Einstein
https://plus.maths.org/content/taxonomy/term/740
enCelebrating general relativity
https://plus.maths.org/content/celebrating-general-relativity
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<p>A hundred years ago, on 25 November 1915, Einstein first presented his general theory of relativity. We explore this famous theory and what it says about the world we live in.</p>
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<div style="float: left; max-width: 550px;"><p>A hundred years ago, on 25 November 1915, Einstein
presented his general theory of relativity to the world. But what exactly is this famous theory and what does it say about the world we live in? To celebrate the centenary of general relativity we bring you a collection of articles, videos and podcasts exploring the theory, Einstein's struggle to find it, and some interesting consequences.</p><p><a href="https://plus.maths.org/content/celebrating-general-relativity" target="_blank">read more</a></p>https://plus.maths.org/content/celebrating-general-relativity#commentsblack holeEinsteinFP-carouselgeneral relativitygravitational wavehistory of mathematicsrelativityMon, 16 Nov 2015 13:26:20 +0000mf3446456 at https://plus.maths.org/contentWhat is a black hole – mathematically?
https://plus.maths.org/content/what-black-hole-part-2
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The Plus team </div>
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<p>Pau Figueras explains how Einstein's theories predicted the existence of black holes, and how to describe them mathematically.</p>
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<p><EM>We asked cosmologist <a href="http://www.damtp.cam.ac.uk/people/p.figueras/">Pau Figueras</a> everything you've ever wanted to know about black holes. In the <a href="https://plus.maths.org/content/what-black-hole">other part of the interview</a> he explained what black holes are, physically, and how we hope to observe them. In this second part of the interview, he explains how Einstein's theories predict their existence, and how to describe them mathematically.</em></p>
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<strong>How were black holes first predicted?</strong>
</p><p><a href="https://plus.maths.org/content/what-black-hole-part-2" target="_blank">read more</a></p>https://plus.maths.org/content/what-black-hole-part-2#commentsblack holeEinsteingeneral relativityUniversity of CambridgevideoFri, 13 Nov 2015 16:24:38 +0000Rachel6451 at https://plus.maths.org/contentWhat is a black hole – physically?
https://plus.maths.org/content/what-black-hole
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The Plus team </div>
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<img class="imagefield imagefield-field_abs_img" width="100" height="100" alt="" src="https://plus.maths.org/content/sites/plus.maths.org/files/abstractpics/5/21_jan_2016_-_1202/blackhole_icon.jpg?1453377739" /> </div>
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<p>Small, dark, and very hard to see. This and far more indepth answers to every question you ever wanted to ask about black holes.</p>
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<p><EM>We asked cosmologist <a href="http://www.damtp.cam.ac.uk/people/p.figueras/">Pau Figueras</a> everything you've ever wanted to know about black holes. In this, the first part of the interview, he explained what black holes are, physically, and how we hope to observe them. You can also read the <a href="https://plus.maths.org/content/what-black-hole-part-2">second part of the interview</a> where Pau explains how black holes were predicted, and how the maths of black holes makes them particularly simple to describe.</em></p>
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<strong>What is a black hole?</strong>
</p><p><a href="https://plus.maths.org/content/what-black-hole" target="_blank">read more</a></p>https://plus.maths.org/content/what-black-hole#commentsblack holeEinsteinFP-carouselgeneral relativityUniversity of CambridgevideoFri, 13 Nov 2015 14:12:11 +0000Rachel6449 at https://plus.maths.org/contentWhat is general relativity?
https://plus.maths.org/content/what-general-relativity
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David Tong (with the Plus team) </div>
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<p>To celebrate the centenary of the general theory of relativity we asked physicist David Tong to explain the theory and the equation that expresses it. Watch the video or read the article!</p>
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<p><em>When physicists talk about Einstein's equation they don't
usually mean the famous <em>E=mc<sup>2</sup></em>, but another
formula, which encapsulates the celebrated general theory of
relativity. Einstein published that theory a hundred years ago, in
1915. To celebrate its centenary we asked physicist <a href="http://www.damtp.cam.ac.uk/user/tong/">David Tong</a> of the
University of Cambridge to explain what general relativity is and how
Einstein's equation expresses it. You can watch his explanation in the video
below, or read on.</em></p><p><a href="https://plus.maths.org/content/what-general-relativity" target="_blank">read more</a></p>https://plus.maths.org/content/what-general-relativity#commentsEinsteingeneral relativityhistory of mathematicsrelativityUniversity of CambridgevideoFri, 12 Jun 2015 10:17:46 +0000mf3446375 at https://plus.maths.org/contentEinstein and relativity: Part I
https://plus.maths.org/content/einstein-relativity
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David Tong </div>
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<p>Read about the rocky road to one of Einstein's greatest achievements: the general theory of relativity, which celebrates its centenary this year.</p>
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<p><em>This article is an abridged version of a talk David Tong gave at the Southbank Centre in London in 2013. You can listen to a sound recording of the talk on <a href="https://soundcloud.com/southbankcentre/david-tong-on-einsteins-theory/">Soundcloud</a>, or watch a video of a very similar talk, aimed at 16 to 17 year-olds, <a href="https://plus.maths.org/content/stories-einstein">here</a>.</em></p>
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<p>2015 is a special year for physics. It is the 100th
anniversary of Albert Einstein's greatest achievement: the <em>general theory of relativity</em>. </p><p><a href="https://plus.maths.org/content/einstein-relativity" target="_blank">read more</a></p>https://plus.maths.org/content/einstein-relativity#commentscreativityEinsteinFP-carouselgeneral relativityhistory of mathematicsrelativityspecial relativityUniversity of CambridgeThu, 04 Jun 2015 15:56:07 +0000mf3446360 at https://plus.maths.org/contentEinstein and relativity: Part II
https://plus.maths.org/content/einstein-and-relativity-part-ii
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David Tong </div>
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<p>General relativity, Einstein's rise to international stardom, and his legacy.</p>
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<p><em>To read about Einstein's motivation for the general theory of relativity and his struggle to formulate it, read the <a href="https://plus.maths.org/content/einstein-relativity">first part</a> of this article.</em></p>
<h3>General relativity</h3>
<p>Einstein's theory changed our understanding of space and time. Before Einstein people thought of space as stage on which the laws of physics play out. We could throw in some stars or some planets and they would move around on this stage.</p><p><a href="https://plus.maths.org/content/einstein-and-relativity-part-ii" target="_blank">read more</a></p>https://plus.maths.org/content/einstein-and-relativity-part-ii#commentscreativityEinsteingeneral relativityhistory of mathematicsrelativityUniversity of CambridgeThu, 04 Jun 2015 15:15:38 +0000mf3446374 at https://plus.maths.org/contentSteady on, Einstein
https://plus.maths.org/content/steady-on-Einstein
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Rachel Thomas </div>
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<p>To celebrate the release of more English translations of Einstein's papers, we revisit one of his previously unknown models of the Universe.</p>
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Albert Einstein's impact on our understanding of the Universe is so widely regarded by both the physics community and the general public, that his name is now a synonym for genius.<p><a href="https://plus.maths.org/content/steady-on-Einstein" target="_blank">read more</a></p>https://plus.maths.org/content/steady-on-Einstein#commentscosmologycreativityEinsteinhistory of mathematicsphilosophy of cosmologysteady state modelMon, 12 Jan 2015 13:50:37 +0000Rachel6297 at https://plus.maths.org/contentLight weight
https://plus.maths.org/content/light-weight
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Peter Lynch </div>
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<p>Does light have weight? Newton thought so. His laws predicted that gravity would bend light, two centuries before Einstein's revolution.</p>
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Does light have weight? Newton thought so. He supported the <a href="http://en.wikipedia.org/wiki/Corpuscular_theory_of_light">corpuscular theory of light</a>, regarding it as comprised of particles with small but finite mass. He concluded that such particles would be influenced by a gravitational field. So, using his laws of motion, we can calculate how gravity would bend such a light beam.
</p><p><a href="https://plus.maths.org/content/light-weight" target="_blank">read more</a></p>https://plus.maths.org/content/light-weight#commentsEinsteingravityhistory of mathematicslightNewtonFri, 24 Oct 2014 12:55:11 +0000Rachel6182 at https://plus.maths.org/contentStories about Einstein
https://plus.maths.org/content/stories-einstein
<p><em>"This talk will mostly be stories ... I want to tell you about Albert Einstein, and about his theory of relativity — what it is, why he was thinking about it and also about some of the very latest developments that have happened just this year."</em></p><p><a href="https://plus.maths.org/content/stories-einstein" target="_blank">read more</a></p>https://plus.maths.org/content/stories-einstein#commentsEinsteinphysicsrelativityvideoMon, 29 Sep 2014 12:00:09 +0000mf3446193 at https://plus.maths.org/contentProblems of gravity
https://plus.maths.org/content/problems-gravity
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Marianne Freiberger </div>
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<p>Why (some) physicists want to modify Einstein's general theory of relativity.</p>
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<p>Albert Einstein is an icon and for good reason. His general
theory of relativity, which describes the force of gravity, was an
intellectual tour de force. Not only were his ideas entirely new, they have also stood the test of
time.
Despite this success, some physicists are doing what many would consider sacrilege: they are tinkering with the theory, producing modified versions of it. But why? </p><p><a href="https://plus.maths.org/content/problems-gravity" target="_blank">read more</a></p>https://plus.maths.org/content/problems-gravity#commentsEinsteingeneral relativitygravityphilosophy of cosmologyrelativitysymmetryWed, 23 Jul 2014 09:01:32 +0000mf3446099 at https://plus.maths.org/contentEinstein's evolving Universe
https://plus.maths.org/content/einsteins-evolving-universe
<div class="rightimage" style="width: 250px;"><img src="/issue35/features/ekert/einstein.jpg" alt="Einstein" width="250" height="324" /></div>
<p>Earlier this year we went along to the <a href="http://www.damtp.cam.ac.uk/events/constants2014/">Cosmology and the constants of nature</a> conference at the University of Cambridge, which brought together cosmologists and philosophers to discuss some of the big questions in cosmology.<p><a href='http://plus.maths.org/content/sites/plus.maths.org/files/podcast/pluspodcast_may2014.mp3'>Listen to our interview with Cormac O' Raifeartaigh</a></p><p><a href="https://plus.maths.org/content/einsteins-evolving-universe" target="_blank">read more</a></p>https://plus.maths.org/content/einsteins-evolving-universe#commentsEinsteinphilosophy of cosmologyFri, 30 May 2014 15:36:21 +0000Rachel6110 at https://plus.maths.org/contentThe problem with infinity
https://plus.maths.org/content/problem-infinity
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Marianne Freiberger and Rachel Thomas </div>
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<p>This is the second article in our four-part series exploring quantum electrodynamics. After successfully applying quantum mechanics to the electromagnetic field, physicists faced a problem of boundless proportions: every calculation they made returned infinity as the answer.</p>
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<p><em>This article is the second in a four-part series on quantum electrodynamics. You can read the previous article <a href="https://plus.maths.org/content/let-me-take-you-down-cos-were-going-quantum-fields">here</a> and the next one <a href="https://plus.maths.org/content/rise-qed">here</a>.</em></p>
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<p>Paul Dirac (1902-1984). </p><p><a href="https://plus.maths.org/content/problem-infinity" target="_blank">read more</a></p>https://plus.maths.org/content/problem-infinity#commentsmathematical realityEinsteinelectromagnetismphotonquantum electrodynamicsquantum physicsvirtual particleMon, 22 Jul 2013 07:57:33 +0000mf3445917 at https://plus.maths.org/contentLet me take you down, cos we're going to ... quantum fields
https://plus.maths.org/content/let-me-take-you-down-cos-were-going-quantum-fields
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Marianne Freiberger and Rachel Thomas </div>
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<p>You may have heard of quantum theory and you probably know what a field is. But what is quantum field theory? This article traces the development of quantum electrodynamics in the first half of the 20th century. Hair raising difficulties, heroic struggle and illustrious characters — this story has it all!</p>
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<p><em>You may have heard of quantum theory before and you probably know what a field is. But what is quantum field theory? This four-part article traces the development of an example of a quantum field theory, quantum electrodynamics, in the first half of the 20th century. You can read the next article in the series <a href="https://plus.maths.org/content/problem-infinity">here</a>.</em></p><p><a href="https://plus.maths.org/content/let-me-take-you-down-cos-were-going-quantum-fields" target="_blank">read more</a></p>https://plus.maths.org/content/let-me-take-you-down-cos-were-going-quantum-fields#commentsmathematical realityDirac's equationEinsteinelectromagnetismMaxwell's equations of electromagnetismquantum electrodynamicsquantum mechanicsquantum physicsSchrödinger equationMon, 22 Jul 2013 07:42:44 +0000mf3445916 at https://plus.maths.org/contentHappy pi day, Albert!
https://plus.maths.org/content/happy-pi-day-albert
<p>What a lovely coincidence! Pi day (the 14th of March, written 3.14 in the US) is also Albert Einstein's birthday. How are you going to celebrate? You could join Marcus du Sautoy and over a thousand other people in a <A href="http://oxfordconnect.conted.ox.ac.uk">mass online experiment to calculate pi</a> or you could join <em>Plus</em> in Cambridge to watch our favourite mathematical movie <a href="https://plus.maths.org/content/PvsNP">Travelling Salesman</a>. And to celebrate both the number and the man, here are some favourite articles.</p><p><a href="https://plus.maths.org/content/happy-pi-day-albert" target="_blank">read more</a></p>https://plus.maths.org/content/happy-pi-day-albert#commentsEinsteinPiWed, 13 Mar 2013 10:02:40 +0000mf3445875 at https://plus.maths.org/contentHow does gravity work?
https://plus.maths.org/content/how-does-gravity-work
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And what are gravitational waves? </div>
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<div class="pub_date">29/09/2009</div>
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<p>B.S. Sathyaprakash</p><p><a href="https://plus.maths.org/content/how-does-gravity-work" target="_blank">read more</a></p>https://plus.maths.org/content/how-does-gravity-work#commentsastronomyblack holecosmologyEinsteingeneral relativitygravitational wavegravitational wave detectorgravityinternational year of astronomy 2009Newtonspecial relativityMon, 28 Sep 2009 23:00:00 +0000plusadmin2827 at https://plus.maths.org/content