tag:theconversation.com,2011:/id/topics/gaia-9143/articlesGaia – The Conversation2024-03-18T18:09:02Ztag:theconversation.com,2011:article/2255022024-03-18T18:09:02Z2024-03-18T18:09:02ZFloating crystals slow stellar aging — for some stars, this can delay death by billions of years<p>Imagine the embers of a campfire, slowly dimming over time. That is the fate most stars in the universe face. After their nuclear fuel is spent, 98 per cent of stars — including our sun — will eventually become white dwarfs. These small, dense remnants are thought to <a href="https://esahubble.org/wordbank/white-dwarf/">simply cool down</a>, becoming ever fainter as the universe ages.</p>
<p>In 2019, astronomers discovered <a href="https://doi.org/10.3847/1538-4357/ab4989">a group of white dwarfs</a> that mysteriously stopped cooling. These “forever-young” stars remain at a near-constant surface temperature for at least eight billion years — an incredible length of time, considering the universe is <a href="https://www.space.com/24054-how-old-is-the-universe.html">13.8 billion years old</a>. </p>
<p>Something is fuelling these stars from within, but given that they had run out of their nuclear fuel source, scientists were unsure what could be keeping them shining so brightly. Our research, <a href="https://doi.org/10.1038/s41586-024-07102-y">recently published in <em>Nature</em></a>, presents the solution to this conundrum.</p>
<p>Using information gathered by the <a href="https://www.esa.int/Science_Exploration/Space_Science/Gaia">Gaia space observatory of the European Space Agency</a>, researchers discovered that some white dwarfs essentially stop cooling.</p>
<p>By studying how white dwarfs are distributed as a function of temperature (from hot to cold) <a href="https://sci.esa.int/web/gaia/-/61343-shedding-light-on-white-dwarfs-the-future-of-stars-like-our-sun">in the Gaia data</a>, astronomers noticed an accumulation of white dwarfs at intermediate temperatures. This indicates that some white dwarfs spend more time at these intermediate temperatures — eight billion years more than thought possible.</p>
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<iframe width="440" height="260" src="https://www.youtube.com/embed/nkXR7bpmy7Q?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Interview with University of Victoria astrophysics researcher Simon Blouin.</span></figcaption>
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<h2>Stellar crystals</h2>
<p>White dwarfs are weird. A mere teaspoon of material from their cores <a href="https://astronomy.swin.edu.au/cosmos/W/white+dwarf">weighs several tonnes</a>. Under such extreme densities, matter can behave strangely. Even though the interiors of white dwarfs are millions of degrees hot, the density is high enough that they can freeze into a solid state. They form crystals out of the carbon, oxygen and other elements present in their interiors.</p>
<p>The formation of these crystals normally starts at the centre of the star, where density is highest. As the white dwarf cools down, more crystals are formed in successive layers until almost the whole star is completely solid.</p>
<p>However, this inside-out crystallization does not apply to all white dwarfs. We discovered that the heaviest elements present in white dwarfs are expelled from the crystals as they are formed, just as <a href="https://nsidc.org/learn/parts-cryosphere/sea-ice/science-sea-ice">salt is expelled from ice crystals</a> when seawater freezes.</p>
<p>The crystals become less dense than their surroundings, and float up like ice cubes in a glass of water. As the crystals do not stay in place, the core cannot simply freeze from the inside out.</p>
<p>The movements created by the floating crystals reshuffle the chemical layering inside the star. Gradually, the heaviest elements are transported toward the centre. This releases a steady flow of gravitational energy that keeps the star shining at a near-constant temperature for billions of years.</p>
<p>Floating crystals can pause the stellar aging process, providing a final energy source to otherwise dead stars.</p>
<h2>The exception or the rule?</h2>
<p>So far, this cooling pause has been conclusively identified only for a small fraction of the white dwarf population. The high masses and peculiar compositions of these anomalous white dwarfs suggest that they had quite violent histories. Most likely, they are the products of stellar mergers — events where two stars collide and combine.</p>
<p>But this may be just the tip of the iceberg. Based on our findings, we suspect that almost all white dwarfs, and not just the merged ones, experience some cooling pause during their evolution. However, this more universal cooling pause would be much shorter than the multi-billion-year interruption studied so far.</p>
<p><a href="https://doi.org/10.1093/mnras/stad1719">Observations are ongoing</a> to try to identify this shorter cooling pause in the rest of the white dwarf population.</p>
<h2>Cosmic clocks</h2>
<p>These findings have implications for stellar archaeology. The cooler the white dwarf, the older it must be. Just as archeologists use carbon-14 dating to determine the age of artifacts and reconstruct the history of a city or civilization, astronomers rely on white dwarf cooling to measure the ages of stars and understand the history of our Milky Way galaxy.</p>
<p>Our discovery makes this more complicated. A white dwarf with a certain temperature could be billions of years older than initially assumed because of the formation of these floating crystals. The key now is to figure out which stars experience this cooling pause and which do not.</p><img src="https://counter.theconversation.com/content/225502/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Simon Blouin receives funding from the Natural Sciences and Engineering Research Council of Canada. </span></em></p>Floating crystals can pause the stellar aging process, providing a final energy source to otherwise dead stars.Simon Blouin, CITA National Postdoctoral Fellow, Astrophysics, University of VictoriaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2161372023-10-27T12:17:17Z2023-10-27T12:17:17ZAsteroids in the solar system could contain undiscovered, superheavy elements<figure><img src="https://images.theconversation.com/files/555902/original/file-20231025-23-pgf5be.jpg?ixlib=rb-1.1.0&rect=52%2C30%2C4981%2C3426&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">An illustration of an asteroid orbiting through space. </span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/illustration/illustration-of-an-asteroid-royalty-free-illustration/973895632?phrase=asteroid&adppopup=true">Mark Garlick/Science Photo Library via Getty Images</a></span></figcaption></figure><p>For centuries, the <a href="https://sciencenotes.org/when-were-the-elements-discovered-timeline-and-periodic-table/">quest for new elements</a> was a driving force in many scientific disciplines. Understanding an atom’s structure and the development of nuclear science allowed scientists to accomplish the old goal of <a href="https://www.merriam-webster.com/dictionary/alchemy">alchemists</a> – <a href="https://www.britannica.com/science/transmutation">turning one element into another</a>. </p>
<p>Over the past few decades, scientists in the <a href="https://www.lbl.gov/">United States</a>, <a href="https://www.helmholtz.de/en/about-us/helmholtz-centers/centers-a-z/centre/gsi-helmholtz-centre-for-heavy-ion-research/">Germany</a> and <a href="https://www.iaea.org/contact/joint-institute-for-nuclear-research-jinr">Russia</a> have figured out how to use special tools <a href="https://physicalsciences.lbl.gov/2023/10/16/berkeley-lab-to-test-new-approach-to-making-superheavy-elements/">to combine two atomic nuclei</a> and create new, <a href="https://doi.org/10.1146/annurev-nucl-102912-144535">superheavy elements</a>. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/555904/original/file-20231025-30-pcmast.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A periodic table, with each group a different color." src="https://images.theconversation.com/files/555904/original/file-20231025-30-pcmast.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/555904/original/file-20231025-30-pcmast.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=327&fit=crop&dpr=1 600w, https://images.theconversation.com/files/555904/original/file-20231025-30-pcmast.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=327&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/555904/original/file-20231025-30-pcmast.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=327&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/555904/original/file-20231025-30-pcmast.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=411&fit=crop&dpr=1 754w, https://images.theconversation.com/files/555904/original/file-20231025-30-pcmast.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=411&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/555904/original/file-20231025-30-pcmast.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=411&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 heaviest element on the periodic table has 118 protons.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:Periodic_table_%28JPEG_version%29.jpg">Licks-rocks/Wikimedia Commons</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
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</figure>
<p>These heavy elements usually aren’t stable. Heavier elements <a href="https://www.energy.gov/science/doe-explainsprotons">have more protons</a>, or positively charged particles in the nucleus; some that scientists have created <a href="https://www.smithsonianmag.com/science-nature/when-will-we-reach-end-periodic-table-180957851/">have up to 118</a>. With that many protons, the electromagnetic repulsive forces between protons in the atomic nuclei overwhelm the attractive nuclear force that keeps the nucleus together. </p>
<p>Scientists have <a href="https://doi.org/10.1007/BF01172015">predicted for a long time</a> that elements with around 164 protons could have a relatively long <a href="https://www.britannica.com/science/half-life-radioactivity">half-life</a>, or even be stable. They call this the “<a href="https://www.eurekalert.org/news-releases/627973">island of stability</a>” – here, the attractive nuclear force is strong enough to balance out any electromagnetic repulsion. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/556194/original/file-20231026-23-l75f9c.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A purple piece of machinery in a concrete room with metal boxes and cables coming off it." src="https://images.theconversation.com/files/556194/original/file-20231026-23-l75f9c.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/556194/original/file-20231026-23-l75f9c.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=401&fit=crop&dpr=1 600w, https://images.theconversation.com/files/556194/original/file-20231026-23-l75f9c.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=401&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/556194/original/file-20231026-23-l75f9c.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=401&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/556194/original/file-20231026-23-l75f9c.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/556194/original/file-20231026-23-l75f9c.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/556194/original/file-20231026-23-l75f9c.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Scientists at Lawrence Berkeley National Laboratory have constructed experiments that can weigh superheavy elements.</span>
<span class="attribution"><a class="source" href="https://science.osti.gov/np/Highlights/2019/NP-2019-08-c">Marilyn Chung, Lawrence Berkeley National Laboratory</a></span>
</figcaption>
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<p>Since heavy elements are difficult to make in the lab, <a href="https://scholar.google.com/citations?user=7GzPpUgAAAAJ&hl=en">physicists like me</a> have been looking for these elements everywhere, <a href="https://www.scientificamerican.com/article/the-quest-for-superheavy-elements-and-the-island-of-stability/">even beyond the Earth</a>. To narrow down the search, we need to know what sort of natural processes could produce these elements. We also need to know what properties they have, like their mass densities. </p>
<h2>Calculating density</h2>
<p>From the outset, my team wanted to figure out the mass density of these superheavy elements. This property could tell us more about how the atomic nuclei of these elements behave. And once we had an idea about their density, we could get a better sense of where these elements might be hiding. </p>
<p>To figure out the mass density and other <a href="https://doi.org/10.1007/BFb0116498">chemical properties</a> of these elements, my research team used a model that represents an atom of each of these heavy elements as a single, charged cloud. This model works well for large atoms, particularly metals that are laid out in a lattice structure.</p>
<p>We first <a href="https://doi.org/10.1140/epjp/s13360-023-04454-8">applied this model</a> to atoms with known densities and calculated their chemical properties. Once we knew it worked, we used the model to calculate the density of elements with 164 protons, and other elements in this island of stability. </p>
<p>Based on our calculations, we expect stable metals with atomic numbers around 164 to have densities between 36 to 68 g/cm<sup>3</sup> (21 to 39 oz/in<sup>3</sup>). However, in our calculations, we used a conservative assumption about the mass of atomic nuclei. It’s possible that the actual range is up to 40% higher. </p>
<h2>Asteroids and heavy elements</h2>
<p>Many scientists <a href="https://www.nationalgeographic.com/science/article/101209-asteroid-collisions-earth-gold-science-space">believe that gold</a> and other heavy metals were deposited on Earth’s surface after <a href="https://earthsky.org/earth/did-meteorites-bombard-earth-with-gold/">asteroids collided with the planet</a>. </p>
<p>The same thing could have happened with these superheavy elements, but super mass dense heavy elements sink into ground and are eliminated from near the Earth’s surface by the <a href="https://www.usgs.gov/news/science-snippet/earthword-subduction">subduction of tectonic plates</a>. However, while researchers might not find superheavy elements on Earth’s surface, they could still be in asteroids like the ones that might have brought them to this planet.</p>
<p>Scientists have estimated that some asteroids have mass densities greater than that of <a href="https://www.rsc.org/periodic-table/element/76/osmium">osmium</a> (22.59 g/cm<sup>3</sup>, 13.06 oz/in<sup>3</sup>), the densest element found on Earth. </p>
<p>The largest of these objects is asteroid 33, which is <a href="https://en.wikipedia.org/wiki/33_Polyhymnia">nicknamed Polyhymnia</a> and has a calculated density of 75.3 g/cm<sup>3</sup> (43.5 oz/in<sup>3</sup>). But this density might not be quite right, since it’s quite difficult to measure the mass and volume of far-away asteroids.</p>
<p>Polyhymnia isn’t the only dense asteroid out there. In fact, there’s a whole class of superheavy objects, including asteroids, which could contain these superheavy elements. Some time ago, I introduced the name <a href="https://doi.org/10.1103/PhysRevLett.110.111102">Compact Ultradense Objects, or CUDOs</a>, for this class. </p>
<p>In a study published in October 2023 in the <a href="https://doi.org/10.1140/epjp/s13360-023-04454-8">European Physical Journal Plus</a>, my team suggested some of the CUDOs orbiting in the solar system might still contain some of these <a href="https://www.youtube.com/watch?v=wj7BM6Jt-4I">dense, heavy elements</a> in their cores. Their surfaces would have accumulated normal matter over time and would appear normal to a distant observer.</p>
<p>So how are these <a href="https://doi.org/10.1103/RevModPhys.93.015002">heavy elements produced</a>? Some extreme astronomical events, like <a href="https://www.scientificamerican.com/article/how-star-collisions-forge-the-universes-heaviest-elements/">double star mergers</a> could be hot and dense enough to produce stable superheavy elements. </p>
<p>Some of the superheavy material could then remain on board asteroids created in these events. They could stay packed in these asteroids, which orbit the solar system for billions of years.</p>
<h2>Looking to the future</h2>
<p>The <a href="https://www.esa.int/Science_Exploration/Space_Science/Gaia_overview">Eurpoean Space Agency’s Gaia mission</a> aims to create the largest, most precise three-dimensional map of everything in the sky. Researchers could use these extremely precise results to <a href="https://doi.org/10.3847/1538-3881/ace52b">study the motion of asteroids</a> and figure out which ones might have an unusually large density.</p>
<p>Space missions are being conducted to collect material from the surfaces of asteroids and analyze them back on Earth. Both NASA and the <a href="https://global.jaxa.jp/">Japanese state space agency JAXA</a> have targeted low density near-Earth asteroids with success. Just this month, NASA’s <a href="https://science.nasa.gov/mission/osiris-rex/">OSIRIS-REx</a> mission brought back a sample. Though the sample analysis is just getting started, there is a very small chance it could harbor dust containing superheavy elements accumulated over billions of years. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/556232/original/file-20231026-29-oeel6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A diagram showing the Psyche spacecraft's approach to the asteroid, where it starts at Earth in the center and moves in a counterclockwise spiral to the top of the screen, where it arrives at the asteroid." src="https://images.theconversation.com/files/556232/original/file-20231026-29-oeel6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/556232/original/file-20231026-29-oeel6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=338&fit=crop&dpr=1 600w, https://images.theconversation.com/files/556232/original/file-20231026-29-oeel6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=338&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/556232/original/file-20231026-29-oeel6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=338&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/556232/original/file-20231026-29-oeel6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=424&fit=crop&dpr=1 754w, https://images.theconversation.com/files/556232/original/file-20231026-29-oeel6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=424&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/556232/original/file-20231026-29-oeel6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=424&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The Psyche spacecraft has left Earth. It will use the gravitational field of Mars to carry it closer to the asteroid. It will then orbit the asteroid and collect data.</span>
<span class="attribution"><a class="source" href="https://www.jpl.nasa.gov/images/pia24930-psyches-mission-plan">NASA/JPL-Caltech</a></span>
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<p>One mass-dense dust and rock sample brought back to Earth would be enough. <a href="https://science.nasa.gov/mission/psyche/">NASA’s Psyche mission</a>, which launched in October 2023, will fly to and sample <a href="https://www.smithsonianmag.com/smart-news/nasa-launches-mission-to-study-distant-asteroid-180983072/">a metal-rich asteroid</a> with a greater chance of harboring superheavy elements. More asteroid missions like this will help scientists better understand the properties of asteroids orbiting in the solar system.</p>
<p>Learning more about asteroids and exploring potential sources of superheavy elements will help scientists continue the century-spanning quest to characterize the matter that makes up the universe and better understand how objects in the solar system formed. </p>
<p><em>Evan LaForge, an undergraduate student studying physics and mathematics, is the lead author on <a href="https://doi.org/10.1140/epjp/s13360-023-04454-8">this research</a> and helped with the writing of this article, along with Will Price, a physics graduate student.</em></p><img src="https://counter.theconversation.com/content/216137/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Johann Rafelski does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Scientists have been searching Earth’s surface for superheavy elements too difficult to make in the lab, but now, many are looking to the skies instead.Johann Rafelski, Professor of Physics, University of ArizonaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1924862022-11-15T19:24:20Z2022-11-15T19:24:20ZWhen landscapes come alive: ‘New weird’ stories speculate about the eerie natural world in a climate crisis<figure><img src="https://images.theconversation.com/files/494776/original/file-20221110-17-cer7qz.jpeg?ixlib=rb-1.1.0&rect=407%2C30%2C1490%2C1309&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Raffiella Chapman in 'Vesper.'</span> <span class="attribution"><span class="source">(Signature Entertainment)</span></span></figcaption></figure><p>Extreme weather events have risen globally. In 2022, parts of the world, such as <a href="https://public.wmo.int/en/media/news/climate-change-made-heatwaves-india-and-pakistan-30-times-more-likely">India, Pakistan</a> and <a href="https://www.theguardian.com/world/2022/oct/07/england-excess-deaths-during-2022-heatwave">England</a> witnessed heatwaves that killed many people. </p>
<p>The effects of extreme weather like drought, famine and floods are harming the world’s most vulnerable people, including in <a href="https://theconversation.com/the-unfairness-of-the-climate-crisis-podcast-192469">the Global South</a> in disproportionate ways.</p>
<p>Climate change <a href="https://www.washingtonpost.com/climate-environment/2022/10/11/extreme-heat-heatwave-deaths/">is increasing the frequency</a> of extreme weather events. These are now described <a href="https://www.ifrc.org/sites/default/files/2022-10/Extreme-Heat-Report-IFRC-OCHA-2022.pdf">as unprecedented</a> and expected to grow. </p>
<p>Humans exploit the natural world and its resources, and the consequences are evident in climate change. While people have been able to <a href="https://www.theguardian.com/environment/2021/oct/30/capitalism-is-killing-the-planet-its-time-to-stop-buying-into-our-own-destruction">control resource extraction in our global capitalist economy</a>, extreme weather events make the natural world uncontrollable from a human perspective. The extractionist mindset treats the word as inert, lacking in agency. </p>
<p>In the shadow of the climate crisis, a wave of speculative fiction, named <a href="https://www.jeffvandermeer.com/2009/06/28/the-new-weird-anthology-notes-and-introduction/">the “new weird,”</a> rethinks the role of agency and the natural world. It asks what it means to live in a world where everything is not an extractable resource — and where humans are not in control. </p>
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Read more:
<a href="https://theconversation.com/ending-the-climate-crisis-has-one-simple-solution-stop-using-fossil-fuels-194489">Ending the climate crisis has one simple solution: Stop using fossil fuels</a>
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<h2>Our times</h2>
<p>Scholars have named our current era the time of <a href="https://www.nature.com/articles/415023a">the Anthropocene</a>. The Anthropocene stands for a geological age where human activity has become the biggest cause for geological change. </p>
<p>Not everyone agrees on this name. To highlight the legacies of colonialism, capitalism and racism in this current epoch, some scholars have proposed the name <a href="https://edgeeffects.net/plantation-legacies-plantationocene/">plantationocene</a>. A plantation mode of agriculture is premised on extracting the maximum from land and labour. </p>
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Read more:
<a href="https://theconversation.com/the-term-anthropocene-isnt-perfect-but-it-shows-us-the-scale-of-the-environmental-crisis-weve-caused-169301">The term 'Anthropocene' isn't perfect – but it shows us the scale of the environmental crisis we've caused</a>
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<p>To bring the role of capitalism to the forefront, others have proposed renaming the current age to <a href="https://jasonwmoore.com/wp-content/uploads/2017/08/Moore-The-Capitalocene-Part-I-published-JPS-2017.pdf">capitalocene</a>.</p>
<p>Irrespective of the name, these terms capture how humans have treated the natural world as a resource to be exploited and controlled. </p>
<p>How do we as a species engage with climate anxiety when faced with a world that is beyond our control?</p>
<h2>Speculative narratives</h2>
<p>New weird speculative narratives reimagine the natural world no longer as an inert background that serves as a canvas for action. </p>
<p>The new weird <a href="https://bookriot.com/new-weird-genre/">mixes genres</a> and has elements of science fiction, fantasy and even horror. The genre is also preoccupied with what we might think of as weird ecology. In these narratives, life forms that western thought has traditionally understood not to possess agency are granted it, giving rise to <a href="https://repeaterbooks.com/product/the-weird-and-the-eerie/">an eerie</a> effect. </p>
<p>Take for instance, the 2022 film <a href="https://www.imdb.com/title/tt20225374/"><em>Vesper</em></a>, a <a href="https://www.cineuropa.org/en/newsdetail/427476">Lithuanian-French-Belgian co-production</a> (released in France as <a href="https://www.allocine.fr/film/fichefilm_gen_cfilm=291598.html"><em>Vesper Chronicles</em></a>). The movie opens with a note about its setting. The world has become dangerous because of a genetic engineering project gone awry; viruses have been released into the world. </p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/9dajBhMSd00?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Official trailer for ‘Vesper.’</span></figcaption>
</figure>
<p>Viewers then see a seemingly calm woods. The camera moves closer to the trees and reveals that they possess sensory organs. Tentacles emerge from the ground. The protagonist, who knows the landscape, avoids these traps hidden in the calm landscape. </p>
<p>Similarly, the 2021 South African <a href="https://www.imdb.com/title/tt11881160/">film <em>Gaia</em></a> shows a forestry department employee get injured in a remote national park. </p>
<p>She is found by a father and son who have been surviving in the park. The employee discovers that the forest is home to a species of fungus which infects the humans and consumes them. Viewers are introduced to visually appealing landscapes whose beauty is produced by elements that are beyond any human efforts to control them. </p>
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<iframe width="440" height="260" src="https://www.youtube.com/embed/WwJNP-CX1QQ?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Official trailer for ‘Gaia.’</span></figcaption>
</figure>
<h2>‘The shimmer’</h2>
<p>The 2018 <a href="https://www.imdb.com/title/tt2798920/">American film, <em>Annihilation</em></a>, inspired <a href="https://us.macmillan.com/books/9780374104092">by the novel</a> by American author and literary critic Jeff VanderMeer, also features landscape that is eeriely powerful. The novel and film takes place in a special ecological zone named Area X, which <a href="https://www.macleans.ca/culture/how-annihilation-author-jeff-vandermeer-became-king-of-the-new-weird/">is weird</a> and <a href="https://lareviewofbooks.org/article/weird-ecology-southern-reach-trilogy/">alien</a>. </p>
<p>The film represents the separation between the ordinary world and an ecological anomaly through an iridescent boundary named “the shimmer.” </p>
<p>A team of scientists sent to investigate the anomaly <a href="https://www.inverse.com/article/41706-annihilation-plant-people-hox-genes">finds plants that look like human bodies</a>. These eerie formations contain a mixture of different DNAs. Here again, a seemingly pristine landscape encroaches on the human body, operating under principles beyond human understanding or control. </p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/89OP78l9oF0?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Official trailer for ‘Annihilation.’</span></figcaption>
</figure>
<h2>Agency of the world</h2>
<p>In the above instances, the natural world capable of having effects beyond human control is a cause for concern. From a western humancentric worldview, a natural world that is not an inert resource, potentially awaiting extraction, is horrific. </p>
<p>Contrary to this perspective, Indigenous cosmologies have long maintained that <a href="https://jps.library.utoronto.ca/index.php/des/article/view/19145/16234">agency is not a uniquely human trait</a>. <a href="https://www.versobooks.com/blogs/4611-not-murdered-not-missing-rebelling-against-colonial-gender-violence">Casting the natural world and land as resources</a> effectively removes their agency. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/from-the-amazon-indigenous-peoples-offer-new-compass-to-navigate-climate-change-167768">From the Amazon, Indigenous Peoples offer new compass to navigate climate change</a>
</strong>
</em>
</p>
<hr>
<p>Even though extreme weather events show that a climate crisis is now unfolding, reporting about effects in the West sometimes stresses that the direst state of affairs <a href="https://www.washingtonpost.com/climate-environment/2022/10/11/extreme-heat-heatwave-deaths/">will unfold in the future</a>. </p>
<p>However, scholars remind us that for some communities, <a href="https://kylewhyte.marcom.cal.msu.edu/wp-content/uploads/sites/12/2018/07/Our_Ancestors_Dystopia_Now_Indigenous_Co3.pdf">apocalypse is not futuristic</a>, it is now and has happened many times before. </p>
<p>Speculative narratives can be a tool to draw attention to the inequalities of the status quo. They can also offer hints in <a href="https://ecwpress.com/products/moon-of-the-crusted-snow">imagining different futures</a>, not reliant upon exploiting the natural world solely for human gain.</p><img src="https://counter.theconversation.com/content/192486/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Priscilla Jolly does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>In the shadow of the climate crisis, a wave of speculative stories ask what it means to live in a world where everything is not an extractable resource — and where humans are not in control.Priscilla Jolly, PhD Candidate, Department of English, Concordia UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1878702022-07-28T15:21:36Z2022-07-28T15:21:36ZJames Lovelock: the scientist-inventor who transformed our view of life on Earth<p>James Lovelock, the maverick scientist and inventor, died surrounded by his family on July 27 2022 – his 103rd birthday. Jim led an extraordinary life. He is best known for his Gaia hypothesis, developed with the brilliant US biologist <a href="https://www.theguardian.com/science/2011/dec/11/lynn-margulis-obtiuary">Lynn Margulis</a> in the 1970s, which transformed the way we think of life on Earth. </p>
<p>Gaia challenged the orthodox view that life simply evolved and adapted to the ever-changing environment. Instead, Lovelock and Margulis argued that species not only competed but also cooperated to create the most favourable conditions for life.</p>
<p>Earth is a self-regulating system maintained by communities of living organisms, they claimed. These communities adjust oxygen and carbon dioxide levels in the atmosphere, salinity in the ocean and even the planet’s temperature to keep them within the acceptable bounds for life to thrive.</p>
<p>Just like Charles Darwin before him, Lovelock published his new, radical idea in a popular book, Gaia: A new look at life on Earth (1979). It was an instant hit that challenged mature researchers to reassess their science and encouraged new ones. As my friend and colleague Professor Richard Betts at the Met Office Hadley Centre put it:</p>
<blockquote>
<p>He was a source of inspiration to me for my entire career, and in fact his first book on Gaia was a major reason why I chose to work on climate change and Earth system modelling. </p>
</blockquote>
<p>Not only did the book challenge the classical Darwinism notion that life evolved and prospered through constant competition and dogged self-interest, it founded a whole new field: Earth system science. We Earth system scientists study all the interactions between the atmosphere, land, ocean, ice sheets and, of course, living things. </p>
<p>Lovelock also inspired the environmental movement by giving his ideas a spiritual overtone: Gaia was the goddess who personified the Earth in Greek mythology. </p>
<p>This antagonised many scientists, but created a lot of fruitful debate in the 1980s and 1990s. It is now generally accepted that organisms can enhance their local environment to make it more habitable. For example, forests can <a href="https://theconversation.com/rewilding-is-essential-to-the-uks-commitment-to-zero-carbon-emissions-107541">recycle half the moisture</a> they receive, keeping the local climate mild and stabilising rainfall. </p>
<p>But the original Gaia hypothesis, that life regulates the environment so that the planet resembles an organism in its own right, is still treated with scepticism among most scientists. This is because no workable mechanism has been discovered to explain how the forces of natural selection, which operate on individual organisms, birthed the evolution of such planetary-scale homeostasis.</p>
<figure class="align-center ">
<img alt="An aerial view of morning mist over a rainforest." src="https://images.theconversation.com/files/476503/original/file-20220728-23-2v155p.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/476503/original/file-20220728-23-2v155p.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=337&fit=crop&dpr=1 600w, https://images.theconversation.com/files/476503/original/file-20220728-23-2v155p.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=337&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/476503/original/file-20220728-23-2v155p.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=337&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/476503/original/file-20220728-23-2v155p.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=424&fit=crop&dpr=1 754w, https://images.theconversation.com/files/476503/original/file-20220728-23-2v155p.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=424&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/476503/original/file-20220728-23-2v155p.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=424&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Organisms alter their environment to make it more favourable to life.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/aerial-view-morning-mist-tropical-rainforest-1511729195">Avigator Fortuner/Shutterstock</a></span>
</figcaption>
</figure>
<h2>An independent scientist</h2>
<p>There was much more to James Lovelock, who described himself as an “<a href="https://blog.sciencemuseum.org.uk/a-lifetime-of-work-the-lovelock-archive/">independent scientist since 1964</a>”, because of the income generated from his invention of the <a href="https://www.newscientist.com/article/mg23331130-700-how-to-accidentally-save-the-planet/">electron capture detector</a> while studying for a PhD in 1957.</p>
<p>This matchbox-sized device could measure tiny traces of toxic chemicals. It was essential in demonstrating that chlorofluorocarbons (CFCs) in the atmosphere, which originated in aerosols and refrigerators at the time, were destroying the ozone layer. It also showed that pesticide residues exist in the tissues of virtually all living creatures, from penguins in Antarctica to human breast milk.</p>
<figure class="align-center ">
<img alt="A small device resembling a spindle with a white band in the middle." src="https://images.theconversation.com/files/476491/original/file-20220728-27951-d1d795.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/476491/original/file-20220728-27951-d1d795.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=387&fit=crop&dpr=1 600w, https://images.theconversation.com/files/476491/original/file-20220728-27951-d1d795.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=387&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/476491/original/file-20220728-27951-d1d795.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=387&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/476491/original/file-20220728-27951-d1d795.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=486&fit=crop&dpr=1 754w, https://images.theconversation.com/files/476491/original/file-20220728-27951-d1d795.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=486&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/476491/original/file-20220728-27951-d1d795.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=486&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">The electron capture detector Lovelock invented for measuring air pollution.</span>
<span class="attribution"><a class="source" href="https://en.wikipedia.org/wiki/James_Lovelock#/media/File:James_Lovelocks_Electron_capture_detector_for_a_gas_chromatograph,_1960._(9660569973).jpg">Science Museum London</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<p>The money he earned from the electron capture detector gave him his freedom because, as he was fond of telling people, the best science comes from an unfettered mind – and he hated being directed. The detector was just the start of his inventing career and he filed more than 40 patents. </p>
<p>He also wrote over 200 scientific papers and many popular books expanding on the Gaia hypothesis. He was awarded scientific medals, international prizes and honorary doctorates by universities all around the world.</p>
<p>Dr Roger Highfield, the science director at the London Science Museum, summed Jim up perfectly: </p>
<blockquote>
<p>Jim was a nonconformist who had a unique vantage point that came from being, as he put it, half-scientist and half-inventor. Endless ideas bubbled forth from this synergy between making and thinking. Although he is most associated with Gaia, he did an extraordinary range of research, from freezing hamsters to detecting life on Mars … He was more than happy to bristle a few feathers, whether by articulating his dislike of consensus views, formal education and committees, or by voicing his enthusiastic support for nuclear power.</p>
</blockquote>
<p>Jim was deeply concerned by what he saw humanity doing to the planet. In his 1995 book The Ages of Gaia, he suggested that the <a href="https://theconversation.com/ice-ages-have-been-linked-to-the-earths-wobbly-orbit-but-when-is-the-next-one-70069">warm periods between ice ages</a>, like the current Holocene, are the fevered state of our planet. Because over the last two million years the Earth has shown a clear preference for a colder average global temperature, Jim understood global warming as humanity adding to this fever. </p>
<p>Jim did despair at humanity’s inability to look after the environment and much of his writing reflected this, particularly his book The Revenge of Gaia in 2006. But at the age of 99, he published <a href="https://www.theguardian.com/books/2019/jun/27/novacene-by-james-lovelock-review">Novacene: The Coming Age of Hyperintelligence</a> (2019), an optimistic view which envisaged humanity creating artificially intelligent life forms that would, unlike us, understand the importance of other living things in maintaining a habitable planet. </p>
<p>His dwindling faith in humanity was replaced by trust in the logic and rationality of AI. He left us with hope that cyborgs would take over and save us from ourselves.</p><img src="https://counter.theconversation.com/content/187870/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Mark Maslin is a Founding Director of Rezatec Ltd, Co-Director of The London NERC Doctoral Training Partnership, a member of Cheltenham Science Festival Advisory Committee and a member of the Climate Crisis Advisory Group. He is an unpaid member of the Sopra-Steria CSR Board, Sheep Included Ltd and NetZeroNow Advisory Boards. He has received grant funding in the past from the NERC, EPSRC, ESRC, DFG, Royal Society, DIFD, BEIS, DECC, FCO, Innovate UK, Carbon Trust, UK Space Agency, European Space Agency, Research England, Wellcome Trust, Leverhulme Trust, The Children's Investment Fund Foundation, Sprint2020, and British Council. He has received research funding in the past from The Lancet, Laithwaites, Seventh Generation, Channel 4, JLT Re, WWF, Hermes, CAFOD, HP, and Royal Institute of Chartered Surveyors.
</span></em></p>Lovelock’s Gaia hypothesis suggested that Earth could be considered a single, self-regulating organism.Mark Maslin, Professor of Earth System Science, UCLLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1338592020-03-18T11:02:40Z2020-03-18T11:02:40ZPhilosopher in Italian coronavirus lockdown on how to think positively about isolation<p><em>“I am facing 14 days of self isolation and I find the prospect terrifying. Chances are it will continue much longer too, as we may soon face lockdown. But I also wonder whether it may be good for us to slow down and reflect on the human condition. Could this pandemic help us change how we think and act for the better?”</em> Dan, 44, Southampton</p>
<p>“They say when trouble comes, close ranks.” So begins Jean Rhys’s novel <a href="https://www.bl.uk/20th-century-literature/articles/an-introduction-to-wide-sargasso-sea">Wide Sargasso Sea</a>. When the novel coronavirus started spreading in Europe, my first impulse was to travel home, to Italy, to be with my family. Lesson number one learned from the virus: you remember what matters to you.</p>
<p>Rhys was, of course, talking about racial tensions in colonial times, not families vs other commitments, or humans vs viruses. But she knew that there are good ways and bad ways of closing ranks. It seems to me we are now experiencing both. As a philosopher in <a href="https://theconversation.com/italys-darkest-hour-how-coronavirus-became-a-very-political-problem-133178">lockdown in Piedmont</a>, I am trying to take the opportunity to think about what the outbreak can tell us about ourselves – and our planet.</p>
<p>One way to think about the pandemic is in terms of humanity coming together to fight a natural threat in the form of a virus. I find this thought both inspiring and absurd. The reminder that we are all similarly vulnerable, similarly worried, and that we need concerted action across the globe to address this disease, brings some hope. On the other hand, while this threat is impersonal, we know that whenever a “we” is formed, there is a “they”.</p>
<hr>
<figure class="align-right ">
<img alt="" src="https://images.theconversation.com/files/313328/original/file-20200203-41485-1foofme.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/313328/original/file-20200203-41485-1foofme.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/313328/original/file-20200203-41485-1foofme.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/313328/original/file-20200203-41485-1foofme.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/313328/original/file-20200203-41485-1foofme.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/313328/original/file-20200203-41485-1foofme.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/313328/original/file-20200203-41485-1foofme.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=754&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption"></span>
</figcaption>
</figure>
<p><strong><em>This article is part of <a href="https://theconversation.com/uk/topics/lifes-big-questions-80040?utm_source=TCUK&utm_medium=linkback&utm_campaign=TCUKengagement&utm_content=LifesBigQuestionsUK">Life’s Big Questions</a></em></strong>
<br><em>The Conversation’s new series, co-published with BBC Future, seeks to answer our readers’ nagging questions about life, love, death and the universe. We work with professional researchers who have dedicated their lives to uncovering new perspectives on the questions that shape our lives.</em></p>
<hr>
<p>For Rhys, it was Jamaican natives and African slaves. Today, there are many different forms of “they”, starting broadly with <a href="https://theconversation.com/have-humans-evolved-beyond-nature-and-do-we-even-need-it-128790">the obscure “other” that is nature</a> – humans versus everything that is neither human nor human-made. This may bring a sense of unity for us, but the same worldview may have enabled the virus in the first place. That’s because one of its manifestations is thinking of non-human animals as objects of consumption – and we know a seafood market is one of the <a href="https://www.telegraph.co.uk/global-health/science-and-disease/coronavirus-outbreakchinese-live-animal-markets-recipe-disaster/">possible sources of the disease</a>.</p>
<p>More broadly, our view of “nature” as radically separate from humanity is arguably to blame for climate change, which scientists <a href="https://www.newscientist.com/article/2219981-how-deadly-disease-outbreaks-could-worsen-as-the-climate-changes/">have suggested</a> makes it easier for viruses to spread. So perhaps it isn’t enough to broaden our perspectives from the individual to all of humanity to achieve positive change.</p>
<h2>Me and Gaia</h2>
<p>If there is one thing philosophy can do quite effectively it is to unearth our implicit, habitual vision of the world and show us what follows. <a href="https://www.theguardian.com/education/2018/oct/12/mary-midgley-obituary">Mary Midgley</a> was a philosopher strikingly capable of imaginative transformation and forward vision. She supported the idea of “Gaia” – the personification of the Earth and one of the Greek primordial deities – and its implications for how we live. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/321142/original/file-20200317-60901-1dyh7cv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/321142/original/file-20200317-60901-1dyh7cv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=480&fit=crop&dpr=1 600w, https://images.theconversation.com/files/321142/original/file-20200317-60901-1dyh7cv.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=480&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/321142/original/file-20200317-60901-1dyh7cv.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=480&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/321142/original/file-20200317-60901-1dyh7cv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=603&fit=crop&dpr=1 754w, https://images.theconversation.com/files/321142/original/file-20200317-60901-1dyh7cv.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=603&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/321142/original/file-20200317-60901-1dyh7cv.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=603&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">We are all part of nature.</span>
<span class="attribution"><a class="source" href="http://shutterstock.com/image-photo/little-boy-girl-pretending-fish-wooden-217352713">CreativeAngela</a></span>
</figcaption>
</figure>
<p>Thinking of life on Earth as a unified, non hierarchical and self-sustaining system, <a href="https://web.archive.org/web/20050830013608/http://www.demos.co.uk/catalogue/gaia/">Midgley argued</a>, is not only more realistic, but helps us think of ourselves beyond unapologetic individualism. “Gaia is angry”, I have heard someone say in the context of this pandemic. Some people will laugh at this sentence. Others will be moved to picture the Earth aiming for internal balance. </p>
<p>Back in the “red zones” of Italy, most of us don’t see nor imagine much of this living organism around us. Our immediate problem, in lockdown, is avoiding contagion from another human. We are back in the narrowest of circles: me vs you. In rare outings, each person on your way becomes a threat. If they are careless and walk too close to you, you feel anger. Others are not friends when you fear for your health. Yet, thinking about how we used to ignore each other in the streets, this is at least a new form of awareness. We are forced to pay attention to each other.</p>
<p>And sometimes, this attention can take altruistic forms. My aunt, in her 70s, volunteering for the Red Cross to check temperatures in the local hospital, is an example of this. China sending supplies and medical experts <a href="https://www.aljazeera.com/news/2020/03/china-sends-essential-coronavirus-supplies-italy-200313195241031.html">to help Italy</a> is another. These cases are received with as much surprise as praise. Generosity seems extraordinary. This is something else I think we should reflect on.</p>
<h2>Rethinking freedom</h2>
<p>In philosophy, individualism is <a href="https://philosophynow.org/issues/120/Is_The_Age_Of_Individualism_Coming_To_An_End">closely linked</a> with the concept of <a href="http://www.informationphilosopher.com/freedom/idea_of_freedom.html">freedom</a>. As soon as restrictive measures were imposed in Italy, many people felt that their freedom was threatened and started to assert their individuality in various ways. Some disagreed with the necessity of cancelling group gatherings and organised unofficial ones themselves. Others continued to go out and live as they always did.</p>
<p>We often assume that freedom is to do as we choose, and that is contrasted with being told what to do. As long as I am doing what the government tells me, I am not free. I am going out, not because I want to, but because that shows I am free.</p>
<p>But there is another route to freedom, which goes back to some of Midgley’s notions about oneself as part of something larger. If we thought we were part of Gaia, wouldn’t inflicting potential damage to our community feel like self-harm rather than freedom? Here we could think of freedom in the philosopher Immanuel Kant’s way – as <a href="https://www.cambridge.org/core/books/immanuel-kant/freedom-will-autonomy/0940F88329670E44759F0DD4AE4F6B50">choosing what you understand to be right</a>. Or, with Plato, as <a href="https://digitalrepository.unm.edu/cgi/viewcontent.cgi?article=1014&context=phil_etds">answering to the pull of what is good</a>. That could mean accepting some discomfort and boredom to protect someone else.</p>
<p>There are worries with taking a broader perspective though. One is that it may ignore individuals. Some environmentalists claim to <a href="https://archive.org/details/clpbpl/mode/2up">dislike humans</a> from the perspective of the whole planet and the damage we have done to Earth. Perhaps some people welcome or at least accept pandemics for that reason. Yet if we place ourselves closer to individual suffering, we may struggle to keep that view: the director of a hospital ward in Lombardy nearly broke down when interviewed on TV, talking about the deaths he witnesses, relentlessly, every day. </p>
<p>Can the two perspectives, being part of the whole and caring for individuals, be reconciled? Sometimes this possibility runs up against conflicting interests and resistance. Sometimes it does not: we have, with a smile, seen pictures of dolphins reclaiming the waters near the port of Cagliari, Sardinia, and shoals of tiny of fish <a href="https://edition.cnn.com/travel/article/venice-canals-clear-water-scli-intl/index.html">glittering under the sun in Venice’s canals</a>. We don’t have to die for such things to happen. But we do have to significantly rethink our lifestyle and our role within the planet.</p>
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<p>For someone like me, quarantine may not be a huge sacrifice. Not facing the pressure to be sociable, productive and successful actually brings some relief. But as I was writing this, a loud clapping started in the street. I opened the window and remembered that there was a general ovation planned for 12 o’clock to show appreciation for each other’s sacrifice for not going out. On the balcony opposite mine, a small elderly lady was enthusiastically clapping, leaning forward, smiling and waving at us. Staying in can truly be a sacrifice if you live alone. </p>
<p>I hope isolation and lockdown can also be an opportunity for reflection and change. These thoughts about who we are as individuals and as parts of a large, wonderful web of life are my two cents.</p>
<p>On the packages from China containing protective masks, they wrote: “We are waves of the same sea, leaves of the same tree, flowers of the same garden.” These words were written by the Roman philosopher <a href="https://plato.stanford.edu/entries/seneca/">Seneca</a>, but they could be from Midgley. In another context, it would sound sentimental. Now we can take it at face value. If that is what we are - if we can think of ourselves that way — what follows from it? If the lockdown helps us to think about the answer, we may have gained something from it.</p>
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<ul>
<li><p><em><a href="https://theconversation.com/happiness-is-feeling-content-more-important-than-purpose-and-goals-131503?utm_source=TCUK&utm_medium=linkback&utm_campaign=TCUKengagement&utm_content=LifesBigQuestionsUK">Happiness: is contentment more important than purpose and goals?</a></em></p></li>
<li><p><em><a href="https://theconversation.com/free-thought-can-you-ever-be-a-truly-independent-thinker-129033?utm_source=TCUK&utm_medium=linkback&utm_campaign=TCUKengagement&utm_content=LifesBigQuestionsUK">Free thought: can you ever be a truly independent thinker?</a></em></p></li>
<li><p><em><a href="https://theconversation.com/could-we-live-in-a-world-without-rules-128664?utm_source=TCUK&utm_medium=linkback&utm_campaign=TCUKengagement&utm_content=LifesBigQuestionsUK">Could we live in a world without rules?</a></em></p></li>
<li><p><em><a href="https://theconversation.com/feelings-whats-the-point-of-rational-thought-if-emotions-always-take-over-128592?utm_source=TCUK&utm_medium=linkback&utm_campaign=TCUKengagement&utm_content=LifesBigQuestionsUK">Feelings: What’s the point of rational thought if emotions always take over?</a></em></p></li>
<li><p><em><a href="https://theconversation.com/death-can-our-final-moment-be-euphoric-129648?utm_source=TCUK&utm_medium=linkback&utm_campaign=TCUKengagement&utm_content=LifesBigQuestionsUK">Death: can our final moment be euphoric?</a></em></p></li>
<li><p><em><a href="https://theconversation.com/are-humans-still-part-of-nature-or-is-it-now-just-our-dominion-128790?utm_source=TCUK&utm_medium=linkback&utm_campaign=TCUKengagement&utm_content=LifesBigQuestionsUK">Nature: have humans now evolved beyond the natural world, and do we still need it?</a></em></p></li>
<li><p><em><a href="https://theconversation.com/love-is-it-just-a-fleeting-high-fuelled-by-brain-chemicals-129201?utm_source=TCUK&utm_medium=linkback&utm_campaign=TCUKengagement&utm_content=LifesBigQuestionsUK">Love: is it just a fleeting high fuelled by brain chemicals?</a></em></p></li>
</ul><img src="https://counter.theconversation.com/content/133859/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Silvia Caprioglio Panizza 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>The coronavirus outbreak shows it is time to start thinking of ourselves as part of something bigger - while also respecting the individual.Silvia Caprioglio Panizza, Teaching Fellow, University College DublinLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1059972018-10-31T18:35:26Z2018-10-31T18:35:26ZDramatic galaxy collision filled the Milky Way with stars, astronomers discover<figure><img src="https://images.theconversation.com/files/243206/original/file-20181031-76393-1ycnfy8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Milky Way from Moke Lake in New Zealand.</span> <span class="attribution"><a class="source" href="https://www.flickr.com/photos/astrostew/31049934788/in/photolist-PiM2Rf-DTYdPp-2aySeHh-qUdcNf-psWYSX-dbxkLz-Vyg6rq-f8jPP8-gxEMaa-MrjT5s-28dHEkD-HD4phm-seHxm5-T5fxnk-f9B4LT-fwrNvb-29Rk9us-s3yApg-2a6cvVz-nsYnDK-s56TCV-ihrxvP-VuMVLF-hyzMyT-o2V8an-9Z2nQc-oQEYoZ-T5fwLR-Eyyec-fQPC34-p8UoDx-RYPris-cWgyJj-T4RGnk-Wp2HuC-ekw9yc-bf1jNF-f9AR7c-MT5g1p-WWr1u3-sto9s8-p2pzYr-eaArfj-cB5n83-a1CMfn-cfrD4w-6FJX8d-jG1Zcs-ormPTq-2npF7w">Paul Stewart/Flickr</a></span></figcaption></figure><p>Imagine trying to map out your home town using only information you could gather from your window. Even with a pair of binoculars you’d find it a difficult task. Mapping out our own galaxy, the Milky Way, is a similarly daunting mission. Unlike other galaxies that we can view from a distance, we sit inside the Milky Way – around 26,000 light years from its centre. This means that when we try to look at the opposite side of the galaxy, much of our view is blocked by the stars and dust in between. </p>
<p>But on April 25, our view of the Milky Way became much clearer. The <a href="http://sci.esa.int/gaia/">European Space Agency’s Gaia satellite</a> <a href="https://theconversation.com/gaia-mission-releases-map-of-more-than-a-billion-stars-heres-what-it-can-teach-us-95602">provided us with</a> positions, distances and motions of 1.3 billion stars measured to a higher precision than ever before. Now this same data has helped researchers work out how our galaxy filled up with a considerable amount of its stars. The results <a href="https://www.nature.com/articles/s41586-018-0625-x">have just been published</a> in Nature.</p>
<p>Gaia, which aims to chart the stars in the Milky Way in unprecedented detail, has a resolution comparable to being able to measure the width of a human hair on top of the Empire State Building. But in this scenario, Gaia wouldn’t be down on the New York streets, squinting up 443 metres to the top of the tower. It is the equivalent of being sat on the roof of Buckingham Palace in London, staring out more than 5,500 kilometres across the Atlantic Ocean. </p>
<h2>Funny moving stars</h2>
<p>The team of astronomers behind the new study, from the Netherlands and France, discovered stars with retrograde motions – moving in a different direction to the majority of the galaxy’s stars. They suspected that this could be the debris from a collision between the Milky Way and another galaxy ten billion years ago. This second galaxy would have been a smaller “satellite” companion of the Milky Way, travelling around it.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/243006/original/file-20181030-76396-wyc5a9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/243006/original/file-20181030-76396-wyc5a9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=516&fit=crop&dpr=1 600w, https://images.theconversation.com/files/243006/original/file-20181030-76396-wyc5a9.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=516&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/243006/original/file-20181030-76396-wyc5a9.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=516&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/243006/original/file-20181030-76396-wyc5a9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=649&fit=crop&dpr=1 754w, https://images.theconversation.com/files/243006/original/file-20181030-76396-wyc5a9.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=649&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/243006/original/file-20181030-76396-wyc5a9.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=649&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">An image of galaxy UGC 12158, which is thought to resemble the Milky Way in appearance.</span>
<span class="attribution"><span class="source">ESA/Hubble & NASA</span></span>
</figcaption>
</figure>
<p>Collisions of galaxies are dramatic events. They reshape large galaxies and can entirely consume smaller galaxies. In fact, this <a href="http://www.sdss3.org/press/20111130.fourtails.php">has happened before</a>, with the debris from satellite galaxies caught up in the Milky Way’s gravitational pull often seen as a stream of stars, tracing out the orbit of the ill-fated satellite. However, ten billion years is a long time (even for astronomy) – long enough to scatter the debris from a merger all over the sky, rather than just in a clear stream. </p>
<p>So while the discovery of a collection of oddly rotating stars scattered over the whole sky is interesting, the scientists couldn’t be sure these stars were actually associated with each other. To find out, they decided to compare the chemical properties of the stars with the remaining ones in the Milky Way.</p>
<h2>Chemical clues</h2>
<p>The team used spectroscopic observations from the <a href="https://www.sdss.org/surveys/apogee-2/">APOGEE-2 survey</a> – which measures the amounts of different elements in individual stars. Measurements of heavy elements were essential, as we know that these are formed when stars <a href="https://www.space.com/6638-supernova.html">explode as supernovae</a>, filling the interstellar medium of a galaxy. Exactly which element is formed depends on the star. Alpha elements – formed by combining multiple helium atoms – are created in explosions of massive, rapidly evolving stars, while iron is formed in supernovae from star systems where two stars orbit each other. </p>
<figure>
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<p>We know that the fraction of alpha elements in a galaxy decreases with time, while the fraction of iron increases. By comparing the trends for the retrograde stars with stars in the Milky Way’s disk components, it was clear that the retrograde stars must have formed in a system with a different chemical composition. Adding in this extra piece of the puzzle makes it clear that they were originally a separate galaxy. </p>
<p>The authors have named the crashing satellite galaxy “Gaia-Enceladus”, which is very fitting. In Greek mythology, <a href="https://en.wikipedia.org/wiki/Enceladus_(giant)">Enceladus</a> was a child of the gods Gaia and Uranus. It was one of the giants, buried under Mount Etna, where it caused earthquakes disrupting the land. </p>
<p>Similarly, Gaia-Enceladus was a giant compared to most of the Milky Way’s current satellites – it would have had a mass around one quarter of the Milky Way’s at the time of the merger. It shook the Milky Way, changing the structure of the galactic disk, setting off bursts of star formation in its wake. Like Enceladus the giant, Gaia-Enceladus was buried, hidden deep inside the galaxy. If Gaia could dig out the remains of this event that happened ten billion years ago, it is exciting to think what else it will uncover.</p><img src="https://counter.theconversation.com/content/105997/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Victoria Scowcroft has previously received funding from NASA/JPL. </span></em></p>The Gaia satellite has uncovered the remains of a galaxy buried deep in the Milky Way.Victoria Scowcroft, Lecturer of Physics, University of BathLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/991532018-07-02T15:06:07Z2018-07-02T15:06:07ZScientists finally have an explanation for the ‘Gaia puzzle’<figure><img src="https://images.theconversation.com/files/225505/original/file-20180629-117382-asep9l.jpg?ixlib=rb-1.1.0&rect=8%2C422%2C5742%2C3526&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Romolo Tavani / shutterstock</span></span></figcaption></figure><p>We will likely never know how life on Earth started. Perhaps in a shallow sunlit pool. Or in the crushing ocean depths miles beneath the surface near fissures in the Earth’s crust that spewed out hot mineral-rich soup. While there is good evidence for life <a href="https://www.nature.com/news/oldest-traces-of-life-on-earth-may-lurk-in-canadian-rocks-1.22685#/ref-link-2">at least 3.7 billion years ago</a>, we don’t know precisely when it started. </p>
<p>But these passing aeons have produced something perhaps even more remarkable: life has persisted. Despite massive asteroid impacts, cataclysmic volcano activity and extreme climate change, life has managed to not just cling on to our rocky world but to thrive. </p>
<p>How did this happen? Research we recently published with colleagues in <a href="https://www.cell.com/trends/ecology-evolution/fulltext/S0169-5347(18)30118-6">Trends in Ecology and Evolution</a> offers an important part of the answer, providing a new explanation for the Gaia hypothesis.</p>
<p>Developed by scientist and inventor <a href="http://www.jameslovelock.org">James Lovelock</a>, and microbiologist <a href="https://www.telegraph.co.uk/news/obituaries/science-obituaries/8954456/Lynn-Margulis.html">Lynn Margulis</a>, the <a href="https://courses.seas.harvard.edu/climate/eli/Courses/EPS281r/Sources/Gaia/Gaia-hypothesis-wikipedia.pdf">Gaia hypothesis</a> originally proposed that life, through its interactions with the Earth’s crust, oceans, and atmosphere, produced a stabilising effect on conditions on the surface of the planet – in particular the composition of the atmosphere and the climate. With such a self-regulating process in place, life has been able to survive under conditions which would have wiped it out on non-regulating planets.</p>
<p>Lovelock formulated the Gaia hypothesis while working for NASA in the 1960s. He recognised that life has not been a passive passenger on Earth. Rather it has profoundly remodelled the planet, creating new rocks such as limestone, affecting the atmosphere by producing oxygen, and driving the cycles of elements such as nitrogen, phosphorus and carbon. Human-produced climate change, which is largely a consequence of us burning fossil fuels and so releasing carbon dioxide, is just the latest way life affects the Earth system. </p>
<p>While it is now accepted that life is a powerful force on the planet, the Gaia hypothesis remains controversial. Despite evidence that surface temperatures have, bar a few notable exceptions, remained within the range required for widespread liquid water, many scientists attribute this simply to good luck. If the Earth had descended completely into an ice house or hot house (think Mars or Venus) then life would have become extinct and we would not be here to wonder about how it had persisted for so long. This is a form of <a href="https://ndpr.nd.edu/news/anthropic-bias-observation-selection-effects-in-science-and-philosophy/">anthropic selection argument</a> that says there is nothing to explain.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/225664/original/file-20180702-116135-1m4js29.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/225664/original/file-20180702-116135-1m4js29.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/225664/original/file-20180702-116135-1m4js29.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=247&fit=crop&dpr=1 600w, https://images.theconversation.com/files/225664/original/file-20180702-116135-1m4js29.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=247&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/225664/original/file-20180702-116135-1m4js29.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=247&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/225664/original/file-20180702-116135-1m4js29.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=310&fit=crop&dpr=1 754w, https://images.theconversation.com/files/225664/original/file-20180702-116135-1m4js29.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=310&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/225664/original/file-20180702-116135-1m4js29.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=310&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Two billion years ago, before multi-cellular life, the planet went through a ‘snowball’ phase.</span>
<span class="attribution"><span class="source">NASA</span></span>
</figcaption>
</figure>
<p>Clearly, life on Earth has been lucky. In the first instance, the Earth is within the habitable zone – it orbits the sun at a distance that produces surface temperatures required for liquid water. There are alternative and perhaps more exotic forms of life in the universe, but life as we know it requires water. Life has also been lucky to avoid very large asteroid impacts. A lump of rock significantly larger than the one that lead to the demise of the dinosaurs <a href="http://www.sciencemag.org/news/2016/11/updated-drilling-dinosaur-killing-impact-crater-explains-buried-circular-hills">some 66m years ago</a> could have completely sterilised the Earth.</p>
<p>But what if life had been able to push down on one side of the scales of fortune? What if life in some sense made its own luck by reducing the impacts of planetary-scale disturbances? This leads to the central outstanding issue in the Gaia hypothesis: how is planetary self-regulation meant to work? </p>
<p>While natural selection is a powerful explanatory mechanism that can account for much of the change we observe in species over time, we have been lacking a theory that could explain how the living and non-living elements of a planet produce self-regulation. Consequently the Gaia hypothesis has typically been considered as interesting but speculative – and not <a href="https://pdfs.semanticscholar.org/1291/1013d6cf90f9db980395eb74db3880d9e405.pdf">grounded in any testable theory</a>.</p>
<h2>Selecting for stability</h2>
<p>We think there is finally an explanation for the Gaia hypothesis. The mechanism is based on “<a href="https://digital.nmla.metoffice.gov.uk/download/file/sdb%3AdigitalFile%7Cd5b84c8c-60db-4273-909b-4695732bc0c8/">sequential selection</a>”, a concept first suggested by climate scientist <a href="http://geography.exeter.ac.uk/staff/?web_id=Richard_Betts">Richard Betts</a> in the early 2000s. In principle it’s very simple. As life emerges on a planet it begins to affect environmental conditions, and this can organise into stabilising states which act like a thermostat and tend to persist, or destabilising runaway states such as the <a href="http://www.snowballearth.org/index.html">snowball Earth events</a> that nearly extinguished the beginnings of complex life more than 600m years ago. </p>
<p>If it stabilises then the scene is set for further biological evolution that will in time reconfigure the set of interactions between life and planet. A famous example is the <a href="https://www.scientificamerican.com/article/origin-of-oxygen-in-atmosphere/">origin of oxygen-producing photosynthesis</a> around 3 billion years ago, in a world previously devoid of oxygen. If these newer interactions are stabilising, then the planetary-system continues to self-regulate. But new interactions can also produce disruptions and runaway feedbacks. In the case of photosynthesis it led to an abrupt rise in atmospheric oxygen levels in the “<a href="https://watermark.silverchair.com/biv193.pdf?token=AQECAHi208BE49Ooan9kkhW_Ercy7Dm3ZL_9Cf3qfKAc485ysgAAAa4wggGqBgkqhkiG9w0BBwagggGbMIIBlwIBADCCAZAGCSqGSIb3DQEHATAeBglghkgBZQMEAS4wEQQMZgre2R0WD9pCKSf5AgEQgIIBYdrmnpoHsycmASfJvC2PtjemZe9SLAjqTY3xLT0LzpPYkjT_sQTVKqpvdqSjuYbxbf1obzu1EjlEK_wuJgSHg9VndwyI0dy-6BL0PjXiVqaL869iScdrDcVA-R5BtguQiw5MySR-wZcLe1Y3obgZQjFzIagxkYEP8L48Ntq0hIxSGeJ9vCRRtkft5KtBdoY1ufwP-Cmt1ubJrXLs3K7O1rEXBIqeDW6bo0gK5s1EnDxXWOuLaNAmu9QzORZMWoBS_ilChgkUoK-4PnhFm4A26rSNEGtQ6UG-e27u9Fk2Kw_5xkGJVd4eeKdcSB8NwjgmFQVxip_D79qoKvyzGCy0DlRtmf8GhL5Ou8B2kbV2ELuryL9RcTdAR__cnTuQ2FGv_HaikKXZ0zlh4vkyBu4ObEGv1LUwZZ686XU5J5WMU7gU-gN4ceOqzOYLOEl699E91kS2NIAmVoNV6NSsJedsjp5j">Great Oxidation Event</a>” around 2.3 billion years ago. This was one of the rare periods in Earth’s history where the change was so pronounced it probably wiped out much of the incumbent biosphere, effectively rebooting the system.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/3rtNO8O2TKA?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">The selection mechanism.</span></figcaption>
</figure>
<p>The chances of life and environment spontaneously organising into self-regulating states may be much higher than you would expect. If fact, given sufficient biodiversity, <a href="http://journals.plos.org/ploscompbiol/article?id=10.1371/journal.pcbi.1003050">it may be extremely likely</a>. But there is a limit to this stability. Push the system too far and it may go beyond a tipping point and rapidly collapse to a new and potentially very different state.</p>
<p>This isn’t a purely theoretical exercise, as we think we may able to test the theory in a number of different ways. At the smallest scale that would involve experiments with diverse bacterial colonies. On a much larger scale it would involve searching for other biospheres around other stars which we could use to estimate the total number of biospheres in the universe – and so not only how likely it is for life to emerge, but also to persist.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/225526/original/file-20180629-117389-136qwj6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/225526/original/file-20180629-117389-136qwj6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/225526/original/file-20180629-117389-136qwj6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/225526/original/file-20180629-117389-136qwj6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/225526/original/file-20180629-117389-136qwj6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/225526/original/file-20180629-117389-136qwj6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/225526/original/file-20180629-117389-136qwj6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/225526/original/file-20180629-117389-136qwj6.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">James Lovelock, next to a statue of Gaia, the Greek godess of the Earth.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:James_Lovelock_in_2005.jpg">Bruno Comby, Environmentalists For Nuclear Energy</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<p>The relevance of our findings to current concerns over climate change has not escaped us. Whatever humans do life will carry on in one way or another. But if we continue to emit greenhouse gasses and so change the atmosphere, then we risk producing dangerous and potentially runaway climate change. This could eventually stop human civilisation affecting the atmosphere, if only because there will not be any human civilisation left.</p>
<p>Gaian self-regulation may be very effective. But there is no evidence that it prefers one form of life over another. Countless species have emerged and then disappeared from the Earth over the past 3.7 billion years. We have no reason to think that <em>Homo sapiens</em> are any different in that respect.</p>
<hr>
<p><em>This article was updated on July 10 to add the reference to Richard Betts.</em></p><img src="https://counter.theconversation.com/content/99153/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Tim Lenton works for the University of Exeter and receives funding from the Royal Society (Wolfson Research Merit Award) and the Natural Environment Research Council (NE/P013651/1).</span></em></p><p class="fine-print"><em><span>James Dyke 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>We have long wondered why Earth has stayed habitable enough for life to evolve over billions of years.James Dyke, Associate Professor of Sustainability Science, University of SouthamptonTim Lenton, Director, Global Systems Institute, University of ExeterLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/956022018-04-25T14:26:05Z2018-04-25T14:26:05ZGaia mission releases map of more than a billion stars – here’s what it can teach us<figure><img src="https://images.theconversation.com/files/216303/original/file-20180425-175035-1h0dvim.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Gaia’s view of our Milky Way and neighbouring galaxies.</span> <span class="attribution"><span class="source"> ESA/Gaia/DPAC</span>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span></figcaption></figure><p>Most of us have looked up at the night sky and wondered how far away the stars are or in what direction they are moving. The truth is, scientists don’t know the exact positions or velocities of the vast majority of the stars in the Milky Way. But now a new tranche of data from the European Space Agency’s <a href="http://sci.esa.int/gaia/">Gaia satellite</a>, aiming to map stars in our galaxy in unprecedented detail, has come in to shed light on the issue. </p>
<p>The <a href="https://gea.esac.esa.int/archive/">Gaia Archive</a> opened on April 25, making public Gaia’s second data release to everyone. To quote the character Dave Bowman in the sci-fi classic <a href="https://www.imdb.com/title/tt0062622/">2001: A Space Odyssey</a>: “It’s full of stars”. In fact, it contains data on the distances to more than 1.3 billion stars.</p>
<p>The Gaia satellite was launched in 2013 and has been scanning the sky with its two telescopes continuously ever since, with the aim of deciphering how our Milky Way galaxy formed and evolved. To do this, it is measuring something called <a href="https://en.wikipedia.org/wiki/Parallax">parallax</a>. If you hold a finger at arms length and look at it with one eye and then the other, your finger appears to shift position compared to the background. The angular change is called parallax.</p>
<p>Being in space allows Gaia to see similar tiny shifts in star positions. Observations at different locations six months apart (half way of its orbit around the sun) are akin to looking at your finger with one eye and then the other. When you know the parallax as well as the distance from Gaia to the sun (or the distance from your nose to your eye), you can use simple trigonometry to work out the distance to each star (or your finger).</p>
<p>Gaia also sees stars move in the plane of the sky over time. These units of “angle per time” can be converted to a physical unit of speed (for example kilometres per second) if we know the distance to the stars. However, to know how a star is moving in three dimensions in space requires that we also measure the speed perpendicular to the sky along the line-of-sight. This requires a galactic speed camera!</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/216322/original/file-20180425-175047-ks10jq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/216322/original/file-20180425-175047-ks10jq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=381&fit=crop&dpr=1 600w, https://images.theconversation.com/files/216322/original/file-20180425-175047-ks10jq.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=381&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/216322/original/file-20180425-175047-ks10jq.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=381&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/216322/original/file-20180425-175047-ks10jq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=478&fit=crop&dpr=1 754w, https://images.theconversation.com/files/216322/original/file-20180425-175047-ks10jq.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=478&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/216322/original/file-20180425-175047-ks10jq.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=478&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">The all-sky map of median velocities of stars towards or away from the sun.</span>
<span class="attribution"><span class="source">DPAC/ESA</span>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<p>A normal radar speed camera uses the <a href="https://theconversation.com/explainer-the-doppler-effect-7475">Doppler effect</a> – the stretching or squashing of waves because of motion – by measuring the change in the radio frequency from signals bounced off cars to measure their speed. Similarly, Gaia measures the change in frequency in the light from stars to check their speed. The star light is bluer if the star is moving towards us or redder if the star is moving away from us. This is called radial velocity.</p>
<h2>Revolutionising data</h2>
<p>Gaia’s <a href="https://theconversation.com/how-were-helping-the-gaia-mission-map-a-billion-stars-to-unparalleled-precision-65602">first data release</a> in 2016 published the distances of around two million stars but did not include any radial velocities. However we already knew the radial velocity of less than 400,000 of these stars – measured from the ground by many different surveys.</p>
<p>Gaia’s second data release includes information on sky positions and brightness for nearly 1.7 billion stars and more than seven million radial velocities. Not only does this make Gaia the largest radial velocity survey ever – it increases the number of stars with accurate 3D space velocities by a factor of 18. </p>
<p>A series of Gaia science demonstration papers have also been published alongside the star catalogue. I was involved in the research behind <a href="https://www.cosmos.esa.int/web/gaia/dr2-papers">one of these papers</a>, constructing the most detailed map ever of 3D space velocities to date. </p>
<p>Excitingly, the map revealed that there’s a global arrangement of stars in the Milky Way, most of which reside in our galaxy’s thin disc. These are organised in thin substructures with the shape of circular arches. This is a vital clue to how the Milky Way formed and how it is still evolving. The baton now passes to the astronomical community to interpret this finding and explore the full potential of Gaia’s second data release. </p>
<p>Eventually, the catalogue produced by Gaia could help us make many new discoveries – including mapping tens of thousands of asteroids in our solar system. By looking at dips in the stars’ brightness, we could also find exoplanets orbiting stars other than our own. </p>
<p>Perhaps more surprising, the measurements could even help us predict exactly where dark matter – an unknown, invisible substance thought to make up most of the matter in the universe – resides in the galaxy. Gaia has also found nearly 5,000 objects that can be followed by ground-based telescopes before they disappear. Most of these are supernovas, exploding stars, which may help to reveal the nature of dark energy that is causing the expansion of the universe to accelerate.</p>
<p>The next data release by Gaia will be in 2020. This is expected to boost the numbers of stars with known radial velocities from seven million today to around 30m – keeping our team busy for several years yet.</p><img src="https://counter.theconversation.com/content/95602/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>George Seabroke works for the Mullard Space Science Laboratory, University College London's Department of Space and Climate Physics, where much the code that derived Gaia's radial velocities was written. He is funded by the UK Space Agency.</span></em></p>Detailed information about stars in our galaxy could help us discover new exoplanets.George Seabroke, Senior Research Associate of Astrophysics, UCLLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/656022016-09-20T16:01:18Z2016-09-20T16:01:18ZHow we’re helping the Gaia mission map a billion stars to unparalleled precision<figure><img src="https://images.theconversation.com/files/138427/original/image-20160920-11131-pecule.png?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Gaia's first sky map
</span> <span class="attribution"><a class="source" href="http://www.esa.int/spaceinimages/Images/2016/09/Gaia_s_first_sky_map">ESA/Gaia/DPAC</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span></figcaption></figure><p>The positions and velocities of a billion stars in our own galaxy <a href="http://gea.esac.esa.int/archive/">have been released</a>, measured to a precision never achieved before. The data, obtained by the European Space Agency’s <a href="http://sci.esa.int/gaia/">Gaia spacecraft</a> is a milestone in stellar cartography. The brightest stars will eventually be measured to the nearest five-hundred-millionth of a degree. That’s like using a telescope in London to see the width of a human hair in Rome. </p>
<p>The <a href="http://gea.esac.esa.int/archive/">Gaia catalogue</a> is the first part of an incredibly clear and precise snapshot, revealing the three-dimensional layout and motion of all stars in our part of the Milky Way galaxy. This data will revolutionise our understanding of our place in the universe. </p>
<p>But this incredible precision requires a lot of effort and depends in part on accurate tracking of the Gaia spacecraft itself – a task achieved by <a href="http://telescope.livjm.ac.uk/">The Liverpool Telescope</a> (LT) on the Canary Island of La Palma and the <a href="http://www.eso.org/public/unitedkingdom/teles-instr/surveytelescopes/vst/">VLT Survey Telescope</a> in Paranal, Chile.</p>
<h2>Sensitive measurements</h2>
<p>The Gaia spacecraft was launched in 2013, and is now in a special orbit, effectively hovering 1.5m kilometres over the Earth’s night side. Both Gaia and Earth are moving in tandem around the sun at an average speed of 30 kilometres per second.</p>
<p>Because Gaia is physically moving relative to the stars, an effect called “<a href="http://www-spof.gsfc.nasa.gov/stargaze/Saberr.htm">aberration of starlight</a>” takes place. This causes the position of a star in the sky to appear to be shifted slightly towards the direction of motion. The size of the shift varies throughout the year due to variations in both Gaia’s and the Earth’s speed through space, but at most it’s just 1/180th of a degree (just over 1% of the apparent size of the moon).</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/138282/original/image-20160919-11134-1u5fpfx.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/138282/original/image-20160919-11134-1u5fpfx.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=397&fit=crop&dpr=1 600w, https://images.theconversation.com/files/138282/original/image-20160919-11134-1u5fpfx.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=397&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/138282/original/image-20160919-11134-1u5fpfx.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=397&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/138282/original/image-20160919-11134-1u5fpfx.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=499&fit=crop&dpr=1 754w, https://images.theconversation.com/files/138282/original/image-20160919-11134-1u5fpfx.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=499&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/138282/original/image-20160919-11134-1u5fpfx.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=499&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Artist’s impression of the Gaia spacecraft.</span>
<span class="attribution"><span class="source">ESA/ATG medialab; background image: ESO/S. Brunier</span></span>
</figcaption>
</figure>
<p>As small as that shift seems, it’s more than enough to spoil Gaia’s measurements unless it’s precisely corrected for. To achieve this correction to that degree of precision, the absolute velocity of Gaia must be known to just 2.5 millimetres per second.</p>
<p>Also, Gaia is detecting objects in the solar system. To measure their positions and velocities accurately enough, the exact location of Gaia itself must be known to within 150 metres. Knowing its position at all times makes sure we have an accurate baseline so we can determine the location of another body by triangulating from known points. </p>
<p>All this means that Gaia’s position and velocity need to be regularly known to high precision. Surprisingly, this can actually be achieved by tracking Gaia from the Earth’s surface, 1.5m kilometres away. This is no mean feat; at that distance 150 metres makes an angle (of the triangle) of just 1/180,000 of a degree, the apparent size of a 1p coin 200 kilometres away.</p>
<p>Using special radar techniques, the European Space Agency (ESA) can track Gaia this precisely using their <a href="http://www.esa.int/Our_Activities/Operations/Estrack/Estrack_ground_stations">Deep Space Antenna (DSA) network</a>. However they can’t do this all the time because those antennae are also used to monitor other space missions, and Gaia can’t hog the network. So to fill the gaps in coverage, ESA also tracks Gaia optically with large ground-based telescopes as part of their <a href="http://gbot.obspm.fr/index.php?page=presentation">Ground-Based Optical Tracking (GBOT) programme</a>. </p>
<p>GBOT was built up over 2008-2013 by <a href="http://sci.esa.int/gaia/58274-the-role-of-dpac/">the team of astronomers</a> scientifically conducting the mission. Gaia is seen only by reflected sunlight and at that distance is incredibly faint. So the telescopes have to be big, with a main mirror at least two meters in diameter. They must also be flexible enough time-wise to allow regular observations of the same target for months on end. Telescopes this big are professional facilities that don’t usually observe targets in this manner, they are normally involved in a number of different observations.</p>
<h2>Reliable tracking</h2>
<p>Only a very few facilities can tick both of those boxes, and one of them is the Liverpool Telescope.</p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/138272/original/image-20160919-11123-vriim.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/138272/original/image-20160919-11123-vriim.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/138272/original/image-20160919-11123-vriim.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/138272/original/image-20160919-11123-vriim.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/138272/original/image-20160919-11123-vriim.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/138272/original/image-20160919-11123-vriim.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/138272/original/image-20160919-11123-vriim.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/138272/original/image-20160919-11123-vriim.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The Liverpool Telescope with the centre of our galaxy in the background.</span>
<span class="attribution"><span class="source">Daniel López/IAC</span></span>
</figcaption>
</figure>
<p>The Liverpool Telescope came online in 2004. Though based in La Palma, it’s run by Liverpool John Moores University’s <a href="http://www.astro.ljmu.ac.uk/">Astrophysics Research Institute</a>. It’s completely robotic, opening itself up at sunset, protecting itself from the elements, and deciding for itself what to observe – all without human intervention. </p>
<p>Astronomers can drop their observing requests into the telescope’s database at any time, and its robotic scheduler picks those requests that best match sky conditions throughout the night. Astronomers can therefore spread out their allocated time through the semester any way they like. This unique flexibility for a professional telescope of this size makes it perfect for tracking Gaia.</p>
<p>The Gaia team therefore recruited the Liverpool Telescope, along with the 2.6-metre VLT Survey Telescope. Its scheduler suggests potential observations, but a human on duty all night makes the decisions on what to observe.</p>
<p>Also, the <a href="https://lcogt.net/about/">Las Cumbres Observatory</a>’s two two-metre <a href="https://lcogt.net/observatory/2m/">Faulkes Telescopes</a> in Hawaii and Australia provide backup observations, in case both the LT and VST are not available due to bad weather or other reasons.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/138289/original/image-20160919-11090-4r0v3t.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/138289/original/image-20160919-11090-4r0v3t.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=500&fit=crop&dpr=1 600w, https://images.theconversation.com/files/138289/original/image-20160919-11090-4r0v3t.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=500&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/138289/original/image-20160919-11090-4r0v3t.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=500&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/138289/original/image-20160919-11090-4r0v3t.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=628&fit=crop&dpr=1 754w, https://images.theconversation.com/files/138289/original/image-20160919-11090-4r0v3t.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=628&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/138289/original/image-20160919-11090-4r0v3t.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=628&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">One night’s LT observation of Gaia. Multiple images combined to show the spacecraft’s movement against stationary background stars.</span>
<span class="attribution"><span class="source">J. Marchant/LT Group</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>The Liverpool Telescope takes about 20 exposures of Gaia every night with its main camera. The raw images are processed the next morning in Liverpool, and then sent to other GBOT astronomers at the <a href="https://www.obspm.fr/-observatoire-de-paris-.html?lang=en">Observatoire de Paris</a> in France. There, Gaia’s position is very precisely measured relative to the background stars in the image.</p>
<p>These measurements are then sent to ESA’s <a href="http://www.esa.int/About_Us/ESOC/Where_missions_come_alive">European Space Operations Centre</a> in Darmstadt, Germany, where they’re used to calculate Gaia’s exact path, and so help to refine the Gaia catalogue’s amazing precision.</p>
<p>The recent data release is just the first; a small portion of the entire wealth of information we expect in the near future. There will be more such releases in coming years as Gaia continues its five-year mission, and the final complete catalogue will be ready sometime in 2022.</p>
<p>The information will give us a better understanding of how stars travel around the galaxy, how they’re born and evolve, and how (and why) planets form around them. This will also help discover thousands of extra-solar planets. Closer to home, hundreds of thousands of minor planets in the solar system will be mapped to a much better precision, and new ones may be discovered.</p>
<p>We’ll even be able to see how the gravity of the sun and the major planets (Jupiter, Saturn, Uranus and Neptune) bend starlight as Gaia flies through the solar system, revealing information about the structure of <a href="http://www.huffingtonpost.com/2014/07/22/what-is-gravity-video_n_5610340.html">space-time</a> itself.</p><img src="https://counter.theconversation.com/content/65602/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Jon Marchant receives funding from the Science and Technology Facilities Council.</span></em></p>The Gaia catalogue’s incredible precision is only possible due to accurate tracking of Gaia itself from the ground.Jon Marchant, Liverpool Telescope Operations Scientist and Astronomy Support, Liverpool John Moores UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/271562014-05-27T04:52:08Z2014-05-27T04:52:08ZForget ‘saving the Earth’ – it’s an angry beast that we’ve awoken<p>Environmentalism is undergoing a radical transformation. New science has shown how long-held notions about trying to “save the planet” and preserve the life we have today no longer apply. </p>
<p>Instead, a growing chorus of senior scientists refer to the Earth with metaphors such as “the wakened giant” and “the ornery beast”, a planet that is “fighting back” and seeking “revenge”, and a new era of “<a href="https://theconversation.com/angry-summer-shaped-by-a-shifting-climate-12580">angry summers</a>” and “death spirals”.</p>
<p>Whether you consider yourself to be an environmentalist or not, the warnings from Earth system science have far-reaching implications for us all.</p>
<h2>Nature fights back</h2>
<p>In its early days, the science of ecology showed how easily complex ecosystems could be degraded and species obliterated. In 1962, by observing the damage to humans and nature caused by factories and industrial agriculture, <a href="http://www.nytimes.com/2012/09/23/magazine/how-silent-spring-ignited-the-environmental-movement.html?pagewanted=all&_r=0">Rachel Carson in Silent Spring</a> presented nature as highly vulnerable to destruction by the power of synthetic chemicals.</p>
<p>The early view of nature as fragile, that is, easily disrupted and unable to repair itself, has been tempered somewhat by evidence that many ecosystems are more resilient and can adapt to new circumstances. </p>
<p>But whether fragile or robust, the Earth has been understood as unresponsive, neutral and essentially benign. </p>
<p>This understanding has various expressions, including “Mother Earth” as nurturing, feminine and easily damaged entity. The notion of living harmoniously with nature took hold, inspired by images of pre-industrial peoples living close to the natural world. </p>
<p>Underlying these conceptions is a view that, while humans can cause a great deal of damage, nature is passive and always our victim. </p>
<p>Yet now we see that the planet has been disturbed from its resting state, jolted out of the providential era of climatic stability characteristic of the last 10,000 years, and is now on a new and largely uncontrollable path that is creating conditions dangerous for human life.</p>
<h2>Seeing the bigger picture</h2>
<p>The rise of <a href="http://en.wikipedia.org/wiki/Earth_system_science">Earth system science</a> – which has brought together many different fields of science so that we can better understand how the Earth’s atmosphere, oceans, land and other systems work together – has changed the way we see the world.</p>
<p>Now, the Earth is understood as a dynamic system with strong feedback effects, which can suddenly shift it to a new state when critical points are crossed. </p>
<p>So profound has been the influence of humans that scientists have proposed that the Earth has entered a new geological epoch, <a href="https://theconversation.com/human-global-domination-began-with-fire-not-factories-or-farms-20317">the Anthropocene</a> or the Age of Humans, defined by the fact that the “human imprint on the global environment has now become so large and active that it rivals some of the great forces of Nature in its impact on the functioning of the Earth system”.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/ciV6Uaeobxk?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">NASA explains the basics of Earth systems science.</span></figcaption>
</figure>
<p>As <a href="http://www.igbp.net/download/18.1081640c135c7c04eb480001178/1376383107963/NL78-anthropocene.pdf">Earth scientist James Syvitski</a> writes:</p>
<blockquote>
<p>At some point, we graduated from adapting to our environment to making it adapt to us … But now we regularly decelerate and accelerate natural processes, focus energy in extraordinary ways and alter, destroy or create ecosystems. </p>
</blockquote>
<p>That means we must no longer see the Earth as the submissive repository for supplying our resources or taking our wastes, nor as the docile victim of our rapacity or carelessness. </p>
<p>This newer understanding of the Earth has been vividly expressed by <a href="http://www.college.columbia.edu/cct/summer12/features4">palaeoclimatologist Wally Broecker</a>:</p>
<blockquote>
<p>The palaeoclimate record shouts out to us that, far from being self-stabilizing, the Earth’s climate system is an ornery beast which overreacts even to small nudges. </p>
</blockquote>
<p>When the Earth is understood this way, the task of environmentalism can no longer be to “save” or preserve the planet, for the planet we wanted to save has already become something else. Our task now is to do what we can to pacify, or at least not aggravate further, something vastly more powerful than we are. </p>
<p>If we have wakened the slumbering beast by poking and prodding it, the prudent course is firstly to stop. But we cannot put it back to sleep. </p>
<p>There is no return to the peaceful conditions of the Holocene, at least not for thousands of years; but to provoke it further, as we still are, is foolishness on an epic scale.</p>
<h2>Respect, not love</h2>
<p>Yes, the Earth still demands our respect, but it is a respect founded on trepidation rather than love. If we are inclined to think of the planet as <a href="http://en.wikipedia.org/wiki/Gaia_hypothesis">Gaia</a>, we would do better to regard it not as the all-loving, all-nurturing Mother Earth of the romantics, but more like the half-crazed, bloodthirsty and vindictive goddess of the original Greek tales.</p>
<p>Some like French philosopher <a href="http://books.google.com.au/books?id=Jt2VsWB4Ie8C&pg=PA38&lpg=PA38&dq=Michel+Serres+in+favour+of+admiring+attention,+reciprocity,+contemplation,+and+respect&source=bl&ots=a81ZIq14Qx&sig=TaHmg6jMBpDsMfIcpKWmn7w0sIU&hl=en&sa=X&ei=_42CU5zLCMrrkAXCqIHoAQ&ved=0CCsQ6AEwAQ#v=onepage&q=Michel%20Serres%20in%20favour%20of%20admiring%20attention%2C%20reciprocity%2C%20contemplation%2C%20and%20respect&f=false">Michel Serres have argued </a> we must negotiate a new contract with nature. Under the terms of this natural contract humanity would reject mastery “in favour of admiring attention, reciprocity, contemplation, and respect”. The contract would grant nature rights and make reparations.</p>
<p>Twenty years ago, that kind of thinking seemed to make sense. But today we must ask whether the Earth, roused from its slumber, is in any mood to sign a contract with us. </p>
<p>Earth system science now teaches us that the planet to which we might have hoped to graciously offer a peace deal – the receptive, predictable object of our exploitation and neglect – existed only in our imaginations.</p>
<p>The Earth does not want our love. Instead of talking restitution, would we perhaps be wiser to be preparing for retribution?</p>
<p><em>This article is based on a <a href="http://clivehamilton.com/can-humans-survive-the-anthropocene/">speech at this year’s Sydney Writers’ Festival</a>.</em></p><img src="https://counter.theconversation.com/content/27156/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Clive Hamilton 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>Environmentalism is undergoing a radical transformation. New science has shown how long-held notions about trying to “save the planet” and preserve the life we have today no longer apply. Instead, a growing…Clive Hamilton, Vice Chancellor's Chair, Centre For Applied Philosophy & Public Ethics (CAPPE), Charles Sturt UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/236782014-02-26T05:59:40Z2014-02-26T05:59:40ZLargest ever space camera is ready to map a billion stars<figure><img src="https://images.theconversation.com/files/42476/original/wjyvkhq3-1393340244.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Now whizzing through space, 1.5 million km from Earth.</span> <span class="attribution"><a class="source" href="http://sci.esa.int/gaia/53094-deployment-of-the-gaia-sunshield-array/">ESA-CNES-Arianespace / Optique Vidéo du CSG - G. Barbaste</a></span></figcaption></figure><p>After its successful launch in December, European Space Agency’s (ESA) Gaia has now taken up its position in space and is ready to survey the skies. With the help of two onboard telescopes focused onto the largest ever space camera, Gaia is estimated to catalogue nearly one billion stars in its 5-year mission.</p>
<p>Like Hipparcos before it, ESA’s Gaia will map stars in the Milky Way. It will do this by measuring the brightest billion objects and determine their three-dimensional distribution and velocities. It also has the ability to measure the temperature, mass, and chemical composition of these billion objects. </p>
<p>Gaia will be able to discern objects up to 400,000 times dimmer than those visible to the naked eye. The positional accuracy of its measurements are akin to measuring the width of a human hair at a distance of 500 km. </p>
<p>The process will involve scanning each part of the sky an average of 70 times over its five-year mission lifetime, which means scanning the entire sky twice every 63 days, once through each of the two telescopes, making it a powerful tool for spotting time-evolving phenomena such as binary systems, supernovae, and exoplanets. Compared to Hipparcos, Gaia will be able to measure 500 times the number of stars, extending to objects 1000 times dimmer than the dimmest that Hipparcos could catalogue.</p>
<p>The technology that makes this possible is the largest camera ever launched into space – 940 million pixels. That is why a lot of effort before launch was on figuring out exactly how to get the huge amount of data Gaia will produce back down to Earth. </p>
<p>When a picture is taken a number of charged-coupled devices (CCDs) – the stuff most digital camera sensors are made off – are dedicated to spotting objects before they fall onto the main focal plane. This allows the instrument to track the objects as they pass and only retain small regions around the object, reducing the file-size needed to be sent to Earth. In five years it will send only 100 TB of data (1 TB is 1000 GB). Once the data arrives to Earth, there is a system in place to analyse the data and distribute alerts to ground-based observatories if anything quickly evolving and potentially interesting is spotted, such as supernovae.</p>
<p>The catalogue produced by Gaia is expected to contribute to many areas of astrophysics, multiply our database of exotic objects such as exoplanets, white and brown dwarfs, and supernovae many-fold, contribute to more precise measurements of General Relativity, help to constrain the measurements of the presence and location of dark matter, and give us more accurate information about our galactic neighbourhood and its evolution. </p>
<p>Gaia was successfully launched on December 19. After a month’s transit, it is now in orbit at about 1.5 million km away from Earth. By virtue of its position opposite the Sun from the Earth and its large sunshield, it will be able to see objects as close as 45⁰ from the Sun, allowing it to spot asteroids with orbits that lie between the Earth and the Sun, which are candidates for Earth collision, and very difficult to observe from the ground. </p>
<p>Staff on the ground are conducting in-orbit testing, during which the exact orbital parameters are determined, and all systems are tested for performance. <a href="http://www.cosmos.esa.int/web/gaia/iow_20140214">Calibration images</a> have been obtained, and the ground team is working on procedures to resolve a few remaining issues, such as reducing contamination on the CCDs and dealing with sunlight diffracted around the sun-shield.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/42475/original/dp7kk92f-1393340118.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/42475/original/dp7kk92f-1393340118.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/42475/original/dp7kk92f-1393340118.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/42475/original/dp7kk92f-1393340118.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/42475/original/dp7kk92f-1393340118.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/42475/original/dp7kk92f-1393340118.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/42475/original/dp7kk92f-1393340118.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=754&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Test image from Gaia: Slightly shaky to start with, but it’ll get there.</span>
<span class="attribution"><a class="source" href="http://sci.esa.int/gaia/53654-gaia-calibration-image/">ESA/DPAC/Airbus DS</a></span>
</figcaption>
</figure>
<p>Beyond the alert system allowing quick ground-based follow up, the first proper Gaia catalogue will take two years to complete and will be made available to the wider scientific community. Following this, new iterations will be issued about once a year, which will add more precisely determined characteristics of these objects. It is expected that Gaia’s database will have many new discoveries waiting to be mined from it, fuelling astronomers for decades to come.</p><img src="https://counter.theconversation.com/content/23678/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Ben Dryer has received funding from the UK Space Agency to perform Gaia data analysis.</span></em></p>After its successful launch in December, European Space Agency’s (ESA) Gaia has now taken up its position in space and is ready to survey the skies. With the help of two onboard telescopes focused onto…Ben Dryer, Postdoctoral Researcher, The Open UniversityLicensed as Creative Commons – attribution, no derivatives.