tag:theconversation.com,2011:/us/topics/south-pole-9518/articlesSouth Pole – The Conversation2023-06-29T20:01:42Ztag:theconversation.com,2011:article/2086222023-06-29T20:01:42Z2023-06-29T20:01:42ZA neutrino portrait of our galaxy reveals high-energy particles from within the Milky Way<figure><img src="https://images.theconversation.com/files/534726/original/file-20230629-23-u6xkg.jpg?ixlib=rb-1.1.0&rect=643%2C0%2C1211%2C850&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">IceCube Collaboration/Science Communication Lab for CRC 1491</span></span></figcaption></figure><p>Our Milky Way galaxy is an awe-inspiring feature of the night sky, viewable with the naked eye as a hazy band of stars stretching from horizon to horizon.</p>
<p>For the first time, the IceCube Neutrino Observatory in Antarctica has produced an image of the Milky Way using neutrinos – tiny, ghost-like astronomical messengers. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/534734/original/file-20230629-25-v10rmi.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A photo of the band of the Milky Way with extra shading in blue." src="https://images.theconversation.com/files/534734/original/file-20230629-25-v10rmi.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/534734/original/file-20230629-25-v10rmi.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=337&fit=crop&dpr=1 600w, https://images.theconversation.com/files/534734/original/file-20230629-25-v10rmi.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=337&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/534734/original/file-20230629-25-v10rmi.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=337&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/534734/original/file-20230629-25-v10rmi.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=424&fit=crop&dpr=1 754w, https://images.theconversation.com/files/534734/original/file-20230629-25-v10rmi.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=424&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/534734/original/file-20230629-25-v10rmi.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=424&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">A portrait of the Milky Way combining visible light and neutrino emissions (in blue).</span>
<span class="attribution"><span class="source">IceCube Collaboration/US National Science Foundation (Lily Le & Shawn Johnson)/ESO (S. Brunier)</span></span>
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<p>In <a href="http://dx.doi.org/10.1126/science.adc9818">research published today</a> in the journal Science, the IceCube Collaboration – an international group of more than 350 scientists – presents evidence of high-energy neutrino emission coming from the Milky Way.</p>
<p>We have not yet figured out exactly where in our galaxy these particles are coming from. But today’s result brings us closer to finding some of the galaxy’s most extreme environments.</p>
<h2>Neutrino astronomy</h2>
<p>Neutrinos offer a unique view of the cosmos as they can travel directly from places no other radiation or particles can escape from. This makes them very interesting to astronomers, because neutrinos offer a window into the extreme cosmic environments that create another kind of particle called cosmic rays.</p>
<p>Cosmic rays are high-energy particles that permeate our Universe, but their origins are difficult to pin down. Cosmic rays are electrically charged, which means their path through space is scrambled by magnetic fields, and by the time one arrives at Earth there is no way to tell where it came from. </p>
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Read more:
<a href="https://theconversation.com/spotting-astrophysical-neutrinos-is-just-the-tip-of-the-icecube-20499">Spotting astrophysical neutrinos is just the tip of the IceCube</a>
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<p>However, the environments that accelerate cosmic rays to extraordinary energies also produce neutrinos – and neutrinos have no electric charge, so they travel in nice straight lines. So if we can detect the path of neutrinos arriving at Earth, this will point back to where the neutrinos were created. </p>
<p>But detecting those neutrinos is not so easy. </p>
<h2>How to hunt neutrinos</h2>
<p>The IceCube Neutrino Observatory is not far from the South Pole. It uses more than 5,000 light sensors arrayed throughout a cubic kilometre of pristine Antarctic ice to search for signs of high-energy neutrinos from our galaxy and beyond. </p>
<p>Vast numbers of neutrinos are streaming through Earth all the time, but only a tiny fraction of them bump into anything on their way through.</p>
<p>Each neutrino interaction makes a tiny flash of light – and those tiny flashes are what the IceCube sensors look out for. The direction and energy of the neutrino can be determined from the amount and pattern of light detected.</p>
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<a href="https://images.theconversation.com/files/534733/original/file-20230629-23-b8qav.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/534733/original/file-20230629-23-b8qav.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/534733/original/file-20230629-23-b8qav.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/534733/original/file-20230629-23-b8qav.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/534733/original/file-20230629-23-b8qav.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/534733/original/file-20230629-23-b8qav.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/534733/original/file-20230629-23-b8qav.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/534733/original/file-20230629-23-b8qav.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="attribution"><span class="source">IceCube Collaboration</span></span>
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<p>IceCube has previously detected high-energy neutrinos coming from outside the Milky Way. However, it has been more challenging to isolate the lower-energy neutrinos coming from within our galaxy.</p>
<p>This is because some flashes IceCube detected can be traced to cosmic rays hitting Earth’s atmosphere, which create neutrinos and other particles called muons. To filter out these flashes, IceCube researchers have developed ways to distinguish particles created in the atmosphere and those from further afield by the shape of the light patterns they create in the ice. </p>
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<em>
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Read more:
<a href="https://theconversation.com/an-antarctic-neutrino-telescope-has-detected-a-signal-from-the-heart-of-a-nearby-active-galaxy-193845">An Antarctic neutrino telescope has detected a signal from the heart of a nearby active galaxy</a>
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<p>Filtering out the unwanted detections has made IceCube more sensitive to astrophysical neutrinos. The final breakthrough that allowed the creation of a neutrino image of the Milky Way came from machine-learning methods that improve the identification of cascades of light produced by neutrinos, as well as the determination of the neutrino’s direction and energy.</p>
<h2>Closing in on cosmic rays</h2>
<p>The new neutrino lens on our galaxy will help reveal where the most powerful accelerators of galactic cosmic rays are located. We hope to learn how energetic these particles can get, and the inner workings of these high-energy galactic engines.</p>
<p>However, we are yet to pinpoint these accelerators within the Milky Way. The new IceCube analysis found evidence for neutrinos coming from broad regions of the galaxy, but was not able to discern individual sources.</p>
<p>Our team, at the University of Canterbury in New Zealand and the University of Adelaide in Australia, has a plan to realise that next step.</p>
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<a href="https://images.theconversation.com/files/534735/original/file-20230629-17-4f6jrd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/534735/original/file-20230629-17-4f6jrd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/534735/original/file-20230629-17-4f6jrd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=342&fit=crop&dpr=1 600w, https://images.theconversation.com/files/534735/original/file-20230629-17-4f6jrd.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=342&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/534735/original/file-20230629-17-4f6jrd.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=342&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/534735/original/file-20230629-17-4f6jrd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=430&fit=crop&dpr=1 754w, https://images.theconversation.com/files/534735/original/file-20230629-17-4f6jrd.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=430&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/534735/original/file-20230629-17-4f6jrd.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=430&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">Five views of the Milky Way: the top two bands show visible light and gamma rays, while the lower three show expected and real neutrino results, plus a measure of the significance of neutrino events detected by IceCube.</span>
<span class="attribution"><span class="source">IceCube Collaboration</span></span>
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<p>We are making models to predict the neutrino signal close to likely particle accelerators so we can target our searches for neutrinos. </p>
<p>Undergraduate student Rhia Hewett and PhD student Ryan Burley are examining pairs of accelerator candidates and molecular dust clouds. They plan to estimate the flux of neutrinos produced by cosmic rays interacting in the clouds, after the neutrinos travel from the accelerators. </p>
<p>They will use their results to enable a focused search of IceCube data for the sources of neutrino emissions. We believe this will provide the key to using IceCube to unlock the secrets of the most energetic processes in the Milky Way.</p>
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<a href="https://images.theconversation.com/files/534731/original/file-20230629-22-fmkvpi.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/534731/original/file-20230629-22-fmkvpi.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/534731/original/file-20230629-22-fmkvpi.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=2067&fit=crop&dpr=1 600w, https://images.theconversation.com/files/534731/original/file-20230629-22-fmkvpi.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=2067&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/534731/original/file-20230629-22-fmkvpi.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=2067&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/534731/original/file-20230629-22-fmkvpi.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=2597&fit=crop&dpr=1 754w, https://images.theconversation.com/files/534731/original/file-20230629-22-fmkvpi.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=2597&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/534731/original/file-20230629-22-fmkvpi.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=2597&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">A timeline of neutrino astronomy.</span>
<span class="attribution"><span class="source">IceCube Collaboration</span></span>
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</figure><img src="https://counter.theconversation.com/content/208622/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Jenni Adams has received funding from the Marsden Fund Council from New Zealand Government funding, managed by the Royal Society Te Apārangi. </span></em></p>Neutrinos are some of nature’s most elusive particles, but new research has used them to create an image of our own galaxy.Jenni Adams, Professor, Physics and Astronomy, University of CanterburyLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1649032021-09-07T12:54:21Z2021-09-07T12:54:21ZWhy are planets round?<figure><img src="https://images.theconversation.com/files/413571/original/file-20210728-23-c5bsvh.jpg?ixlib=rb-1.1.0&rect=362%2C137%2C5018%2C3690&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The Earth is round.</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/boy-holding-up-a-large-globe-outdoors-royalty-free-image/1279305617?adppopup=true">Alistair Berg/DigitalVision via Getty Images</a></span></figcaption></figure><figure class="align-left ">
<img alt="" src="https://images.theconversation.com/files/281719/original/file-20190628-76743-26slbc.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/281719/original/file-20190628-76743-26slbc.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=293&fit=crop&dpr=1 600w, https://images.theconversation.com/files/281719/original/file-20190628-76743-26slbc.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=293&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/281719/original/file-20190628-76743-26slbc.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=293&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/281719/original/file-20190628-76743-26slbc.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=368&fit=crop&dpr=1 754w, https://images.theconversation.com/files/281719/original/file-20190628-76743-26slbc.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=368&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/281719/original/file-20190628-76743-26slbc.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=368&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><a href="https://theconversation.com/us/topics/curious-kids-us-74795">Curious Kids</a> is a series for children of all ages. If you have a question you’d like an expert to answer, send it to <a href="mailto:curiouskidsus@theconversation.com">curiouskidsus@theconversation.com</a>.</em></p>
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<blockquote>
<p><strong>Why are planets round? – Daniel B., La Crosse, Wisconsin</strong></p>
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<p>The <a href="https://www.aps.org/publications/apsnews/200606/history.cfm">ancient Greeks proved</a> over 2,000 years ago that the Earth was round and figured out how big it was by using simple observations of the Sun. </p>
<p>But how do people know this today? When you drop anything, gravity causes it to fall directly toward the center of the Earth, at least until it hits the ground. <a href="https://plato.stanford.edu/entries/newton-principia/">Gravity</a> is a force that is caused by nearly everything that has mass. <a href="https://plato.stanford.edu/entries/newton-principia/">Mass</a> is a measure of how much material there is in anything. It could be in the form of rocks, water, metal, people – anything. Everything material has mass, and therefore everything causes gravity. Gravity always pulls toward the center of mass. </p>
<p><div data-react-class="Tweet" data-react-props="{"tweetId":"1171426852340207617"}"></div></p>
<p>The Earth and all planets are round because when the <a href="https://phys.org/news/2015-01-planets.html">planets formed</a>, they were composed of molten material – essentially very hot liquid. Since gravity always points toward the center of a mass, it squeezed the stuff the Earth is made of equally in all directions and formed a ball. When the Earth cooled down and became a solid, it was a round ball. If the Earth didn’t spin, then it would have been a perfectly round planet. Scientists call something that is perfectly round in all directions a “sphere.” </p>
<p>The gas cloud that the Earth was made from was slowly rotating in one direction around an axis. The top and bottom of this <a href="https://www.nationalgeographic.org/encyclopedia/axis/">axis are the north and south poles of Earth</a>.</p>
<p>Now, hold out your right hand. Point your thumb on your right hand straight up, and curl your fingers around the direction of rotation. Your thumb is pointing toward the North pole. The equator is defined as the plane, halfway between the North and South Poles. </p>
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<a href="https://images.theconversation.com/files/413592/original/file-20210728-15-1x6e081.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Three young girls playing on a playground carousel" src="https://images.theconversation.com/files/413592/original/file-20210728-15-1x6e081.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/413592/original/file-20210728-15-1x6e081.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/413592/original/file-20210728-15-1x6e081.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/413592/original/file-20210728-15-1x6e081.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/413592/original/file-20210728-15-1x6e081.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/413592/original/file-20210728-15-1x6e081.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/413592/original/file-20210728-15-1x6e081.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">Centrifugal force in action on this carousel.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/kids-on-carousal-in-playground-royalty-free-image/82980840?adppopup=true">Todd Warnock/DigitalVision via Getty Images</a></span>
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<p>If you ever played on a merry-go-round, you know that the spinning merry-go-round tends to throw you off. The faster it spins, the harder it is to stay on. This tendency to be flung off is called <a href="https://www.sciencedirect.com/topics/earth-and-planetary-sciences/centrifugal-force">centrifugal force</a> and pushes the mass on the equator outward. This makes the planet bulge at the equator.</p>
<p>The faster the spin, the more unround it becomes. Then, when it cools and hardens, it retains that shape. If a molten planet starts off spinning faster, it would be less round and have a bigger bulge. </p>
<p>The <a href="https://phys.org/news/2015-08-planet-saturn.html">planet Saturn</a> is very oblate – non-spherical – because it rotates very fast. Because of gravity, all planets are round, and because they rotate at different rates, some have fatter equators than their poles. So the shape of the planet and the speed and direction that it rotates depends on the initial condition of the material out of which it forms.</p>
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<p><em>Hello, curious kids! Do you have a question you’d like an expert to answer? Ask an adult to send your question to <a href="mailto:curiouskidsus@theconversation.com">CuriousKidsUS@theconversation.com</a>. Please tell us your name, age and the city where you live.</em></p>
<p><em>And since curiosity has no age limit – adults, let us know what you’re wondering, too. We won’t be able to answer every question, but we will do our best.</em></p><img src="https://counter.theconversation.com/content/164903/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>James Webb is affiliated with American Astronomical Society -full member
Planetary society - member
National Space Society- member
Southern Cross Astronomical Society lifetime member</span></em></p>Gravity, mass and centrifugal force all contribute to the final shape of a planet.James Webb, Professor and Director, Stocker AstroScience Center for Physics; Stocker AstroScience Center, Florida International UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1342942020-03-30T12:14:32Z2020-03-30T12:14:32ZFighting boredom with banjos and Russian grammar – tips from polar explorers for surviving months of isolation<figure><img src="https://images.theconversation.com/files/323034/original/file-20200325-168872-5offth.jpg?ixlib=rb-1.1.0&rect=8%2C24%2C5371%2C3726&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Members of Shackleton's Nimrod Expedition (1907–1909) gather round a gramophone player in Antarctica.</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/music-in-the-hut-circa-1908-expedition-members-gather-round-news-photo/1036138474?adppopup=true">Artist Unknown/Getty Images</a></span></figcaption></figure><p>Due to Antarctica’s extreme winter, which includes four months of total darkness, polar explorers endured intense confinement in close quarters for long periods of time. </p>
<p>American pioneer <a href="https://islandpress.org/books/alone">Richard Byrd</a> explained, “little things … have the power to drive even the most disciplined … to the edge of insanity. The ones who survive with a measure of happiness are those who can live profoundly off their intellectual resources, as hibernating animals live off their fat.” </p>
<p>How did the Antarctic explorers of the early 1900s survive tedium in the time long before the internet? </p>
<h2>Music</h2>
<p>Music was vital to the sanity and welfare of the explorers. “It is necessary to be cut off from civilization … to realize fully the power music has to recall the past…to soothe the present and give hope for the future,” said <a href="https://books.google.com/books?id=bkPDBAAAQBAJ&printsec=frontcover&dq=apsley+Cherry-Garrard&hl=en&newbks=1&newbks_redir=0&sa=X&ved=2ahUKEwjmxKfzsbHoAhUFrZ4KHUsGBAUQ6AEwAHoECAMQAg#v=onepage&q=apsley%20Cherry-Garrard&f=false">one of the youngest members</a> of the Terra Nova Expedition (1910-1913).</p>
<p>The Scottish National Antarctic Expedition (1902-04) included an official bagpiper. Admiral Byrd brought a phonograph to the Advance Base in 1934, calling music his “only real luxury.” </p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/322654/original/file-20200324-155674-15dvqk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/322654/original/file-20200324-155674-15dvqk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/322654/original/file-20200324-155674-15dvqk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=847&fit=crop&dpr=1 600w, https://images.theconversation.com/files/322654/original/file-20200324-155674-15dvqk.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=847&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/322654/original/file-20200324-155674-15dvqk.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=847&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/322654/original/file-20200324-155674-15dvqk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1065&fit=crop&dpr=1 754w, https://images.theconversation.com/files/322654/original/file-20200324-155674-15dvqk.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1065&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/322654/original/file-20200324-155674-15dvqk.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1065&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Shackleton’s ship Endurance, slowly being crushed by an ice floe in 1915.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:StateLibQld_1_242813_Frank_Hurley%27s_photograph_of_the_Endurance_being_crushed_by_the_ice_in_Antarctica,_1915.jpg">Frank Hurley/Wikimedia</a></span>
</figcaption>
</figure>
<p>When abandoning the slowly sinking ship Endurance, Ernest Shackleton’s men were allowed to carry only two pounds of personal effects. But <a href="https://books.google.com/books?id=uMGUCgAAQBAJ&pg=PA190&lpg=PA190&dq=it%E2%80%99s+vital+mental+medicine,+and+we+shall+need+it.%E2%80%9D&source=bl&ots=--BC_xeUxY&sig=ACfU3U2oXjz-icNd7Pya4Nb-ErzARiwPiw&hl=en&sa=X&ved=2ahUKEwiuoaDusrHoAhUMqZ4KHeyYD_kQ6AEwAXoECAgQAQ#v=onepage&q=it%E2%80%99s%20vital%20mental%20medicine%2C%20and%20we%20shall%20need%20it.%E2%80%9D&f=false">Shackleton</a> insisted that meteorologist Leonard Hussey take his six-pound banjo along, saying, “It’s vital mental medicine, and we shall need it.”</p>
<h2>Reading</h2>
<p>Books played an huge role in the lives of polar explorers. The library aboard Endurance included plays, poetry, books on exploration, the Encyclopedia Britannica and novels like “The Brothers Karamazov.” When the ship went down, <a href="https://books.google.com/books?id=EexAIe_QGb0C&printsec=frontcover&dq=south+shackleton&hl=en&newbks=1&newbks_redir=0&sa=X&ved=2ahUKEwidoNevsbHoAhUVgp4KHf9jC0kQ6AEwBXoECAIQAg#v=onepage&q=south%20shackleton&f=false">Shackleton</a> rescued a Rudyard Kipling poem. He tore the first page out of a bible given to him by Queen Alexandra, abandoning the rest of the heavy text, though a crew member secretly saved it.</p>
<p>Poetry, <a href="https://books.google.com/books?id=bkPDBAAAQBAJ&printsec=frontcover&dq=apsley+Cherry-Garrard&hl=en&newbks=1&newbks_redir=0&sa=X&ved=2ahUKEwjmxKfzsbHoAhUFrZ4KHUsGBAUQ6AEwAHoECAMQAg#v=onepage&q=apsley%20Cherry-Garrard&f=false">one explorer</a> explained, “was useful, because it gave one something to learn by heart and repeat during the blank hour … when the idle mind is all too apt to think … of purely imaginary grievances.”</p>
<p>Some men even attempted to learn a language. <a href="https://www.amazon.com/South-Pole-Norwegian-Antarctic-Expedition/dp/0814706983">Roald Amundsen</a>, the leader of the Norwegian Fram Expedition (1910-1914), studied Russian grammar. While others quickly finished their lighter stories, Amundsen’s reading “had the advantage of being incomparably stiffer. Russian verbs are uncommonly difficult of digestion, and not to be swallowed in a hurry.”</p>
<h2>Diary writing</h2>
<p>Daily diaries were extremely common among polar explorers. First, men were aware accounts of their experiences could have monetary value in the future. Second, diaries served as records and keepsakes for their families. Third, as many days tended to run together, diaries became a way to differentiate one day from another. Finally, as one <a href="https://books.google.com/books?id=bkPDBAAAQBAJ&printsec=frontcover&dq=apsley+Cherry-Garrard&hl=en&newbks=1&newbks_redir=0&sa=X&ved=2ahUKEwjmxKfzsbHoAhUFrZ4KHUsGBAUQ6AEwAHoECAMQAg#v=onepage&q=apsley%20Cherry-Garrard&f=false">explorer</a> explained, “A diary in this life is one of the only ways in which a man can blow off steam.” </p>
<h2>Expedition newspapers</h2>
<p>There is a long tradition of polar explorers creating newspapers for themselves. Reports on the weather or accounts of visits to penguin colonies were interspersed with short stories, poetry, interviews, crossword puzzles and word games. They were illustrated with both humorous and artistic drawings. Over time, these texts took on a great deal of sexual content, including lewd jokes and fantasies.</p>
<p>As <a href="https://books.google.com/books?id=bkPDBAAAQBAJ&printsec=frontcover&dq=apsley+Cherry-Garrard&hl=en&newbks=1&newbks_redir=0&sa=X&ved=2ahUKEwjmxKfzsbHoAhUFrZ4KHUsGBAUQ6AEwAHoECAMQAg#v=onepage&q=apsley%20Cherry-Garrard&f=false">one explorer explained</a>, “The importance of not allowing any sense of depression to become a part of the atmosphere of our life was clear to all.”</p>
<h2>Games</h2>
<p><a href="https://babel.hathitrust.org/cgi/pt?id=osu.32435011215852&view=1up&seq=1">Carsten Borchgrevink</a>, the leader of the Southern Cross Expedition (1898-1900) said, “The sameness of those cold, dark nights attacks the minds of men like a sneaking evil spirit. We found that … playing chess and cards were very valuable pastimes.” Sometimes men “shouted and jumped during their game and it is a wonder they did not upset the little board on which they played.”</p>
<p>Chess was also king on the Terra Nova Expedition (1910-1913). According to <a href="http://wordsworthclassics.com/collections/world-literature/scott's-last-expedition">Robert Falcon Scott</a>, “Our most popular game for evening recreation is chess; so many players have developed that our two sets of chessmen are inadequate.” </p>
<h2>Food</h2>
<p>For Antarctic explorers, almost all food was dried or consumed from tins. Hoosh, a stew made from a mix of dried meat and fat, called pemmican, thickened with cereal, provided many of the calories of the earliest expeditions. </p>
<p>To break up the monotonous cuisine, men experimented with new foods, such as penguin or seal meat. In a few cases, such as the Fram expedition and the Imperial Trans-Antarctic expedition, they even ate their dogs. </p>
<p>The often lackluster fare meant the men were often obsessed with food. Many of their conversations revolved around their ideal meals from home. In 1934, <a href="https://books.google.com/books?id=N4vdBmEvTL8C&printsec=frontcover&dq=alone+byrd&hl=en&newbks=1&newbks_redir=0&sa=X&ved=2ahUKEwi0sKjs7HoAhVTrp4KHbzVCy0Q6AEwAnoECAcQAg#v=onepage&q=alone%20byrd&f=false">Byrd</a> wrote in his diary, “I found the cook book! … The whoop of joy I uttered sounded so loud that I was actually embarrassed. … No book washed ashore to a castaway could have been more avidly studied.”</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/323041/original/file-20200325-168876-lxybf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/323041/original/file-20200325-168876-lxybf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/323041/original/file-20200325-168876-lxybf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=402&fit=crop&dpr=1 600w, https://images.theconversation.com/files/323041/original/file-20200325-168876-lxybf.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=402&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/323041/original/file-20200325-168876-lxybf.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=402&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/323041/original/file-20200325-168876-lxybf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=505&fit=crop&dpr=1 754w, https://images.theconversation.com/files/323041/original/file-20200325-168876-lxybf.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=505&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/323041/original/file-20200325-168876-lxybf.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=505&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Midwinter meal in 1912 on the Terra Nova Expedition led by British Antarctic explorer Captain Robert Falcon Scott.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/midwinter-day-1912-the-men-the-final-expedition-of-british-news-photo/1020544324?adppopup=true">Frank Debenham/The Print Collector via Getty Images</a></span>
</figcaption>
</figure>
<h2>Alcohol</h2>
<p>Polar expeditions were usually very well stocked with beer, wine and spirits. </p>
<p>There was debate over the value of alcohol on these expeditions – no one wanted to encourage drunkenness and alcohol could be dangerous in the field. But <a href="https://books.google.com/books/about/The_South_Pole.html?id=FaCqL5GlCD4C">Amundsen</a>, the first man to the South Pole, felt differently: “An occasional glass of wine or a tot of spirits were things that we all, without exception, were very glad of. … Personally, I regard alcohol, used in moderation, as a medicine in the Polar regions. … Two men who have fallen out a little in the course of the week are reconciled at once by the scent of rum.” </p>
<h2>Brains or brawn?</h2>
<p>So what kind of man survived the best under severe isolation? According to <a href="https://books.google.com/books?id=bkPDBAAAQBAJ&printsec=frontcover&dq=apsley+Cherry-Garrard&hl=en&newbks=1&newbks_redir=0&sa=X&ved=2ahUKEwjmxKfzsbHoAhUFrZ4KHUsGBAUQ6AEwAHoECAMQAg#v=onepage&q=apsley%20Cherry-Garrard&f=false">Apsley Cherry-Garrard</a> of the Terra Nova Expedition (1910-1913), “The men with the greatest store of nervous energy came best through this expedition … their strength of mind triumphed over their weakness of body. If you want a good polar traveler, get a man without too much muscle … and let his mind be on wires—of steel.”</p>
<p>[<em>Get facts about coronavirus and the latest research.</em> <a href="https://theconversation.com/us/newsletters?utm_source=TCUS&utm_medium=inline-link&utm_campaign=newsletter-text&utm_content=upper-coronavirus-facts">Sign up for our newsletter.</a>]</p><img src="https://counter.theconversation.com/content/134294/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Daniella McCahey has received funding from the American Institute of Physics, the National Science Foundation, the Royal Society of New Zealand, and the Newkirk Center for Science and Society.</span></em></p>A strong mind was key to surviving the monotony faced by Antarctic explorers enduring the isolation of long, remote winters.Daniella McCahey, History Lecturer, University of IdahoLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1128562019-03-04T19:02:37Z2019-03-04T19:02:37ZFor the first time, we can measure the human footprint on Antarctica<figure><img src="https://images.theconversation.com/files/261794/original/file-20190304-110110-1o2c5ev.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The Casey Station is part of Australia's permanent outpost in Antarctica.</span> <span class="attribution"><span class="source">Shaun Brooks</span>, <span class="license">Author provided</span></span></figcaption></figure><p>Most people picture Antarctica as a frozen continent of wilderness, but people have been living – and building – there for decades. Now, for the first time, we can reveal the human footprint across the entire continent. </p>
<p>Our research, published today in the journal <a href="http://dx.doi.org/%2010.1038/s41893-019-0237-y">Nature Sustainability</a>, found that while buildings and disturbance cover a small portion of the whole continent, it has an outsized impact on Antartica’s ecosystem.</p>
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<em>
<strong>
Read more:
<a href="https://theconversation.com/explainer-what-any-country-can-and-cant-do-in-antarctica-in-the-name-of-science-105858">Explainer: what any country can and can't do in Antarctica, in the name of science</a>
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</p>
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<p>Our data show 76% of buildings in Antarctica are within just 0.06% of the continent: the ice-free areas within 5km of the coast. This coastal fringe is particularly important as it provides access to the Southern Ocean for penguins and seals, as well as providing a typically wetter climate suitable for plant life.</p>
<h2>A hard question to answer</h2>
<p>How much land we collectively impact with infrastructure in Antarctica has been a question raised for decades, but until now has been difficult to answer. The good news is it’s a relatively small area. The bigger issue is where it is. Together with our colleagues Dana Bergstrom and John van den Hoff, we have made the first measurement of the “footprint” of buildings and disturbed ice-free ground across Antarctica.</p>
<p>This equates to more than 390,000 square metres of buildings on the icy continent, with a further 5,200,000m² of disturbance just to ice-free land. To put it another way, there is more than 1,100m² of disturbed ground per person in Antarctica at its most populated in summer. This is caused primarily by the 30 nations with infrastructure in Antarctica, along with some presence from the tourism industry.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/261791/original/file-20190304-110134-1xjs0bb.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/261791/original/file-20190304-110134-1xjs0bb.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/261791/original/file-20190304-110134-1xjs0bb.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/261791/original/file-20190304-110134-1xjs0bb.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/261791/original/file-20190304-110134-1xjs0bb.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/261791/original/file-20190304-110134-1xjs0bb.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/261791/original/file-20190304-110134-1xjs0bb.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/261791/original/file-20190304-110134-1xjs0bb.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"></a>
<figcaption>
<span class="caption">Figure Building footprint density.</span>
<span class="attribution"><span class="source">Nature Sustainability</span></span>
</figcaption>
</figure>
<p>It has taken until now to find the extent of our impact because of difficulty in gathering the data. Because so many countries are active in Antarctica, getting them to provide data on their infrastructure has been very slow. As two-thirds of research stations were built before the adoption of the <a href="http://www.ats.aq/">Protocol on Environmental Protection to the Antarctic Treaty</a>, they did not require environmental impact assessments or monitoring, so it is quite likely many of the operators do not have accessible data on their footprints. In addition, due to the inherent difficulty in accessing Antarctica, and the vast distances between each station, it is not possible to conduct field measurements on a continental scale.</p>
<p>To address these problems, our team took an established <a href="https://doi.org/10.1142/S1464333214500379">approach</a> to measuring a single station’s footprint, and applied it to 158 locations across the continent using satellite imagery. The majority of images used were freely sourced from Google Earth, enabled by continually increasing improvements in resolution and coverage. </p>
<p>This process took hours of painstaking “digitisation” – where the spatially accurate images of buildings and disturbed ground were manually mapped within a computer program to create the data.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/261797/original/file-20190304-110119-1khs4xj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/261797/original/file-20190304-110119-1khs4xj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/261797/original/file-20190304-110119-1khs4xj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=289&fit=crop&dpr=1 600w, https://images.theconversation.com/files/261797/original/file-20190304-110119-1khs4xj.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=289&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/261797/original/file-20190304-110119-1khs4xj.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=289&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/261797/original/file-20190304-110119-1khs4xj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=363&fit=crop&dpr=1 754w, https://images.theconversation.com/files/261797/original/file-20190304-110119-1khs4xj.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=363&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/261797/original/file-20190304-110119-1khs4xj.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=363&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Davis Station, one of Australia’s three permanent research outposts in Antartica. Researchers used Google Earth images to map the footprint of human infrastructure across the continent.</span>
<span class="attribution"><span class="source">Shaun Brooks</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>Interestingly, one of the most difficult sites was the United States’ Amundsen-Scott Station. As this station is located on the geographic South Pole, very few satellites pass overhead. This problem was eventually solved by trawling through thousands of aerial images produced by NASA’s <a href="https://www.nasa.gov/mission_pages/icebridge/index.html">Operation IceBridge</a>, where we found their aircraft had flown over the station in 2010. After capturing these data, we then compared our measurements against existing known building sizes and found our accuracy was within 2%. </p>
<p>Unlike buildings, we didn’t have measurements to compare for disturbed ground such as roadways, airstrips, quarries and the like. We believe we have produced a significant underestimate, due to factors including snow cover and insufficient image resolution obscuring smaller features such as walking tracks.</p>
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<p>
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<strong>
Read more:
<a href="https://theconversation.com/antarctic-seas-host-a-surprising-mix-of-lifeforms-and-now-we-can-map-them-99667">Antarctic seas host a surprising mix of lifeforms – and now we can map them</a>
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</p>
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<h2>Location, location, location</h2>
<p>After mapping the footprint of buildings and ground disturbance our data has yielded some interesting results. For practical reasons, most stations in Antarctica are located within the small ice-free areas spread across the continent, particularly around the coast. In addition to being attractive to us, these areas are essential for <a href="http://www.jstor.org/stable/43187888">much of Antarctica’s biodiversity</a> by providing nesting sites for seabirds and penguins, substrate for mosses, lichens, and two vascular plants, and habitat for the continent’s invertebrate species. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/261795/original/file-20190304-110110-1l1ajh6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/261795/original/file-20190304-110110-1l1ajh6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/261795/original/file-20190304-110110-1l1ajh6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=395&fit=crop&dpr=1 600w, https://images.theconversation.com/files/261795/original/file-20190304-110110-1l1ajh6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=395&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/261795/original/file-20190304-110110-1l1ajh6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=395&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/261795/original/file-20190304-110110-1l1ajh6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=496&fit=crop&dpr=1 754w, https://images.theconversation.com/files/261795/original/file-20190304-110110-1l1ajh6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=496&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/261795/original/file-20190304-110110-1l1ajh6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=496&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Adelie penguins need ice-free areas to access the ocean.</span>
<span class="attribution"><span class="source">Shaun Brooks</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>Another interesting finding from these data is what they tell us about wilderness on the continent. Although the current footprint covers a very small fraction of the more than 12 million square kilometres of Antarctica, we found disturbance is present in more than half of all large ice-free areas along the coast. Furthermore, by using the building data we captured, along with existing work by <a href="http://hdl.handle.net/11343/38369">Rupert Summerson</a>, we were also able to estimate the visual footprint, which amounts to an area similar in size to the total ice-free land across the whole continent.</p>
<p>The release of this research is timely, with significant increases in infrastructure proposed for Antarctica. Currently there are new stations proposed by <a href="https://theconversation.com/as-china-flexes-its-muscles-in-antarctica-science-is-the-best-diplomatic-tool-on-the-frozen-continent-86059">several nations</a>, major rebuilding projects of <a href="https://www.sciencemag.org/news/2015/12/overhaul-works-aging-us-antarctic-station">existing stations</a> underway (including the US’s McMurdo and New Zealand’s Scott Base), and Italy is building a <a href="https://www.ats.aq/documents/EIA/01877enFINAL_CEE.pdf">new runway in ice-free areas</a>.</p>
<p>Australia has proposed Antarctica’s <a href="https://www.lowyinstitute.org/the-interpreter/building-paved-runway-antarctica">first concrete runway</a>, which if built would be the continent’s largest. </p>
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Read more:
<a href="https://theconversation.com/why-antarcticas-sea-ice-cover-is-so-low-and-no-its-not-just-about-climate-change-109572">Why Antarctica's sea ice cover is so low (and no, it's not just about climate change)</a>
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<p>Until now, decisions on expanding infrastructure have been without the context of how much is already present. We hope informed decisions can now be made by the international community about how much building in Antarctica is appropriate, where it should occur, and how to manage the future of the last great wilderness.</p><img src="https://counter.theconversation.com/content/112856/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Shaun Brooks receives funding from the Australian Government Research Training Program.</span></em></p><p class="fine-print"><em><span>Julia Jabour 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>Buildings and human disturbance in Antartica is clustered in an ice-free zone that is essential to most of the continent’s biodiversity.Shaun Brooks, PhD Candidate, University of TasmaniaJulia Jabour, Leader, Ocean and Antarctic Governance Research Program, University of TasmaniaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1051482018-11-20T13:19:59Z2018-11-20T13:19:59ZRocks hold clues about how falling sea levels caused havoc 400 million years ago<figure><img src="https://images.theconversation.com/files/245155/original/file-20181112-83596-og9ffx.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Klipbokberg, Grootrivierhoogte, in the Cederberg. These mountains contain clues about ancient landscapes.</span> <span class="attribution"><span class="source">Cameron Penn-Clarke</span></span></figcaption></figure><p>The Earth was a very different place 400 million years ago, during what’s known as the <a href="https://www.livescience.com/43596-devonian-period.html">Devonian Period</a>. Africa, Antarctica, South America, India, Australia, Madagascar, parts of Asia and even Florida were part of the large super-continent, <a href="https://www.livescience.com/37285-gondwana.html">Gondwana</a>. It occupied a substantial area south of the equator. </p>
<p>Large parts of southernmost Gondwana (including what we know today as South Africa, Antarctica, Falkland Islands and parts of South America) were situated over the South Pole throughout this period. </p>
<p>By observing the types of rocks, minerals and sediments that form in different climates today, we are able to use this information to get a picture about what the climate was like during the Devonian Period. Similarly, we can use Devonian fossils to work out climates based on the environments and climates these organisms are found in today. </p>
<p>They’re also vital for inferring sea-level changes through time – and how both climate and sea-level affected marine creatures of the Devonian.</p>
<p>What is interesting is that there is no evidence of extensive ice sheets at the South Pole during the Devonian Period, as we have today covering Antarctica. Of course, there are polar ice caps in the region today. This suggests that climatic belts were distributed differently then, and have shifted through time.</p>
<p>During the Devonian, certain groups of animals congregated around the equator. Others were found in more temperate regions. A group known as the Malvinokaffric Fauna was located around the South Pole. The Malvinokaffric Fauna were a group of marine invertebrates only found in what we know as South Africa, Antarctica, the Falkland Islands and parts of South America. </p>
<p>We don’t know much about their ecology, where they came from or why they disappeared, nor about the environments they lived in around what was then the South Pole and is South Africa today. That’s where <a href="https://www.researchgate.net/profile/Cameron_Penn-Clarke2">my research</a> comes in. </p>
<p>My findings, drawn from the study of certain rocks and their sediment, as well as remnants of biological activity called trace fossils, suggest the Malvinokaffric Fauna in the Devonian South Pole were wiped out because of falling sea levels. </p>
<p>We don’t yet know what caused the drop in sea levels. But my research offers evidence of a previously unrecorded large extinction event during the Devonian, a period which experienced several such events.</p>
<h2>Wiped out</h2>
<p>South Africa has perhaps one of the best preserved and most complete records of Gondwana during the Devonian Period at polar latitudes. This record is preserved in the rocks of the uppermost Table Mountain, Bokkeveld and lower Witteberg Groups within the Cape Mountains along the country’s southern margin. </p>
<p>I study and interpret both the palaeontology and sedimentology of these rocks. I also look for any trace fossils such as trackways and burrows in the rocks. Trace fossils indicate a biological organism’s activity, which is directly related to its ecology and environment. </p>
<p>By examining sedimentary rocks, fossils and trace fossils, I’ve been able to form a picture of the lives and times of the Malvinokaffric Fauna in South Africa. From there, I can infer whether environmental changes were sudden and rapid or long-lived and gradual and how they affected the Malvinokaffric Fauna.</p>
<p>I’ve found that because this group of animals lived in certain environments, they were very sensitive to periods of excessive falling in sea-level, particularly sea level drops greater than 10 m. </p>
<p>Coincidently, the disappearance of the Malvinokaffric Fauna in South Africa is gradual and occurs with a gradual trend of falling sea-level that is observed in the rocks of the upper Bokkeveld Group. Evidence from the meagre fossil and trace fossil record after this event suggest that the disappearance of the Malvinokaffric Fauna resulted in a total collapse in marine ecosystems around the South Pole. </p>
<p>Even though different immigrant organisms from elsewhere moved in during a subsequent rise in sea-level, they never truly were able to reach the diversity of the Malvinokaffric Fauna, nor to form stable ecosystems. Life around the South Pole seems to have only truly recovered in South Africa in the Late Devonian, between 370 and 360 million years ago.</p>
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Read more:
<a href="https://theconversation.com/fossil-find-offers-first-evidence-of-four-legged-aquatic-ancestors-in-africa-97747">Fossil find offers first evidence of four-legged aquatic ancestors in Africa</a>
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<p>What I have found suggests that many shallow marine environments – beaches, shorefaces, deltas, barrier islands, lagoons and estuaries – dotted South Africa’s shoreline throughout the Devonian. </p>
<p>Initially, sea levels were low. Then about 400 million years ago they rose, only to gradually fall some 10-15 million years later. It was during this period of rising sea-level that the Malvinokaffric Fauna made their appearance in South Africa and are found in the rocks of the upper Table Mountain Group and the lower Bokkeveld Group. </p>
<p>My research indicates that these animals lived and thrived in deeper water conditions, preferably within the deepest portions of the shoreface and offshore environments where they formed specific ecosystems.</p>
<p>Now that we know that falling sea-levels probably caused the fauna to vanish. The hunt is now on to find what caused sea-level to drop.</p>
<h2>Tracking the extinction</h2>
<p>There are several possible answers, which I’m exploring in new, ongoing research. </p>
<p>For instance, local tectonic events may have caused the sea to change its configuration and sea-level to fall. Or, perhaps a global event like climatic shifts caused sea-level fall.</p>
<p>The Devonian, after all, is a time marred by extinction events that seem to be on a global scale, ultimately linked to changes in climate. </p>
<p>Right now, I don’t have the answers. But I’m exploring ways to precisely date these rocks, and see if they correlate with known local or global events and tease out the solutions from there. Hopefully soon we’ll know more about the event that wiped out the Malvinokaffric Fauna.</p><img src="https://counter.theconversation.com/content/105148/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Cameron Penn-Clarke receives funding from the South African Department of Science and Technology-National Research Foundation Centre of Excellence in Palaeosciences (DST-NRF CoE in Palaeosciences), the African Origins Platform (DST-NRF AoP) as well as the Palaeontological Scientific Trust (PAST).
He is a scientist at the Council for Geoscience, Bellville Office and is an honorary research associate of the Evolutionary Studies Institute, University of the Witwatersrand. He is also a stratigrapher for the South African Committee on Stratigraphy and is the South African associate member for the International Subcommission on Devonian Stratigraphy (International Commission on Stratigraphy).</span></em></p>A record of sea-level change from 400 million years ago in South Africa, reveals how ecosystems and environments collapsed at the South Pole.Cameron Penn-Clarke, Scientist and Honorary Research Associate, University of the WitwatersrandLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/999342018-07-22T20:07:11Z2018-07-22T20:07:11ZRemembering Antarctica’s nuclear past with ‘Nukey Poo’<figure><img src="https://images.theconversation.com/files/227917/original/file-20180717-44076-cnr07w.JPG?ixlib=rb-1.1.0&rect=0%2C2%2C1920%2C1184&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">PM-3A McMurdo Station, Antarctica
</span> <span class="attribution"><span class="source">US Army Engineer Research and Development Labs - United States Antarctic Program, Antarctic Photo Library</span></span></figcaption></figure><p>We think of Antarctica as a place to protect. It’s “pristine”, “remote” and “untouched”. (Although a recent discovery reveals it’s <a href="https://theconversation.com/how-an-alien-seaweed-invasion-spawned-an-antarctic-mystery-99944">less isolated from the world than previously thought</a>.)</p>
<p>But it wasn’t always this way. Between 1961 and 1972 McMurdo Station was home to Antarctica’s first and only portable nuclear reactor, known as PM-3A, or “Nukey Poo.” The little-known story of <a href="https://books.google.se/books?id=wwoAAAAAMBAJ&lpg=PA32&ots=VkjNgAvyhE&dq=PM-3A+Nukey+Poo&pg=PA32&redir_esc=y#v=onepage&q&f=false">Nukey Poo</a> offers a useful lens through which to examine two ways of valuing the far south: as a place to develop, or a place to protect.</p>
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Read more:
<a href="https://theconversation.com/how-an-alien-seaweed-invasion-spawned-an-antarctic-mystery-99944">How an alien seaweed invasion spawned an Antarctic mystery</a>
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<h2>The story of Nukey Poo</h2>
<p>By the late 1950s nuclear power was viewed with optimism, as an exciting new solution to both the world’s energy and social problems. The <a href="https://www.ats.aq/e/ats.htm">Antarctic Treaty</a> was signed in 1959, designating Antarctica as a place for international scientific cooperation. Both the USA and USSR were original signatories, and both were concerned about the possible use of nuclear weapons in the far south.</p>
<p>The Antarctic Treaty therefore included freedom of inspection of all facilities, and stipulated “any nuclear explosions in Antarctica and the disposal there of radioactive waste material shall be prohibited”. </p>
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Read more:
<a href="https://theconversation.com/in-30-years-the-antarctic-treaty-becomes-modifiable-and-the-fate-of-a-continent-could-hang-in-the-balance-98654">In 30 years the Antarctic Treaty becomes modifiable, and the fate of a continent could hang in the balance</a>
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<p>When Nukey Poo was built by the US Navy it was described by Admiral George Dufek as “a dramatic new era in man’s conquest of the remotest continent.”</p>
<p>While the early explorers set out with flags, pitting their bodies against the elements to claim new territory, nuclear technology represented a modern way for man to triumph over the hostile environment. PM-3A was seen as a trailblazer, and – if all went well – it was planned to be first of many installed in Antarctica.</p>
<p>Dufek also envisaged nuclear energy making possible a wide range of human activities in the far south. His imagined version of “<a href="https://trove.nla.gov.au/work/10568532?q&versionId=42474799">Antarctica in the Year 2000</a>” included nuclear-driven greenhouse crop production, geoengineering of the world’s weather, and mining ventures that helped broker world peace. </p>
<p>While geoengineering in the forms of <a href="https://www.nature.com/articles/d41586-018-03036-4">slowing the melt of glacial ice</a>, <a href="https://agupubs.onlinelibrary.wiley.com/doi/epdf/10.1002/2016EF000454">solar geoengineering</a>, and <a href="http://www.imas.utas.edu.au/news/news-items/imas-hosts-marine-geoengineering-symposium">marine geoengineering</a> continue to be discussed, mining is prohibited by the 1991 <a href="https://www.ats.aq/e/ep.htm">Protocol on Environmental Protection to the Antarctic Treaty</a>. Contemporary visions of <a href="https://www.nature.com/articles/s41586-018-0173-4">Antarctic futures</a> tend to focus on environmental change and reducing human impacts, rather than enhancing the human presence.</p>
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Read more:
<a href="https://theconversation.com/pristine-antarctic-fjords-contain-similar-levels-of-microplastics-to-open-oceans-near-big-civilisations-91360">Pristine Antarctic fjords contain similar levels of microplastics to open oceans near big civilisations</a>
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<h2>Nuclear optimism fades</h2>
<p>“Nukey Poo” began producing power for the McMurdo station in 1962, and was refuelled for the first time in 1964. A decade later, the optimism around the plant had faded. The 25-man team required to run the plant was expensive, while concerns over possible chloride stress corrosion emerged after the discovery of wet insulation during a routine inspection. Both costs and environmental impacts conspired to close the plant in September 1972.</p>
<p>This precipitated a major clean up that saw 12,000 tonnes of contaminated rock removed and shipped back to the USA through <a href="https://nzhistory.govt.nz/politics/nuclear-free-new-zealand/ship-visits">nuclear-free New Zealand</a>. The clean up pre-dated Antarctica’s modern environmental protection regime by two decades, and required the development of new standards for soil contamination levels.</p>
<p>This elaborate process ensured that the US did not violate the Antarctic Treaty by disposing of nuclear waste on the continent. It also foreshadowed a shift in environmental attitudes away from development and use, towards protection; the removal of so much as one pebble from the Antarctic without requisite permits <a href="http://www.antarctica.gov.au/law-and-treaty/the-madrid-protocol">is now prohibited</a>.</p>
<p>Today, all that physically remains at the site of the PM-3A reactor is a missing hillside and <a href="https://photolibrary.usap.gov/PhotoDetails.aspx?filename=nukey-poo-plaque.jpg">a plaque</a>. Nuclear power is no longer viewed with the optimism of the 1960s, thanks to disasters such as <a href="https://theconversation.com/forget-fukushima-chernobyl-still-holds-record-as-worst-nuclear-accident-for-public-health-57942">Chernobyl and Fukushima</a>.</p>
<p>The site where Nukey Poo once stood has been designated as a <a href="https://www.ats.aq/documents/recatt/att580_e.pdf">Historic Site and Monument</a> under the Antarctic Treaty System, putting it in the same category as the <a href="https://nzaht.org/#newsletter-signup-modal">huts of early explorers</a> such as Mawson and Shackleton.</p>
<p>However, a site with a past of nuclear contamination does not sit well within modern narratives of Antarctica as a place to protect, so this episode in the continent’s history is not often told.</p>
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<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/why-remote-antarctica-is-so-important-in-a-warming-world-88197">Why remote Antarctica is so important in a warming world</a>
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<p>When Admiral Dufek wrote in 1960 “Antarctica will be a fantastic land in the future” he had a very different vision in mind to the Antarctica we see today. Today, the far south is not a place to be improved upon with human innovation, so much as a place to be protected from our influence – including <a href="https://theconversation.com/melting-antarctic-ice-sheets-and-sea-level-rise-a-warning-from-the-future-50065">climate change</a>.</p>
<p>The episode of Nukey Poo reveals the modern association between science and the Antarctic environment has not always been so. In demonstrating how Antarctica went from being seen as territory to conquer to a fragile environment, we are reminded that its protection cannot be taken for granted</p><img src="https://counter.theconversation.com/content/99934/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Hanne E.F. Nielsen received funding from the Scientific Committee on Antarctic Research as a 2017 SCAR Fellow, and undertook research for this article whilst hosted at KTH Stockholm. </span></em></p>For just ten years Antarctica was home to a nuclear power station called “Nukey Poo”.Hanne E F Nielsen, PhD Candidate in Antarctic Representations, University of TasmaniaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/676552016-11-16T16:04:06Z2016-11-16T16:04:06ZExplainer: the search for Earth’s ‘missing fingerprint’<figure><img src="https://images.theconversation.com/files/146077/original/image-20161115-31123-1s531q8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The earth's missing 'fingerprint' sits somewhere in the upper atmosphere, but for some reason eludes climatologists.</span> <span class="attribution"><span class="source">Shutterstock</span></span></figcaption></figure><p>Our understanding of the Earth’s climate has advanced rapidly in recent years. In response to global warming, climatologists have developed excellent models looking at the behaviour of the atmosphere and its linkage to both the solid land and the oceans. </p>
<p>For instance, we have <a href="http://oceanmotion.org/html/impact/el-nino.htm">uncovered</a> the driving force behind El Niño, and can now make quite confident predictions of when it will strike and impact the global rainfall. We have also even learned how to <a href="http://www.hko.gov.hk/informtc/tracking.htm">predict</a> the wild turbulence of tropical cyclones with sufficient accuracy to save thousands of lives.</p>
<p>But, frustratingly, there are still aspects of the atmosphere’s behaviour that we do not fully understand. One of these is the missing “fingerprint”. All our models say there <a href="http://link.springer.com/article/10.1007/s003820050291">should</a> be a signal caused by increasing carbon dioxide which is so characteristic that it is like a fingerprint proving that the thief was there. The signal is part of the upper atmosphere warming more quickly than at the surface. The result should be a doughnut of air circling the earth at the tropics, which is warming far faster than the rest of the atmosphere.</p>
<p>The Fourth Assessment by the Intergovernmental Panel on Climate Change <a href="http://www.ipcc.ch/report/ar4/wg1/">in 2007</a> not only showed the fingerprint very clearly, but also showed how it would grow and contribute to global warming as carbon dioxide concentrations increased:</p>
<blockquote>
<p>These are cross-sections through the Earth’s atmosphere, from the South Pole on the left to the North Pole on the right, with altitude shown as pressure on the left-hand axis and as approximate height on the right. The “fingerprint” appears between the Tropics, between about 8 and 12km above the Earth’s surface.</p>
</blockquote>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/146188/original/image-20161116-13555-vxarpp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/146188/original/image-20161116-13555-vxarpp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/146188/original/image-20161116-13555-vxarpp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=271&fit=crop&dpr=1 600w, https://images.theconversation.com/files/146188/original/image-20161116-13555-vxarpp.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=271&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/146188/original/image-20161116-13555-vxarpp.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=271&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/146188/original/image-20161116-13555-vxarpp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=341&fit=crop&dpr=1 754w, https://images.theconversation.com/files/146188/original/image-20161116-13555-vxarpp.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=341&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/146188/original/image-20161116-13555-vxarpp.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=341&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 missing fingerprint.</span>
<span class="attribution"><span class="source">Phillip Lloyd</span></span>
</figcaption>
</figure>
<h2>Still missing</h2>
<p>The report triggered a great search for the fingerprint. But, by the Fifth Assessment, <a href="http://www.ipcc.ch/report/ar5/wg1/">in 2013</a>, there was low confidence in the data. In 2014, the American Physical Society <a href="http://www.aps.org/policy/statements/upload/climate-seminar-transcript.pdf">convened a debate</a> on the topic. Now, four sets of really reliable data had been found. These were records of balloons flown from four different weather stations. As they rose, instruments on the balloons had radioed back their position, the pressure and the local temperature. Such instrumented balloons are called radiosondes or just sondes. They showed that the fingerprint really was missing.</p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/145827/original/image-20161114-5105-9abvhh.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/145827/original/image-20161114-5105-9abvhh.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/145827/original/image-20161114-5105-9abvhh.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=655&fit=crop&dpr=1 600w, https://images.theconversation.com/files/145827/original/image-20161114-5105-9abvhh.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=655&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/145827/original/image-20161114-5105-9abvhh.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=655&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/145827/original/image-20161114-5105-9abvhh.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=823&fit=crop&dpr=1 754w, https://images.theconversation.com/files/145827/original/image-20161114-5105-9abvhh.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=823&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/145827/original/image-20161114-5105-9abvhh.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=823&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption"></span>
<span class="attribution"><span class="source">Philip Lloyd</span></span>
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</figure>
<p>The tropical temperature profiles are shown on the diagram. The horizontal axis is the rate of change of temperature per decade, over the period 1979 to 2012, and the vertical axis shows the altitude. The red lines show the results of 29 different runs of the models. They had a wide range, between the solid maximum (“max”) and dashed minimum (“min”) line, with the average (“avg”) shown by the red squares. The blue lines show the same features of the sonde data, with the average shown by the blue dots.</p>
<h2>Why we should worry</h2>
<p>The models predict that the atmosphere should warm faster than the ground as the altitude increases. The sondes show an effectively constant rate of warming of 0.1°C per decade up to 10,000m.</p>
<p>The data all predict faster warming at the North Pole, and that is precisely what we observe. So the models are almost right.</p>
<p>But without understanding why the fingerprint has failed to appear, our predictions of precisely how the rest of the globe will warm as carbon dioxide concentrations increase are rather uncertain. Wrestling with the complexities of the atmosphere, using the largest computers available, makes climatology one of the most fascinating of all sciences – and life depends on it.</p><img src="https://counter.theconversation.com/content/67655/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Philip Lloyd 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>Without understanding why the ‘fingerprint’ has failed to appear our predictions about global warming - as carbon dioxide concentrations increase - are uncertain.Philip Lloyd, Research Professor of Energy, Cape Peninsula University of TechnologyLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/620502016-07-06T20:05:29Z2016-07-06T20:05:29ZWhy Australians should care about the South Pole<figure><img src="https://images.theconversation.com/files/129505/original/image-20160706-789-1usj3rn.jpg?ixlib=rb-1.1.0&rect=0%2C131%2C1024%2C579&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Australia (whose flag is pictured on the right) is one of several countries with a big stake in the South Pole.</span> <span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File%3ACeremonial_South_Pole.jpg">Josh Landis/US NSF/Wikimedia </a></span></figcaption></figure><p>Earth’s geographic poles have been making a lot of news lately. Canada is looking to <a href="http://www.rcinet.ca/en/2016/05/08/why-canada-cant-have-the-north-pole/">make a claim on the North Pole</a> within the next couple of years, arguing that the pole (along with a large slab of the Arctic seabed) falls within the limits of its continental shelf, despite similar existing claims by Denmark and Russia.</p>
<p>The pole, however, seems to have its own view on this. Scientists <a href="https://www.newscientist.com/article/2083481-why-the-north-pole-is-now-slowly-moving-towards-london/">recently reported</a> that, having drifted towards Canada’s Hudson Bay for many decades, it has abruptly changed direction and is now headed for London.</p>
<p>It comes as a surprise to many people that Earth’s geographic poles move at all. We tend to think of them as stationary, the points where all the lines of longitude meet. Ninety degrees north and south, however, are defined as averages of the poles’ actual positions over a particular period.</p>
<p>If defined as the places where the Earth’s rotational axis meets its surface, the geographic poles are constantly on the move, with a periodic, spiral motion as well as a <a href="http://advances.sciencemag.org/content/2/4/e1501693">linear one</a>. This happens because our planet is not, as we might like to imagine, a perfect sphere, but in fact is rather lumpy. Seasonal displacement of air and water on its surface, as well as changes within its mantle, contribute to the shifting of its axis and hence the movement of the poles.</p>
<p>The distances involved are not large – the linear drift can be measured in centimetres per year – but they are revealing. The North Pole’s lurch towards London, <a href="http://news.nationalgeographic.com/2016/04/160408-climate-change-shifts-earth-poles-water-loss/">scientists suggest</a>, is a result of recent melting of glacial ice and the emptying of underground aquifers for water supplies.</p>
<p>A century ago humans had barely managed to reach either pole; now, it seems, we have inadvertently managed to move them. Our decisions and actions are more closely connected with these symbolically most remote of places than we might imagine.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/129341/original/image-20160705-19088-lpktem.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/129341/original/image-20160705-19088-lpktem.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/129341/original/image-20160705-19088-lpktem.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=352&fit=crop&dpr=1 600w, https://images.theconversation.com/files/129341/original/image-20160705-19088-lpktem.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=352&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/129341/original/image-20160705-19088-lpktem.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=352&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/129341/original/image-20160705-19088-lpktem.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=442&fit=crop&dpr=1 754w, https://images.theconversation.com/files/129341/original/image-20160705-19088-lpktem.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=442&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/129341/original/image-20160705-19088-lpktem.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=442&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Windswept and remote, but still claimed by six countries.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File%3ASastrugi.jpg">Bill McAfee/US NSF/Wikimedia Commons</a></span>
</figcaption>
</figure>
<h2>The ‘other’ pole</h2>
<p>In humanity’s thinking about the Arctic and Antarctic regions, the South Pole has long been the underdog. Due to the cartographical convention that defines north as “up”, we think of it lying under us, hidden away at the very bottom of the planet.</p>
<p>As I discuss in my book <a href="http://www.reaktionbooks.co.uk/display.asp?ISB=9781780235967">South Pole: Nature and Culture</a>, the place conjures ideas of remoteness, isolation, hostile weather, tragic explorers, altruistic scientists and even extreme tourists. But we rarely consider it in political terms.</p>
<p>The 1959 <a href="http://www.state.gov/documents/organization/81421.pdf">Antarctic Treaty</a>, which declared the continent a place of peace and science and put national claims on hold, seemed to leave behind the imperial ambitions that produced the “race to the pole” in the early 20th century. And while Antarctica’s potential mineral resources are an <a href="https://theconversation.com/in-conversation-what-does-the-future-hold-for-antarctica-28607">ongoing source of concern</a>, the South Pole, sitting atop almost 3km of ice, is not an obvious place to drill.</p>
<p>Now occupied by a large scientific research station, where (among other activities) astronomers use giant telescopes to study cosmological events, the South Pole is often assumed to be a politically neutral place, immune to the clamour going on in the north.</p>
<h2>Polar positions</h2>
<p>Why, then, should Australians care about the South Pole? Surprisingly, the pole featured in the celebrations that marked the nation’s federation in 1901. A spectacular pantomime entitled <a href="http://www.austlit.edu.au/austlit/page/C399348">Australis</a>, performed in Sydney over the summer of 1900-01, imagined a future in which Australia annexes Antarctica and takes as its capital the “City of Zero” sitting exactly at the pole – a satirical wink to the rivalry at the time between Sydney and Melbourne for the honour.</p>
<p>Although this unlikely future did not come to pass, Australia does indeed have a claim on the pole – or rather, a fraction of it. Although the pole is not the geographical centre of the continent by any means, the various wedge-shaped territorial claims – including Australia’s – meet there, like pieces of a meringue pie with the pole in the middle. The only exception is Norway’s claim, which has an undefined southern limit – ironically enough, given that Norwegians were the <a href="http://www.coolantarctica.com/Antarctica%20fact%20file/History/roald-amundsen.php">first to set foot at the pole</a>.</p>
<p>The scientific base at 90ºS – the United States’ <a href="https://www.nsf.gov/geo/plr/support/southp.jsp">Amundsen-Scott South Pole Station</a> – thus sits across six territorial claims. This is a highly strategic position for a nation that recognises none of the existing claims but reserves the right to make its own in the future.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/129343/original/image-20160705-789-mdfmoz.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/129343/original/image-20160705-789-mdfmoz.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/129343/original/image-20160705-789-mdfmoz.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=740&fit=crop&dpr=1 600w, https://images.theconversation.com/files/129343/original/image-20160705-789-mdfmoz.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=740&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/129343/original/image-20160705-789-mdfmoz.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=740&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/129343/original/image-20160705-789-mdfmoz.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=930&fit=crop&dpr=1 754w, https://images.theconversation.com/files/129343/original/image-20160705-789-mdfmoz.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=930&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/129343/original/image-20160705-789-mdfmoz.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=930&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Antarctic territorial claims.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File%3AAntarctic_Region.png">CIA World Factbook</a></span>
</figcaption>
</figure>
<h2>Connecting Australia to the pole</h2>
<p>Australia’s claim to 42% of Antarctica is also, then, a claim (indeed, the largest of any nation) on the South Pole – if it makes any sense to claim a percentage of what is, after all, technically a dot. </p>
<p>Our domestic politics, such as the recently announced <a href="http://www.antarctica.gov.au/about-us/antarctic-strategy-and-action-plan">Australian Antarctic Strategy</a>, which confirms our continued interest in the region and includes plans for greater access to the continent’s interior, are thus inextricably connected to the site sometimes described as the last place on Earth.</p>
<p>While the South Pole may not be subject to the contemporary claim-making that besets its northern cousin, this symbolic heart of Antarctica remains a deeply political place and one that Australians – both those keen to maintain our claim and those who believe that all territorial claims there are misplaced – should know and care about.</p>
<hr>
<p><em>This is the first in a series of articles on Australian science and diplomacy in Antarctica. Look out for more in the coming days.</em></p><img src="https://counter.theconversation.com/content/62050/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Elizabeth Leane receives funding from the Australian Research Council. </span></em></p>It’s one of the remotest places on Earth and yet is still claimed by six nations – including Australia.Elizabeth Leane, Assoc. Professor of English and ARC Future Fellow, University of TasmaniaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/499792015-11-13T10:52:30Z2015-11-13T10:52:30ZScientist at work: searching for tiny neutrinos in the South Pole’s thick ice<figure><img src="https://images.theconversation.com/files/101719/original/image-20151112-9362-1al7h43.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Ice cold physics: hunting for neutrinos in Antarctica.</span> <span class="attribution"><a class="source" href="http://icecube.wisc.edu/gallery/press/view/1336">Sven Lidström, IceCube/NSF</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc/4.0/">CC BY-NC</a></span></figcaption></figure><p>Standing at the South Pole is the next-best thing to being on another planet. If you walk a few hundred yards away from the buildings that make up the National Science Foundation’s <a href="https://www.nsf.gov/news/special_reports/livingsouthpole/intro.jsp">research station</a>, you see a featureless plain of snow and ice, most likely empty of living creatures larger than microbes for hundreds of miles. With nothing but snow for sound waves to echo off, there’s an eerie silence. It’s easy to get lost in reverie, contemplating the stark landscape. But then you remember that you’re here for a reason: to work on what may be the world’s weirdest telescope, searching for some of nature’s most mysterious subatomic particles.</p>
<p>Every second, more than <a href="http://pdg.lbl.gov/2015/reviews/rpp2014-rev-cosmic-rays.pdf">10,000 high-energy particles</a> – protons and atomic nuclei – rain down on every square meter of the Earth’s atmosphere. Some of them carry more than a million times the energy of the protons at the most powerful particle accelerator, CERN’s <a href="http://home.cern/topics/large-hadron-collider">Large Hadron Collider</a>. Fortunately, the atmosphere absorbs most of them, but a few stray particles pass through your body every second – they’re the reason intercontinental airline crews are classified as <a href="http://www.cdc.gov/niosh/topics/aircrew/cosmicionizingradiation.html">radiation workers</a>.</p>
<p>Scientists discovered these particles, known as cosmic rays, more than a century ago, before <a href="https://theconversation.com/from-newton-to-einstein-the-origins-of-general-relativity-50013">Einstein’s theory of general relativity</a> or <a href="http://www.nbi.ku.dk/english/www/niels/bohr/bohratomet/">Bohr’s quantum mechanical model</a> of the atom. But even today, despite half a dozen Nobel Prizes awarded for research related to cosmic rays, we’re not sure where these particles come from. The magnetic fields that fill the universe deflect cosmic rays on their way to Earth, so the direction they’re traveling when they reach us doesn’t tell us where they were originally produced. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/101731/original/image-20151112-9381-3cnoxx.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/101731/original/image-20151112-9381-3cnoxx.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/101731/original/image-20151112-9381-3cnoxx.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=449&fit=crop&dpr=1 600w, https://images.theconversation.com/files/101731/original/image-20151112-9381-3cnoxx.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=449&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/101731/original/image-20151112-9381-3cnoxx.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=449&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/101731/original/image-20151112-9381-3cnoxx.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=564&fit=crop&dpr=1 754w, https://images.theconversation.com/files/101731/original/image-20151112-9381-3cnoxx.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=564&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/101731/original/image-20151112-9381-3cnoxx.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=564&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Constructing the support tower for the hot water ‘drill’ used to melt holes 1.5 miles deep in the Antarctic ice to install IceCube sensors.</span>
<span class="attribution"><a class="source" href="http://icecube.wisc.edu/gallery/view/170">Jeff Cherwinka, IceCube/NSF</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc/4.0/">CC BY-NC</a></span>
</figcaption>
</figure>
<h2>Neutrinos hint at where cosmic rays come from</h2>
<p>I’m part of an international team of scientists who built an unusual type of telescope to look for the sources of the cosmic rays. Since the cosmic rays themselves don’t point back to their sources, we look instead for neutrinos, a type of subatomic particle that should be produced as a byproduct of cosmic ray acceleration, wherever it’s happening. (The same process occurs when cosmic rays hit our atmosphere; these “atmospheric” neutrinos were used to discover neutrino oscillations by one of the two experiments that won <a href="http://www.nobelprize.org/nobel_prizes/physics/laureates/2015/">2015’s Nobel Prize in Physics</a>.)</p>
<p><a href="https://theconversation.com/how-neutrinos-which-barely-exist-just-ran-off-with-another-nobel-prize-48726">Neutrinos are very strange</a> – they’ve been called ghost particles. They very rarely interact with other matter, so to see them, you need a very large detector. Our telescope is called <a href="http://icecube.wisc.edu">IceCube</a>, because we use a cubic kilometer – a billion tons – of the Antarctic ice cap to catch neutrinos.</p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/101746/original/image-20151112-9366-17htjfm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/101746/original/image-20151112-9366-17htjfm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/101746/original/image-20151112-9366-17htjfm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=800&fit=crop&dpr=1 600w, https://images.theconversation.com/files/101746/original/image-20151112-9366-17htjfm.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=800&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/101746/original/image-20151112-9366-17htjfm.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=800&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/101746/original/image-20151112-9366-17htjfm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1005&fit=crop&dpr=1 754w, https://images.theconversation.com/files/101746/original/image-20151112-9366-17htjfm.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1005&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/101746/original/image-20151112-9366-17htjfm.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1005&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">One of IceCube’s 86 strings of sensors, called DOMs (digital optical modules), being lowered into the ice. They’re vertically spaced about 17 meters apart and meant to catch the visual repercussions of a neutrino collision.</span>
<span class="attribution"><a class="source" href="http://icecube.wisc.edu/gallery/press/view/1336">Jim Haugen, IceCube/NSF</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc/4.0/">CC BY-NC</a></span>
</figcaption>
</figure>
<p>Most neutrinos pass invisibly through IceCube, but by chance a few of them will smash into a proton or neutron in the ice, releasing a shower of relativistic particles we <em>can</em> see. By measuring the number and direction of these visible particles, we can determine the direction the original neutrino came from, its energy, and its type or “flavor.” One by one, we build up a picture of the sky as it shines in neutrinos, rather than starlight.</p>
<p>Antarctica may not sound like the obvious place to build such a telescope, but in fact it’s the easiest and cheapest place to do it. The US maintains a <a href="https://www.nsf.gov/geo/plr/support/southp.jsp">scientific facility at the South Pole</a>, home to several other experiments besides IceCube. Most importantly for us, the South Pole station sits on top of nearly three kilometers of the purest, clearest ice in the world – a perfect neutrino target just waiting to be used.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/101729/original/image-20151112-9385-s93ygo.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/101729/original/image-20151112-9385-s93ygo.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/101729/original/image-20151112-9385-s93ygo.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/101729/original/image-20151112-9385-s93ygo.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/101729/original/image-20151112-9385-s93ygo.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/101729/original/image-20151112-9385-s93ygo.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/101729/original/image-20151112-9385-s93ygo.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/101729/original/image-20151112-9385-s93ygo.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">Planes need skis to land and take off at the South Pole.</span>
<span class="attribution"><a class="source" href="http://icecube.wisc.edu/gallery/view/211">Mark Krasberg, IceCube/NSF</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc/4.0/">CC BY-NC</a></span>
</figcaption>
</figure>
<h2>Good for science, tough for people</h2>
<p>But “easiest” is not the same as “easy” – the South Pole is a challenging place to work. Traveling to the pole from the US can take a week or more. The last leg of the trip is on a special ski-equipped C-130 cargo aircraft operated by the Air National Guard, which lands on a runway made of compressed snow. These aircraft can only reach the pole for four months of the year: at midsummer (January, in the southern hemisphere), the average temperature is a balmy -15 degrees Fahrenheit (-26 degrees Celsius), but by March temperatures have fallen to -50F (-45C), too cold for C-130s to operate. We pack our work into those summer months, then hand IceCube off to two hardy “winter-over” scientists. Our winter-overs are part of a team of 45 people who stay at the station for the rest of the year, cut off from the rest of the world for eight months except for internet and radio communications. </p>
<p>In the summer, the station population expands to about 150. The South Pole is a high-altitude desert, so the air is thin and very, very dry. But the cold isn’t the toughest part of working at the South Pole – at least in the summer. The strangest thing, at least for me, is the constant daylight. At the South Pole, the sun stays up for six months, circling along the horizon and slowly spiraling down until it sets at the autumn equinox. Then our winter-overs get six months of constant darkness until sunrise in the spring. This plays havoc with circadian rhythms; I’ve awoken to see the clock read 3:00, not knowing whether it’s am or pm, whether I’ve slept for four hours or 16.</p>
<p>Despite being one of the most isolated places on Earth, the station is also very crowded in the summer. It takes a lot of expensive fuel to heat buildings, so space is at a premium, and needless to say most of us work indoors. It also takes fuel to melt water, so showers are rationed to two minutes of running water twice a week, contributing to the unique working atmosphere at the South Pole. </p>
<h2>Results starting to roll in</h2>
<p>After seven years of work, IceCube was fully commissioned in 2011, on schedule and on budget. Coordinating the efforts of around 250 scientists around the world was another challenge, and that was only the beginning. Most new telescopes are validated by observing known sources: stars, pulsars, radio galaxies. But there are no known high-energy neutrino sources – IceCube is opening an entirely new window on the universe – so we had to convince ourselves and the rest of the scientific community that we know what we are seeing.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/3PZgfPHULHw?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">A neutrino interacting with the ice inside the IceCube telescope produces electrically charged secondary particles that are detected thanks to a process called Cherenkov radiation. The Cherenkov light, a blue light emitted by charged particles passing through a medium at a speed greater than the speed of light in that medium, will spread through the ice over hundreds of meters.</span></figcaption>
</figure>
<p>Two years after IceCube was completed, we <a href="http://inspirehep.net/record/1265461">announced</a> that we had identified our first two neutrinos from outside the solar system – the first entries in our map of the neutrino sky. (We named them Bert and Ernie.) Last year we recorded the <a href="http://www.astronomerstelegram.org/?read=7856">highest-energy neutrino ever seen</a>: 1,000 times the energy of the protons accelerated at CERN.</p>
<p>There’s a wonderful debate in the scientific community over where these neutrinos come from, whether any of them might be produced in our own galaxy or even be related to exotic new particles like dark matter. As we take more data, we hope more exciting new discoveries are in store.</p><img src="https://counter.theconversation.com/content/49979/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Tyce DeYoung receives funding from the US National Science Foundation. </span></em></p>A cubic kilometer of clear, stable ice could help physicists answer big questions about cosmic rays and neutrinos. Hardy scientists collect data via a unique telescope at the frozen bottom of the world.Tyce DeYoung, Associate Professor of Physics and Astronomy, Michigan State UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/275032014-06-05T20:39:22Z2014-06-05T20:39:22ZWhat is the paradox of increasing Antarctic sea ice really telling us?<figure><img src="https://images.theconversation.com/files/50366/original/6wyxmp67-1401951702.jpg?ixlib=rb-1.1.0&rect=11%2C9%2C1510%2C928&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The Ross Sea: one of the places where sea ice extent is increasing.</span> <span class="attribution"><a class="source" href="http://commons.wikimedia.org/wiki/File%3ASea_ice_in_ross_sea.jpg">Brocken Inaglory/Wikimedia Commons</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span></figcaption></figure><p>This year could well see a new record set for the extent of Antarctic sea ice – hot on the heels of <a href="https://theconversation.com/why-is-antarctic-sea-ice-growing-19605">last year’s record</a>, which in turn is part of a puzzling 33-year trend in increasing sea ice around Antarctica. </p>
<p>Unsurprisingly, these records have provided fodder for those wishing to cast doubt on climate science or to resist action on climate change. The Intergovernmental Panel on Climate Change (IPCC) itself states that while hypotheses exist for Antarctic sea ice trends, they are “incomplete and competing” (<a href="http://www.climatechange2013.org/images/report/WG1AR5_Chapter10_FINAL.pdf">see page 909 here</a>).</p>
<p>But far from waving the white flag, or falling on their ice corers, Antarctic sea ice researchers are relishing this grand puzzle of the Southern Ocean.</p>
<p>In terms of natural experiments, they don’t come much bigger or more exciting than those unfolding across the Antarctic climate system right now. What’s more, the science is beginning to yield answers. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/50365/original/zp9gsvgd-1401951501.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/50365/original/zp9gsvgd-1401951501.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/50365/original/zp9gsvgd-1401951501.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=416&fit=crop&dpr=1 600w, https://images.theconversation.com/files/50365/original/zp9gsvgd-1401951501.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=416&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/50365/original/zp9gsvgd-1401951501.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=416&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/50365/original/zp9gsvgd-1401951501.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=523&fit=crop&dpr=1 754w, https://images.theconversation.com/files/50365/original/zp9gsvgd-1401951501.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=523&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/50365/original/zp9gsvgd-1401951501.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=523&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">This year is on track to set another record for Antarctic sea ice extent. Data from National Snow and Ice Data Center.</span>
<span class="attribution"><span class="source">Guy Williams</span></span>
</figcaption>
</figure>
<h2>Canaries in different coalmines</h2>
<p>It’s currently autumn in the Southern Hemisphere — which means that Antarctic sea ice is once again marching north, responding to the cold, dark polar winter. It’s one of Earth’s greatest seasonal changes. </p>
<p>Sea ice is the ephemeral lovechild born from an ocean coupled with a cold atmosphere. It is very sensitive to the complex interplay of thermodynamic (freezing and melting) and mechanical (compacting, ridging, rafting, breaking) processes driven by both parents. </p>
<p>As such, sea ice is a canary in the coalmine for changes to polar climate.</p>
<p>That much has certainly been obvious in the Arctic. The <a href="http://www.the-cryosphere.net/6/881/2012/tc-6-881-2012.pdf">dramatic decline of Arctic sea ice since 1981</a> is now firmly in the public consciousness as proof that global warming is real, and that it is a serious and pressing issue. The Arctic canary is unwell, to say the least.</p>
<p>However at the other end of the planet, the Antarctic canary seems to be singing away happily, as the total extent has <a href="http://www.the-cryosphere.net/6/871/2012/tc-6-871-2012.html">grown, albeit weakly, over the same period</a>. The past two years have each been record-breakers, and 2014 looks to be building the same way. You can track how it’s going <a href="http://www.cawcr.gov.au/staff/preid/seaice/gsfc_sh_extent_anom.html">here</a>, which shows how much more sea ice there is relative to the 1981-2010 average. </p>
<h2>Highs and lows</h2>
<p>Perhaps the most important fact about the (slight) increase in total Antarctic sea ice extent is that it masks major and contrasting regional changes. For example, there has been a <a href="http://pubs.giss.nasa.gov/abs/st06020o.html">strong decrease in sea ice duration in the Bellingshausen Sea, while the duration has increased in the western Ross Sea</a>. Such curiosities have led sea ice scientists to investigate several possible mechanisms, and explanations for these patterns are now starting to emerge.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/50360/original/2fv4ksjk-1401950478.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/50360/original/2fv4ksjk-1401950478.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/50360/original/2fv4ksjk-1401950478.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=668&fit=crop&dpr=1 600w, https://images.theconversation.com/files/50360/original/2fv4ksjk-1401950478.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=668&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/50360/original/2fv4ksjk-1401950478.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=668&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/50360/original/2fv4ksjk-1401950478.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=840&fit=crop&dpr=1 754w, https://images.theconversation.com/files/50360/original/2fv4ksjk-1401950478.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=840&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/50360/original/2fv4ksjk-1401950478.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=840&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Trends in sea ice duration, 1979-2010, showing large regional variations. Figure from Maksym et al. 2012.</span>
<span class="attribution"><span class="source">Guy Williams</span></span>
</figcaption>
</figure>
<p>The <a href="http://www.antarctica.ac.uk/data/absl">Amundsen Sea Low</a> is a pattern of low atmospheric pressure in the Pacific part of the Southern Ocean, which drags warm air south and pushes cold air north. This southward flow of warm air meets Antarctica in the Bellingshausen Sea, explaining why ice in this area is now in decline.</p>
<p>Meanwhile, the cold air is being pushed north from the western Ross sea — where sea ice extent is increasing. So the Amundsen Sea Low can be used to explain at least two variations in Antarctic sea ice.</p>
<p>The <a href="http://www.bom.gov.au/climate/enso/history/ln-2010-12/SAM-what.shtml">Southern Annular Mode (SAM)</a> (also called the Antarctic Oscillation) is a term that describes the north-south position of the westerly wind belt that encircles Antarctica in the Southern Ocean. These winds are known variously as the “roaring 40s”, “furious 50s”, and “screaming 60s” depending on their latitude, and when they meet sea ice they drive it northwards (away from Antarctica). </p>
<p>Like many other climate patterns (such as El Niño/La Niña), SAM has “positive” and “negative” phases. A positive SAM <a href="http://www.agu.org/pubs/crossref/pip/2012GL052810.shtml">pushes the winds south to higher latitudes</a>, meaning they encounter more sea ice, pushing more of it northwards and <a href="http://www.nature.com/ngeo/journal/v5/n12/full/ngeo1627.html">increasing the total ice extent</a>. </p>
<p>The Amundsen Sea Low also <a href="http://onlinelibrary.wiley.com/doi/10.1002/joc.3558/abstract">strengthens with the Southern Annular Mode’s positive phase</a>. The mode has been strongly positive over the past three decades, helping to explain the overall increase in Antarctic sea ice extent, as well as the regional variations.</p>
<h2>But that isn’t global warming… or is it?</h2>
<p>Here’s the kicker: the strengthening of SAM over recent decades has been directly linked to human activity. Since the 1940s, ozone depletion and increasing greenhouse gases have caused the westerly winds to <a href="http://www.nature.com/nclimate/journal/vaop/ncurrent/full/nclimate2235.html">intensify and migrate south towards Antarctica</a>. The net effect of this drives sea ice further north and increases its total extent.</p>
<p>There is still plenty of great work ahead to improve our understanding and modelling of Antarctica’s climate, but a basic message is emerging. Far from discounting climate change in the Southern Hemisphere, the apparent paradox of Antarctic sea ice is telling us that it is real and that we are contributing to it.</p>
<p>The Antarctic canary is alive, but its feathers are increasingly wind-ruffled. </p><img src="https://counter.theconversation.com/content/27503/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Guy Williams has previously received funding from the Australian Research Council and will commence an ARC Future Fellowship on June 30.</span></em></p>This year could well see a new record set for the extent of Antarctic sea ice – hot on the heels of last year’s record, which in turn is part of a puzzling 33-year trend in increasing sea ice around Antarctica…Guy Williams, AUV/Sea Ice Specialist, Antarctic Climate and Ecosystem CRC, University of TasmaniaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/246102014-03-28T06:12:10Z2014-03-28T06:12:10ZScientists at work: building up BICEP2 at the South Pole to make discovery of the year<figure><img src="https://images.theconversation.com/files/44925/original/vyxq6wmz-1395924878.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">BICEP2 is on the roof of the building on the left.</span> <span class="attribution"><span class="source">Rashmi Sudiwala</span></span></figcaption></figure><p>The astronomical instrument BICEP2 was deployed at the South Pole in 2009 to look for evidence that would support the theory of inflation, which tries to explain how the universe looked a trillionth of a second after the Big Bang.</p>
<p>Why the South Pole? Because there the sky is the cleanest and the clearest – no man-made light or radio pollution and minimal water vapour in the atmosphere. These would absorb the signals that the instrument was developed to record. The regions of sky targeted for observation are known to be particularly clear of contaminating microwave emissions from the galaxy and are always above the horizon. </p>
<p>On March 17, headlines around the world hailed the BICEP2 as having made <a href="http://www.wired.com/wiredscience/2014/03/secret-bicep-inflation/">biggest scientific discovery of the year</a>. So what was it like to work on this historic project?</p>
<h2>Where penguins wouldn’t dare</h2>
<p>BICEP2 was designed and built at the California Institute of Technology (Caltech), Pasadena. The team was assembled by the late Andrew Lange and then led by Kovac (now at Harvard), Jamie Bock at Caltech, Chao-Lin Kuo at Stanford University and Clem Pryke at the University of Minnesota. I joined the BICEP2 team in 2007, on loan from Cardiff University, as their instrument development scientist. In the autumn of 2009, together with three fellow BICEP2 adventurers (others would follow as the season progressed), we headed out from sunny southern California to the Amundsen-Scott South Pole Station.</p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/44722/original/zvtxzdf3-1395771326.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/44722/original/zvtxzdf3-1395771326.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/44722/original/zvtxzdf3-1395771326.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=900&fit=crop&dpr=1 600w, https://images.theconversation.com/files/44722/original/zvtxzdf3-1395771326.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=900&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/44722/original/zvtxzdf3-1395771326.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=900&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/44722/original/zvtxzdf3-1395771326.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1131&fit=crop&dpr=1 754w, https://images.theconversation.com/files/44722/original/zvtxzdf3-1395771326.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1131&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/44722/original/zvtxzdf3-1395771326.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1131&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Aligning the receiver and camera insert before the telescope tube is lowered onto it.</span>
<span class="attribution"><span class="source">Rashmi Sudiwala</span></span>
</figcaption>
</figure>
<p>We first flew to New Zealand, to be kitted out with extreme weather clothing. Then onwards for a stopover at McMurdo Station on Ross Island before heading out to the South Pole. The −50 centigrade air stung my eyes and lungs as I got off the plane. The short walk from apron to station left us gasping for breath: the altitude is 10,000 feet above sea level. The BICEP2 telescope location was only a quarter-mile from the station but the hike felt a lot further the first few times.</p>
<p>It was my second time at the South Pole. I had briefly visited the previous season to help decommission the original BICEP. That experience, coupled with my intimate knowledge of BICEP2, meant I was team leader for the first week. Not that the team needed leading – our collective desire to make the project work was by far the greatest motivator.</p>
<h2>For the love of science</h2>
<p>There were many tasks to be performed in readying the instrument for service. We didn’t have the option of simply fielding a ready-made, pre-calibrated machine. The telescope shell, camera tube, optics, cooling system, cables (so many cables), and the all-important detectors had to be prepared, assembled and calibrated on site whilst control software had to be written or tweaked. Plus, the detector assembly we actually wanted to deploy was still under test in Pasadena in our test system.</p>
<p>Our first tasks were organising the observatory and checking the telescope mount for wear and tear – polar winters are brutal. With brooms, vacuum cleaners and snow shovels, it was all hands on deck. Shovelling snow certainly gets the heart pounding – so much for taking it easy as we acclimatised to the high altitude!</p>
<p>Over the following days and weeks, crates containing what would become the BICEP2 instrument arrived, along with more team members. The workload was huge and the schedule relentless – the clock was ticking.</p>
<p>We played to each other’s strengths. Team specialists and station staff chipped in doing whatever, wherever, whenever. Trained as a physicist and employed as an instrument scientist and systems engineer, my skills were more general. I had particular expertise in cryogenics (handling really cold things), electronics and control systems. At the South Pole, it seemed as if I only made cables, routed cables, and tested cables. How many PhDs does it take to thread a cable? Five, and then some.</p>
<figure class="align-left ">
<img alt="" src="https://images.theconversation.com/files/44717/original/tf9cnrg8-1395770774.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/44717/original/tf9cnrg8-1395770774.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=900&fit=crop&dpr=1 600w, https://images.theconversation.com/files/44717/original/tf9cnrg8-1395770774.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=900&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/44717/original/tf9cnrg8-1395770774.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=900&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/44717/original/tf9cnrg8-1395770774.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1131&fit=crop&dpr=1 754w, https://images.theconversation.com/files/44717/original/tf9cnrg8-1395770774.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1131&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/44717/original/tf9cnrg8-1395770774.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1131&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">The team at Caltech bid farewell to the BICEP2 instrument before shipping it to the South Pole.</span>
<span class="attribution"><span class="source">Rashmi Sudiwala</span></span>
</figcaption>
</figure>
<p>On December 13, 2009, the BICEP2 instrument was ready for action. Procedures honed over a period of two years in Pasadena had been implemented in just three weeks here. By December 16 the system was fully cold, meaning that experiments could begin. Following initial checks, we were able to take our first measurements: first light.</p>
<p>There was never great doubt that the instrument would work – we had all done our homework. But for me there had been a concern. The detectors in BICEP2 operate at a temperature close to the coldest temperature that we can ever reach. To achieve this, we use a fridge that is colder than liquid helium. Back in Pasadena, we had experienced huge problems with running this fridge, but after many long nights I had stumbled upon a solution which seemed promising. With some tweaking at the South Pole, the fridge held its temperature for 85 hours. </p>
<h2>Humour at the pole</h2>
<p>It helps to have a sense of humour, although sometimes the humour was against us. Like when a colleague’s flight was forced to circle a few hours above the station only to be turned back to McMurdo (our breakfast meeting notes record, “… Angiola still circling overhead”). Medical health is of paramount concern and this was the year the swine flu virus was all the rage. I dutifully took my jabs, only to go down with the most horrendous aches, pains and fever imaginable. After four or five days, groggy and worse for wear, I managed to drag myself to the galley for some food – to others’ amusement. </p>
<p>It was not all work. The station has recreational facilities, including a full-size sports gymnasium and music room. There was a wealth of talent amongst the station staff and scientists from other experiments. You might find yourself attending impromptu classes in everything from photography to flamenco dancing. There are other experiments at the South Pole: IceCube, the South Pole Telescope, meteorology and a self-sufficiency experiment for long-duration space missions. Everyone liked to show and tell, with open-days and seminars. My highlight was one given by a film crew shooting the BBC’s Frozen Planet documentary, and I was thrilled to bits to have met Sir David Attenborough. </p>
<p>By mid-January most systems had come together. There was still much to do in terms of testing and calibration, but on January 18 it was time for me to leave. After lunch, with a stiff upper lip, it was a manly handshake for the men, a warm hug for the ladies, and with that my Polar adventure came to an end.</p>
<h2>Fruits of our labour</h2>
<p>It was known from the outset that my role was to get the instrument built, tested and deployed. It was thrilling to see the first light data in December 2009. But I’m no theorist or data analyst. I remained on the BICEP2 mailing list, and from a distance, kept in touch with the program as data accumulated. Data analysis started from the outset and there was a long wait for the statistical noise to average down. The mood of the team, rising and falling with every new problem encountered and solved, could be judged from the email traffic.</p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/44926/original/vbb878sm-1395925885.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/44926/original/vbb878sm-1395925885.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/44926/original/vbb878sm-1395925885.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=755&fit=crop&dpr=1 600w, https://images.theconversation.com/files/44926/original/vbb878sm-1395925885.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=755&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/44926/original/vbb878sm-1395925885.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=755&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/44926/original/vbb878sm-1395925885.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=949&fit=crop&dpr=1 754w, https://images.theconversation.com/files/44926/original/vbb878sm-1395925885.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=949&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/44926/original/vbb878sm-1395925885.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=949&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption"></span>
<span class="attribution"><span class="source">Rashmi Sudiwala</span></span>
</figcaption>
</figure>
<p>The BICEP2 data analysis team is a small, tight-lipped group. I knew perhaps a year ago that there was talk of possible primordial gravitational wave detection by BICEP2 but I was taken completely by surprise of news of the imminent media release from the Harvard press office. </p>
<p>To think that this machine, of modest size, located in the harshest of environments, was so sensitive and characterised to such exquisite detail
that from it we could extract the faintest of signals from the farthest reaches of the Universe and the tiniest fractions of a second after the Big Bang is amazing. That this signal itself represents compelling evidence for inflation, arguably one of craziest scientific theories describing the birth of our universe, is staggering. And there will no doubt be more revelations to come.</p><img src="https://counter.theconversation.com/content/24610/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>My thanks to the late Andrew Lange, John Kovac and the BICEP2 team for allowing me to work on the program; to the NFS, USAP, JPL, Caltech, the Moore Foundation and the Keck Foundation for funding the program; and to Peter Ade and Cardiff University for granting me leave.</span></em></p>The astronomical instrument BICEP2 was deployed at the South Pole in 2009 to look for evidence that would support the theory of inflation, which tries to explain how the universe looked a trillionth of…Rashmi Sudiwala, Senior Research Associate, Cardiff UniversityLicensed as Creative Commons – attribution, no derivatives.