tag:theconversation.com,2011:/africa/topics/theory-of-everything-5831/articlesTheory of Everything – The Conversation2024-03-03T19:19:44Ztag: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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<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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<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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<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/2030102023-05-15T15:43:17Z2023-05-15T15:43:17ZTheory of everything: how progress in physics depends on asking the right questions<figure><img src="https://images.theconversation.com/files/524343/original/file-20230504-29-15yttd.jpg?ixlib=rb-1.1.0&rect=152%2C197%2C5838%2C5793&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Calabi-Yau manifold: a proposed structure of extra dimensions of space in string theory. </span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-illustration/calabiyau-manifold-structure-extra-dimensions-space-1228700050">vchal/Shutterstock</a></span></figcaption></figure><iframe src="https://embed.acast.com/638f4b009a65b10011b94c5e/64353c62de066f001110361d" frameborder="0" width="100%" height="190px"></iframe>
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<p>When I began my undergraduate physics degree (around 20 years ago), “What is the <a href="https://theconversation.com/great-mysteries-of-physics-do-we-really-need-a-theory-of-everything-203534">theory of everything</a>?” was a question that I heard often. It was used as a label for how theoretical physicists were trying to develop a deeper understanding of the elementary building blocks of our universe and the forces that govern their dynamics.</p>
<p>But is it a good question? Is it helpful in guiding scientists towards the discoveries that will advance our understanding to the next level? After all, good science relies on asking good questions. Or is it just <a href="https://bigthink.com/starts-with-a-bang/theories-of-everything/">“wishful thinking”</a>?</p>
<p>Arguably, the question “What is the theory of everything?” reminds us that good science doesn’t have to start with the best questions. Let me explain what I mean.</p>
<p>Suppose we play a game. I have a deck of cards, and each card is printed with the name and a photograph of a different animal. I choose a card, and your job is to ask questions to find out which animal I have chosen. Of course, to ask a discerning question, you first need to know something about animals.</p>
<p>The first time you play, you may not be familiar with which animals are in the deck, and your first question is “Does it live in the sea?”. My answer is “No,” and the game continues. Then it is your turn to pick a card. You look carefully through the deck to make your choice, and you realise that it only contains land animals. “Does it live in the sea?” seemed like a good question to start with, but it was not.</p>
<p>We take turns, and the more we play, the quicker we seem to figure out which card has been chosen. Why? We have become better at asking good questions.</p>
<p>The role that questions play in scientific research is similar. We start from some level of understanding, and we ask questions based on that level of understanding to try to improve it. As our understanding builds, we refine our questions and get more insightful answers.</p>
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<img alt="" src="https://images.theconversation.com/files/513939/original/file-20230307-20-pgea9d.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/513939/original/file-20230307-20-pgea9d.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/513939/original/file-20230307-20-pgea9d.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/513939/original/file-20230307-20-pgea9d.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/513939/original/file-20230307-20-pgea9d.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/513939/original/file-20230307-20-pgea9d.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/513939/original/file-20230307-20-pgea9d.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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<p><em>This is article is accompanied by a podcast series called <a href="https://podfollow.com/great-mysteries-of-physics">Great Mysteries of Physics</a> which uncovers the greatest mysteries facing physicists today – and discusses the radical proposals for solving them.</em></p>
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<p>This is how progress is made. The same is true of asking “What is the theory of everything?”: the goodness of a scientific question is not immutable.</p>
<h2>Why a ‘theory of everything’?</h2>
<p>The <a href="https://home.cern/tags/standard-model#:%7E:text=The%20Standard%20Model%20of%20particle,of%20scientists%20around%20the%20world.">Standard Model of Particle Physics</a>, one <a href="https://theconversation.com/the-standard-model-of-particle-physics-may-be-broken-an-expert-explains-182081">of the pillars of modern science</a>, is a success of reductionism - the idea that things can be explained by breaking them down into smaller parts.</p>
<p>The model, which is written in a mathematical language called <a href="https://www.damtp.cam.ac.uk/user/tong/whatisqft.html">quantum field theory</a>, describes how elementary particles move around and interact with one another. It explains the nature of three out of four of the known fundamental forces: electromagnetism, and the weak and strong forces that govern processes on subatomic scales. It does not include gravity, the fourth force.</p>
<p>The model accounts for <a href="https://theconversation.com/great-mysteries-of-physics-4-does-objective-reality-exist-202550">quantum mechanics</a>, which describes the probabilistic nature of the dynamics of subatomic particles, and Einstein’s special theory of relativity, which describes what happens when relative speeds are close to the speed of light – no small achievement.</p>
<p>The assumption in asking “What is the theory of everything?” is that the Standard Model will one day be found to be embedded within a larger structure (with more elemental ingredients) that provides us with a unified explanation of the fundamental forces including gravity. Gravity, in fact, is this question’s ultimate focus. </p>
<p>But the question “What is the theory of everything?” gives very little guidance as to what such a theory of everything might look like. We need some better questions.</p>
<p>Now, there are good reasons to expect that such a unified explanation of the fundamental forces might exist: the Standard Model includes the celebrated Higgs mechanism, from which the <a href="https://theconversation.com/higgs-boson-ten-years-after-its-discovery-why-this-particle-could-unlock-new-physics-beyond-the-standard-model-186076">Higgs boson</a> arises. It explains why fundamental particles known as the W and Z bosons, which transmit the weak force, acquire a mass. It also explains why the photon, which transmits the electromagnetic force, does not.</p>
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<img alt="CMS experiment at Cern." src="https://images.theconversation.com/files/524347/original/file-20230504-17-wd6j6c.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/524347/original/file-20230504-17-wd6j6c.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=393&fit=crop&dpr=1 600w, https://images.theconversation.com/files/524347/original/file-20230504-17-wd6j6c.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=393&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/524347/original/file-20230504-17-wd6j6c.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=393&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/524347/original/file-20230504-17-wd6j6c.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=494&fit=crop&dpr=1 754w, https://images.theconversation.com/files/524347/original/file-20230504-17-wd6j6c.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=494&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/524347/original/file-20230504-17-wd6j6c.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=494&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">CMS experiment at Cern.</span>
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<p>As a result, electromagnetism and the weak force, which is involved in the nuclear fusion that powers stars, behave differently at low energies: the electromagnetic force acts over very large distances, whereas the weak force acts only over very short distances. The Higgs mechanism also explains why, at higher energies, these two forces start to behave as a single “electroweak” force. This is called electroweak unification.</p>
<p>Now, if electromagnetism and the weak force combine in this way, why not all the forces in the Standard Model? Unifying these two with the strong force, the force that holds the ingredients of atomic nuclei together, is the aim of grand unified theories. Theoretical ideas such as <a href="https://home.cern/science/physics/supersymmetry">supersymmetry</a>, which postulates a symmetry between force carriers and matter particles, suggest that <a href="https://bigthink.com/starts-with-a-bang/theories-of-everything/">the strength of these three forces could get tantalisingly close at high enough energies</a>.</p>
<p>And if the electromagnetic, weak and strong forces turn out to be unified, why not gravity, too?</p>
<p>Gravity is described by <a href="https://theconversation.com/how-einsteins-general-theory-of-relativity-killed-off-common-sense-physics-50042">Einstein’s General Theory of Relativity</a>, which applies on large scales or at low energies. But if we want a consistent quantum theory of gravity that applies on the smallest scales, quantum field theory isn’t enough. We need mathematical frameworks that can consistently incorporate both general relativity and quantum mechanics.</p>
<p>The “everything” in a “theory of everything” refers to all the known forces of nature: electromagnetism, the weak force, the strong force, and gravity (and new, <a href="https://theconversation.com/new-physics-latest-results-from-cern-further-boost-tantalising-evidence-170133">hypothetical forces</a>, too) and the particles that they act between. The “theory” refers to the existence of some common mathematical framework that describes all of the “everything”.</p>
<p>One such common mathematical framework is <a href="https://theconversation.com/stephen-hawking-had-pinned-his-hopes-on-m-theory-to-fully-explain-the-universe-heres-what-it-is-93440">string theory</a>, which supposes that the most fundamental building blocks of the universe are tiny strings that vibrate in extra spatial dimensions beyond the three of our everyday experience. </p>
<h2>Better questions</h2>
<p>Questions are the guide to scientific inquiry. The question “What is the theory of everything?” only speculates at a destination, but it gives very little direction.</p>
<p>Frameworks such as supersymmetry and string theory were not developed to answer the question “What is the theory of everything?” directly. They were motivated by better questions about what a theory of all the fundamental forces needs to explain and what it might look like, questions like: Why is there a huge discrepancy between the energy scales of the Standard Model and quantum gravity? Why do quantum mechanics and general relativity seem to be incompatible?</p>
<p>But the “whys” that theoretical physicists ask develop as our understanding develops, and the questions that we are now posing are getting us even closer than ever to an understanding of all the known forces of nature. </p>
<p>These new “whys” hint at <a href="https://doi.org/10.48550/arXiv.2006.06872">remarkable connections between very different areas of physics and mathematics</a>: Why does the physics of holograms seem to help us to understand gravity? Why does this seem to be connected to the properties of large collections of random numbers? Why do the rules of quantum information seem to explain the physics of black holes?</p>
<p>But this is not a case of “out with the old and in with the new”. Instead, these new questions have been reached by building on what has been learnt from developing and studying possible “Theories of Everything”, like string theory.</p>
<p>And these new questions are good questions. The exciting thing is that they still may not be the best questions, and having them to guide us doesn’t necessarily mean that we know where we will end up. That is what scientific discovery is all about.</p>
<p><em>You can listen to Great Mysteries of Physics via any of the apps listed above, our <a href="https://feeds.acast.com/public/shows/638f4b009a65b10011b94c5e">RSS feed</a>, or find out how else to listen here. You can also read a <a href="https://cdn.theconversation.com/static_files/files/2634/MoP__Ep6_-_Theory_of_Everything_TRANSCRIPT.docx.pdf?1681292977">transcript of the episode here</a>.</em></p><img src="https://counter.theconversation.com/content/203010/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Peter Millington is a Senior Research Fellow in the Particle Theory Group at the University of Manchester, UK, where he holds a UK Research and Innovation Future Leaders Fellowship and a Royal Society International Exchanges Grant. Peter Millington is a Member of the Institute of Physics, UK and serves on the Institute of Physics High Energy Particle Physics Group Committee.</span></em></p>Good questions guide good science, but that doesn’t mean we know where we’ll end up.Peter Millington, Senior Research Fellow and UKRI Future Leaders Fellow in the Particle Theory Group, Department of Physics and Astronomy, University of ManchesterLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2035342023-04-12T10:17:57Z2023-04-12T10:17:57ZGreat Mysteries of Physics: do we really need a theory of everything?<figure><img src="https://images.theconversation.com/files/520260/original/file-20230411-16-7sokyy.jpg?ixlib=rb-1.1.0&rect=57%2C44%2C4173%2C1911&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Particle physics has failed to find some of the evidence physicists were hoping for.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/switzerland-april-2010-cern-european-organization-1287557629">D-Visions/Shutterstock</a></span></figcaption></figure><iframe src="https://embed.acast.com/638f4b009a65b10011b94c5e/64353c62de066f001110361d" frameborder="0" width="100%" height="190px"></iframe>
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<p>Finding a theory of everything – explaining all the forces and particles in the universe – is arguably the holy grail of physics. While each of its main theories works extraordinarily well, they clash also with each other – leaving physicists to search for a deeper, more fundamental theory.</p>
<p>But do we really need a theory of everything? And are we anywhere near achieving one? That’s what we discuss in the sixth and final episode of our Great Mysteries of Physics podcast – hosted by me, Miriam Frankel, science editor at The Conversation, and supported by FQxI, the Foundational Questions Institute.</p>
<p>Our two best theories of nature are <a href="https://theconversation.com/great-mysteries-of-physics-4-does-objective-reality-exist-202550">quantum mechanics</a> and general relativity, describing the smallest and biggest scales of the universe, respectively. Each is tremendously successful and has been experimentally tested over and over. The trouble is, they are incompatible with one another in many ways – including mathematically.</p>
<p>“General relativity is all about geometry. It’s how space is curved and how space-time – this unified entity that contains three dimensions of space and one dimension of time – is itself also curved,” explains Vlatko Vedral, a professor of physics at Oxford University in the UK. “Quantum physics is actually all about algebra.”</p>
<p>Physicists have already managed to unite quantum theory with Einstein’s other big theory: special relativity (explaining how speed affects mass, time and space). Together, these form a framework called “quantum field theory”, which is the basis for the <a href="https://theconversation.com/the-standard-model-of-particle-physics-may-be-broken-an-expert-explains-182081">Standard Model of Particle Physics</a> – our best framework for describing the most basic building blocks of the universe. </p>
<p>The standard model describes three out of the four fundamental forces in the universe – electromagnetism, and the “strong” and “weak” forces which govern the atomic nucleus – excluding gravity. </p>
<p>While the standard model explains most of what we see in particle physics experiments, there are a few gaps. To bridge these, an extension called “<a href="https://home.cern/science/physics/supersymmetry#:%7E:text=Supersymmetry%20is%20an%20extension%20of,mass%20of%20the%20Higgs%20boson.">supersymmetry</a>”, suggesting particles are connected through a deep relationship, has been proposed. Supersymmetry suggests each particle has a “super partner” with the same mass, but opposite spin. Unfortunately, particle accelerators such as the Large Hadron Collider (LHC) at Cern in Switzerland have failed to find evidence of supersymmetry – despite being explicitly designed to do so.</p>
<p>On the other hand, there are recent hints from both <a href="https://theconversation.com/new-physics-latest-results-from-cern-further-boost-tantalising-evidence-170133">LHC</a> and <a href="https://theconversation.com/how-we-found-hints-of-new-particles-or-forces-of-nature-and-why-it-could-change-physics-158564">Fermilab</a> in the US suggesting that there may be a fifth force of nature. If these results could be replicated and confirmed as actual discoveries, that would have implications for uniting quantum mechanics and gravity.</p>
<p>“I think [the discovery of a new force] would be amazing,” says Vedral. “It would challenge this thing that that has now existed for well over half a century that there are four fundamental forces”. </p>
<p>Vedral argues the first thing to do if we discovered a fifth force would be to establish whether it can be described by quantum mechanics.</p>
<p>If it could, it would indicate that quantum theory might ultimately be more fundamental than general relativity, accounting for four out of five forces – suggesting general relativity ultimately may need to be modified. If it couldn’t, that would shake up physics – suggesting we may need to modify quantum mechanics, too.</p>
<h2>What about other mysterious properties?</h2>
<p>But what should a theory of everything include? Would it be enough to unite gravity and quantum mechanics? And what about other mysterious properties such as dark energy, which causes the universe to expand at an accelerated rate, or dark matter, an invisible substance making up most of the matter in the universe? </p>
<p>As Chanda Prescod-Weinstein, an assistant professor in physics and astronomy at the University of New Hampshire in the US, explains, physicists prefer to use the term “theory of quantum gravity” over “theory of everything”. </p>
<p>“Dark matter and dark energy are most of the matter energy content in the universe. So it’s not really a theory of everything if it’s not accounting for most of the matter energy content in the universe,” she argues. “This is why I’m glad we don’t actually use ‘theory of everything’ in our work.”</p>
<p>Although they might not explain everything, several proposed theories of quantum gravity exist. One is string theory, which suggests the universe is ultimately made up of tiny, vibrating strings. Another is loop quantum gravity, which suggests Einstein’s space-time arises from quantum effects.</p>
<p>“One of the strengths that people will point to with string theory is that string theory built on quantum field theory,” explains Prescod-Weinstein. “It brings the whole standard model with it, which loop quantum gravity doesn’t do in the same way.” But string theory also has its weaknesses, she argues, such as requiring extra dimensions that we’ve never seen any evidence of.</p>
<p>The theories are difficult to test experimentally – requiring much more energy than we can produce in any laboratory. Vedral argues that while we ultimately can’t directly probe the tiny scales needed to find evidence for theories of quantum gravity, it may be possible to amplify such effects so that we could indirectly observe them on larger scales with table-top experiments.</p>
<p><em>You can listen to Great Mysteries of Physics via any of the apps listed above, our <a href="https://feeds.acast.com/public/shows/638f4b009a65b10011b94c5e">RSS feed</a>, or find out how else to listen here. You can also read a <a href="https://cdn.theconversation.com/static_files/files/2634/MoP__Ep6_-_Theory_of_Everything_TRANSCRIPT.docx.pdf?1681292977">transcript of the episode here</a>.</em></p><img src="https://counter.theconversation.com/content/203534/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Vlatko Vedral has had funding from The Templeton and the Moore Foundations. Chanda Prescod-Weinstein has had funding from the NSF, DoE, NASA, FQxI and Heising-Simons Foundation. She is a member of the American Physical Society, American Astronomical Society, FQxI, NASEM Elementary Particle Physics: Progress and Promise Committee
</span></em></p>Our two best theories of nature, quantum mechanics and general relativity, are incompatible with each other in many ways – leaving physicists to dig deeper.Miriam Frankel, Podcast host, The ConversationLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1248192019-10-11T09:27:47Z2019-10-11T09:27:47ZHuman intelligence: have we reached the limit of knowledge?<figure><img src="https://images.theconversation.com/files/295858/original/file-20191007-121083-zvv8xp.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/man-lighting-badwater-basin-night-under-537260542?src=4Ek8jOc5M0tsQXzq7dcq6Q-1-12">Mike Ver Sprill/Shutterstock</a></span></figcaption></figure><p>Despite huge advances in science over the past century, our understanding of nature is still far from complete. Not only have scientists failed to find the Holy Grail of physics – unifying <a href="https://theconversation.com/will-we-have-to-rewrite-einsteins-theory-of-general-relativity-50057">the very large</a> (general relativity) with <a href="https://theconversation.com/physicists-prove-quantum-spookiness-and-start-chasing-schrodingers-cat-48190">the very small</a> (quantum mechanics) – they still don’t know what the <a href="https://theconversation.com/the-search-for-dark-matter-and-dark-energy-just-got-interesting-46422">vast majority of the universe</a> is made up of. The <a href="https://theconversation.com/stephen-hawking-had-pinned-his-hopes-on-m-theory-to-fully-explain-the-universe-heres-what-it-is-93440">sought after</a> Theory of Everything continues to elude us. And there are other outstanding puzzles, too, such as how consciousness arises from mere matter. </p>
<p>Will science ever be able to provide all the answers? Human brains are the product of blind and unguided evolution. They were designed to solve practical problems impinging on our survival and reproduction, not to unravel the fabric of the universe. This realisation has led some philosophers to embrace a <a href="https://en.wikipedia.org/wiki/New_mysterianism">curious form of pessimism</a>, arguing there are bound to be things we will never understand. Human science will therefore one day hit a hard limit – and may already have done so.</p>
<p>Some questions may be doomed to remain what the American linguist and philosopher <a href="https://linguistics.arizona.edu/user/noam-chomsky">Noam Chomsky</a> <a href="https://www.abc.net.au/radionational/programs/philosopherszone/noam-chomsky-galileo-challenge-origin-of-language/7284178">called “mysteries”</a>. If you think that humans alone have unlimited cognitive powers – setting us apart from all other animals – you have not fully digested Darwin’s insight that <em>Homo Sapiens</em> is very much part of the natural world. </p>
<p>But does this argument really hold up? Consider that human brains did not evolve to discover their own origins either. And yet somehow we managed to do just that. Perhaps the pessimists are missing something.</p>
<h2>Mysterian arguments</h2>
<p><a href="https://observer.com/2000/10/the-mysterian-manifesto-shakespeare-mcginn-and-me/">“Mysterian” thinkers</a> give a prominent role to biological arguments and analogies. In his 1983 landmark book <a href="https://plato.stanford.edu/entries/modularity-mind/">The Modularity of Mind</a>, the late philosopher <a href="https://www.theguardian.com/books/2017/dec/06/jerry-fodor-obituary">Jerry Fodor</a> claimed that there are bound to be “thoughts that we are unequipped to think”.</p>
<p>Similarly, the philosopher <a href="https://en.wikipedia.org/wiki/Colin_McGinn">Colin McGinn</a> has argued in a series of <a href="https://books.google.be/books?id=6vTJtAEACAAJ&dq=McGinn+The+mysterious+flame:+Conscious+minds+in+a+material+world.+Basic+Books.&hl=nl&sa=X&ved=0ahUKEwi8vYHhqI_lAhUEKuwKHVYVBOsQ6AEILDAA">books</a> and <a href="https://link.springer.com/article/10.1007%2FBF00989821?LI=true">articles</a> that all minds suffer from “cognitive closure” with respect to certain problems. Just as dogs or cats will never understand prime numbers, human brains must be closed off from some of the world’s wonders. McGinn suspects that the reason why philosophical conundrums such as the mind/body problem – how physical processes in our brain give rise to consciousness – prove to be intractable is that their true solutions are simply inaccessible to the human mind.</p>
<p>If McGinn is right that our brains are simply not equipped to solve certain problems, there is no point in even trying, as they will continue to baffle and bewilder us. McGinn himself is convinced that there is, in fact, a perfectly natural solution to the mind–body problem, but that human brains will never find it.</p>
<p>Even the psychologist <a href="https://en.wikipedia.org/wiki/Steven_Pinker">Steven Pinker</a>, someone who is often accused of scientific <a href="https://newrepublic.com/article/114548/leon-wieseltier-responds-steven-pinkers-scientism">hubris himself</a>, is sympathetic to the argument of the mysterians. If our ancestors had no need to understand the wider cosmos in order to spread their genes, <a href="https://books.google.be/books?id=5cXKQUh6bVQC&lpg=PA563&ots=4RwlE3iV0S&dq=%E2%80%9Cif%20the%20mind%20is%20a%20system%20of%20organs%20designed%20by%20natural%20selection%2C%20why%20should%20we%20ever%20have%20expected%20it%20to%20comprehend%20all%20mysteries%2C%20to%20grasp%20all%20truths%3F%E2%80%9D&hl=nl&pg=PA563#v=onepage&q&f=false">he argues</a>, why would natural selection have given us the brainpower to do so? </p>
<h2>Mind-boggling theories</h2>
<p>Mysterians typically present the question of cognitive limits in stark, black-or-white terms: either we can solve a problem, or it will forever defy us. Either we have cognitive access or we suffer from closure. At some point, human inquiry will suddenly slam into a metaphorical brick wall, after which we will be forever condemned to stare in blank incomprehension.</p>
<p>Another possibility, however, which mysterians often overlook, is one of slowly diminishing returns. Reaching the limits of inquiry might feel less like hitting a wall than getting bogged down in a quagmire. We keep slowing down, even as we exert more and more effort, and yet there is no discrete point beyond which any further progress at all becomes impossible. </p>
<p>There is another ambiguity in the thesis of the mysterians, which my colleague <a href="https://www.michaelvlerick.com/">Michael Vlerick</a> and I <a href="https://theconversation.com/particle-physics-discovery-raises-hope-for-a-theory-of-everything-41778">have pointed out</a> in an academic paper. Are the mysterians claiming that we will never find the true scientific theory of some aspect of reality, or alternatively, that we may well find this theory but will never truly comprehend it?</p>
<p>In the science fiction series <a href="https://www.theguardian.com/tv-and-radio/2018/feb/27/the-hitchhikers-guide-to-the-galaxy-bbc-radio-4">The Hitchhiker’s Guide to The Galaxy</a>, an alien civilisation builds a massive supercomputer to calculate the Answer to the Ultimate Question of Life, the Universe and Everything. When the computer finally announces that the answer is “42”, no one has a clue what this means (in fact, they go on to construct an even bigger supercomputer to figure out precisely this).</p>
<p>Is a question still a “mystery” if you have arrived at the correct answer, but you have no idea what it means or cannot wrap your head around it? Mysterians often conflate those two possibilities. </p>
<p>In some places, McGinn suggests that the mind–body problem is inaccessible to human science, presumably meaning that we will never find the true scientific theory describing the mind–body nexus. At other moments, however, he <a href="https://philpapers.org/rec/MCGPIP-3">writes</a> that the problem will always remain “numbingly difficult to make sense of” for human beings, and that “the head spins in theoretical disarray” when we try to think about it.</p>
<p>This suggests that we may well arrive at the true scientific theory, but it will have a 42-like quality to it. But then again, some people would argue that this is already true of a theory like quantum mechanics. Even the quantum physicist <a href="https://bouman.chem.georgetown.edu/general/feynman.html">Richard Feynman admitted</a>, “I think I can safely say that nobody understands quantum mechanics.” </p>
<p>Would the mysterians say that we humans are “cognitively closed” to the quantum world? According to quantum mechanics, particles can be in two places at once, or randomly pop out of empty space. While this is extremely hard to make sense of, quantum theory leads to incredibly accurate predictions. The phenomena of “quantum weirdness” have been confirmed by several <a href="https://theconversation.com/quantum-weirdness-passes-the-atomic-walk-test-37495">experimental tests</a>, and scientists are now also creating <a href="https://theconversation.com/scientists-discover-how-to-harness-the-power-of-quantum-spookiness-by-entangling-clouds-of-atoms-95612">applications based on the theory</a>. </p>
<p>Mysterians also tend to forget how mindboggling some earlier scientific theories and concepts were when initially proposed. Nothing in our cognitive make-up prepared us for relativity theory, evolutionary biology or heliocentrism. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/296177/original/file-20191009-3872-12d1m5r.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/296177/original/file-20191009-3872-12d1m5r.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/296177/original/file-20191009-3872-12d1m5r.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/296177/original/file-20191009-3872-12d1m5r.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/296177/original/file-20191009-3872-12d1m5r.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/296177/original/file-20191009-3872-12d1m5r.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/296177/original/file-20191009-3872-12d1m5r.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">Are we cognitively closed to cosmology?</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-illustration/abstract-artistic-3d-illustration-digital-modern-1319265665?src=FhxMADK5LvK9VbWiwcDhxg-2-18">Mohamed Ali Elmeshad/Shutterstock</a></span>
</figcaption>
</figure>
<p>As the philosopher <a href="http://www.robertmccauley.com/">Robert McCauley</a> <a href="https://scholarblogs.emory.edu/robertnmccauley/files/2013/12/Naturalness-of-Religion.pdf">writes</a>: “When first advanced, the suggestions that the Earth moves, that microscopic organisms can kill human beings, and that solid objects are mostly empty space were no less contrary to intuition and common sense than the most counterintuitive consequences of quantum mechanics have proved for us in the twentieth century.” McCauley’s astute observation provides reason for optimism, not pessimism.</p>
<h2>Mind extensions</h2>
<p>But can our puny brains really answer all conceivable questions and understand all problems? This depends on whether we are talking about bare, unaided brains or not. There’s a lot of things you can’t do with your naked brain. But <em>Homo Sapiens</em> is a tool-making species, and this includes a range of cognitive tools. </p>
<p>For example, our unaided sense organs cannot detect UV-light, ultrasound waves, X-rays or gravitational waves. But if you’re equipped with some fancy technology you <em>can</em> detect all those things. To overcome our perceptual limitations, scientists have developed a suite of tools and techniques: microscopes, X-ray film, Geiger counters, radio satellites detectors and so forth. </p>
<p>All these devices extend the reach of our minds by “translating” physical processes into some format that our sense organs can digest. So are we perceptually “closed” to UV light? In one sense, yes. But not if you take into account all our technological equipment and measuring devices. </p>
<p>In a similar way, we use physical objects (such as paper and pencil) to vastly increase the memory capacity of our naked brains. According to the British philosopher <a href="http://www.sussex.ac.uk/profiles/493">Andy Clark</a>, our minds quite literally <a href="https://www.newyorker.com/magazine/2018/04/02/the-mind-expanding-ideas-of-andy-clark">extend</a> beyond our skins and skulls, in the form of notebooks, computers screens, maps and file drawers.</p>
<p>Mathematics is another fantastic mind-extension technology, which enables us to represent concepts that we couldn’t think of with our bare brains. For instance, no scientist could hope to form a mental representation of all the complex interlocking processes that make up our climate system. That’s exactly why we have constructed mathematical models and computers to do the heavy lifting for us.</p>
<h2>Cumulative knowledge</h2>
<p>Most importantly, we can extend our own minds to those of our fellow human beings. What makes our species unique is that we are capable of culture, in particular cumulative cultural knowledge. A population of human brains is much smarter than any individual brain in isolation.</p>
<p>And the collaborative enterprise par excellence is science. It goes without saying that no single scientist would be capable of unravelling the mysteries of the cosmos on her own. But collectively, they do. As Isaac Newton wrote, he could see further by “standing on the shoulders of giants”. By collaborating with their peers, scientists can extend the scope of their understanding, achieving much more than any of them would be capable of individually. </p>
<p>Today, fewer and fewer people understand what is going on at the cutting edge of theoretical physics – even physicists. The unification of quantum mechanics and relativity theory will undoubtedly be exceptionally daunting, or else scientists would have nailed it long ago already.</p>
<p>The same is true for our understanding of how the human brain gives rise to consciousness, meaning and intentionality. But is there any good reason to suppose that these problems will forever remain out of reach? Or that our sense of bafflement when thinking of them will never diminish? </p>
<p>In a <a href="https://www.youtube.com/watch?v=9tH3AnYyAI8&t=20s">public debate</a> I moderated a few years ago, the philosopher <a href="https://ase.tufts.edu/cogstud/dennett/">Daniel Dennett</a> pointed out a very simple objection to the mysterians’ analogies with the minds of other animals: other animals cannot even understand the questions. Not only will a dog never figure out if there’s a largest prime, but it will never even understand the question. By contrast, human beings can pose questions to each other and to themselves, reflect on these questions, and in doing so come up with ever better and more refined versions.</p>
<p>Mysterians are inviting us to imagine the existence of a class of questions that are themselves perfectly comprehensible to humans, but the answers to which will forever remain out of reach. Is this notion really plausible (or even coherent)?</p>
<h2>Alien anthropologists</h2>
<figure class="align-right ">
<img alt="" src="https://images.theconversation.com/files/296428/original/file-20191010-188783-ivkx4v.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/296428/original/file-20191010-188783-ivkx4v.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/296428/original/file-20191010-188783-ivkx4v.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/296428/original/file-20191010-188783-ivkx4v.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/296428/original/file-20191010-188783-ivkx4v.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/296428/original/file-20191010-188783-ivkx4v.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/296428/original/file-20191010-188783-ivkx4v.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">‘Simpletons.’</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/3d-rendered-illustration-humanoid-alien-1176861685?src=V8Ly21Y6xZlwII6yBz3tiQ-1-0">Sebastian Kaulitzki/Shutterstock</a></span>
</figcaption>
</figure>
<p>To see how these arguments come together, let’s do a thought experiment. Imagine that some extraterrestrial “anthropologists” had visited our planet around 40,000 years ago to prepare a scientific report about the cognitive potential of our species. Would this strange, naked ape ever find out about the structure of its solar system, the curvature of space-time or even its own evolutionary origins?</p>
<p>At that moment in time, when our ancestors were living in small <a href="https://theconversation.com/why-our-ancestors-were-more-gender-equal-than-us-41902">bands of hunter-gatherers</a>, such an outcome may have seemed quite unlikely. Although humans possessed quite extensive knowledge about the animals and plants in their immediate environment, and knew enough about the physics of everyday objects to know their way around and come up with some clever tools, there was nothing resembling scientific activity. </p>
<p>There was no writing, no mathematics, no artificial devices for extending the range of our sense organs. As a consequence, almost all of the beliefs held by these people about the broader structure of the world were completely wrong. Human beings didn’t have a clue about the true causes of natural disaster, disease, heavenly bodies, the turn of the seasons or almost any other natural phenomenon. </p>
<p>Our extraterrestrial anthropologist might have reported the following: </p>
<blockquote>
<p>Evolution has equipped this upright, walking ape with primitive sense organs to pick up some information that is locally relevant to them, such as vibrations in the air (caused by nearby objects and persons) and electromagnetic waves within the 400-700 nanometer range, as well as certain larger molecules dispersed in their atmosphere. </p>
</blockquote>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/296180/original/file-20191009-3851-1qr22os.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/296180/original/file-20191009-3851-1qr22os.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=338&fit=crop&dpr=1 600w, https://images.theconversation.com/files/296180/original/file-20191009-3851-1qr22os.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=338&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/296180/original/file-20191009-3851-1qr22os.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=338&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/296180/original/file-20191009-3851-1qr22os.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=424&fit=crop&dpr=1 754w, https://images.theconversation.com/files/296180/original/file-20191009-3851-1qr22os.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=424&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/296180/original/file-20191009-3851-1qr22os.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">We’ve come a long way,.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-illustration/primitive-man-cave-164724497?src=V7BsG9_IQa5FYoBSR_r7Ew-1-61">iurii/Shuttestock</a></span>
</figcaption>
</figure>
<blockquote>
<p>However, these creatures are completely oblivious to anything that falls outside their narrow perceptual range. Moreover, they can’t even see most of the single-cell life forms in their own environment, because these are simply too small for their eyes to detect. Likewise, their brains have evolved to think about the behaviour of medium-sized objects (mostly solid) under conditions of low gravity.</p>
<p>None of these earthlings has ever escaped the gravitational field of their planet to experience weightlessness, or been artificially accelerated so as to experience stronger gravitational forces. They can’t even conceive of space-time curvature, since evolution has hard-wired zero-curvature geometry of space into their puny brains. </p>
<p>In conclusion, we’re sorry to report that most of the cosmos is simply beyond their ken.</p>
</blockquote>
<p>But those extraterrestrials would have been dead wrong. Biologically, we are no different than we were 40,000 years ago, but now we know about bacteria and viruses, DNA and molecules, supernovas and black holes, the full range of the electromagnetic spectrum and a wide array of other strange things. </p>
<p>We also know about non-Euclidean geometry and space-time curvature, courtesy of <a href="https://theconversation.com/how-einsteins-general-theory-of-relativity-killed-off-common-sense-physics-50042">Einstein’s general theory of relativity</a>. Our minds have “reached out” to objects millions of light years away from our planet, and also to extremely tiny objects far below the perceptual limits of our sense organs. By using various tricks and tools, humans have vastly extended their grasp on the world.</p>
<h2>The verdict: biology is not destiny</h2>
<p>The thought experiment above should be a counsel against pessimism about human knowledge. Who knows what other mind-extending devices we will hit upon to overcome our biological limitations? Biology is not destiny. If you look at what we have already accomplished in the span of a few centuries, any rash pronouncements about cognitive closure seem highly premature.</p>
<p>Mysterians often pay lip service to the values of “humility” and “modesty”, but on closer examination, their position is far less restrained than it appears. Take McGinn’s <a href="http://movies2.nytimes.com/books/first/m/mcginn-flame.html">confident pronouncement</a> that the mind–body problem is “an ultimate mystery” that we will “never unravel”. In making such a claim, McGinn assumes knowledge of three things: the nature of the mind–body problem itself, the structure of the human mind, and the reason why never the twain shall meet. But McGinn offers only a superficial overview of the science of human cognition, and pays little or no attention to the various devices for mind extension. </p>
<p>I think it’s time to turn the tables on the mysterians. If you claim that some problem will forever elude human understanding, you have to show in some detail why no possible combination of mind extension devices will bring us any closer to a solution. That is a taller order than most mysterians have acknowledged.</p>
<p>Moreover, by spelling out exactly why some problems will remain mysterious, mysterians risk being hoisted by their own petard. As Dennett wrote in his <a href="https://books.google.be/books?id=XuJoDQAAQBAJ&lpg=RA1-PR39&ots=51XeO_K_Rd&dq=%22As%20soon%20as%20you%20frame%20a%20question%20that%20you%20claim%20we%20will%22&hl=nl&pg=RA1-PR39#v=onepage&q&f=false">latest book</a>: “As soon as you frame a question that you claim we will never be able to answer, you set in motion the very process that might well prove you wrong: you raise a topic of investigation.” </p>
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<p>In one of his infamous memorandum notes on Iraq, former US secretary of defense, Donald Rumsfeld, <a href="https://en.wikipedia.org/wiki/There_are_known_knowns">makes a distinction</a> between two forms of ignorance: the “known unknowns” and “unknown unknowns”. In the first category belong the things that we know we don’t know. We can frame the right questions, but we haven’t found the answers yet. And then there are the things that “we don’t know we don’t know”. For these unknown unknowns, we can’t even frame the questions yet. </p>
<p>It is quite true that we can never rule out the possibility that there are such unknown unknowns, and that some of them will forever remain unknown, because for some (unknown) reason human intelligence is not up to the task.</p>
<p>But the important thing to note about these unknown unknowns is that nothing can be said about them. To presume from the outset that some unknown unknowns will always remain unknown, as mysterians do, is not modesty – it’s arrogance.</p><img src="https://counter.theconversation.com/content/124819/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Maarten Boudry receives funding from the Research Foundation – Flanders (FWO).</span></em></p>We know that pigs or dogs will never understand prime numbers. Some philosophers think that concepts like consciousness are similarly inaccessible to humans.Maarten Boudry, Postdoctoral Researcher of the Philosophy of Science, Ghent UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1016222018-08-15T15:17:11Z2018-08-15T15:17:11ZAnthill 28: On nothing<figure><img src="https://images.theconversation.com/files/232073/original/file-20180815-2912-3no9rk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">shutterstock</span> </figcaption></figure><p>Why is it so hard for us to just sit and do nothing? We don’t mean mindlessly scrolling through social media, while you watch TV. Actually sitting still and letting your mind wander.</p>
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<p><a href="https://itunes.apple.com/gb/podcast/the-anthill/id1114423002?mt=2"><img src="https://images.theconversation.com/files/321534/original/file-20200319-22606-q84y3k.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=182&fit=crop&dpr=1" alt="Listen on Apple Podcasts" width="268" height="68"></a> <a href="https://open.spotify.com/show/265Bnp4BgwaEmFv2QciIOC?si=-WMr1ecDTsO_6avrkxZu8g"><img src="https://images.theconversation.com/files/321535/original/file-20200319-22606-1l4copl.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=183&fit=crop&dpr=1" width="268" height="70"></a> </p>
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<p>Busyness seems to be a status symbol of our time. Everybody everywhere is busy – busy with work, busy with family, busy exercising, busy meditating. Busy being busy. Busyness is associated with success and fulfilment in most societies, so we view busyness as something to aspire to.</p>
<p>But what if you could achieve more by doing less? Psychologist Giulia Poerio shares some of her research about the benefits of daydreaming.</p>
<p>We also explore what it’s like when this is taken to the extreme and all you have are your own thoughts for company. Solitary confinement has been used systematically in prisons since the 19th century. Historian Hilary Marland explains the thinking behind what was called the “separate system” and how time alone was meant to give prisoners room to reflect on their crimes and repent of their sins. But as prison memoirs of the time reveal, solitary confinement was blamed for huge numbers of mental breakdowns, and its purpose as a tool for rehabilitation began to be questioned.</p>
<p>Peter Scharff Smith then talks us through how and why solitary confinement is still used in prisons around the world today, despite clear evidence of its negative health effects. And neuroscientist Ross Vanderwert explains why our brains react the way they do when we are deprived of meaningful social contact for long periods.</p>
<p>Finally, we explore the <a href="https://theconversation.com/what-is-nothing-martin-rees-qa-101498">physics of nothing</a> with astronomer royal, Martin Rees. By explaining how physicists are trying to understand what empty space is, he takes us on a journey from the beginning of the universe to the end.</p>
<p><a href="https://pca.st/5Hul"><img src="https://images.theconversation.com/files/321533/original/file-20200319-22598-afljnr.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=212&fit=crop&dpr=1" alt="Listen on Pocket Casts" width="268" height="68"></a> <a href="https://castbox.fm/channel/The-Anthill-id2625863?country=gb"><img src="https://images.theconversation.com/files/321531/original/file-20200319-22632-t8ds9t.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=232&fit=crop&dpr=1" width="268" height="70"></a> </p>
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<p><a href="https://tunein.com/podcasts/Technology-Podcasts/The-Anthill-p877873/"><img src="https://images.theconversation.com/files/233723/original/file-20180827-75984-f0y2gb.png" alt="Listen on TuneIn" width="318" height="125"></a> <a href="https://radiopublic.com/the-anthill-GOJ1vz"><img class="alignnone size-medium wp-image-152" src="https://images.theconversation.com/files/233717/original/file-20180827-75990-86y5tg.png?ixlib=rb-1.1.0&q=45&auto=format&w=268&fit=clip" alt="Listen on RadioPublic" width="268" height="87"></a> </p>
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<p><em>The Anthill theme music is by Alex Grey for Melody Loops. Music in the daydreaming segment is <a href="http://freemusicarchive.org/music/Just_Plain_Ant/All_Becomes_Dust/16_-_Ant__Stop_Daydreaming">Ant! Stop Daydreaming!</a> by Just Plain Ant. Music in the solitary confinement segment is <a href="http://freemusicarchive.org/music/Ascetic/The_Citizen_Made_of_Glass/06_Falling_into_Darkness">Falling into Darkness</a> by Ascetic. And music in the physics of nothing segment is <a href="http://freemusicarchive.org/music/Lee_Rosevere/All_These_Simple_Things/09_-_The_Idea_of_Space">The Idea of Space</a> by Lee Rosevere</em> </p>
<p><em>Click here to listen to more episodes of The Anthill, on themes including <a href="https://theconversation.com/anthill-26-twins-98271">Twins</a>, <a href="https://theconversation.com/anthill-25-intuition-96677">Intuition</a>, and <a href="https://theconversation.com/anthill-27-confidence-100183">Confidence</a>. And browse <a href="https://theconversation.com/podcasts">other podcasts</a> from The Conversation here.</em> </p>
<p><em>Thank you to City, University of London’s Department of Journalism for letting us use their studios to record The Anthill.</em></p><img src="https://counter.theconversation.com/content/101622/count.gif" alt="The Conversation" width="1" height="1" />
A podcast all about nothing. From the importance of doing nothing to the ill-effects of time spent in solitary confinement and what nothing means in space.Annabel Bligh, Business & Economy Editor and Podcast Producer, The Conversation UKGemma Ware, Head of AudioMiriam Frankel, Senior Science EditorHolly Squire, Special Projects Editor, The Conversation UKLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/500572015-11-24T17:08:28Z2015-11-24T17:08:28ZWill we have to rewrite Einstein’s theory of general relativity?<figure><img src="https://images.theconversation.com/files/102735/original/image-20151122-435-1eaferq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The fathers of modern physics, including Einstein, Millikan, Planck and others, in debate.</span> <span class="attribution"><a class="source" href="https://en.wikipedia.org/wiki/Max_Planck#/media/File:Nernst,_Einstein,_Planck,_Millikan,_Laue_in_1931.jpg">Materialscientist/wikimedia</a></span></figcaption></figure><p>Einstein famously <a href="https://theconversation.com/how-einsteins-general-theory-of-relativity-killed-off-common-sense-physics-50042">laboured hard</a> to create the theory of general relativity, but it is less well known that he also helped to launch quantum mechanics, which <a href="http://physicsworld.com/cws/article/multimedia/2013/mar/04/why-did-einstein-say-god-doesnt-play-dice">he didn’t much care for</a>. These two views of the world are the very foundation stones of modern physics – without them we would not have things such as space travel, medical imaging, GPS systems or nuclear energy.</p>
<p>General relativity is unparalleled when it comes to describing the world on a large scale, such as planets and galaxies, while quantum mechanics perfectly describes physics on the smallest scale, such as the atom or even parts of the atom. Uniting the two into a consistent “theory of everything” is the single biggest challenge in physics today – and progress is slow.</p>
<h2>The birth of modern physics</h2>
<p>Our knowledge of the universe is based on a sequence of “natural laws”. With time many laws become morphed into new ones as a result of experimental evidence or changing conceptual prejudices. Einstein’s rejection of the concept of universal time was one of the most radical shifts in the history of physics. Its consequences have proved crucial to shaping some of the most profound developments in our understanding of nature. </p>
<p>By fusing the three dimensions of space (height, width and depth) with that of a time direction to construct a “spacetime structure”, a new symmetry of nature could be uncovered. When Einstein later added gravitation to his theories, it led to experimentally verifiable predictions as well as the prediction of gravitational waves and black holes, beyond the natural scope of Newton’s existing law of gravitation.</p>
<p>But Einstein didn’t just work on relativity. A <a href="http://physics.info/photoelectric/">big problem</a> at the time was the fact that Maxwell’s laws, describing electromagnetic phenomena, were unable to explain why faint ultraviolet light falling on metallic electrodes could induce sparks more easily than bright red light. Einstein suggested that this could be understood if the energy in the light wave wasn’t continuously distributed as a wave but rather as a shower of individual “light bullets” (photons – also known as “light quanta”), each with an energy proportional to the colour (frequency) of the light. Many scientists were sceptical of this groundbreaking thought, as so many experiments had already shown that light was a wave.</p>
<figure class="align-right ">
<img alt="" src="https://images.theconversation.com/files/102884/original/image-20151123-18230-bbj53b.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/102884/original/image-20151123-18230-bbj53b.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=849&fit=crop&dpr=1 600w, https://images.theconversation.com/files/102884/original/image-20151123-18230-bbj53b.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=849&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/102884/original/image-20151123-18230-bbj53b.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=849&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/102884/original/image-20151123-18230-bbj53b.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1066&fit=crop&dpr=1 754w, https://images.theconversation.com/files/102884/original/image-20151123-18230-bbj53b.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1066&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/102884/original/image-20151123-18230-bbj53b.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1066&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Millikan proved Einstein right.</span>
<span class="attribution"><a class="source" href="https://en.wikipedia.org/wiki/Robert_Andrews_Millikan#/media/File:Millikan.jpg">Nobel foundation/wikipedia</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
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<p>One of them was Robert Millikan, who ironically eventually ended up <a href="http://www.nobelprize.org/nobel_prizes/physics/laureates/1923/millikan-bio.html">experimentally verifying</a> Einstein’s theory. Millikan also discovered that charged particles known as electrons have wave-like properties. Together with Einstein’s discovery, this pointed to a duality where both matter and light could be described as a particle or as a wave – an idea which led to the development of quantum mechanics by a number of scientists. </p>
<p>This theory has had wide applicability on the smallest of scales, where gravity can often be neglected as it is so weak compared to the other forces affecting particles. Not only has it led to a consistent description of matter and radiation observed in everyday life, it has also made predictions of new particles and processes that are now observed in high-energy accelerator experiments on Earth or cosmic events in space.</p>
<h2>The contenders</h2>
<p>To unify the description of matter and radiation quanta with gravitation it became natural to contemplate “gravitational quanta” that carry the force of gravitation. String theory has emerged as a candidate to do this. It states that matter is made up of vibrating extended structures, like tiny strings or membranes, rather than point-like particles. Each type of vibration of these structures corresponds to a particular state of matter. </p>
<p>One type of vibration also corresponds to a gravitational quantum. However, for the resulting quantum description to be consistent it becomes necessary to boost the dimension of spacetime by introducing additional space dimensions that are unobservable to the eye and current technology. To date, there has been <a href="http://discovermagazine.com/2005/aug/cover">no firm experimental confirmation</a> of string theory.</p>
<p>By contrast, in domains where gravitation appears irrelevant, quantum mechanics remains unchallenged, despite describing a very strange world. It states that particles can be in a number of different possible states at once. While the theory can predict a set of probabilities for the particle to be in a particular state, it cannot, in general, predict which probability will actually occur. </p>
<p>In such cases, one must take a large number of observations and then calculate average measurements. Furthermore, such averages depend on what properties are to be measured and when such measurement decisions are made. This peculiar world picture sits uncomfortably alongside Einstein’s world view of causal events and frozen histories in spacetime.</p>
<p>What’s more, according to quantum mechanics, one particle’s state can be correlated with another particle’s state, even if it is in a distant location. Einstein didn’t like this because it seemed to imply that correlations could occur over events that could not be connected by a beam of light, thereby breaking a rule that says nothing can travel faster than the speed of light. He felt that such “spooky action at a distance” was proof for the incompleteness of the theory, although <a href="https://theconversation.com/physicists-prove-quantum-spookiness-and-start-chasing-schrodingers-cat-48190">experimental evidence</a> since points to the contrary.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/102885/original/image-20151123-18257-fypsul.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/102885/original/image-20151123-18257-fypsul.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=399&fit=crop&dpr=1 600w, https://images.theconversation.com/files/102885/original/image-20151123-18257-fypsul.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=399&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/102885/original/image-20151123-18257-fypsul.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=399&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/102885/original/image-20151123-18257-fypsul.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=501&fit=crop&dpr=1 754w, https://images.theconversation.com/files/102885/original/image-20151123-18257-fypsul.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=501&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/102885/original/image-20151123-18257-fypsul.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=501&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Could the International Space Station be the key to probe the effects of gravity on quantum entanglement?</span>
<span class="attribution"><a class="source" href="https://en.wikipedia.org/wiki/Psychological_and_sociological_effects_of_spaceflight#/media/File:STS132_undocking_iss2.jpg">NASA/wikipedia</a></span>
</figcaption>
</figure>
<p>However, new experiments are underway to see whether gravitational interactions might influence such eerie action in unexpected ways. A research group in Vienna <a href="http://www.iop.org/news/13/apr/page_59834.html">proposes to use the International Space Station</a> to see how gravity might influence this action. A collection of entangled photon pairs will be created on Earth before one member of each pair is sent to the orbiting space station. There, a state known as polarisation will be recorded and compared with the state of its partner on Earth.</p>
<p>It is unclear whether quantum mechanics or general relativity will need either mathematical or conceptual modification in response to future experimental probing. But while the outcome is difficult to predict, Einstein’s influence has been and remains pivotal in this quest.</p><img src="https://counter.theconversation.com/content/50057/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Robin Tucker receives funding from EPSRC and STFC.</span></em></p>Physicists are working hard to unite Einstein’s theory of relativity with quantum mechanics. It’s no easy task.Robin Tucker, Professor in mathematical physics, Lancaster UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/346762014-12-03T10:49:42Z2014-12-03T10:49:42ZTheory of Everything debunks myth of Hawking as disembodied mind<p>Early in The Theory of Everything, the student Stephen Hawking strides across the grounds at Cambridge University in the 1960s, his face dreamy. He is lost in thought about the nature of time. </p>
<p>Then he trips and smacks his head on the concrete, cracking his glasses and bruising his face. </p>
<p>It’s a pivotal incident in the film, as it triggers the battery of tests that lead to his diagnosis of Lou Gehrig’s disease and the prediction that he had only two years to live. </p>
<p>The rest of the film follows the British cosmologist as he confounded that grim forecast. It dramatizes how he achieved renown within physics because of his ground-breaking 1970s work on black holes.</p>
<p>In less detail, the movie goes on to show how he became a pop culture star after <a href="http://www.randomhouse.com/book/77010/a-brief-history-of-time-by-stephen-hawking">A Brief History of Time</a>, his 1988 explanation of cosmology for nonspecialists, became the bestselling general science book ever. </p>
<p>As he’s grown older, Hawking has become progressively weaker as his condition wasted his muscles, but his brilliant mind continued to whir. In the process, a dominant myth took shape around him, a myth that presented to wider society a misleading view of the physicist and his research.</p>
<p>The myth was best articulated by <a href="http://sts.ucdavis.edu/humans/helene-mialet">Hélène Mialet</a> in her book <a href="http://www.press.uchicago.edu/ucp/books/book/chicago/H/bo3750667.html">Hawking Incorporated</a>. She noted that the cosmologist is overwhelmingly presented in popular culture as an intellect “liberated from his body and seemingly emancipated from everything that clutters the mundane mind (such as emotions, values, and prejudices).”</p>
<p>This image of Hawking as disembodied mind has crystallized in public opinion. It’s reproduced in <a href="http://www.theguardian.com/science/2011/may/15/stephen-hawking-interview-there-is-no-heaven">photographs</a> and <a href="http://content.time.com/time/magazine/article/0,9171,966650,00.html">articles</a> and the BBC documentary <a href="http://www.bbc.co.uk/sn/tvradio/programmes/horizon/hawking_prog_summary.shtml">The Hawking Paradox</a>. Moreover, the latest published biography of him was named <a href="http://us.macmillan.com/stephenhawkinganunfetteredmind/kittyferguson">Stephen Hawking: An Unfettered Mind.</a></p>
<p>Missing in these images are the vast networks of support systems that allow Hawking to live and work. Research students support him as he writes his papers and delivers his presentations. Nurses tend to his daily needs. Technological staff ensures he can communicate with the world. And, crucially, his family have provided decades of care and emotional support.</p>
<p>Yet as Mialet writes, when Hawking is presented in popular culture, these collective support systems “‘magically’ disappear.” All that remains is Hawking as a lone researcher, a pure intellect, an unfettered mind.</p>
<p>But The Theory of Everything debunks this myth. By showing Hawking cracking his head on the concrete, it inverts the central idea of the myth: Hawking’s mind is not free of his body, but is instead bound inextricably to it.</p>
<p>Moreover, the film makes Hawking’s support systems visible and vivid. His wife Jane Hawking dresses him, feeds him and cares for him. She and, later, nurse Elaine Mason teach him to communicate after a tracheotomy takes away his ability to speak. A system of technology then grants him a new, robotic voice. With these systems, his science has flourished.</p>
<p>The film also anchors Hawking in the physical world. Far from being a purely cerebral creature, he is shown choking on food, coughing up blood and trying in vain to count on his fingers as his muscles waste. His physical attraction to Elaine is obvious. He breaks down in tears as he tells Jane he is leaving her for Elaine.</p>
<p>It is not surprising that these images dominate, as the film’s source material is Jane Hawking’s biographical account of their life together, <a href="http://www.almabooks.com/travelling-to-infinity-p-717-book.html">Travelling to Infinity</a>, itself a 500-page debunking of any notion of Hawking as totally cerebral genius.</p>
<p>The film challenges this notion from the start. One of its first scenes shows Hawking in 1963 speeding on a bike around Cambridge. As Rolling Stone wrote in <a href="http://www.rollingstone.com/movies/reviews/the-theory-of-everything-20141105">its review</a>, the scene “will be a revelation to those stuck with the image of Hawking shackled to a motorized wheelchair, his head lolling, his muscles limp, his voice computer-generated.”</p>
<p>I’ve traced Stephen Hawking’s development as a world famous scientist in my <a href="https://rowman.com/ISBN/9781442233430">forthcoming book</a>. I believe The Theory of Everything gives the most rounded picture of the man since the first sustained coverage of him in the late 1970s and early 1980s after his most significant finding: that black holes leak heat. At the time, a series of long profiles in a range of magazines from New Scientist and Reader’s Digest to Vanity Fair explored his science and his family and his collaboration with colleagues.</p>
<p>The film has been <a href="http://www.nytimes.com/2014/10/28/science/stephen-hawkings-movie-life-story-is-not-very-scientific.html">criticized</a> for leaving out or glossing over important scientific details. But, for me, it illuminates a deeper truth about the work of Hawking and all scientific researchers: the creation of knowledge is an ongoing collaborative endeavor that involves vast networks of researchers, each with their own lives, each with their own systems of support. </p>
<p>Dramatizing this idea, the film underlined a prescient point made in the early 1990s by the late novelist Anthony Burgess when he reviewed two early biographies of the physicist. Burgess did not identify Hawking as the books’ real star. Jane, he wrote, was “the true heroine of his story, sustained in her care of [Hawking] and their children by a profound belief in God.”</p><img src="https://counter.theconversation.com/content/34676/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Declan Fahy 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>Early in The Theory of Everything, the student Stephen Hawking strides across the grounds at Cambridge University in the 1960s, his face dreamy. He is lost in thought about the nature of time. Then he…Declan Fahy, Assistant Professor of Communication, American University School of CommunicationLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/149982013-06-06T20:41:50Z2013-06-06T20:41:50ZEinstein to Weinstein: the lone genius is an exception to the rule<figure><img src="https://images.theconversation.com/files/25144/original/rfxqytxc-1370498534.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Albert Einstein was considered to be a 'lone genius' – but this was not the case, and it's certainly not the norm.</span> <span class="attribution"><span class="source">tsweden</span></span></figcaption></figure><p>Developing a Theory of Everything is physics’ Holy Grail. So could it have been completed in recent weeks? And by an outsider, working alone?</p>
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<span class="caption">Eric Weinstein - the new Einstein?</span>
<span class="attribution"><span class="source">Wikimedia Commons</span></span>
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<p>American mathematical physicist-turned-hedge-fund-consultant <a href="http://en.wikipedia.org/wiki/Eric_Weinstein">Eric Weinstein</a> is in the (very) early stages of <a href="http://www.guardian.co.uk/science/2013/may/23/eric-weinstein-answer-physics-problems">revealing to the public</a> his homemade <a href="http://www.guardian.co.uk/science/blog/2013/may/23/roll-over-einstein-meet-weinstein">theory of everything</a>, developed over two decades, alone, in his spare time.</p>
<p>I haven’t attended Weinstein’s lectures and I haven’t seen his work (<a href="http://www.newscientist.com/article/dn23595-weinsteins-theory-of-everything-is-probably-nothing.html">very few people have so far</a>), so I’m not going to comment on its genius or lack thereof. Nor will I comment on the media attention <em>per se</em>, as <a href="http://blogs.scientificamerican.com/cocktail-party-physics/2013/05/24/dear-guardian-youve-been-played/">others</a> have done <a href="http://telescoper.wordpress.com/2013/05/29/the-curious-case-of-weinsteins-theory/">plenty</a> of <a href="http://ronininstitute.org/an-outsiders-theory-of-everything/608/">that</a>. </p>
<p>But I will say the Weinstein lone-genius model of theoretical physics is in stark contrast to how theoretical physics is nearly always done.</p>
<h2>But … Einstein!</h2>
<p>One of the reasons Einstein carries such a hefty cultural weight is that he, like <a href="http://en.wikipedia.org/wiki/Isaac_Newton">Newton</a> a few centuries before him, appears to have basically single-handedly invented a fundamentally new view of the universe. </p>
<p>Newton did it over the course of 18 months, starting in 1665 while isolated to avoid the Plague, revolutionising optics and gravity, and <a href="http://www.uiowa.edu/%7Ec22m025c/history.html">inventing calculus</a> along the way. </p>
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<span class="attribution"><span class="source">Recuerdos de Pandora</span></span>
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<p>Einstein’s turn came in his “<a href="http://en.wikipedia.org/wiki/Annus_Mirabilis_papers">Annus Mirabilus</a>” (miracle year) in 1905, when he published four groundbreaking papers and a PhD thesis, touching on optics, the size and motions of atoms, and the <a href="https://en.wikipedia.org/wiki/Special_relativity">theory of special relativity</a>. </p>
<p>Einstein is frequently depicted as having been completely cut off from the academic establishment during this time – and being “just a patent clerk”. </p>
<p>But, although he was certainly not a working academic physicist, he still had connections with the community, people to bounce ideas off and a (stalled) PhD-in-progress at the University of Zurich. </p>
<p>He is, I will grant, probably the best example in the modern era of a theoretical physicist revolutionising science from outside “the establishment”. In fact, he’s the only one I can think of.</p>
<h2>“Hey, who invented quantum mechanics?”</h2>
<p>I asked this question of a colleague of mine while writing this, not because I thought he’d have a single answer, but because I was curious what the list might look like. There are a few people who should probably get some credit:</p>
<ul>
<li><a href="http://en.wikipedia.org/wiki/James_Clerk_Maxwell">Maxwell</a>, who first formulated the <a href="http://hyperphysics.phy-astr.gsu.edu/hbase/electric/maxeq.html">basic equations of electromagnetism</a></li>
<li><a href="http://www.nobelprize.org/nobel_prizes/physics/laureates/1925/hertz-bio.html">Hertz</a>, an experimentalist who helped demonstrate the photoelectric effect</li>
<li><a href="http://www.nobelprize.org/nobel_prizes/physics/laureates/1918/planck-bio.html">Planck</a>, who was so important to quantum theory that its most <a href="http://en.wikipedia.org/wiki/Planck_constant">fundamental constant</a> is named after him</li>
<li><a href="http://www.nobelprize.org/nobel_prizes/physics/laureates/1921/einstein-bio.html">Einstein</a>, who first explained the photoelectric effect from a theoretical point of view</li>
<li>or <a href="http://www.nobelprize.org/nobel_prizes/physics/laureates/1945/pauli-bio.html">Pauli</a>, or <a href="https://theconversation.com/explainer-heisenbergs-uncertainty-principle-7512">Heisenberg</a>, or <a href="http://www.nobelprize.org/nobel_prizes/physics/laureates/1922/bohr-bio.html">Bohr</a>, or <a href="http://www.nobelprize.org/nobel_prizes/chemistry/laureates/1920/nernst-bio.html">Nernst</a>, or <a href="http://www.nobelprize.org/nobel_prizes/physics/laureates/1933/schrodinger-bio.html">Schrödinger</a> … </li>
</ul>
<p><a href="https://theconversation.com/explainer-quantum-physics-570">Quantum mechanics</a> is a great illustration of the fact that it doesn’t take a lone iconoclast to revolutionise our understanding of the universe. </p>
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<span class="attribution"><span class="source">Kennedy Goodkey</span></span>
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<p>Even huge breakthroughs that fundamentally change how we see and do physics can – and do – come about in a series of incremental steps. Experimentalists see something odd in their experiments, theorists propose possible explanations, experimentalists go back and test the consequences of each theory, and the cycle begins again. </p>
<p>This has happened a number of times since Einstein’s era. In addition to quantum mechanics, we’ve seen the appearance of the <a href="https://theconversation.com/explainer-standard-model-of-particle-physics-2539">Standard Model of Particle Physics</a>, <a href="http://www.damtp.cam.ac.uk/user/tong/qft.html">quantum field theory</a>, the <a href="http://astronomy.swin.edu.au/cosmos/c/concordance+model">concordance model of cosmology</a> (including <a href="http://astrokatie.blogspot.com.au/2013/04/the-art-of-darkness.html">dark matter</a> and <a href="http://astrokatie.blogspot.com.au/2012/07/you-dont-have-to-blow-up-universe-to-be.html">dark energy</a>), and the as-yet purely theoretical frameworks of <a href="http://hitoshi.berkeley.edu/public_html/susy/susy.html">supersymmetry</a> and <a href="https://theconversation.com/explainer-string-theory-2983">string theory</a>. </p>
<p>None of these advances could be attributed to one person, nor did they generally involve people working in isolation on theories of their very own. </p>
<h2>So how does it usually work?</h2>
<p>Physics is, these days, an immensely collaborative field. There are a <a href="http://inspirehep.net/search?ln=en&cc=Conferences&p=fin+date+%3E+today&sf=year&so=a">lot of conferences</a> as well as institutes and workshops and collaboration visits; there are endless seminars and dissections of research papers. </p>
<p>Newly-built physics institutes tend to have hallways lined with blackboards or dry-erase-glass cubicles to get people out of their offices to collaborate. We talk to each other, not because we are inherently very social (though <a href="http://www.youtube.com/watch?v=s0_53RCZIZM">a lot of us</a> <a href="http://www.youtube.com/watch?v=52CL3-gWyJs">are</a>), but because it’s a really productive way to proceed. </p>
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<span class="attribution"><span class="source">Fellowship of the Rich</span></span>
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<p>Personally, I find I think better when I’m explaining my ideas to someone. Some people, after staring at the same equations for days, just need to get the math written down and show it to other people to make sure it really makes sense. Even more importantly, we’re not all experts on all areas of physics. </p>
<p>One person might have spent four years working on a particular quantum mechanical process in the early universe while another might be an expert on strong-field gravitation, and together they can create a much clearer picture of how, say, how <a href="https://theconversation.com/rippling-space-time-how-to-catch-einsteins-gravitational-waves-7058">gravitational waves</a> might be produced right after the <a href="https://theconversation.com/back-to-where-we-started-tracing-the-origins-of-galaxies-3776">Big Bang</a>. </p>
<p>And here I’m just talking about pure theory - if you want to actually test theories, you have to be in touch with experimentalists and observers and find out what kind of tools they have available. </p>
<p>So why are we hearing about Weinstein’s (still unpublished) ideas now, for the first time? I don’t know. Maybe he had a really good reason not to talk to other physicists about his work.</p>
<p>Perhaps he was worried it might be wrong and didn’t want to embarrass himself, or perhaps he was worried it might be right and he’d be scooped or not get all the credit. Or maybe he just doesn’t like to talk to physicists all that much. </p>
<p>It’s even possible he thought his ideas were so revolutionary that no one else would understand. But I kind of doubt that. </p>
<p>We physicists love finding new ways to think. We love stretching our minds and seeing things from another point of view. It’s why we do the work we do - and it’s why we spend so much time talking to each other about it.</p>
<p><br>
<em>A version of this article appeared on <a href="http://astrokatie.blogspot.co.uk/2013/06/the-lone-genius-hypothesis.html">The Universe, in Theory</a>.</em></p><img src="https://counter.theconversation.com/content/14998/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Katherine J Mack receives funding from the Australian Research Council in the form of a Discovery Early Career Researcher Award.</span></em></p>Developing a Theory of Everything is physics’ Holy Grail. So could it have been completed in recent weeks? And by an outsider, working alone? American mathematical physicist-turned-hedge-fund-consultant…Katherine J Mack, DECRA Fellow, Astrophysics, The University of MelbourneLicensed as Creative Commons – attribution, no derivatives.