><img src="https://counter.theconversation.com/content/146638/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Monica Grady is Professor of Planetary and Space Science at The Open University, Chancellor of Liverpool Hope University and Senior Research Fellow at the Natural History Museum. She receives funding from the STFC and the UK Space Agency. Follow her on Twitter @MonicaGrady</span></em></p>If God could break the laws of physics, why haven’t we seen any evidence of the laws ever being broken in the universe?Monica Grady, Professor of Planetary and Space Sciences, The Open UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1546872021-02-10T20:45:08Z2021-02-10T20:45:08ZNew postage stamp honors Chien-Shiung Wu, trailblazing nuclear physicist<figure><img src="https://images.theconversation.com/files/383602/original/file-20210210-17-1ra43r9.jpg?ixlib=rb-1.1.0&rect=62%2C178%2C2915%2C2120&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Chien-Shiung Wu's experiments were instrumental in supporting some of the biggest 20th-century theories in physics.</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/physics-professor-dr-chien-shiung-wu-in-a-laboratory-at-news-photo/515185238">Bettmann via Getty Images</a></span></figcaption></figure><figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/383299/original/file-20210209-23-13scq0b.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Forever stamp with portrait of Chien-Shiung Wu." src="https://images.theconversation.com/files/383299/original/file-20210209-23-13scq0b.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/383299/original/file-20210209-23-13scq0b.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=944&fit=crop&dpr=1 600w, https://images.theconversation.com/files/383299/original/file-20210209-23-13scq0b.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=944&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/383299/original/file-20210209-23-13scq0b.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=944&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/383299/original/file-20210209-23-13scq0b.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1187&fit=crop&dpr=1 754w, https://images.theconversation.com/files/383299/original/file-20210209-23-13scq0b.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1187&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/383299/original/file-20210209-23-13scq0b.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1187&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">The new U.S. postage stamp featuring Wu.</span>
<span class="attribution"><a class="source" href="https://about.usps.com/newsroom/national-releases/2021/0201ma-nuclear-physicist-chien-shiung-wu-to-be-honored-on-forever-stamp.htm">U.S. Postal Service</a></span>
</figcaption>
</figure>
<p>On Feb. 11, 2021, the sixth <a href="https://www.un.org/en/observances/women-and-girls-in-science-day">International Day of Women and Girls in Science</a>, the U.S. Postal Service issued <a href="https://store.usps.com/store/product/buy-stamps/chien-shiung-wu-S_480204">a new Forever stamp to honor</a> Chien-Shiung Wu, one of the most influential nuclear physicists of the 20th century.</p>
<p>A Chinese American woman, Wu performed experiments that tested the fundamental laws of physics. In a male-dominated field, she won many honors and awards, including the <a href="https://www.nsf.gov/news/special_reports/medalofscience50/wu.jsp">National Medal of Science</a> (1975), the inaugural <a href="https://wolffund.org.il/2018/12/09/chien-shiung-wu/">Wolf Prize in Physics</a> (1978) and honorary degrees from universities around the world. </p>
<p>In China, where I grew up, Wu is an icon who is sometimes called the “Chinese Marie Curie.” I first read about Wu’s extraordinary story in my physics textbook, when I was a teenager in high school. Chien-Shiung Wu became a scientific role model for me, inspiring me to <a href="https://scholar.google.com/citations?user=-x2wJigAAAAJ&hl=en&oi=ao">pursue an academic career in physics</a> and follow her path to the U.S.</p>
<h2>From China to the US, to pursue physics</h2>
<p>In 1912, <a href="https://www.biography.com/scientist/chien-shiung-wu">Wu was born in Liuhe</a> in Jiangsu province, a town about 40 miles north of Shanghai. Although it was uncommon in China for girls to attend school at that time, her father founded a school for girls where she received her elementary education.</p>
<p>In 1930, Wu attended National Central University in Nanjing to study mathematics. But the revolutionary triumphs of late 19th-century modern physics – such as the <a href="http://www.pbs.org/wgbh/aso/databank/entries/dp13at.html">discoveries of atomic structure</a> and <a href="https://theconversation.com/on-the-120th-anniversary-of-the-x-ray-a-look-at-how-it-changed-our-view-of-the-world-50154">of X-rays</a> – attracted Wu’s attention. She changed her major to physics and graduated at the top of her class in 1934.</p>
<p>Encouraged by her college advisor and financially supported by her uncle, Wu booked the month-long steamship trip to the United States in 1936 to pursue her doctoral education. She arrived in San Francisco, where she met her future husband, <a href="https://www.nytimes.com/2003/02/23/world/luke-yuan-90-senior-physicist-at-brookhaven.html">Luke Chia-Liu Yuan</a>, another physicist, when he showed her around the Radiation Laboratory at the University of California, Berkeley. Scientists at the lab had only <a href="https://www2.lbl.gov/Science-Articles/Archive/early-years.html">recently invented the cyclotron</a>, the most advanced instrument for accelerating charged particles in a spiral trajectory.</p>
<p>Enticed by the atomic nuclei research being done in the lab, Wu abandoned her original plan to attend the University of Michigan and successfully enrolled in the physics doctoral program at Berkeley.</p>
<p>In her graduate research, Wu worked closely with nuclear scientist <a href="https://www.nobelprize.org/prizes/physics/1939/lawrence/biographical/">Ernest Lawrence</a>, who had won the Nobel Prize in Physics in 1939, and <a href="https://www.nobelprize.org/prizes/physics/1959/segre/biographical/">Emillo Segrè</a>, who went on to win the Nobel Prize in Physics in 1959. She studied the <a href="https://doi.org/10.1103/PhysRev.59.481">electromagnetic radiation produced when charged particles decelerate</a>, as well as <a href="https://doi.org/10.1103/PhysRev.67.142">radioactive isotopes of xenon generated by splitting uranium atoms</a> via nuclear fission. In June 1940, Wu completed her Ph.D. with honors.</p>
<p>After a short period of postdoctoral research still at the Radiation Laboratory, Wu moved to the East Coast, where she taught at Smith College and then Princeton University.</p>
<h2>Experimental work in radioactive decay</h2>
<p>In 1944, Wu became a research scientist at Columbia University, where she joined <a href="https://www.energy.gov/sites/prod/files/The%20Manhattan%20Project.pdf">the Manhattan Project</a>, the top-secret U.S. effort to turn basic research in physics into a new kind of weapon, the atomic bomb. As a team member, Wu helped develop the process for separating uranium atoms into the charged uranium-235 and uranium-238 isotopes using gaseous diffusion. This work eventually led to enriched uranium, a critical component for nuclear reactions.</p>
<p>After World War II, Wu remained at Columbia and focused her research on the radioactive process of <a href="https://www2.lbl.gov/abc/wallchart/chapters/03/2.html">beta decay</a>. She investigated beta particles: fast-moving electrons or positrons emitted from an atomic nucleus in the radioactive decay process.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/383606/original/file-20210210-13-1geajf5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Beta particles leave one atom and transform it into another" src="https://images.theconversation.com/files/383606/original/file-20210210-13-1geajf5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/383606/original/file-20210210-13-1geajf5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=655&fit=crop&dpr=1 600w, https://images.theconversation.com/files/383606/original/file-20210210-13-1geajf5.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=655&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/383606/original/file-20210210-13-1geajf5.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=655&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/383606/original/file-20210210-13-1geajf5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=823&fit=crop&dpr=1 754w, https://images.theconversation.com/files/383606/original/file-20210210-13-1geajf5.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=823&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/383606/original/file-20210210-13-1geajf5.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=823&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Beta decay describes the process when a fast-moving electron or positron leaves an atom’s nucleus, leaving behind a different kind of atom.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/illustration/beta-plus-and-beta-minus-decay-royalty-free-illustration/1195604225?adppopup=true">ttsz/iStock via Getty Images Plus</a></span>
</figcaption>
</figure>
<p>In the mid-1950s, Wu performed a famous experiment to test the <a href="https://physics.aps.org/story/v22/st19">law of parity conservation</a>. This was a widely accepted but unproven principle implying that a physical process and its mirror reflection are identical. As proposed by theoretical physicists <a href="https://www.nobelprize.org/prizes/physics/1957/yang/biographical/">Chen Ning Yang</a> and <a href="https://www.nobelprize.org/prizes/physics/1957/lee/biographical/">Tsung-Dao Lee</a>, Wu designed an experiment to see if reality matched the theory.</p>
<p>Observing the beta decay of cobalt-60 atoms, Wu measured the radiation intensity as a function of the radiation direction. To increase the accuracy of her experimental measurements, Wu figured out techniques to get her cobalt-60 atoms all spinning in the same direction. She observed that more particles flew off in the direction opposite to the direction the nuclei were spinning. The law of parity conservation predicted that the atoms would emit beta particles in symmetrical ways. But Wu’s observations meant the “law” did not hold and she had discovered parity nonconservation.</p>
<p>This breakthrough achievement helped Wu’s theoretical colleagues win the <a href="https://www.nobelprize.org/prizes/physics/1957/summary/">1957 Nobel Prize in Physics</a>, but unfortunately, the Nobel Committee <a href="https://physicsworld.com/a/overlooked-for-the-nobel-chien-shiung-wu/">overlooked Wu’s experimental contribution</a>. </p>
<p>In addition to her famous parity law research, Wu carried out <a href="https://doi.org/10.1142/S0217751X15300501">a series of important experiments</a> in nuclear physics and quantum physics. In 1949, she experimentally verified <a href="https://www.nobelprize.org/prizes/physics/1938/fermi/biographical/">Enrico Fermi</a>’s theory of beta decay, <a href="https://doi.org/10.1103/PhysRev.75.1107.2">correcting the discrepancies</a> between the theory and previous inaccurate experimental results and <a href="https://doi.org/10.1103/PhysRevLett.10.253">developing a universal version of his theory</a>. She also <a href="https://doi.org/10.1103/PhysRev.77.136">proved the quantum phenomenon</a> relevant to a pair of <a href="https://www.nist.gov/itl/entangled-photon-pair-sources">entangled photons</a>.</p>
<p>In 1958, Wu was the first Chinese-American <a href="http://www.nasonline.org/member-directory/deceased-members/48916.html">elected to the National Academy of Sciences</a>. In 1967, she served as the first female <a href="https://aps.org/about/governance/presidents.cfm">president of the American Physical Society</a>.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/383605/original/file-20210210-13-1tao3qm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Wu stands with other honorary degree recipients in academic gowns." src="https://images.theconversation.com/files/383605/original/file-20210210-13-1tao3qm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/383605/original/file-20210210-13-1tao3qm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=402&fit=crop&dpr=1 600w, https://images.theconversation.com/files/383605/original/file-20210210-13-1tao3qm.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=402&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/383605/original/file-20210210-13-1tao3qm.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=402&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/383605/original/file-20210210-13-1tao3qm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=505&fit=crop&dpr=1 754w, https://images.theconversation.com/files/383605/original/file-20210210-13-1tao3qm.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=505&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/383605/original/file-20210210-13-1tao3qm.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=505&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Wu received many accolades, including an honorary doctorate at Harvard in 1974.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/six-of-the-seven-honorary-degree-recipients-at-harvard-news-photo/515112302">Bettmann via Getty Images</a></span>
</figcaption>
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<p>After her retirement in 1981, Wu dedicated herself to public educational programs in both the United States and China, giving numerous lectures and working to inspire younger generations to pursue science, technology, engineering and math education. She died in 1997. </p>
<p>Wu’s legacy continues with the issuing of her postage stamp. She joined a short list of physicists featured on U.S. stamps, including Albert Einstein, Richard Feynman and Maria Goeppert-Mayer.</p>
<p>[<em>Understand new developments in science, health and technology, each week.</em> <a href="https://theconversation.com/us/newsletters/science-editors-picks-71/?utm_source=TCUS&utm_medium=inline-link&utm_campaign=newsletter-text&utm_content=science-understand">Subscribe to The Conversation’s science newsletter</a>.]</p><img src="https://counter.theconversation.com/content/154687/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Xuejian Wu does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Chinese American physicist Wu worked on the Manhattan Project and performed groundbreaking experiments throughout her long career.Xuejian Wu, Assistant Professor of Physics, Rutgers University - NewarkLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1477522020-10-14T19:10:03Z2020-10-14T19:10:03ZCould Schrödinger’s cat exist in real life? Our research may provide the answer<figure><img src="https://images.theconversation.com/files/363348/original/file-20201014-17-m7ixup.jpg?ixlib=rb-1.1.0&rect=53%2C58%2C3877%2C1967&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Shutterstock</span></span></figcaption></figure><p>Have you ever been in more than one place at the same time? If you’re much bigger than an atom, the answer will be no. </p>
<p>But atoms and particles are governed by the rules of quantum mechanics, in which several different possible situations can coexist at once.</p>
<p>Quantum systems are ruled by what’s called a “wave function”: a mathematical object that describes the probabilities of these different possible situations.</p>
<p>And these different possibilities can coexist in the wave function as what is called a “superposition” of different states. For example, a particle existing in several different places at once is what we call “spatial superposition”.</p>
<p>It’s only when a measurement is carried out that the wave function “collapses” and the system ends up in one definite state.</p>
<p>Generally, quantum mechanics applies to the tiny world of atoms and particles. The jury is still out on what it means for large-scale objects. </p>
<p>In our research, <a href="https://www.osapublishing.org/optica/abstract.cfm?uri=optica-7-10-1427">published today in Optica</a>, we propose an experiment that may resolve this thorny question once and for all.</p>
<h2>Erwin Schrödinger’s cat</h2>
<p>In the 1930s, Austrian physicist Erwin Schrödinger came up with his famous thought experiment about a cat in a box which, according to quantum mechanics, could be alive and dead at the same time.</p>
<p>In it, a cat is placed in a sealed box in which a random quantum event has a 50–50 chance of killing it. Until the box is opened and the cat is observed, the cat is both dead <em>and</em> alive at the same time. </p>
<p>In other words, the cat exists as a wave function (with multiple possibilities) before it’s observed. When it’s observed, it becomes a definite object.</p>
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<iframe width="440" height="260" src="https://www.youtube.com/embed/UpGO2kuQyZw?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">What is Schrödinger’s Cat?</span></figcaption>
</figure>
<p>After much debate, the scientific community at the time reached a consensus with the “<a href="https://science.howstuffworks.com/innovation/science-questions/quantum-suicide4.htm">Copenhagen interpretation</a>”. This basically says quantum mechanics can only apply to atoms and molecules, but can’t describe much larger objects. </p>
<p>Turns out they were wrong.</p>
<p>In the past two decades or so, physicists <a href="https://theconversation.com/experiment-shows-einsteins-quantum-spooky-action-approaches-the-human-scale-95372">have created</a> quantum states in <a href="https://www.nature.com/articles/s41586-018-0038-x">objects made of trillions of atoms</a> — large enough to be seen with the naked eye. Although, this has <em>not yet</em> included spatial superposition.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/experiment-shows-einsteins-quantum-spooky-action-approaches-the-human-scale-95372">Experiment shows Einstein's quantum 'spooky action' approaches the human scale</a>
</strong>
</em>
</p>
<hr>
<h2>How does a wave function become real?</h2>
<p>But how does the wave function become a “real” object?</p>
<p>This is what physicists call the “quantum measurement problem”. It has puzzled scientists and philosophers for about a century.</p>
<p>If there is a mechanism that removes the potential for quantum superposition from large-scale objects, it would require somehow “disturbing” the wave function — and this would create heat. </p>
<p>If such heat is found, this implies large-scale quantum superposition is impossible. If such heat is ruled out, then it’s likely nature doesn’t mind “being quantum” at any size. </p>
<p>If the latter is the case, with advancing technology we could put large objects, <a href="https://iopscience.iop.org/article/10.1088/1367-2630/12/3/033015/meta">maybe even sentient beings</a>, into quantum states.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/363109/original/file-20201013-19-9172xn.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Illustration of a wave function." src="https://images.theconversation.com/files/363109/original/file-20201013-19-9172xn.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/363109/original/file-20201013-19-9172xn.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=338&fit=crop&dpr=1 600w, https://images.theconversation.com/files/363109/original/file-20201013-19-9172xn.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=338&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/363109/original/file-20201013-19-9172xn.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=338&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/363109/original/file-20201013-19-9172xn.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=424&fit=crop&dpr=1 754w, https://images.theconversation.com/files/363109/original/file-20201013-19-9172xn.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=424&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/363109/original/file-20201013-19-9172xn.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=424&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">This is an illustration of a resonator in quantum superposition. The red wave represents the wave function.</span>
<span class="attribution"><span class="source">Christopher Baker</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>Physicists don’t know what a mechanism preventing large-scale quantum superpositions would look like. According to some, it’s an <a href="https://iopscience.iop.org/article/10.1209/0295-5075/92/50006/meta">unknown cosmological field</a>. Others <a href="https://link.springer.com/article/10.1007/BF02105068">suspect gravity</a> could have something to do with it. </p>
<p>This year’s Nobel Prize winner for physics, Roger Penrose, thinks it could be a consequence of <a href="https://www.sciencedirect.com/science/article/pii/S1571064513001188">living beings’ consciousness</a>.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/2020-nobel-prize-in-physics-awarded-for-work-on-black-holes-an-astrophysicist-explains-the-trailblazing-discoveries-147614">2020 Nobel Prize in physics awarded for work on black holes – an astrophysicist explains the trailblazing discoveries</a>
</strong>
</em>
</p>
<hr>
<h2>Chasing miniscule movements</h2>
<p>Over the past decade or so, physicists have been feverishly seeking a trace amount of heat which would indicate a disturbance in the wave function.</p>
<p>To find this out, we’d need a method that can suppress (as perfectly as is possible) all other sources of “excess” heat that may get in the way of an accurate measurement.</p>
<p>We would also need to keep an effect called quantum “backaction” in check, in which the act of observing itself creates heat.</p>
<p>In our research, we’ve formulated such an experiment, which could reveal whether spatial superposition is possible for large-scale objects. The best <a href="https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.125.100404">experiments thus far</a> have not been able to achieve this.</p>
<h2>Finding the answer in tiny beams that vibrate</h2>
<p>Our research shows tiny resonators in an ultra-cold fridge might finally provide the answer. The resonators are tiny physical beams that vibrate, similar to guitar strings, just on a much smaller level and at a much higher frequency.</p>
<p>As was the case in previous experiments, we would need to use a fridge at 0.01 degrees kelvin above absolute zero. (Absoloute zero is the lowest temperature theoretically possible).</p>
<p>Unlike previous experiments, our experiment would use resonators vibrating inside the fridge at much higher frequencies than have ever been used before. This would remove the issue of any heat from the fridge itself getting in the way.</p>
<p>With this combination of very low fridge temperatures and very high frequencies, vibrations in the resonators undergo a process called “Bose condensation”.</p>
<p>You can picture this as a state of matter in which the resonator becomes so solidly frozen that heat from the fridge can’t wiggle it, not even a bit. The atoms or particules are chilled to such low energies, they “condense” into a single quantum state.</p>
<p>We would also use a different measurement strategy that doesn’t observe the resonator’s movement at all, but rather measures the amount of energy it has. This method would strongly suppress backaction heat, too. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/seven-common-myths-about-quantum-physics-115029">Seven common myths about quantum physics</a>
</strong>
</em>
</p>
<hr>
<p>But how would we do this?</p>
<p>Single particles of light would enter the resonator and bounce back and forth a few million times, absorbing excess energy. They would eventually leave the resonator, carrying the excess energy away.</p>
<p>By measuring the energy of the light particles coming out, we could determine if there was heat present in the resonator.</p>
<p>If heat was present, this would indicate an unknown source (which we didn’t control for) had disturbed the wave function. And this would mean it’s impossible for superposition to happen at a large scale.</p>
<h2>Is everything quantum?</h2>
<p>The experiment we propose is challenging. It’s not the kind of thing you can casually set up on a Sunday afternoon. It may take years of development, millions of dollars and a whole bunch of skilled experimental physicists. </p>
<p>Nonetheless, it could answer one of the most fascinating questions about our reality: is everything quantum? And so, we certainly think it’s worth the effort.</p>
<p>As for putting a human, or cat, into quantum superposition — there’s really no way for us to know how this would effect that being. </p>
<p>Luckily, this is a question we don’t have to think about, for now.</p><img src="https://counter.theconversation.com/content/147752/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>To carry out this reasearch, I received an Australian Postgraduate Award from the Australian Government.
I am currently employed in the Queensland Quantum Optics lab at the University of Queensland with Professor Warwick Bowen.</span></em></p>We identify an experimental method which could finally reveal whether objects much larger than atoms - such as humans or animals - can exist in several places at once.Stefan Forstner, Postdoctoral Research Fellow, The University of QueenslandLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1451392020-09-02T21:09:28Z2020-09-02T21:09:28ZOur quantum internet breakthrough could help make hacking a thing of the past<figure><img src="https://images.theconversation.com/files/356048/original/file-20200902-20-1d4vw1b.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/serious-caucasian-programmer-casual-wears-using-1771878971">Videoflow/Shutterstock</a></span></figcaption></figure><p>The advent of mass working from home has made many people more aware of the security risks of sending sensitive information via the internet. The best we can do at the moment is make it difficult to intercept and hack your messages – but we can’t make it impossible.</p>
<p>What we need is a new type of internet: the <a href="https://theconversation.com/quantum-internet-the-next-global-network-is-already-being-laid-131355">quantum internet</a>. In this version of the global network, data is secure, connections are private and your worries about information being intercepted are a thing of the past. </p>
<p>My colleagues and I have just made a breakthrough, <a href="https://advances.sciencemag.org/lookup/doi/10.1126/sciadv.aba0959">published in Science Advances</a>, that will make such a quantum internet possible by scaling up the concepts behind it using existing telecommunications infrastructure.</p>
<p>Our current way of protecting online data is to encrypt it using <a href="https://theconversation.com/encryption-today-how-safe-is-it-really-37806">mathematical problems</a> that are easy to solve if you have a digital “key” to unlock the encryption but hard to solve without it. However, hard does not mean impossible and, with enough time and computer power, today’s methods of encryption can be broken.</p>
<p>Quantum communication, on the other hand, creates keys using individual particles of light (photons) , which – according to the principles of quantum physics – <a href="https://doi.org/10.1038%252F299802a0">are impossible</a> to make an exact copy of. Any attempt to copy these keys will unavoidably cause errors that can be detected. This means a hacker, no matter how clever or powerful they are or what kind of supercomputer they possess, cannot replicate a quantum key or read the message it encrypts.</p>
<p>This concept has already been demonstrated <a href="https://www.nature.com/articles/nature23655/">in satellites</a> and over <a href="https://www.nature.com/articles/s41534-019-0238-8">fibre-optic cables</a>, and used to send secure messages between <a href="https://www.nature.com/news/quantum-communications-leap-out-of-the-lab-1.15093">different countries</a>. So why are we not already using in everyday life? The problem is that it requires expensive, specialised technology that means it’s not currently scalable.</p>
<figure class="align-center ">
<img alt="Planet Earth overlaid with network of connected lights" src="https://images.theconversation.com/files/356056/original/file-20200902-24-1wsgjfl.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/356056/original/file-20200902-24-1wsgjfl.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=401&fit=crop&dpr=1 600w, https://images.theconversation.com/files/356056/original/file-20200902-24-1wsgjfl.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=401&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/356056/original/file-20200902-24-1wsgjfl.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=401&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/356056/original/file-20200902-24-1wsgjfl.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/356056/original/file-20200902-24-1wsgjfl.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/356056/original/file-20200902-24-1wsgjfl.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Quantum communication is now possible across the world but not yet scalable.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-illustration/best-internet-concept-global-business-concepts-173610971">Toria/Shutterstock</a></span>
</figcaption>
</figure>
<p><a href="https://doi.org/10.1364/OE.19.010387">Previous quantum communication techniques</a> were like pairs of children’s walkie talkies. You need one pair of handsets for every pair of users that want to securely communicate. So if three children want to talk to each other they will need three pairs of handsets (or six walkie talkies) and each child must have two of them. If eight children want to talk to each other they would need 56 walkie talkies. </p>
<p>Obviously it’s not practical for someone to have a separate device for every person or website they want to communicate with over the internet. So we figured out a way to securely connect every user with just one device each, more similar to phones than walkie talkies.</p>
<p>Each walkie talkie handset acts as both a transmitter and a receiver in order to share the quantum keys that make communication secure. In our model, users only need a receiver because they get the photons to generate their keys from a central transmitter.</p>
<p>This is possible because of another principle of quantum physics called “entanglement”. A photon can’t be exactly copied but it can be entangled with another photon so that they both behave in the same way when measured, no matter how far apart they are – what Albert Einstein called “spooky action at a distance”. </p>
<h2>Full network</h2>
<p>When two users want to communicate, our transmitter sends them an entangled pair of photons – one particle for each user. The users’ devices then perform a series of measurements on these photons to create a shared secret quantum key. They can then encrypt their messages with this key and transfer them securely. </p>
<p>By using multiplexing, a common telecommunications technique of combining or splitting signals, we can effectively send these entangled photon pairs to multiple combinations of people at once.</p>
<p>We can also send many signals to each user in a way that they can all be simultaneously decoded. In this way we’ve effectively replaced pairs of walkie talkies with a system more similar to a video call with multiple participants, in which you can communicate with each user privately and independently as well as all at once.</p>
<p>We’ve so far tested this concept by connecting eight users across a single city. We are now working to improve the speed of our network and interconnect several such networks. Collaborators have already started using our quantum network as a test bed for several exciting applications beyond just quantum communication. </p>
<p>We also hope to develop even better quantum networks based on this technology with commercial partners in the next few years. With innovations like this, I hope to witness the beginning of the quantum internet in the next ten years.</p><img src="https://counter.theconversation.com/content/145139/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>The research leading to this work has received funding from the Engineering and Physical Science Research Council (EPSRC) Quantum Communications Hubs EP/M013472/1 & EP/T001011/1 and equipment procured by the QuPIC project EP/N015126/1. We acknowledge the Ministry of Science and Education (MSE) of Croatia, contract No. KK.01.1.1.01.0001. We acknowledge financial support from the Austrian Research Promotion Agency (FFG) project ASAP12-85 and project SatNetQ 854022. This work was partially supported by the European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement number 675662 (QCALL) and through the Quantum Engineering Centre for Doctoral Training EP/LO15730/1.</span></em></p>New research shows how the next generation of ultra-secure communication could be possible with existing infrastructure.Siddarth Koduru Joshi, Research Fellow in Quantum Communication, University of BristolLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1343222020-06-16T11:50:19Z2020-06-16T11:50:19ZWhat Buddhism and science can teach each other – and us – about the universe<figure><img src="https://images.theconversation.com/files/341489/original/file-20200612-153827-v7sa1f.jpg?ixlib=rb-1.1.0&rect=44%2C35%2C2914%2C1747&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The Dalai Lama speaks about quantum effects with Chinese scientists at the Main Tibetan Temple, Nov. 1, 2018, in Dharamshala, India. </span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/tibetan-spiritual-leader-the-dalai-lama-delivers-his-news-photo/1056118136?adppopup=true">Shyam Sharma/Hindustan Times via Getty Images</a></span></figcaption></figure><p>These are trying times. A global recession sparked by the coronavirus pandemic, and widespread civil unrest, have created a combustible mix of angst – stressors that heighten the risk for long-term health woes. The Centers for Disease Control and Prevention recently issued guidelines to <a href="https://www.cdc.gov/coronavirus/2019-ncov/daily-life-coping/managing-stress-anxiety.html">cope with this anxiety</a>. Among them is meditation.</p>
<p>Buddhists have been familiar with this strategy for thousands of years. And as the CDC example shows, scientists increasingly believe they can learn from Buddhism. </p>
<p>Momentum for dialogue between Buddhism and science comes from the top. When <a href="https://www.harpercollins.com/9780060987015/freedom-in-exile/">Tenzin Gyatso – now serving as the 14th Dalai Lama</a> – was a child in rural Tibet, he saw the moon through a telescope and marveled at its craters and mountains. His tutor told him that, according to Buddhist texts, the moon emitted its own light. But Gyatso had his doubts. He discovered what <a href="https://www.forbes.com/sites/kionasmith/2018/11/30/how-galileo-discovered-mountains-on-the-moon/#434317934bdd">Galileo saw 400 years earlier</a>, and he became convinced that dogma should bend to observation. </p>
<p>As the Dalai Lama, Gyatso has engaged in dialog with scientists ever since. “If science proved some belief of Buddhism wrong, then Buddhism will have to change,” <a href="https://www.nytimes.com/2005/11/12/opinion/our-faith-in-science.html">he has said</a>.</p>
<p>These are striking words from the leader of a major world religion. Most Americans believe <a href="https://www.pewresearch.org/science/2015/10/22/science-and-religion/">science and religion clash</a>. But <a href="https://www.pewforum.org/2009/02/04/religious-differences-on-the-question-of-evolution/">Buddhists accept evolution</a> as the source of human origins more than any other religious group.</p>
<p>As a <a href="http://chrisimpey-astronomy.com/">professor of astronomy</a> who has been <a href="http://www.scienceformonksandnuns.org/">teaching Tibetan monks and nuns</a> for over a decade, I’ve found them to be <a href="https://www.templetonpress.org/books/humble-void">highly receptive to science</a> as a way of understanding the natural world. </p>
<p>The program I teach started in response to the Dalai Lama’s desire to inject science into the training of Buddhist monastics. In our spartan classroom – the windows are open to catch a breeze in the monsoon heat and monkeys chatter in the pine trees outside – <a href="https://blogs.scientificamerican.com/observations/tibetan-monks-meet-science-near-the-roof-of-the-world/">we talk cosmology</a>. </p>
<p>The monks and nuns eagerly absorb the latest research I present – dark energy, the multiverse, <a href="https://www.penguinrandomhouse.com/books/80501/the-universe-in-a-single-atom-by-his-holiness-the-dalai-lama/">the big bang as a quantum event</a>. Their questions are simple but profound. They approach learning with joy and humility. Outside class, I see them applying critical thinking to decisions in their daily lives. </p>
<p>Yes, the Buddhist monastic tradition has been rebooted with a dose of 21st-century science. But how has Buddhism influenced science?</p>
<h2>Buddhists as skeptics</h2>
<p>Scientists are increasingly using Buddhist wisdom for <a href="https://www.lionsroar.com/buddhism-science-teachings-reports-commentaries-and-conversations/">insight into several research topics</a> and to illuminate the human condition. When psychologists use Buddhist concepts in their work, for example, they find their patients are less inclined to <a href="https://www.psypost.org/2015/04/study-finds-being-exposed-to-buddhist-concepts-reduces-prejudice-and-increases-prosociality-33103">exhibit prejudice</a> against people outside their social and religious group. And scientists have used the harmonic principles built into <a href="https://www.businessinsider.com.au/the-shape-of-a-buddhist-singing-bowl-has-inspired-a-more-efficient-solar-panel-2014-8">Buddhist “singing” bowls</a> to design more efficient solar panels.</p>
<p>Both disciplines share an empirical approach. Buddhists are trained to be skeptics, and to only accept a proposition after examining evidence. The following <a href="https://www.wayofbodhi.org/buddha-quote-examining-like-goldsmith/">words are attributed to the Buddha</a>: “Just as a goldsmith would test his gold by burning, cutting, and rubbing it, so must you examine my words and accept them, not merely out of reverence for me.” </p>
<p>Numerous studies show that meditation has a positive effect on health and well-being. <a href="https://www.lionsroar.com/how-meditation-changes-your-brain-and-your-life/">EEG tests to measure monks’ brain waves</a> provide proof. Monks and other expert meditators produce <a href="https://braintap.com/study-of-meditation-and-brain-waves-in-buddhist-monks-confounds-wisconsin-researchers/">high levels of gamma brain waves</a>, which have a series of benefits to cognitive functioning. </p>
<p>Meditation also <a href="https://www.ncbi.nlm.nih.gov/pubmed/12883106">benefits the immune system</a>. And it’s been shown to <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5866730/">reduce mind wandering</a>, which increases happiness and reduces depression. Meditation can even <a href="https://www.frontiersin.org/articles/10.3389/fpsyg.2014.01551/full">slow the rate of brain atrophy</a>. In one remarkable case, meditation may have <a href="https://www.livescience.com/buddhist-monk-meditation-brain.html">shaved eight years off a Buddhist monk’s brain</a>.</p>
<p>Western scientists and Buddhist scholars have also collaborated on one of the profound mysteries of the human experience: consciousness. Researchers have used neuroscience to support the idea of an <a href="https://qz.com/506229/neuroscience-backs-up-the-buddhist-belief-that-the-self-isnt-constant-but-ever-changing/">ever-changing self</a>. Neuroscientists have modeled the sense of self in terms of <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3163487/">shifting networks and circuits</a> in the brain. Your sense of a stable and rooted “you” is an illusion, they concluded. </p>
<p>Christof Koch is a leading expert on consciousness. Koch and his colleague Giulio Tononi have come up with an <a href="https://www.lionsroar.com/christof-koch-unites-buddhist-neuroscience-universal-nature-mind/">audacious theory of consciousness</a>. They argue that it’s not localized and cannot be identified in any part of the brain. They also write that plants, animals and microbes can be conscious. Their theory <a href="https://royalsocietypublishing.org/doi/full/10.1098/rstb.2014.0167">“treats consciousness [as] an intrinsic, fundamental property of reality.”</a> </p>
<p>Wait. The self is nowhere and consciousness is everywhere? This sounds like Zen sophistry rather than scientific analysis. But I see it as a sign of the fruitful convergence of Western science and Eastern philosophy.</p>
<p>It’s early to determine what this ambitious research will deliver. But it shows that input from Buddhist thought is forcing scientists to question their methods, assumptions and logical constructs. Koch and Tononi, for example, are less concerned with the physical mechanisms and localized structures of the brain than they are with the network of transient connections that may underlie consciousness.</p>
<p>The best lesson Buddhism has for science concerns balance. In his gentle way, the Dalai Lama chastises scientists for not paying enough attention to the negative implications of their quest for knowledge. <a href="https://www.nytimes.com/2005/11/12/opinion/our-faith-in-science.html">He writes</a>: “It is all too evident that our moral thinking simply has not been able to keep pace with the speed of scientific advancement.” </p>
<p>In a troubled world, being guided by science but insisting that it reflect human values may be the best advice of all.</p>
<p>[<em>Deep knowledge, daily.</em> <a href="https://theconversation.com/us/newsletters?utm_source=TCUS&utm_medium=inline-link&utm_campaign=newsletter-text&utm_content=deepknowledge">Sign up for The Conversation’s newsletter</a>.]</p><img src="https://counter.theconversation.com/content/134322/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Chris Impey does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Amid trying times, the collaboration between Western science and Eastern philosophy provides numerous health benefits and a path to understanding the natural world.Chris Impey, University Distinguished Professor of Astronomy, University of ArizonaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/807072020-06-03T12:15:52Z2020-06-03T12:15:52ZPhysicists hunt for room-temperature superconductors that could revolutionize the world’s energy system<figure><img src="https://images.theconversation.com/files/331514/original/file-20200429-51495-1gds604.jpg?ixlib=rb-1.1.0&rect=44%2C0%2C6886%2C4285&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Wind turbines and solar panels in Southern California.</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/wind-turbines-and-solar-panels-royalty-free-image/1133686786?adppopup=true">4kodiak/E+ via Getty Images</a></span></figcaption></figure><p>Waste heat is all around you. On a small scale, if your phone or laptop feels warm, that’s because some of the energy powering the device is being transformed into unwanted heat. </p>
<p>On a larger scale, electric grids, such as high power lines, lose over <a href="https://www.eia.gov/tools/faqs/faq.php?id=105&t=3">5% of their energy</a> in the process of transmission. In an electric power industry that generated more than <a href="https://www.statista.com/statistics/190548/revenue-of-the-us-electric-power-industry-since-1970/#statisticContainer">US$400 billion in 2018</a>, that’s a tremendous amount of wasted money. </p>
<p>Globally, the computer systems of Google, Microsoft, Facebook and others require enormous amounts of energy to power massive cloud servers and data centers. <a href="https://www.greenbiz.com/article/microsoft-facebook-take-plunge-novel-cloud-cooling-approaches">Even more energy</a>, to power water and air cooling systems, is required to offset the heat generated by these computers. </p>
<p>Where does this wasted heat come from? Electrons. These elementary particles of an atom move around and interact with other electrons and atoms. Because they have an electric charge, as they move through a material – like metals, which can easily conduct electricity – they scatter off other atoms and generate heat. </p>
<p>Superconductors are materials that address this problem by allowing energy to flow efficiently through them without generating unwanted heat. They have great potential and many cost-effective applications. They operate magnetically levitated trains, generate magnetic fields for MRI machines and recently have been used to build <a href="https://www.scientificamerican.com/article/hands-on-with-googles-quantum-computer/">quantum computers</a>, though a fully operating one does not yet exist.</p>
<p>But superconductors have an essential problem when it comes to other practical applications: They operate at ultra-low temperatures. There are no room-temperature superconductors. That “room-temperature” part is what scientists have been working on for more than a century. Billions of dollars have funded research to solve this problem. Scientists around the world, <a href="https://scholar.google.com/citations?user=B_5QhO4AAAAJ&hl=en">including me</a>, are trying to understand the physics of superconductors and how they can be enhanced.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/331829/original/file-20200430-42942-1p6pah7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/331829/original/file-20200430-42942-1p6pah7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=397&fit=crop&dpr=1 600w, https://images.theconversation.com/files/331829/original/file-20200430-42942-1p6pah7.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=397&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/331829/original/file-20200430-42942-1p6pah7.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=397&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/331829/original/file-20200430-42942-1p6pah7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=498&fit=crop&dpr=1 754w, https://images.theconversation.com/files/331829/original/file-20200430-42942-1p6pah7.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=498&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/331829/original/file-20200430-42942-1p6pah7.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=498&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">The U.S. power grid sheds heat at a loss of billions of dollars each year.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/multiple-power-lines-on-overhead-towers-royalty-free-image/639773156?adppopup=true">Douglas Sacha/Moment via Getty Images</a></span>
</figcaption>
</figure>
<h2>Understanding the mechanism</h2>
<p>A superconductor is a material, such as a pure metal like aluminum or lead, that when cooled to ultra-low temperatures allows electricity to move through it with absolutely zero resistance. How a material becomes a superconductor at the microscopic level is not a simple question. It took the scientific community 45 years to understand and formulate a <a href="https://journals.aps.org/pr/abstract/10.1103/PhysRev.108.1175">successful theory of superconductivity</a> in 1956.</p>
<p>While physicists researched an understanding of the mechanisms of superconductivity, chemists mixed different elements, such as the rare metal niobium and tin, and tried recipes guided by other experiments to discover new and stronger superconductors. There was progress, but mostly incremental. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/331828/original/file-20200430-42929-ksbrj3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/331828/original/file-20200430-42929-ksbrj3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/331828/original/file-20200430-42929-ksbrj3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/331828/original/file-20200430-42929-ksbrj3.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/331828/original/file-20200430-42929-ksbrj3.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/331828/original/file-20200430-42929-ksbrj3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/331828/original/file-20200430-42929-ksbrj3.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/331828/original/file-20200430-42929-ksbrj3.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Copper rods.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/copper-rods-used-to-machine-parts-are-stacked-on-a-shelf-at-news-photo/1179652884?adppopup=true">Scott Olson/Getty Images News via Getty Images</a></span>
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</figure>
<p>Simply put, superconductivity occurs when two electrons bind together at low temperatures. They form the building block of superconductors, the Cooper pair. Elementary physics and chemistry tell us that electrons repel each other. This holds true even for a potential superconductor like lead when it is above a certain temperature. </p>
<p>When the temperature falls to a certain point, though, the electrons become more amenable to pairing up. Instead of one electron opposing the other, a kind of “glue” emerges to hold them together. </p>
<h2>Keeping matter cool</h2>
<p>Discovered in 1911, the first superconductor was mercury (Hg), the basic element of old-fashioned thermometers. In order for mercury to become a superconductor, it had to be cooled to ultra-low temperatures. <a href="https://www.nobelprize.org/prizes/physics/1913/onnes/biographical/">Kamerlingh Onnes</a> was the first scientist who figured out exactly how to do that – by compressing and liquefying helium gas. During the process, once helium gas becomes a liquid, the temperature drops to -452 degrees Fahrenheit. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/333710/original/file-20200508-49556-1d4es8f.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/333710/original/file-20200508-49556-1d4es8f.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/333710/original/file-20200508-49556-1d4es8f.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=511&fit=crop&dpr=1 600w, https://images.theconversation.com/files/333710/original/file-20200508-49556-1d4es8f.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=511&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/333710/original/file-20200508-49556-1d4es8f.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=511&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/333710/original/file-20200508-49556-1d4es8f.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=642&fit=crop&dpr=1 754w, https://images.theconversation.com/files/333710/original/file-20200508-49556-1d4es8f.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=642&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/333710/original/file-20200508-49556-1d4es8f.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=642&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Quicksilver or mercury, the only metal that is liquid at room temperature.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/quicksilver-royalty-free-image/93292637?adppopup=true">videophoto/E+ via Getty Images</a></span>
</figcaption>
</figure>
<p>When Onnes was <a href="https://en.wikipedia.org/wiki/Heike_Kamerlingh_Onnes">experimenting with mercury</a>, he discovered that when it was placed inside a liquid helium container and cooled to very low temperatures, its electric resistance, the opposition of the electric current in the material, suddenly dropped to zero ohms, a unit of measurement that describes resistance. Not close to zero, but zero exactly. No resistance, no heat waste.</p>
<p>This meant that an electric current, once generated, would flow continuously with nothing to stop it, at least in the lab. Many superconducting materials were soon discovered, but practical applications were another matter. </p>
<p>These superconductors shared one problem – they needed to be cooled down. The amount of energy needed to cool a material down to its superconducting state was too expensive for daily applications. By the early 1980s, the research on superconductors had nearly reached its conclusion. </p>
<h2>A surprising discovery</h2>
<p>In a dramatic turn of events, a new kind of superconductor material was discovered in 1987 at <a href="https://www.zurich.ibm.com/">IBM in Zurich, Switzerland</a>. Within months, superconductors operating at less extreme temperatures were being synthesized globally. The material was a kind of a ceramic. </p>
<p>These new ceramic superconductors were made of copper and oxygen mixed with other elements such as lanthanum, barium and bismuth. They contradicted everything physicists thought they knew about making superconductors. Researchers had been looking for very good conductors, yet these ceramics were nearly insulators, meaning that very little electrical current can flow through. Magnetism destroyed conventional superconductors, yet these were themselves magnets. </p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/x6OhDE_AYaw?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
</figure>
<p>Scientists were seeking materials where electrons were free to move around, yet in these materials, the electrons were locked in and confined. The scientists at IBM, <a href="https://www.nobelprize.org/prizes/physics/1987/summary/">Alex Müller and Georg Bednorz</a>, had actually discovered a new kind of superconductor. These were the high-temperature superconductors. And they played by their own rules. </p>
<h2>Elusive solutions</h2>
<p>Scientists now have a new challenge. Three decades after the high-temperature superconductors were discovered, we are still struggling to understand how they work at the microscopic level. Creative experiments are being conducted every day in universities and research labs around the world. </p>
<p>In my laboratory, we have built a microscope known as a <a href="https://www.youtube.com/watch?v=Yi6q1j_QjSc&feature=youtube">scanning tunneling microscope</a> that helps our research team “see” the electrons at the surface of the material. This allows us to understand how electrons bind and form superconductivity at an atomic scale. </p>
<p>We have come a long way in our research and now know that electrons also pair up in these high-temperature superconductors. There is great value and utility in answering how high-temperature superconductors work because that may be the route to room-temperature superconductivity. If we succeed in making a room-temperature superconductor, then we can address the billions of dollars that it costs in wasted heat to transmit energy from power plants to cities. </p>
<p>More remarkably, solar energy harvested in the vast empty deserts around the world could be stored and transmitted without any loss of energy, which could power cities and dramatically reduce greenhouse gas emissions. The potential is hard to imagine. Finding the glue for room-temperature superconductors is the next million-dollar question.</p>
<p>[<em>You’re too busy to read everything. We get it. That’s why we’ve got a weekly newsletter.</em> <a href="https://theconversation.com/us/newsletters/weekly-highlights-61?utm_source=TCUS&utm_medium=inline-link&utm_campaign=newsletter-text&utm_content=weeklybusy">Sign up for good Sunday reading.</a> ]</p><img src="https://counter.theconversation.com/content/80707/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Pegor Aynajian received funding from National Science Foundation (NSF) CAREER under Award No. DMR-1654482.</span></em></p>Generating energy usually means wasted heat. Semiconductors let the electrons flow with zero waste – but so far scientists only know how to get them to work at ultra-low temperatures.Pegor Aynajian, Associate Professor of Physics, Binghamton University, State University of New YorkLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1390032020-05-25T17:09:45Z2020-05-25T17:09:45ZEinstein’s two mistakes<figure><img src="https://images.theconversation.com/files/336116/original/file-20200519-152302-1xblde8.jpg?ixlib=rb-1.1.0&rect=179%2C561%2C2622%2C1738&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Woodcut from Camille Flammarion's 1888 book _L'Atmosphère : météorologie populaire_. The caption reads: 'A missionary of the Middle Ages tells that he had found the point where the sky and the Earth touch' and continues, 'What is there, then, in this blue sky, which certainly exists, and which veils the stars during the day?' </span> <span class="attribution"><a class="source" href="https://fr.wikipedia.org/wiki/Gravure_sur_bois_de_Flammarion#/media/Fichier:Flammarion.jpg">Wikipedia</a></span></figcaption></figure><p>Scientific research is based on the relationship between the reality of nature, as it is observed, and a representation of this reality, formulated by a theory in mathematical language. If all the consequences of the theory are experimentally proven, it is considered as validated. This approach, which has been used for nearly four centuries, has built a consistent body of knowledge. But these advances have been made thanks to the intelligence of human beings who, despite all, can still hold onto their preexisting beliefs and biases. This can affect the progress of science, even for the greatest minds.</p>
<h2>The first mistake</h2>
<p>In Enstein’s master work of general relativity, he wrote the equation describing the <a href="https://astronomia.fr/6eme_partie/cosmologie.php">evolution of the universe</a> over time. The solution to this equation shows that the universe is unstable, not a huge sphere with constant volume with stars sliding around, as was believed at the time.</p>
<p>At the beginning of the 20th century, people lived with the well-established idea of a static universe where the motion of stars never varies. This is probably due to Aristotle’s teachings, stating that the sky is immutable, unlike Earth, which is perishable. This idea caused a historical anomaly: in 1054, the Chinese <a href="https://blogs.futura-sciences.com/luminet/2015/10/12/la-nebuleuse-du-crabe-hier-et-aujourdhui/">noticed the appearance of a new light in the sky</a>, but no European document mentions it. Yet it could be seen in full daylight and lasted for several weeks. It was a <a href="https://fr.wikipedia.org/wiki/Supernova">supernova</a>, that is, a dying star, the remnants of which can still be seen as the Crab Nebula. Predominant thought in Europe prevented people from accepting a phenomenon that so utterly contradicted the idea of an unchanging sky. A supernova is a very rare event, which can only be observed by the naked eye once a century. The most recent one dates back to 1987. So Aristotle was <em>almost</em> right in thinking that the sky was unchanging – on the scale of a human life at least.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/332650/original/file-20200505-83730-p9trq1.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/332650/original/file-20200505-83730-p9trq1.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/332650/original/file-20200505-83730-p9trq1.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=139&fit=crop&dpr=1 600w, https://images.theconversation.com/files/332650/original/file-20200505-83730-p9trq1.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=139&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/332650/original/file-20200505-83730-p9trq1.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=139&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/332650/original/file-20200505-83730-p9trq1.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=175&fit=crop&dpr=1 754w, https://images.theconversation.com/files/332650/original/file-20200505-83730-p9trq1.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=175&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/332650/original/file-20200505-83730-p9trq1.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=175&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The Crab nebula, observed today at different wavelengths, was not recorded by Europeans when it appeared in 1054.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:Crab_Nebula_in_Multiple_Wavelengths.png">Torres997/Wikimedia, Radio: NRAO/AUI and M. Bietenholz, J.M. Uson, T.J. Cornwell; Infrared: NASA/JPL-Caltech/R. Gehrz, University of Minnesota; Visible light: NASA, ESA, J. Hester and A. Loll, Arizona State University; Ultraviolet: NASA/Swift/E. Hoversten, PSU; X-rays: NASA/CXC/SAO/F.Seward and collaborators; Gamma rays: NASA/DOE/Fermi LAT/R. Buehler</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<p>To remain in accordance with the idea of a static universe, Einstein introduced a cosmological constant into his equations, which froze the state of the universe. His intuition led him astray: in 1929, when Hubble demonstrated that the universe is expanding, Einstein admitted that he had made “his biggest mistake”.</p>
<h2>Quantum randomness</h2>
<p>Quantum mechanics developed around the same time as relativity. It describes the physics at the infinitely small scale. Einstein contributed greatly to the field in 1905, by interpreting the <a href="https://en.wikipedia.org/wiki/Photoelectric_effect">photoelectric effect</a> as being a collision between electrons and photons – that is, infinitesimal particles carrying pure energy. In other words, light, which has traditionally been described as a wave, behaves like a stream of particles. It was this step forward, not the theory of relativity, that earned Einstein the Nobel Prize in 1921.</p>
<p>But despite this <a href="http://culturesciencesphysique.ens-lyon.fr/ressource/conference-udppc-Einstein-lumiere-Jech.xml">vital contribution</a>, he remained stubborn in rejecting the key lesson of <a href="https://fr.wikipedia.org/wiki/M%C3%A9canique_quantique">quantum mechanics</a> – that the world of particles is not bound by the strict <a href="https://en.wikipedia.org/wiki/Determinism">determinism</a> of classical physics. The quantum world is probabilistic. We only know how to predict the probability of an occurrence among a range of possibilities.</p>
<p>In Einstein’s blindness, once again we can see the influence of Greek philosophy. Plato taught that thought should remain ideal, free from the contingencies of reality – a noble idea, but one that does not follow the precepts of science. Knowledge demands perfect consistency with all predicted facts, whereas belief is based on likelyhood, produced by partial observations. Einstein himself was convinced that pure thought was capable of fully capturing reality, but quantum randomness contradicts this hypothesis.</p>
<p>In practice, this randomness is not a pure noise, as it is constrained by <a href="https://theconversation.com/explainer-heisenbergs-uncertainty-principle-7512">Heisenberg’s uncertainty principle</a>. This principle imposes collective determinism on groups of particles – an electron is free by itself, as we do not know how to calculate its trajectory when leaving a hole, but a million electrons draw a diffraction figure, showing dark and light fringes that we do know how to calculate.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/332652/original/file-20200505-83764-h8qfu5.gif?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/332652/original/file-20200505-83764-h8qfu5.gif?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=441&fit=crop&dpr=1 600w, https://images.theconversation.com/files/332652/original/file-20200505-83764-h8qfu5.gif?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=441&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/332652/original/file-20200505-83764-h8qfu5.gif?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=441&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/332652/original/file-20200505-83764-h8qfu5.gif?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=554&fit=crop&dpr=1 754w, https://images.theconversation.com/files/332652/original/file-20200505-83764-h8qfu5.gif?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=554&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/332652/original/file-20200505-83764-h8qfu5.gif?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=554&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Result of a Young interference experiment: the pattern is formed bit by bit with the arrival of electrons (8 electrons on photo a, 270 electrons on photo b, 2,000 on photo c, and 60,000 on photo d) that eventually form vertical fringes called interference fringes.</span>
<span class="attribution"><a class="source" href="https://upload.wikimedia.org/wikipedia/commons/7/79/Doubleslitexperiment_results_Tanamura_1.gif">Dr. Tonomura/Wikimedia</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<p>Einstein did not accept this fundamental indeterminism, as summed up by his <a href="https://editions.flammarion.com/Catalogue/champs-sciences/einstein">provocative verdict</a>: “God does not play dice with the universe.” He imagined the existence of <a href="https://fr.wikipedia.org/wiki/Variable_cach%C3%A9e">hidden variables</a>, i.e., yet-to-be-discovered numbers beyond mass, charge and spin that physicists use to describe particles. But the experiment did not support this idea. It is undeniable that a reality exists that transcends our understanding – we cannot know everything about the world of the infinitely small.</p>
<h2>The fortuitous whims of the imagination</h2>
<p>Within the process of the scientific method, there is still a stage that is not completely objective. This is what leads to conceptualising a theory, and Einstein, with his <a href="https://plato.stanford.edu/entries/thought-experiment/">thought experiments</a>, gives a famous example of it. He stated that “imagination is more important than knowledge”. Indeed, when looking at disparate observations, a physicist must imagine an underlying law. Sometimes, several theoretical models compete to explain a phenomenon, and it is only at this point that logic takes over again.</p>
<blockquote>
<p>“The role of intelligence is not to discover, but to prepare. It is only good for service tasks.” (Simone Weil, “Gravity and Grace”)</p>
</blockquote>
<p>In this way, the progress of ideas springs from what is called intuition. It is a sort of jump in knowledge that goes beyond pure rationality. The line between objective and subjective is no longer completely solid. Thoughts come from neurons under the effect of electromagnetic impulses, some of them being particularly fertile, as if there was a short circuit between cells, where chance is at work.</p>
<p>But these intuitions, or “flowers” of the human spirit, are not the same for everybody – Einstein’s brain produced “E=mc<sup>2</sup>”, whereas Proust’s brain came up with an admirable metaphor. Intuition pops up randomly, but this randomness is constrained by each individual’s experience, culture and knowledge.</p>
<h2>The benefits of randomness</h2>
<p>It should not come as shocking news that there is a reality not grasped by our own intelligence. Without randomness, we are guided by our instincts and habits, everything that makes us predictable. What we do is limited almost exclusively to this first layer of reality, with ordinary concerns and obligatory tasks. But there is another layer of reality, the one where obvious randomness is the trademark.</p>
<blockquote>
<p>“Never will an administrative or academic effort replace the miracles of chance to which we owe great men.” (Honoré de Balzac, “Cousin Pons”)</p>
</blockquote>
<p>Einstein is an example of an inventive and free spirit; yet he still kept his biases. His “first mistake” can be summed up saying: “I refuse to believe in a beginning of the universe.” However, experiments proved him wrong. His verdict on God playing dice means, “I refuse to believe in chance”. Yet quantum mechanics involves obligatory randomness. His sentence begs the question of whether he would believe in God in a world without chance, which would greatly curtail our freedom, as we would then be confined in absolute determinism. Einstein was stubborn in his refusal. For him, the human brain should be capable of knowing what the universe is. With a lot more modesty, Heisenberg teaches us that physics is limited to describing how nature reacts in given circumstances.</p>
<p>Quantum theory demonstrates that total understanding is not available to us. In return, it offers randomness which brings frustrations and dangers, but also benefits.</p>
<blockquote>
<p>“Man can only escape the laws of this world for a flash of time. Instants of pausing, of contemplating, of pure intuition… It’s with these flashes that he is capable of the superhuman.” (Simone Weil, “Gravity and Grace”)</p>
</blockquote>
<p>Einstein, a legendary physicist, is the perfect example of an imaginative being. His refusal of randomness is therefore a paradox, because randomness is what makes intuition possible allowing for creative processes in both science and art.</p>
<hr>
<p><em>Translated from the French by Rosie Marsland for <a href="http://www.fastforword.fr/en">Fast ForWord</a>.</em></p><img src="https://counter.theconversation.com/content/139003/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>François Vannucci ne travaille pas, ne conseille pas, ne possède pas de parts, ne reçoit pas de fonds d'une organisation qui pourrait tirer profit de cet article, et n'a déclaré aucune autre affiliation que son organisme de recherche.</span></em></p>Albert Einstein may have been the ultimate example of a visionary genius, but that did not stop him from twice losing his way due to beliefs that were perhaps not so scientific.François Vannucci, Professeur émérite, chercheur en physique des particules, spécialiste des neutrinos, Université Paris CitéLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1265032019-12-03T12:58:03Z2019-12-03T12:58:03ZA quantum computing future is unlikely, due to random hardware errors<figure><img src="https://images.theconversation.com/files/304539/original/file-20191130-156095-1m7msum.jpg?ixlib=rb-1.1.0&rect=603%2C11%2C3069%2C2121&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Will quantum computers ever reliably best classical computers?</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-illustration/3d-render-qubits-1015677376">Amin Van/Shutterstock.com</a></span></figcaption></figure><figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/303588/original/file-20191125-74588-1s17qy1.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/303588/original/file-20191125-74588-1s17qy1.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/303588/original/file-20191125-74588-1s17qy1.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=801&fit=crop&dpr=1 600w, https://images.theconversation.com/files/303588/original/file-20191125-74588-1s17qy1.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=801&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/303588/original/file-20191125-74588-1s17qy1.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=801&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/303588/original/file-20191125-74588-1s17qy1.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1007&fit=crop&dpr=1 754w, https://images.theconversation.com/files/303588/original/file-20191125-74588-1s17qy1.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1007&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/303588/original/file-20191125-74588-1s17qy1.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1007&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Artist’s rendition of the Google processor.</span>
<span class="attribution"><a class="source" href="https://ai.googleblog.com/2019/10/quantum-supremacy-using-programmable.html">Forest Stearns, Google AI Quantum Artist in Residence</a>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<p><a href="https://www.nature.com/articles/s41586-019-1666-5">Google announced</a> this fall to much fanfare that it had demonstrated “quantum supremacy” – that is, it performed a specific quantum computation far faster than the best classical computers could achieve. IBM <a href="https://www.quantamagazine.org/google-and-ibm-clash-over-quantum-supremacy-claim-20191023/">promptly critiqued the claim</a>, saying that its own classical supercomputer could perform the computation at <a href="https://www.ibm.com/blogs/research/2019/10/on-quantum-supremacy/">nearly the same speed with far greater fidelity</a> and, therefore, the Google announcement should be taken “with a large dose of skepticism.”</p>
<p>This wasn’t the first time someone cast doubt on quantum computing. Last year, <a href="https://scholar.google.com/citations?user=EsHfKvUAAAAJ&hl=en&oi=sra">Michel Dyakonov</a>, a theoretical physicist at the University of Montpellier in France, offered a slew of technical reasons <a href="https://spectrum.ieee.org/computing/hardware/the-case-against-quantum-computing">why practical quantum supercomputers will never be built</a> in an article in IEEE Spectrum, the flagship journal of electrical and computer engineering.</p>
<p>So how can you make sense of what is going on?</p>
<p>As someone who has worked on <a href="https://arxiv.org/abs/quant-ph/0206144">quantum computing</a> for <a href="https://arxiv.org/abs/quant-ph/0503027">many years</a>, I believe that due to the inevitability of random errors in the hardware, useful quantum computers are unlikely to ever be built. </p>
<h2>What’s a quantum computer?</h2>
<p>To understand why, you need to understand how quantum computers work since they’re fundamentally different from classical computers.</p>
<p>A classical computer uses 0s and 1s to store data. These numbers could be voltages on different points in a circuit. But a quantum computer works on quantum bits, also known as qubits. You can picture them as waves that are associated with amplitude and phase.</p>
<p>Qubits have special properties: They can exist in superposition, where they are both 0 and 1 at the same time, and they may be entangled so they share physical properties even though they may be separated by large distances. It’s a behavior that does not exist in the world of classical physics. The <a href="https://en.wikipedia.org/wiki/Quantum_superposition">superposition vanishes when the experimenter interacts</a> with the quantum state. </p>
<p>Due to superposition, a quantum computer with 100 qubits can represent 2<sup>100</sup> solutions simultaneously. For certain problems, this exponential parallelism can be harnessed to create a tremendous speed advantage. Some <a href="https://www.technologyreview.com/s/613596/how-a-quantum-computer-could-break-2048-bit-rsa-encryption-in-8-hours/">code-breaking problems could be solved exponentially faster on a quantum machine</a>, for example.</p>
<p>There is another, narrower approach to quantum computing called <a href="https://en.wikipedia.org/wiki/Quantum_annealing">quantum annealing</a>, where qubits are used to speed up optimization problems. D-Wave Systems, based in Canada, has built optimization systems that use qubits for this purpose, but critics also claim that these systems <a href="https://www.theverge.com/2014/6/19/5824336/google-s-quantum-computer-just-flunked-its-first-big-test">are no better than classical computers</a>.</p>
<p>Regardless, companies and countries are investing massive amounts of money in quantum computing. China has developed a <a href="https://www.scmp.com/news/china/society/article/2110563/china-building-worlds-biggest-quantum-research-facility">new quantum research facility worth US$10 billion</a>, while the European Union has developed a €1 billion ($1.1 billion) <a href="https://ec.europa.eu/digital-single-market/en/news/european-commission-will-launch-eu1-billion-quantum-technologies-flagship">quantum master plan</a>. The United States’ <a href="https://www.technologyreview.com/f/612679/president-trump-has-signed-a-12-billon-law-to-boost-us-quantum-tech/">National Quantum Initiative Act</a> provides $1.2 billion to promote quantum information science over a five-year period.</p>
<p>Breaking encryption algorithms is a powerful motivating factor for many countries – if they could do it successfully, it would give them an enormous intelligence advantage. But these investments are also promoting fundamental research in physics. </p>
<p><a href="https://www.predictiveanalyticstoday.com/what-is-quantum-computing/">Many companies are pushing to build quantum computers</a>, including Intel and Microsoft in addition to Google and IBM. These companies are trying to build hardware that replicates the circuit model of classical computers. However, current experimental systems have less than 100 qubits. To achieve useful computational performance, you probably need machines with hundreds of thousands of qubits.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/303589/original/file-20191125-74588-j0a746.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/303589/original/file-20191125-74588-j0a746.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/303589/original/file-20191125-74588-j0a746.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=395&fit=crop&dpr=1 600w, https://images.theconversation.com/files/303589/original/file-20191125-74588-j0a746.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=395&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/303589/original/file-20191125-74588-j0a746.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=395&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/303589/original/file-20191125-74588-j0a746.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=496&fit=crop&dpr=1 754w, https://images.theconversation.com/files/303589/original/file-20191125-74588-j0a746.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=496&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/303589/original/file-20191125-74588-j0a746.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=496&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Google’s Sycamore processor has only 54 qubits.</span>
<span class="attribution"><a class="source" href="https://ai.googleblog.com/2019/10/quantum-supremacy-using-programmable.html">Erik Lucero, Research Scientist and Lead Production Quantum Hardware, Google</a>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<h2>Noise and error correction</h2>
<p>The mathematics that underpin quantum algorithms is well established, but there are daunting engineering challenges that remain. </p>
<p>For computers to function properly, they must correct all small random errors. In a quantum computer, such errors arise from the non-ideal circuit elements and the interaction of the qubits with the environment around them. For these reasons the qubits can lose coherency in a fraction of a second and, therefore, the computation must be completed in even less time. If random errors – which are inevitable in any physical system – are not corrected, the computer’s results will be worthless.</p>
<p>In classical computers, small noise is corrected by taking advantage of a concept known as thresholding. It works like the rounding of numbers. Thus, in the transmission of integers where it is known that the error is less than 0.5, if what is received is 3.45, the received value can be corrected to 3.</p>
<p>Further errors can be corrected by introducing redundancy. Thus if 0 and 1 are transmitted as 000 and 111, then at most one bit-error during transmission can be corrected easily: A received 001 would be a interpreted as 0, and a received 101 would be interpreted as 1.</p>
<p>Quantum error correction codes are a generalization of the classical ones, but there are crucial differences. For one, the unknown qubits cannot be copied to incorporate redundancy as an error correction technique. Furthermore, errors present within the incoming data before the error-correction coding is introduced cannot be corrected. </p>
<h2>Quantum cryptography</h2>
<p>While the problem of noise is a serious challenge in the implementation of quantum computers, it isn’t so in quantum cryptography, where people are dealing with single qubits, for single qubits can remain isolated from the environment for significant amount of time. Using quantum cryptography, two users can exchange the very large numbers known as keys, which secure data, without anyone able to break the key exchange system. Such key exchange could help secure communications between satellites and naval ships. But the actual encryption algorithm used after the key is exchanged remains classical, and therefore the encryption is theoretically no stronger than classical methods.</p>
<p>Quantum cryptography is being commercially used in a limited sense for high-value banking transactions. But because the two parties must be authenticated using classical protocols, and since a chain is only as strong as its weakest link, it’s not that different from existing systems. Banks are still using a classical-based authentication process, which itself could be used to exchange keys without loss of overall security. </p>
<p>Quantum cryptography technology <a href="https://www.extremetech.com/extreme/287094-quantum-cryptography#disqus_thread">must shift its focus to quantum transmission of information</a> if it’s going to become significantly more secure than existing cryptography techniques. </p>
<h2>Commercial-scale quantum computing challenges</h2>
<p>While quantum cryptography holds some promise if the problems of quantum transmission can be solved, I doubt the same holds true for generalized quantum computing. Error-correction, which is fundamental to a multi-purpose computer, is such a significant challenge in quantum computers that I don’t believe they’ll ever be built at a commercial scale.</p>
<p>[ <em>You’re smart and curious about the world. So are The Conversation’s authors and editors.</em> <a href="https://theconversation.com/us/newsletters/weekly-highlights-61?utm_source=TCUS&utm_medium=inline-link&utm_campaign=newsletter-text&utm_content=weeklysmart">You can get our highlights each weekend</a>. ]</p><img src="https://counter.theconversation.com/content/126503/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Subhash Kak does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Google claims quantum supremacy – IBM says not so fast. One researcher explains why he doesn’t see quantum computers outpacing classical computers any time soon … and maybe not ever.Subhash Kak, Regents Professor of Electrical and Computer Engineering, Oklahoma State UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1215492019-10-06T12:28:38Z2019-10-06T12:28:38ZTeaching young people what really matters for the sake of our collective life on Earth<figure><img src="https://images.theconversation.com/files/295081/original/file-20191001-173407-1k1prhd.jpg?ixlib=rb-1.1.0&rect=8%2C698%2C5302%2C2457&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Autumn Peltier, Chief Water Commissioner with the Anishinabek Nation, addresses the Global Landscapes Forum, at the United Nations, Sept. 28, 2019.</span> <span class="attribution"><span class="source">(AP Photo/Richard Drew)</span></span></figcaption></figure><p>As young people pledge ongoing climate action following <a href="https://www.theguardian.com/environment/2019/sep/27/climate-crisis-6-million-people-join-latest-wave-of-worldwide-protests">a week of global mobilization</a>, it’s clear that the world <a href="https://www.cambridge.org/core/journals/mrs-energy-and-sustainability/article/transforming-the-global-energy-system-is-required-to-avoid-the-sixth-mass-extinction/3B926E20A730AF666D6FCB75E366B703">faces a collective existential climate crisis</a> signalling that we must shift <a href="https://vimeo.com/55073825">to a planetary perspective</a>. But why it is that massive bodies of evidence are being ignored?</p>
<p>As a professor of child and youth studies who is dedicated to <a href="https://brill.com/view/title/37369?rskey=AYcU5M&result=2">fostering critical citizenship</a>, and who
examines how <a href="https://doi.org/10.1080/02604027.2018.1485435">differerent disciplines, knowledge systems</a> <a href="https://doi.org/10.1163/9789004271777_018">and international charters protect young people’s rights</a>, I believe one problem is that learning and research approaches have become so forensically specialized. This is the case in both school systems and universities. </p>
<h2>Transdisciplinary approaches</h2>
<p>There is a 50 year-old reform movement that advocates transforming western educational institutions <a href="https://doi.org/10.22329/celt.v10i0.4745">to be more transdisciplinary</a>: that means teaching in ways that help students learn not only small packets of information, but what really matters for the sake of our collective life on Earth. </p>
<p>Advocacy to reform education to be more holistic and cross-pollinating emerged in the early 1970s, simultaneously through Swiss developmental psychologist Jean Piaget and Austrian astrophysicist Erich Jantsch. Each began discussing the notion <a href="http://jrp.icaap.org/index.php/jrp/article/view/510/412">after attending a conference in France</a> that peered into planning for 21st century education. </p>
<p>In a public school setting, more holistic education might look like what Finnish schools do: As Finnish educator and researcher Pasi Sahlberg shares, Finland’s curriculum emphasizes teaching children so they are able to “<a href="https://www.washingtonpost.com/education/2019/08/30/what-finland-is-really-doing-improve-its-acclaimed-schools/">combine the knowledge and skills learned in different disciplines to form meaningful wholes</a>.”</p>
<h2>Decolonizing learning</h2>
<p>In schools, transdisciplinary approaches also means teaching the reality that <a href="https://www.tandfonline.com/doi/pdf/10.1080/02604027.2018.1485435">there are different ways of knowing</a>. This is particularly relevant in colonial settler societies like Canada where Indigenous people have resisted ongoing histories of enforced assimilation, domination and trauma — and where <a href="https://theconversation.com/its-taken-thousands-of-years-but-western-science-is-finally-catching-up-to-traditional-knowledge-90291">Traditional Knowledge is finally being more widely recognized as holding sophisticated insights and approaches</a>. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/295285/original/file-20191002-49377-o7lw8g.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/295285/original/file-20191002-49377-o7lw8g.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=429&fit=crop&dpr=1 600w, https://images.theconversation.com/files/295285/original/file-20191002-49377-o7lw8g.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=429&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/295285/original/file-20191002-49377-o7lw8g.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=429&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/295285/original/file-20191002-49377-o7lw8g.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=539&fit=crop&dpr=1 754w, https://images.theconversation.com/files/295285/original/file-20191002-49377-o7lw8g.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=539&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/295285/original/file-20191002-49377-o7lw8g.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=539&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">National Chief of the Assembly of First Nations, Perry Bellegarde, at a ceremony to remember children who died in residential schools in Gatineau, Québec, Sept. 30, 2019. The ceremony coincided with Orange Shirt Day, an annual commemorative event for children to learn about residential school experiences.</span>
<span class="attribution"><span class="source">(THE CANADIAN PRESS/Justin Tang)</span></span>
</figcaption>
</figure>
<p>Canada’s Truth and Reconciliation Commission called people to hear with new ears, in order to allow themselves to be changed. While there are many initiatives to decolonize education in Canada, our school systems, like those of Britain, are <a href="https://www.ted.com/talks/ken_robinson_changing_education_paradigms">based on 18th century (Eurocentric) assumptions</a>. </p>
<p>What’s needed is telling difficult truths about our histories, seeking justice for injustices and changing the essentials of what we’re offering young people. Public schooling needs to learn from approaches to education that Indigenous peoples have practised for millenia — getting out into the land, and speaking with Elders (lots!) to allow for development of the whole person. </p>
<p>We’re missing flexible and related ways of thinking, and ways of organizing that foreground the centrality of interconnected relationships between all humans, beings, nature and our so-called school “subjects.”</p>
<h2>Hearing children and youth speak</h2>
<p><a href="https://www.penguin.co.uk/books/315/315787/no-one-is-too-small-to-make-a-difference/9780141991740.html">Swedish teenager Greta Thunberg’s</a> and millions-strong recent climate strikes also suggest how our our dominant western educational and developmental paradigms simply miss what is essential. </p>
<p>This phenomenal young woman has been recognized by the Nobel Academy with a 2019 nomination, although some defensive adult critics have <a href="https://www.theguardian.com/media/2019/aug/02/andrew-bolts-mocking-of-greta-thunberg-leaves-autism-advocates-disgusted">vilified her because of her Asperger’s diagnosis</a> and suggested the teen’s criticism of systems is invalid if she has no comprehensive solution. </p>
<p>By contrast, we can see another example of how a community acknowledges and respects a young person: <a href="https://www.theglobeandmail.com/canada/article-indigenous-teen-autumn-peltier-urges-un-to-respect-clean-water/">Autumn Peltier</a>, from Wiikwemkoong Unceded Territory, is <a href="https://www.cbc.ca/news/canada/sudbury/autumn-peltier-chief-water-commissioner-1.5111137">Chief Water Commissioner with the Anishinabek Nation, a political advocacy body of 40 First Nations across Ontario</a>. Peltier recently told an audience at United Nations headquarters in New York that “<a href="https://www.ctvnews.ca/canada/we-can-t-drink-oil-indigenous-water-activist-tells-un-1.4615016?cache=yes">we can’t eat money, or drink oil</a>.”</p>
<p>Why are politicians, corporate leaders and adults everywhere not urgently advocating changes to how societies are organized — based on the important voices of young people such as Thunberg and Peltier? </p>
<p>Mainstream understandings of what it means to be a child or youth appear to be inadequate to understand what these young people are doing or what they are about — or to take positive action as a result. How can our societies overcome this failure? </p>
<h2>In universities</h2>
<p>For the sake of the generations to come, universities as well as schools must find ways to take into full account the outrageous complexity of the 21st century. No critical problem — such as climate change or the urgent threat to water systems, or a <a href="https://theconversation.com/canada-guilty-of-forging-crisis-in-indigenous-foster-care-90808">crisis in sky-high levels of apprehending children into foster care</a> — can be solved in silos. </p>
<p>As children all over the world are calling us out now, it is the job of adults — as educators, parents and politicians — to listen. </p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/_pQiCew4P34?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Greta Thunberg addresses world leaders at the United Nations.</span></figcaption>
</figure>
<p>And, it’s reasonable to reconsider how we’ve been led into a kind of mass hypnosis. What’s needed is listening in radically new ways — with the ears of “children,” so to speak, as beginners — in relationships where individuals and collective societies are respected, and in dialogue. </p>
<p>To respond to these urgent planetary problems that threaten young people’s futures, researchers in every field are tasked with contributing something relevant. </p>
<h2>‘Flipping’ how we think</h2>
<p>University researchers might learn something from the core assumptions of the body of thinking known as transdisciplinary thought over fifty years.</p>
<p>This thinking is based upon insights from quantum physics that <a href="https://www.scientificamerican.com/article/cosmos-quantum-and-consciousness-is-science-doomed-to-leave-some-questions-unanswered/">predictive measures based upon Newtonian physics and linear thinking cannot predict complex systems</a> such as weather, families or societies; it’s also based on <a href="http://jrp.icaap.org/index.php/jrp/article/view/510/412">respect and reverence for life</a>. </p>
<figure class="align-left ">
<img alt="" src="https://images.theconversation.com/files/294944/original/file-20191001-173375-1gcn3ba.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/294944/original/file-20191001-173375-1gcn3ba.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=913&fit=crop&dpr=1 600w, https://images.theconversation.com/files/294944/original/file-20191001-173375-1gcn3ba.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=913&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/294944/original/file-20191001-173375-1gcn3ba.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=913&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/294944/original/file-20191001-173375-1gcn3ba.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1147&fit=crop&dpr=1 754w, https://images.theconversation.com/files/294944/original/file-20191001-173375-1gcn3ba.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1147&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/294944/original/file-20191001-173375-1gcn3ba.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1147&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">‘The Flip’ by Jeffrey J. Kripal.</span>
<span class="attribution"><span class="source">(Bellevue Literary Press)</span></span>
</figcaption>
</figure>
<p>Jeffrey Kripal, chair in philosophy and religious thought at Rice University, in Texas, argues for shifting our consciousness by rethinking how knowledge is produced and reintegrating humanities with the social and traditional sciences. </p>
<p>Kripal observes that much of the global ecological crisis “is driven by the rules of the game we play at this moment … <a href="https://blpress.org/books/the-flip/">and forms of knowledge that cannot be slotted into … austere rules … and (the) fetishization of quantity</a>.”</p>
<p>His slim 2019 volume <em>The Flip — Epiphanies of Mind and the Future of Knowledge</em>, was described as “mindblowing” by American journalist Michael Pollan. Pollan authored <em><a href="https://www.penguinrandomhouse.com/books/529343/how-to-change-your-mind-by-michael-pollan/">How to Change Your Mind: What the New Science of Psychedelics Teaches Us About Consciousness, Dying, Addiction, Depression and Transcendence</a></em>. </p>
<p>Embracing multiple ways of knowing through education and research is important among the many new approaches we’ll need to honestly and respectfully face and care for the children and youth of the world — and to imagine a collective future. </p>
<p>[ <em>Like what you’ve read? Want more?</em> <a href="https://theconversation.com/ca/newsletters?utm_source=TCCA&utm_medium=inline-link&utm_campaign=newsletter-text&utm_content=likethis">Sign up for The Conversation’s daily newsletter</a>. ]</p><img src="https://counter.theconversation.com/content/121549/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Richard C. Mitchell does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>To protect the futures of today’s children and youth, schools and universities must go beyond Eurocentric approaches that dissect particulars yet miss the larger point.Richard C. Mitchell, Professor, Child and Youth Studies, Brock UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1231152019-09-12T12:52:23Z2019-09-12T12:52:23ZQuantum computers could arrive sooner if we build them with traditional silicon technology<figure><img src="https://images.theconversation.com/files/292222/original/file-20190912-190002-1qou69y.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-illustration/3d-render-quantum-processor-1015677370?src=kwTkio1WBdTyeFGIocGfCQ-1-2">Amin Van/Shutterstoc</a></span></figcaption></figure><p><a href="https://theconversation.com/explainer-quantum-computation-and-communication-technology-7892">Quantum computers</a> have the potential to revolutionise the way we solve hard computing problems, from creating <a href="https://theconversation.com/quantum-computer-were-planning-to-create-one-that-acts-like-a-brain-108716">advanced artificial intelligence</a> to simulating chemical reactions in order to create the next generation of <a href="https://www.technologyreview.com/s/603794/chemists-are-first-in-line-for-quantum-computings-benefits/">materials or drugs</a>. But actually building such machines is very difficult because they involve <a href="https://www.technologyreview.com/s/612760/quantum-computers-component-shortage/">exotic components</a> and have to be kept in highly controlled environments. And the ones we have so far can’t outperform traditional machines as yet. </p>
<p>But with a team of researchers from the UK and France, <a href="https://www.nature.com/articles/s41928-019-0259-5">we have demonstrated</a> that it may well be possible to build a quantum computer from conventional silicon-based electronic components. This could pave the way for large-scale manufacturing of quantum computers much sooner than might otherwise be possible.</p>
<p>The theoretical superior power of quantum computers derives from the laws of nanoscale or <a href="https://theconversation.com/explainer-quantum-physics-570">“quantum” physics</a>. Unlike conventional computers, which store information in binary bits that can be either “0” or “1”, quantum computers use quantum bits (or qubits) that could be in a combination of “0” and “1” at the same time. This is because quantum physics allows particles to be in different states or places simultaneously.</p>
<p>Quantum computer development is still in its infancy and several hardware technologies are available without any single one yet dominating. The most advanced prototypes are currently made from either a few dozen <a href="https://theconversation.com/compute-this-the-quantum-future-is-crystal-clear-6671">ions trapped in a vacuum chamber</a> or <a href="https://theconversation.com/nevens-law-why-it-might-be-too-soon-for-a-moores-law-for-quantum-computers-120706">superconducting circuits</a> kept at near-absolute-zero temperature.</p>
<p>The crucial challenge is scaling up these small demonstrators into large interconnected qubit systems that will have enough computing power to perform useful tasks faster than classical supercomputers. To this end, another technology may eventually turn out to be more suitable. Strikingly enough, this could be the very same technology that today enables our digital society, the silicon transistor, the basic unit of information present in all microprocessors and memory chips.</p>
<p>There are two main reasons why making a quantum computer out of silicon has an aura of great interest around it. First, the <a href="https://theconversation.com/moores-law-is-50-years-old-but-will-it-continue-44511">Moore’s Law</a>-led relentless miniaturisation of silicon devices has enabled the manufacturing of transistors that are only a few tens of atoms wide. This is the scale at which the laws of quantum physics start to apply.</p>
<p>This represents a physical limit that has brought any further miniaturisation of silicon transistors to a halt. But it has also promoted new uses of silicon technology, known as <a href="https://spectrum.ieee.org/video/semiconductors/nanotechnology/how-will-we-go-beyond-moores-law-experts-weigh-in">More-than-Moore electronics</a>. Chief among these new directions is the possibility of encoding a <a href="https://theconversation.com/quantum-computing-poised-for-new-silicon-revolution-32800">quantum bit of information in each silicon transistor</a>, and then using them to build large-scale quantum computers.</p>
<p>By reusing the same technology that the microchip industry has handled for the past 60 years, we could also take advantage of previous multi-billion-dollar infrastructural investments and reduce costs. This means that all the clever engineering and processing that went into the development of modern microelectronics could be adapted to build increasingly powerful quantum processors.</p>
<h2>Silicon quantum chip</h2>
<p>The experiments recently carried out by our collaborating teams at Cambridge University, Hitachi R&D, University College London and CEA-LETI in France, and published in <a href="https://www.nature.com/articles/s41928-019-0259-5">Nature Electronics</a> suggest that this marriage between conventional and quantum electronics can be indeed celebrated. We took engineering solutions from conventional silicon circuits and applied them to interconnect different quantum devices on a chip. This has brought the practical realisation of quantum processors one step closer.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/te_tdvKaMYo?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
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<p>We have developed a circuit that operates at near-absolute-zero temperature and employs all commercial transistors. Some of these are so small that they can be used as qubits, whereas others are slightly larger and can be used to connect to different qubits. This architecture is remarkably similar to the one used for random access memory (RAM) in today’s laptops and smartphones.</p>
<p>In the past half a century or so, ordinary computers evolved from room-sized cabinets full of vacuum tubes to today’s hand-held microchip-based devices. There is still a long way to go before a fully-fledged quantum computer becomes available, but history may well repeat itself. The current progress of research suggests that initial quantum processors may be realised with some exotic technology first. But now that we have learnt that silicon can be used to efficiently interconnect qubits, the quantum future could be made of silicon.</p><img src="https://counter.theconversation.com/content/123115/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Alessandro Rossi receives funding from the UKRI Industrial Strategy Challenge Fund through the Measurement Fellowship Scheme at the National Physical Laboratory. He also holds a Chancellor's Fellowship at the University of Strathclyde.</span></em></p><p class="fine-print"><em><span>M. Fernando Gonzalez-Zalba receives funding from the European Commission H2020 Programme, the Royal Society and the Winton Programme for the Physics of Sustainability . </span></em></p>Manufacturing quantum computers would be a lot easier with existing technology than the exotic components currently used to build them.Alessandro Rossi, Chancellor's Fellow, Department of Physics, University of Strathclyde M. Fernando Gonzalez-Zalba, Honorary Research Fellow, University of CambridgeLicensed as Creative Commons – attribution, no derivatives.