tag:theconversation.com,2011:/fr/topics/bicep2-12473/articlesBICEP2 – The Conversation2016-02-11T16:05:13Ztag:theconversation.com,2011:article/536772016-02-11T16:05:13Z2016-02-11T16:05:13ZThe logic of journal embargoes: why we have to wait for scientific news<figure><img src="https://images.theconversation.com/files/111203/original/image-20160211-29190-1yx92jl.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Extra, extra! The embargo's lifted, read all about it.</span> <span class="attribution"><a class="source" href="http://www.shutterstock.com/pic.mhtml?id=248829895&src=id">Newspapers image via www.shutterstock.com.</a></span></figcaption></figure><p>Rumors were flying through the blogosphere this winter: physicists at the Advanced Laser Interferometer Gravitational-Wave Observatory (<a href="https://www.ligo.caltech.edu/">LIGO</a>) may finally have directly detected <a href="http://www.nature.com/news/gravitational-waves-6-cosmic-questions-they-can-tackle-1.19337">gravitational waves</a>, ripples in the fabric of space-time predicted by Einstein 100 years ago in his general theory of relativity. Gravitational waves were predicted to be produced by cataclysmic events such as the collision of two black holes.</p>
<p>If true, it would be a very big deal: a rare chance for scientists to grab the attention of the public through news of cutting-edge research. So why were the scientists themselves keeping mum?</p>
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<p>This wouldn’t be the first time scientists thought they had detected gravitational waves. In March 2014, a group claimed to have done so. In that case, scientists announced their discovery when they posted an article in <a href="http://arxiv.org">arXiv</a>, a preprint server where physicists and other scientists share research findings prior to acceptance by a peer-reviewed publications. Turns out that group was <a href="http://www.nature.com/news/gravitational-waves-discovery-now-officially-dead-1.16830">wrong</a> – they were actually looking at galactic dust. </p>
<p>The LIGO scientists were more careful. Fred Raab, head of the LIGO laboratory, <a href="http://www.geekwire.com/2016/after-gravitation-wave-rumors-its-getting-close-to-go-time-for-advanced-ligo-results/">explained</a>:</p>
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<p>As we have done for the past 15 years, we take data, analyze the data, write up the results for publication in scientific journals, and once the results are accepted for publication, we announce results broadly on the day of publication or shortly thereafter. </p>
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<p>And that’s what they did, timing their news conferences and media outreach to coincide with the <a href="http://physics.aps.org/featured-article-pdf/10.1103/PhysRevLett.116.061102">official publication</a> in the scientific journal Physical Review Letters about their discovery. Why did they delay their public announcement rather than spread the word as widely as possible as soon as possible?</p>
<h2>Science’s standard operating procedure</h2>
<p>Although it may sound unnecessarily cautious, the process Raab described is how most scientists prepare and vet discoveries prior to announcing them to the world – and, indeed, it’s the process most scientific journals insist upon. <em>Nature</em>, for example, <a href="http://www.nature.com/authors/policies/embargo.html">prohibits</a> authors from speaking with the press about a submitted paper until the week before publication, and then only under conditions set by the journal. </p>
<p>Scientific publishing serves both the scientist and the public. It’s a quid pro quo: the authors get to claim priority for the result – meaning they got there before any other scientists did – and in return the public (including competing scientists) gets access to the experimental design, the data and the reasoning that led to the result. Priority in the form of scientific publishing earns scientists their academic rewards, including more funding for their research, jobs, promotions and prizes; in return, they reveal their work at a level of detail that other scientists can build on and ideally replicate and confirm. </p>
<p>News coverage of a scientific discovery is another way for scientists to claim priority, but without the vetted scientific paper right there alongside it, there is no quid pro quo. The claim is without substance, and the public, while titillated, does not benefit – because no one can act on the claim until the scientific paper and underlying data are available.</p>
<p>Thus, most scientific journals insist on a “press embargo,” a time during which scientists and reporters who are given advanced copies of articles agree not to publish in the popular press until the scientific peer review and publishing process is complete. With the advent of <a href="http://www.infotoday.com/searcher/oct00/tomaiuolo&packer.htm">preprint servers</a>, however, this process itself is evolving. </p>
<p><a href="http://dx.doi.org/10.1056/NEJM197706022962204">First introduced</a> in 1977, journal embargoes reflect a scientific journal’s desire both to protect its own <a href="http://dx.doi.org/10.1056/NEJM198110013051408">newsworthiness</a> and to protect the public from misinformation. If a result is wrong (as was the case with the 2014 gravitational wave result), peer review is supposed to catch it. At the least, it means experts other than the researchers themselves examined the experimental design and the data and agreed that the conclusions were justified and the interpretations reasonable. </p>
<p>Often, results are more “nuanced” than the news article or press conference suggests. Yes, this new drug combination makes a (minor) difference, but it doesn’t cure cancer. Finally, the result could be correct, but not because of the data in that paper, and the premature press conference claims an unwarranted priority that can disrupt other research. In all these cases, having access to the research article and the underlying data is critical for the news to be meaningful.</p>
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<a href="https://images.theconversation.com/files/111035/original/image-20160210-12153-9yc2pi.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/111035/original/image-20160210-12153-9yc2pi.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/111035/original/image-20160210-12153-9yc2pi.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=338&fit=crop&dpr=1 600w, https://images.theconversation.com/files/111035/original/image-20160210-12153-9yc2pi.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=338&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/111035/original/image-20160210-12153-9yc2pi.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=338&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/111035/original/image-20160210-12153-9yc2pi.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=424&fit=crop&dpr=1 754w, https://images.theconversation.com/files/111035/original/image-20160210-12153-9yc2pi.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=424&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/111035/original/image-20160210-12153-9yc2pi.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"></a>
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<span class="caption">Peer-reviewed and published.</span>
<span class="attribution"><span class="source">Maggie Villiger</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
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<h2>Purposes of a press embargo</h2>
<p>A press embargo has additional benefits for the reporter, the journal and the public.</p>
<p>Multiple journalists get an equal chance to publish a well-researched and balanced article. In exchange for respecting the journal’s press embargo, reporters find out what’s being published in advance of publication. This gives multiple journalists a chance to read the scientific article, find experts who can help them make sense of the article, and publish a carefully crafted story. From the scientist’s (and scientific journal’s) perspective, this maximizes the quality and quantity of the coverage by the press.</p>
<p>The public gains access to the scientific article very close to the time they read the news story. The popular press tends to bias a story toward what’s “newsworthy” about it – and that sometimes winds up exaggerating or otherwise inaccurately summarizing the scientific article. When that article relates to human health, for instance, it’s important that doctors have access to the original scientific paper before their patients start inquiring about new treatments they’d heard about in the news.</p>
<p>Other scientific experts gain access to the scientific article as soon as the findings become news. Scientists who jump the gun and allow their research to become news before publication in an academic journal are making unvetted claims that can turn out to be less important once the peer-reviewed article eventually appears.</p>
<p>A press embargo can protect a scientist’s claim for priority in the face of competition from other scientists and journals. Scientists generally accept journal publication dates as indicators of priority – but when a discovery makes news, the journal considering a competitor’s paper often both releases its authors from the embargo and races the paper to publication. And, if your competitor’s paper comes out first, you’ve lost the priority race.</p>
<p>The embargo system allows time for prepublication peer review. Most experiments designed to address research questions are complicated and indirect. Reviewers often require additional experiments or analyses prior to publication. Prepublication peer review can take a long time, and its value <a href="http://dx.doi.org/10.1242/dmm.001388">has been</a> <a href="https://www.theguardian.com/science/occams-corner/2015/sep/07/peer-review-preprints-speed-science-journals">questioned</a>, but it is currently the norm. If a news story came out on the paper while it was under review, the process of peer review could be jeopardized by pressure to “show the data” based on the news article. Many journals would decline publication under those conditions, leaving the authors and public in limbo.</p>
<p>I know of no case in which talking about a discovery in advance of scientific publication helps the public. Yes, “breaking news” is exciting. But journalists and other writers can tell riveting stories about science that convey the excitement of discovery without breaking journal embargoes. And the scientific community can continue to work on speeding its communication with the public while preserving the quid pro quo of scientific publication.</p><img src="https://counter.theconversation.com/content/53677/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Vivian Siegel 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>Sometimes big research news bypasses the usual scientific publishing process. Here’s why that’s not good for scientists or the public.Vivian Siegel, Visiting Instructor of Biological Engineering, Massachusetts Institute of Technology (MIT)Licensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/464932015-09-04T16:55:36Z2015-09-04T16:55:36ZFive myths about gravitational waves<figure><img src="https://images.theconversation.com/files/93044/original/image-20150826-7663-1d6skza.jpg?ixlib=rb-1.1.0&rect=0%2C476%2C2000%2C1350&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Elegant but elusive. Simulation of merging black holes showing gravitational waves.</span> <span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:This_visualization_shows_what_Einstein_envisioned.jpg">NASA/ESA/wikimedia</a></span></figcaption></figure><p>Rumours are swirling around that scientists working at the <a href="http://space.mit.edu/LIGO/more.html">Laser Interferometer Gravitational-Wave Observatory (LIGO)</a> in the US have detected gravitational waves, which are <a href="https://theconversation.com/rippling-space-time-how-to-catch-einsteins-gravitational-waves-7058">ripples in space-time</a>. Is it possible? After all, in 2014, scientists behind the BICEP2 (Background Imaging of Cosmic Extragalactic Polarization) telescope, made an extraordinary claim that they had <a href="https://www.cfa.harvard.edu/news/2014-05">detected them</a>. Initially hailed as the most groundbreaking discovery of the century, it later proved a <a href="http://arxiv.org/abs/1502.00612">false alarm</a>: the signal was merely galactic dust.</p>
<p>So are we likely to ever find gravitational waves? And would they really provide irrefutable evidence for the Big Bang? Here are five common myths and misconceptions about gravitational waves.</p>
<h2>1. Setbacks are just due to teething problems</h2>
<p>It may seem like the search for gravitational waves has only just begun, but it has actually been going on for decades without success. </p>
<p>Gravitational waves are pulsating perturbations, or “ripples” produced in the fabric of space-time as a massive object moves through it. As they propagate, they stretch and squash objects, albeit on subatomic scale. Scientists have therefore been trying to demonstrate the existence of gravitational waves by looking at how nearby objects are affected. </p>
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<img alt="" src="https://images.theconversation.com/files/93903/original/image-20150904-14653-1bggolm.gif?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/93903/original/image-20150904-14653-1bggolm.gif?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/93903/original/image-20150904-14653-1bggolm.gif?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/93903/original/image-20150904-14653-1bggolm.gif?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/93903/original/image-20150904-14653-1bggolm.gif?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/93903/original/image-20150904-14653-1bggolm.gif?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/93903/original/image-20150904-14653-1bggolm.gif?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">A passing gravitational wave stretches and squashes objects in its path.</span>
<span class="attribution"><a class="source" href="https://en.wikipedia.org/wiki/Gravitational_wave#/media/File:GravitationalWave_PlusPolarization.gif">wikimedia</a></span>
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<p>In 1968, American physicist <a href="http://www.nytimes.com/2000/10/09/us/joseph-weber-dies-at-81-a-pioneer-in-laser-theory.html">Joseph Weber</a> claimed he had detected gravitational waves in this way using his esoteric detector made up of enormous aluminium cylinders. This was sadly <a href="http://physics.aps.org/story/v16/st19">later disproved</a>. </p>
<p>These days, scientists prefer using <a href="https://theconversation.com/rippling-space-time-how-to-catch-einsteins-gravitational-waves-7058">laser interferometry</a> to search for gravitational waves. It works by splitting a laser beam in two perpendicular directions and sending each down a long vacuum tunnel. The two paths are then reflected back by mirrors to the point they started, where a detector is placed. If the waves are disturbed by gravitational waves on their way, the recombined beams would be different from the original.</p>
<p>Ground-based interferometers, <a href="http://space.mit.edu/LIGO/more.html">like the Laser Interferometer Gravitational-Wave Observatory (LIGO)</a>, have arms that are about four kilometres long. Future space-based interferometers like the Deci-hertz Interferometer Gravitational Wave Observatory <a href="http://iopscience.iop.org/article/10.1088/1742-6596/122/1/012006/meta;jsessionid=FDBA35DE8AC0B9D01FCE8759208C71DD.c1">(DECIGO)</a> and the Evolved Laser Interferometer Space Antenna <a href="https://www.elisascience.org/articles/lisa-pathfinder/lpf-mission">(eLISA)</a> will use laser arms spanning up to a million kilometres. These experiments are expected to launch within the next decade.</p>
<h2>2. The waves come from the early universe</h2>
<p>The strongest sources of gravitational waves are in fact astrophysical processes, which are happening all the time.</p>
<p>The most dominant of these sources is the rotation of pairs of white dwarfs or black holes (so-called “binary systems”). Such pairs are thought to gradually lose energy by emitting gravitational waves. This was <a href="http://www.astro.cardiff.ac.uk/research/gravity/tutorial/?page=3thehulsetaylor">demonstrated</a> by the discovery of the famous <a href="http://www.nobelprize.org/nobel_prizes/physics/laureates/1993/press.html">Hulse-Taylor pulsar</a> in 1974. The pulsar provided indirect evidence of gravitational waves as it was losing energy at a rate which had been predicted by the general theory of relativity (the waves themselves were not seen).</p>
<p>However, scientists are also looking for gravitational waves created shortly after the universe was born, called primordial gravitational waves, which are much more elusive.</p>
<h2>3. BICEP2 could one day ‘see’ gravitational waves</h2>
<p>One of BICEP2’s goals was try to detect the signature of primordial gravitational waves imprinted in the temperature of the <a href="http://www.bbc.co.uk/science/space/universe/sights/cosmic_microwave_background_radiation">Cosmic Microwave Background</a> (CMB). This radiation contains light that first emerged from the soup of elementary particles when the universe was just 300,000 years old, long before the first stars were born.</p>
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<img alt="" src="https://images.theconversation.com/files/93910/original/image-20150904-14639-10j4bed.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/93910/original/image-20150904-14639-10j4bed.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=300&fit=crop&dpr=1 600w, https://images.theconversation.com/files/93910/original/image-20150904-14639-10j4bed.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=300&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/93910/original/image-20150904-14639-10j4bed.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=300&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/93910/original/image-20150904-14639-10j4bed.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=377&fit=crop&dpr=1 754w, https://images.theconversation.com/files/93910/original/image-20150904-14639-10j4bed.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=377&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/93910/original/image-20150904-14639-10j4bed.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=377&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">The cosmic microwave background, as measured by the Planck satellite.</span>
<span class="attribution"><span class="source">ESA/Planck Collaboration</span></span>
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<p>When light waves vibrate in a certain direction, we say that it has a specific <em>polarisation</em>. If gravitational waves were present at the time when the CMB was born, they should leave behind a unique swirly pattern – a curling in the polarisation of the light – dubbed “B modes”. </p>
<p>Therefore, the B modes are only indirect evidence for gravitational waves. This is an important point: Experiments like BICEP2 will never be able to observe gravitational waves themselves, only the fingerprints they left behind.</p>
<p>Even dusting for these fingerprints is not easy. B-modes are typically masked by much stronger signals from dust emission and an effect called <a href="http://www.cfhtlens.org/public/what-gravitational-lensing">gravitational lensing</a>, which mixes different types of polarisation patterns. Eliminating these and many other contaminants is a most delicate task, often relying on results from other experiments. </p>
<p>This complex challenge will be tackled by the next generation of BICEP-like experiments such as the <a href="http://www.princeton.edu/act/">Atacama Cosmology Telescope</a> (ACT) and its planned successor AdvACT. They will be able to measure CMB to scales beyond the reach of Planck, and would have learned valuable lessons from BICEP in the modelling of dust and other contaminants. The prospects for detecting B-mode within the decade look very promising.</p>
<p>Some have even speculated that space interferometers <a href="http://arxiv.org/abs/1201.0983">might be able to</a> detect primordial waves, perhaps by subtracting the waves detected from known astrophysical processes.</p>
<h2>4. Gravitational waves would ‘prove’ the Big Bang</h2>
<p>The earliest source of gravitational waves is not the Big Bang, but rather <em>cosmological inflation</em>: a period during which the universe underwent a brief flash of exponential expansion just after the Big Bang. </p>
<p>The gravitational waves that BICEP2 claimed to have detected are the by-product of this burst of accelerating expansion of the universe. This is in accordance with general relativity, which <a href="http://www.space.com/11848-gravity-wave-detector-space-time.html">predicts that an accelerating body emits gravitational waves</a> (similar to the way an accelerating charge emits electromagnetic waves).</p>
<p>Inflation is currently regarded as the leading model of the early universe. While many key predictions of inflation have been verified, the predicted existence of primordial gravitational waves remains elusive. If they are observed, they will tell us directly about the energy scale at which inflation occurred, bringing us closer to understanding the Big Bang. But they would not prove the Big Bang, which is a mathematical singularity that we are yet to understand.</p>
<h2>5. We just need one experiment to detect them</h2>
<p>Strong statistical evidence for gravitational waves will certainly require more than one experiment. Like light waves, gravitational waves come in a spectrum of frequencies. The two detection techniques (B-modes and laser interferometry) are searching for waves at different frequencies – 15 orders of magnitude apart. </p>
<p>The simplest theory of inflation predicts a background of primordial gravitational waves with a particular frequency spectrum, in other words we know what the amplitude should be in each frequency. So, if scientists could detect gravitational waves on two of these very different frequencies, it would be strong evidence for inflation that is difficult to refute even by the most hardline sceptic. </p>
<h2>So is the search worth it?</h2>
<p>It is highly unlikely that the first generation of space interferometers would achieve the sensitivity required to detect primordial gravitational waves. Exactly what such a signal would look like is unknown and could, in principle, be forever out of reach by any future interferometers. </p>
<p>Nevertheless, if we could detect astrophysical gravitational waves directly, this would open up new ways to test the validity of Einstein’s theory of general relativity, which is used to describe gravitation in modern physics. The theory, which has been <a href="http://phys.org/news/2014-06-gun-gravity.html">questioned in recent years</a>), predicts the existence of gravitational waves.</p>
<p>It would also provide new insights into the evolution of stars, galaxies and black holes that we could never get any other way.</p>
<p><em>Read other articles in our cosmology series <a href="https://theconversation.com/uk/topics/cosmology-series">here</a></em>.</p>
<p>_This article was updated on January 12, 2016 to reflect latest developments.
_</p><img src="https://counter.theconversation.com/content/46493/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Siri Chongchitnan 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>Gravitational waves: are they worth the hype?Siri Chongchitnan, Lecturer in Mathematics, University of HullLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/372172015-02-10T11:19:06Z2015-02-10T11:19:06ZFailure in real science is good – and different from phony controversies<figure><img src="https://images.theconversation.com/files/71492/original/image-20150209-24700-101mqc1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The BICEP2 telescope at twilight at the South Pole. The supporting data for the inflation of the universe have also gone off into the sunset.</span> <span class="attribution"><a class="source" href="http://bicepkeck.org/visuals.html">Steffen Richter, Harvard University </a>, <a class="license" href="http://creativecommons.org/licenses/by-nc-sa/4.0/">CC BY-NC-SA</a></span></figcaption></figure><p>Last March, the BICEP2 collaboration <a href="http://www.cfa.harvard.edu/news/2014-05">announced</a> that they had used a microwave telescope at the South Pole to detect primordial gravitational waves. These tiny ripples in spacetime would be the <a href="https://theconversation.com/first-hints-of-gravitational-waves-in-the-big-bangs-afterglow-24475">first proof of the theory</a> known as “inflation,” an astonishingly rapid expansion of the universe in the instants after the Big Bang. </p>
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<p>The result was announced in a paper, a press conference, and a viral video of BICEP2 member Chao-Lin Kuo visiting cosmologist Andrei Linde, one of the inventors of inflation, at his home with a bottle of champagne to celebrate.</p>
<p>Last week, a <a href="http://arxiv.org/abs/1502.00612">new paper</a> was released <a href="https://theconversation.com/gravitational-wave-discovery-still-clouded-by-galactic-dust-37106">backtracking on last March’s announcement</a>. The BICEP2 team joined with rivals on the European Space Agency’s Planck experiment, and found that their results were contaminated by dust. The signal is not large enough to constitute proof of inflation, so cosmology returns to its prior uncertain state. Rather than revolutionizing our understanding, the BICEP2 result is just the latest in a long line of highly public flops.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/71498/original/image-20150209-24682-1o02qv.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/71498/original/image-20150209-24682-1o02qv.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/71498/original/image-20150209-24682-1o02qv.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=343&fit=crop&dpr=1 600w, https://images.theconversation.com/files/71498/original/image-20150209-24682-1o02qv.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=343&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/71498/original/image-20150209-24682-1o02qv.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=343&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/71498/original/image-20150209-24682-1o02qv.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=431&fit=crop&dpr=1 754w, https://images.theconversation.com/files/71498/original/image-20150209-24682-1o02qv.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=431&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/71498/original/image-20150209-24682-1o02qv.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=431&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Oh, those gravitational waves we detected…? Yeah, that could have just been dust.</span>
<span class="attribution"><a class="source" href="http://bicepkeck.org/visuals.html">BICEP2 Collaboration</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc-nd/4.0/">CC BY-NC-ND</a></span>
</figcaption>
</figure>
<h2>Did the hype hurt or help science?</h2>
<p>Along with general disappointment, the new announcement has prompted discussion of what, if anything, the BICEP2 team did wrong. Many commentators fault them for over-hyping their results to the mass media before peer review. Some even argue that this has dire consequences – astronomer <a href="http://blogs.discovermagazine.com/crux/2015/01/30/bicep2-wrong-sharing-results/">Marcelo Gleiser says</a> the announcement and revision “harms science because it’s an attack on its integrity,” giving “ammunition” to those who raise doubts about politically charged areas of science.</p>
<p>Looked at another way, though, the BICEP2 story may in fact be ammunition for supporters of science. BICEP2 shows how science is properly done, and makes it easier, not harder, to detect the pseudo-science of attempts to discredit science for political gain.</p>
<p>We tend to think of science as a collection of esoteric information, but science is <a href="http://chadorzel.com/?p=11">best understood as a process</a> for figuring out the workings of the universe. Scientists look at the world, think of models to explain their observations, test those models with further observations and experiment, and tell each other the results. This process is familiar and universal, turning up in everything from <a href="https://medium.com/biblio/waldo-at-the-galaxy-zoo-e1f7cdecd2d1">hidden-object books</a> to <a href="https://theconversation.com/super-bowl-athletes-are-scientists-at-work-36698">sports</a>. More importantly, we can recognize the process even in cases where we don’t understand all the technical details, and use that to distinguish real science from phony controversies.</p>
<h2>Refining real science versus phony controversies</h2>
<p>Real scientific controversies are widespread and mainstream. The BICEP2 results <a href="https://theconversation.com/has-dust-clouded-the-discovery-of-gravitational-waves-27177">were publicly challenged</a> within weeks, by other scientists working in the field, who quickly identified dust as a trouble spot. While few of the participants were disinterested—most complaints came from scientists associated with BICEP2’s competitors and theorists who prefer alternatives to inflation—they were active and respected members of the community.</p>
<p>Phony controversies, on the other hand, can usually be traced to a handful of opponents, often outside their fields of expertise. Challenges to the scientific consensus on climate change mostly come from engineers and economists, not working climate scientists, and tend to originate in think tanks and lobbying groups, not university research labs. Fears about vaccines can be traced to a handful of thoroughly debunked studies, and are stoked by politicians and celebrities, not medical researchers.</p>
<p>Real scientific controversies play out in the scientific literature, through papers drawing on many other sources of data. Within months of the original announcement, a <a href="http://dx.doi.org/10.1088/1475-7516/2014/08/039">detailed re-analysis</a> of the data was posted to the physics arxiv (the online repository physicists and astronomers use to share their results), using multiple alternative models to show how dust could explain the results. Others drew on previous measurements to show that BICEP2’s claims were difficult to reconcile with existing data.</p>
<p>Phony controversies tend to play out in the media, through press releases, stump speeches, and polemical writing reshared via social media. Reliable reports from scientific journals are difficult to find, even after chasing back long chains of references.</p>
<p>And most importantly, real scientific controversies are self-correcting. The final nail in the gravitational-wave coffin was a joint paper by both BICEP2 and Planck, combining their data to settle the question. The end result is professionally embarrassing for scientists involved in the original announcement, but they were at the forefront of the effort to resolve the controversy because for real science reputation is less important than the truth.</p>
<figure class="align-left zoomable">
<a href="https://images.theconversation.com/files/71517/original/image-20150209-24679-9h4b1o.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/71517/original/image-20150209-24679-9h4b1o.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/71517/original/image-20150209-24679-9h4b1o.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/71517/original/image-20150209-24679-9h4b1o.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/71517/original/image-20150209-24679-9h4b1o.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/71517/original/image-20150209-24679-9h4b1o.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/71517/original/image-20150209-24679-9h4b1o.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/71517/original/image-20150209-24679-9h4b1o.jpg?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 media can perpetuate phony controversies.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/cactusbones/4285370145">cactusbones</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc-sa/4.0/">CC BY-NC-SA</a></span>
</figcaption>
</figure>
<p>Phony controversies, on the other hand, are endless, with proponents clinging stubbornly to the same positions year after year. Even as their sources are discredited, their conclusions remain unchanged, because phony science is less interested in truth than in selling a conclusion.</p>
<p>Rather than weakening the standing of science, then, the BICEP2 saga should serve to enhance it. While few of us can follow all the technical details on which the controversy turns, everyone should be able to follow the broad outlines of the process. By providing a clear example of real science done the right way, the controversy over BICEP2 exposes politically motivated phony controversies as hollow frauds.</p><img src="https://counter.theconversation.com/content/37217/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Chad Orzel 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>Last March, the BICEP2 collaboration announced that they had used a microwave telescope at the South Pole to detect primordial gravitational waves. These tiny ripples in spacetime would be the first proof…Chad Orzel, Associate Professor of Physics, Union CollegeLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/351632014-12-29T19:13:17Z2014-12-29T19:13:17ZFrom comet chasing to gravity waves: 2014 in six science stories<figure><img src="https://images.theconversation.com/files/66540/original/image-20141208-20492-ksgibl.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">2014: the year crystallography went mainstream.</span> <span class="attribution"><a class="source" href="http://commons.wikimedia.org/wiki/File:CSIRO_ScienceImage_296_Protein_Crystals_Use_in_XRay_Crystallography.jpg">CSIRO</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span></figcaption></figure><p>’Tis the season for listicles rounding up the stories of the year. So with, the authority vested in me, here is a selection of six top, bottom and forgotten science stories of 2014.</p>
<h2>Bounciest landing</h2>
<p>The Rosetta drama reached fever pitch in November with the descent of Philae to the surface of a comet. But let’s not forget the slow build to the plot, starting with a launch back in 2004 setting <a href="https://theconversation.com/uk/topics/rosetta">Rosetta</a> on a path that involved four gravitational “slingshots” around Earth and Mars, three orbits of the Sun, two close encounters with asteroids and a rendezvous with 67P/Churyumov–Gerasimenko in August. Chasing down the four kilometre-wide comet travelling at 135,000 km/hr and then touching down on its surface was a staggering feet of precision, roughly equivalent to a marksman hitting a bulls-eye on a one metre target from a million kilometres away (three times the distance from the Earth to the Moon).</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/66537/original/image-20141208-20498-1u6ripd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/66537/original/image-20141208-20498-1u6ripd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/66537/original/image-20141208-20498-1u6ripd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=351&fit=crop&dpr=1 600w, https://images.theconversation.com/files/66537/original/image-20141208-20498-1u6ripd.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=351&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/66537/original/image-20141208-20498-1u6ripd.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=351&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/66537/original/image-20141208-20498-1u6ripd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=441&fit=crop&dpr=1 754w, https://images.theconversation.com/files/66537/original/image-20141208-20498-1u6ripd.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=441&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/66537/original/image-20141208-20498-1u6ripd.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=441&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Philae hangs on … just.</span>
<span class="attribution"><a class="source" href="http://www.esa.int/spaceinimages/Images/2014/11/Welcome_to_a_comet">ESA</a></span>
</figcaption>
</figure>
<p>Be prepared for a potential 2015 sequel which may see the hibernating Philae awaken as its ride approaches the Sun and the little probe’s solar panels eke enough power out of the rays to spring back to life.</p>
<h2>Best quiet achiever</h2>
<p>The year 2014 was observed, by the UN, as an <a href="http://www.un.org/en/events/observances/years.shtml">international year</a> for small island developing states, family farming and of crystallography. <a href="https://theconversation.com/explainer-what-is-x-ray-crystallography-22143">Crystallography</a> wins out. It is a technique that usually gets little mainstream attention despite its importance to chemistry, physics and biology. Its implementation has led to no less than 27 Nobel prizes, not to mention the <a href="https://theconversation.com/the-little-known-science-that-improved-everything-around-us-22452">development of countless</a> medical advances, technological discoveries and engineering innovations. </p>
<p>And so 2014 saw an <a href="http://richannel.org/celebrating-crystallography">effort</a> from <a href="http://www.nature.com/news/specials/crystallography-1.14540">major</a> science and <a href="http://www.theguardian.com/science/occams-corner/2014/jan/14/dorothy-hodgkin-year-of-crystallography">media</a> <a href="http://science.time.com/2014/01/09/crystallography-100-years/">outlets</a> to highlight the importance of the 100 year old technique to today’s world.</p>
<h2>Biggest story</h2>
<p>The <a href="https://theconversation.com/uk/topics/ebola">Ebola</a> epidemic started in Guéckédou in Guinea, where a <a href="edition.cnn.com/2014/10/28/health/ebola-patient-zero/index.html?iid=article_sidebar">two-year-old girl</a> who died in late 2013, is believed to be the first case. In March the <a href="http://www.cdc.gov/">CDC</a> announced <a href="http://edition.cnn.com/2014/04/11/health/ebola-fast-facts/">the outbreak</a> and since then the virus and the resting hemorrhagic fever has dominated the science news. By the <a href="http://www.economist.com/blogs/graphicdetail/2014/12/ebola-graphics">end of November</a>
more than 17,000 people had been infected resulting in more than 6,000 deaths. </p>
<p>The ramifications could be felt worldwide, with <a href="http://www.bbc.co.uk/news/health-29549722">health screening</a> at international airports, <a href="http://www.theguardian.com/us-news/2014/dec/02/us-ebola-treatment-hospital">western hospitals prepping</a> to handle Ebola victims, <a href="http://www.telegraph.co.uk/news/worldnews/ebola/11202797/American-Ebola-nurse-wins-court-battle-to-avoid-quarantine-order.html">court rulings</a> on the quarantine of infected health workers and <a href="http://www.bbc.co.uk/news/health-28663217">unprecedented circumvention of drug trials</a> in an attempt to rush experimental drugs and vaccines into use.</p>
<h2>Quickest u-turn</h2>
<p>In 1916 Einstein predicted the existence of waves and a corresponding particle, the graviton, that are responsible for gravity. But almost a century later and despite a plethora of massive experiments, direct evidence of either the waves or particles is sorely lacking. Without this evidence the two dominating pillars of physics, general relativity and quantum mechanics, remain at odds.</p>
<p>So in March the science world was aflutter with the news of the <a href="http://www.theguardian.com/science/2014/mar/17/primordial-gravitational-wave-discovery-physics-bicep">discovery</a> of these allusive gravitational waves. The BICEP2 telescope in the heart of Antarctica peering into the distant Universe and back to the afterglow of the Big Bang found tantalising signs of the long sought gravity waves.</p>
<p>Before the talk of <a href="http://www.theguardian.com/science/2014/mar/21/gravitational-waves-nobel-prize-inflation">Nobel prizes</a> could die down, the evidence <a href="http://physicsworld.com/cws/article/news/2014/sep/22/bicep2-gravitational-wave-result-bites-the-dust-thanks-to-new-planck-data">disappeared in a cloud of dust</a>. The data that looked so promising turned out to be the result of fine matter scattered throughout our galaxy.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/66533/original/image-20141208-20507-zfqpid.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/66533/original/image-20141208-20507-zfqpid.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/66533/original/image-20141208-20507-zfqpid.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/66533/original/image-20141208-20507-zfqpid.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/66533/original/image-20141208-20507-zfqpid.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/66533/original/image-20141208-20507-zfqpid.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/66533/original/image-20141208-20507-zfqpid.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/66533/original/image-20141208-20507-zfqpid.jpg?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">BICEP2 flexes at the South Pole.</span>
<span class="attribution"><a class="source" href="http://en.wikipedia.org/wiki/BICEP_and_Keck_Array#mediaviewer/File:South_pole_spt_dsl.jpg">Amble</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<p>But in science there is no shame in a u-turn. Theories and interpretations are adapted in the face of evidence. And so the hunt for the source of gravity continues.</p>
<h2>Most overlooked innovation</h2>
<p>In the decade that Rosetta was homing in on its target, research into a far less dramatic topic was gaining traction.</p>
<p><a href="http://www.nature.com/articles/504S1a.epdf?shared_access_token=WMGAb3ONLaX--bfGK-8EGtRgN0jAjWel9jnR3ZoTv0NYaB9RDJcu38wBR5pnw6QRFGDQdXK7XdS3I0siGEr0-DRJ5W0NXUI6g2n2ccND_QBIgx75tyg8dJQsg_RxKBSI1Lg7ZAgG3i1P7K41yO71cfuBg7ZsXMQRIUHPLLi9Tn1nLK0fB4sa8oBVA1h9rxZzdiHH-kfgOcOJiq4b7gzb5Q%3D%3D">Cancer immunotherapy</a> went mainstream this year. It may not have had the same media coverage as space science and medical epidemics, but its likely to have a greater impact on many of our lives.</p>
<p>The therapy exploits subtle differences between the surface proteins on cancer and normal cells, then persuades our own immune system to recognise these differences and attack the cancer cells.</p>
<p>The fruits of this research ripened in 2014, with <a href="http://www.tandfonline.com/doi/abs/10.4161/onci.27048#.VIRLFGSsX9c">trials</a> <a href="http://www.cancer.org/treatment/treatmentsandsideeffects/treatmenttypes/immunotherapy/immunotherapy-whats-new-immuno-res">underway</a> and promising successes reported in top the journal <a href="http://www.sciencemag.org/content/344/6184/641">Science</a> and Nature Cancer reviews published <a href="http://www.nature.com/search/executeSearch?pub-date-mode=exact&sp-q-3=&sp-q-2=&siteCode=nrc&sp-q-9%5BNRC%5D=1&sp-c=25&shunter=1416997528296&sp-advanced=true&sp-q=immunotherapy&sp-p=all&sp-s=&sp-date-range=0&sp-q-10=&sp-q-11=&sp-q-12=2014&sp-start-month=&sp-start-year=&sp-end-month=&sp-end-year=">24 articles</a> on the subject.</p>
<h2>Losses</h2>
<p>The year saw the passing of some truly great and <a href="http://www.telegraph.co.uk/news/obituaries/science-obituaries/">influential scientists</a>. To name three:</p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/66532/original/image-20141208-20504-1v4if3w.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/66532/original/image-20141208-20504-1v4if3w.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/66532/original/image-20141208-20504-1v4if3w.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=725&fit=crop&dpr=1 600w, https://images.theconversation.com/files/66532/original/image-20141208-20504-1v4if3w.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=725&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/66532/original/image-20141208-20504-1v4if3w.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=725&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/66532/original/image-20141208-20504-1v4if3w.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=911&fit=crop&dpr=1 754w, https://images.theconversation.com/files/66532/original/image-20141208-20504-1v4if3w.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=911&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/66532/original/image-20141208-20504-1v4if3w.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=911&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Chemistry pioneer Stephanie Kwolek.</span>
<span class="attribution"><a class="source" href="http://en.wikipedia.org/wiki/Stephanie_Kwolek#mediaviewer/File:Stephanie_Kwolek_at_Spinning_Elements_by_Harry_Kalish.TIF">Chemical Heritage Foundation</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<p>Chemist <a href="http://www.telegraph.co.uk/news/obituaries/10923157/Stephanie-Kwolek-obituary.html">Stephanie Kowlek</a> was most well known for her work on a compound beloved by soldiers and cyclists alike. For she invented the kevlar used in bullet-proof vests and puncture-resistant tires. Kowlek’s chemical was patented by Dupont for whom she served for 40 years.</p>
<p><a href="http://blogs.scientificamerican.com/cross-check/2014/05/22/my-testy-encounter-with-the-late-great-gerald-edelman/">Gerald Edelman</a> received a Nobel prize for discovering the structure of antibodies. His work resolved questions about how our bodies deal with invaders. An understanding on which cancer immunotherapy now hangs. He passed away in May aged 84.</p>
<p><a href="http://www.theguardian.com/science/2014/sep/14/dame-julia-polak">Julia Polak</a> was a pioneer in stem cell and tissue engineering. Her own need for a lung transplant triggered her desire to research growing artificial implants. She died aged 75, almost 20 years after her transplant.</p>
<p>Their achievements, of course, live on. So here’s looking forward to a <a href="http://www.light2015.org/Home.html">bright 2015</a>.</p><img src="https://counter.theconversation.com/content/35163/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Mark Lorch 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>’Tis the season for listicles rounding up the stories of the year. So with, the authority vested in me, here is a selection of six top, bottom and forgotten science stories of 2014. Bounciest landing The…Mark Lorch, Senior Lecturer in Biological Chemistry, University of HullLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/320482014-09-23T16:22:31Z2014-09-23T16:22:31ZBICEP2 ‘gravity wave’ finding clouded by interstellar dust<figure><img src="https://images.theconversation.com/files/59787/original/y8tfq73x-1411474080.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Planck telescope and the Cosmic microwave background.</span> <span class="attribution"><a class="source" href="http://www.esa.int/spaceinimages/Images/2013/03/Planck_and_the_cosmic_microwave_background">ESA and Planck</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span></figcaption></figure><p>In March, scientists working on the BICEP2 experiment, a microwave telescope based at the South Pole, <a href="https://theconversation.com/explainer-what-a-flexed-bicep-tells-us-about-the-big-bang-24515">announced</a> that they had seen ‘gravity waves’ from the early universe, created just after the Big Bang. Ever since the announcement, the cosmological community has been excitedly debating the implications of their detection. </p>
<p>However, their claims have been <a href="http://arxiv.org/abs/1405.7351">called into question</a> by <a href="http://arxiv.org/abs/1405.5857">other cosmologists</a>. There is <a href="http://arxiv.org/abs/1409.5738">growing evidence</a> that at least part of what BICEP2 saw might be much more mundane, coming instead from dust in our own Milky Way galaxy.</p>
<p>At the heart of the discussion is the theory of “cosmic inflation”, which suggests the universe underwent a period of very fast expansion, when a microscopic region was stretched to be larger than our observable universe. Inflation provides a mechanism for explaining why matter is spread out evenly throughout the universe, even though some of it forms large lumps in the form of galaxies. </p>
<p>However, the theory also predicts the creation of gravitational waves in the process of inflation. This is what BICEP2 – which stands for the Background Imaging of Cosmic Extragalactic Polarisation telescope – was <a href="https://theconversation.com/scientists-at-work-building-up-bicep2-at-the-south-pole-to-make-discovery-of-the-year-24610">built</a> to seek out. The March results from BICEP2 were based on observations of remnant light from the big bang, known as the cosmic microwave background (CMB). </p>
<p>CMB observations have always been troubled by noise in the form of foreground signals like glowing dust, which was left behind by dying stars in interstellar space. However, the strength of these competing signals depends on the wavelength of light that we observe. Cosmologists have been fortunate that, when we look away from our galaxy and in the right microwave wavelengths, these foreground signals are smaller than the radiation from the early universe. Controlling for these foregrounds is why satellite experiments, such as European Space Agency’s <a href="http://www.rssd.esa.int/index.php?project=planck">Planck mission</a>, have played a crucial role in improving our understanding of the early universe.</p>
<p>The BICEP2 team made their claim based on seeing a particular kind of pattern, or handedness, in the direction of the CMB polarisation, called B-modes. (The CMB is linearly polarised, just as sunlight is if reflected off of a flat surface.) Their case for B-modes seemed very strong, and few questioned that authenticity of the signals. However, what is in doubt is whether the B-modes they have seen actually imply the existence of primordial gravity waves. </p>
<p>In order to see the CMB signals produced by gravity waves, B-mode experiments must be much more sensitive. However, at this sensitivity, our understanding of foreground signals that could contaminate the actual signal is much poorer. In particular, it is possible that the B-modes seen by BICEP2 could actually be coming from galactic dust. This viewpoint has been supported by a <a href="http://arxiv.org/abs/1409.5738">study</a> of the dust B-mode signal obtained by the Planck space telescope.</p>
<p>BICEP2 only observed in one wavelength, which made it difficult for them to prove the B-modes they saw were truly from gravitational waves. To compensate for this, BICEP2 focused on a part of the sky where the dust signal was predicted to be smaller than the gravity wave signal – and so that is why they interpreted their B-modes as evidence of gravity waves.</p>
<p>However, using new data taken at wavelengths dominated by dust, the Planck team has shown that the dust models BICEP2 used were inadequate and the dust B-modes could actually be comparable to the signal that BICEP2 found. This is not to say that BICEP2 didn’t see some gravity waves, as the models are still uncertain, but it is clear that we need to understand dust better before we can have confidence that we have seen the primordial gravity waves.</p>
<p>To fully resolve this uncertainty, we must compare in detail B-modes seen in different microwave wavelengths. This is <a href="http://www.simonsfoundation.org/quanta/20140921-big-bang-signal-could-all-be-dust-planck-says/">already happening</a>, as BICEP2 and Planck are now collaborating to see how similar the dust maps from Planck are to those from BICEP2. The BICEP2 team are also now observing the same part of sky with new set of telescopes, which are sensitive to two wavelengths and will provide a way to filter out the dust signal.</p>
<p>For the moment at least, the detection of primordial gravity waves seems to be clouded by interstellar dust. BICEP2’s interpretation of what they saw seems to have been premature. But the opportunity is there to soon settle the question much more definitively and when the dust finally settles, we may be left with much more confidence that the elusive gravity waves have finally been seen.</p><img src="https://counter.theconversation.com/content/32048/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Robert Crittenden 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>In March, scientists working on the BICEP2 experiment, a microwave telescope based at the South Pole, announced that they had seen ‘gravity waves’ from the early universe, created just after the Big Bang…Robert Crittenden, Reader in Cosmology, University of PortsmouthLicensed as Creative Commons – attribution, no derivatives.