MetaFilter posts tagged with Math and maths
http://www.metafilter.com/tags/Math+maths
Posts tagged with 'Math' and 'maths' at MetaFilter.Sun, 11 Sep 2016 00:21:14 -0800Sun, 11 Sep 2016 00:21:14 -0800en-ushttp://blogs.law.harvard.edu/tech/rss60Animated math
http://www.metafilter.com/162201/Animated%2Dmath
<a href="https://www.youtube.com/playlist?list=PLZHQObOWTQDPD3MizzM2xVFitgF8hE_ab">Essence of linear algebra</a> - "[<a href="https://twitter.com/3blue1brown">Grant Sanderson</a> of <a href="http://www.3blue1brown.com">3Blue1Brown</a> (<a href="https://www.khanacademy.org/math/linear-algebra/eola-topic">now at Khan Academy</a>) <a href="https://twitter.com/3Blue1Brown/status/772904942365347840">animates</a>] the geometric intuitions underlying linear algebra, making the many matrix and vector operations feel less arbitrary." <ol><li><a href="https://www.youtube.com/watch?v=fNk_zzaMoSs">Vectors, what even are they?</a> - "I imagine many viewers are already familiar with vectors in some context, so this video is intended both as a quick review of vector terminology, as well as a chance to make sure we're all on the same page about how specifically to think about vectors in the context of linear algebra." (9:48)</li>
<li><a href="https://www.youtube.com/watch?v=k7RM-ot2NWY">Linear combinations, span, and basis vectors</a> - "The fundamental vector concepts of span, linear combinations, linear dependence and bases all center on one surprisingly important operation: Scaling several vectors and adding them together." (9:55)</li>
<li><a href="https://www.youtube.com/watch?v=kYB8IZa5AuE">Linear transformations and matrices</a> - "Matrices can be thought of as transforming space, and understanding how this work is crucial for understanding many other ideas that follow in linear algebra." (10:54)</li>
<li><a href="https://www.youtube.com/watch?v=XkY2DOUCWMU">Matrix multiplication as composition</a> - "Multiplying two matrices represents applying one transformation after another. Many facts about matrix multiplication become much clearer once you digest this fact." (9:59)
<br> fn. <a href="https://www.youtube.com/watch?v=rHLEWRxRGiM">Three-dimensional linear transformations</a> - "What do 3d linear transformations look like? Having talked about the relationship between matrices and transformations in the last two videos, this one extends those same concepts to three dimensions." (4:42)</li>
<li><a href="https://www.youtube.com/watch?v=Ip3X9LOh2dk">The determinant</a> - "The determinant of a linear transformation measures how much areas/volumes change during the transformation." (9:59)</li>
<li><a href="https://www.youtube.com/watch?v=uQhTuRlWMxw">Inverse matrices, column space and null space</a> - "How to think about linear systems of equations geometrically. The focus here is on gaining an intuition for the concepts of inverse matrices, column space, rank and null space, but the computation of those constructs is not discussed." (12:04)
<br> fn. <a href="https://www.youtube.com/watch?v=v8VSDg_WQlA">Nonsquare matrices as transformations between dimensions</a> - "Because people asked, this is a video briefly showing the geometric interpretation of non-square matrices as linear transformations that go between dimensions." (4:22)</li>
<li><a href="https://www.youtube.com/watch?v=LyGKycYT2v0">Dot products and duality</a> - "Dot products are a nice geometric tool for understanding projection. But now that we know about linear transformations, we can get a deeper feel for what's going on with the dot product, and the connection between its numerical computation and its geometric interpretation." (14:07)</li>
<li><a href="https://www.youtube.com/watch?v=BaM7OCEm3G0">Cross products</a> - "Dot products are a nice geometric tool for understanding projection. But now that we know about linear transformations, we can get a deeper feel for what's going on with the dot product, and the connection between its numerical computation and its geometric interpretation." (8:54)
<br> part 2. <a href="https://www.youtube.com/watch?v=eu6i7WJeinw">Cross products in the light of linear transformations</a> - "This covers the main geometric intuition behind the 2d and 3d cross products." (13:11)</li></ol>
also btw...
<a href="http://setosa.io/ev/eigenvectors-and-eigenvalues/">Eigenvectors and Eigenvalues explained visually</a> - "Eigenvalues/vectors are instrumental to understanding electrical circuits, mechanical systems, ecology and even Google's <a href="http://www.rose-hulman.edu/~bryan/googleFinalVersionFixed.pdf">Page</a><a href="http://www.metafilter.com/140141/Eigendemocracy-crowd-sourced-deliberative-democracy">Rank</a> algorithm. Let's see if visualization can make these ideas more intuitive." (<a href="http://www.epicenecyb.org/archives/date/2016/09#post-22704">via</a>) tag:metafilter.com,2016:site.162201Sun, 11 Sep 2016 00:21:14 -0800kliulessxEuclidx
http://www.metafilter.com/162142/xEuclidx
Compass-and-straightedge construction (aka Euclidean construction) is a method of drawing precise geometric figures using only a compass and a straightedge (like a ruler without the markings). <a href="http://www.mathopenref.com/tocs/constructionstoc.html">MathOpenRef maintains a catalog of many common constructions</a>, each with an explanatory animation and a proof. <a href="https://www.youtube.com/watch?v=LBgIWQcC6lM">This YouTube video</a> demonstrates how to construct almost every <a href="https://en.wikipedia.org/wiki/Constructible_polygon">polygon that can be constructed using these methods</a>. Useful in many decorative arts for laying out figures and patterns, the methods can also be fun to watch, often resulting in an "aha!" moment when one sees how a particular construction is done.
Although not animated, <a href="http://faculty.scf.edu/condorj/256/presentations/Gothic%20Constructions.pdf">this paper</a> [pdf] shows how geometric constructions can be used to create many common Gothic design elements, such as trefoils and arches. tag:metafilter.com,2016:site.162142Thu, 08 Sep 2016 10:29:57 -0800jedicusMonumental Proof to Torment Mathematicians for Years to Come
http://www.metafilter.com/161450/Monumental%2DProof%2Dto%2DTorment%2DMathematicians%2Dfor%2DYears%2Dto%2DCome
Nearly four years after Shinichi Mochizuki (<a href="http://www.metafilter.com/153893/The-likelihood-that-theres-interesting-or-important-math-is-pretty-high">previously</a>, <a href="http://www.metafilter.com/127954/Proof-and-Community-Standards">previously</a>, <a href="http://www.metafilter.com/119847/Mathematics-world-abuzz-with-a-proof-of-the-ABC-Conjecture">previously</a>) unveiled an imposing set of papers (<a href="http://www.kurims.kyoto-u.ac.jp/~motizuki/Inter-universal%20Teichmuller%20Theory%20I.pdf">1</a>, <a href="http://www.kurims.kyoto-u.ac.jp/~motizuki/Inter-universal%20Teichmuller%20Theory%20II.pdf">2</a>, <a href="http://www.kurims.kyoto-u.ac.jp/~motizuki/Inter-universal%20Teichmuller%20Theory%20III.pdf">3</a>, <a href="http://www.kurims.kyoto-u.ac.jp/~motizuki/Inter-universal%20Teichmuller%20Theory%20IV.pdf">4</a>) that could revolutionize the theory of numbers, other mathematicians have yet to understand his work or agree on its validity — <a href="http://www.nature.com/news/monumental-proof-to-torment-mathematicians-for-years-to-come-1.20342">although they have made modest progress</a>.</a> Some <a href="http://www.math.columbia.edu/~woit/wordpress/?p=8663">four dozen mathematicians converged last week</a> for a rare opportunity to hear Mochizuki present his own work at a conference on his home turf, Kyoto University's Research Institute for Mathematical Sciences (RIMS).
Mochizuki's theorem aims to prove the important <a href="https://en.wikipedia.org/wiki/Abc_conjecture">abc conjecture</a>, which dates back to 1985 and relates to prime numbers.
<a href="https://www.newscientist.com/article/2099534-mathematicians-finally-starting-to-understand-epic-abc-proof/">The glimmer of understanding</a> that has started to emerge is well worth the effort, says [University of Nottingham's Ivan] Fesenko. "I expect that at least 100 of the most important open problems in number theory will be solved using Mochizuki's theory and further development." tag:metafilter.com,2016:site.161450Fri, 05 Aug 2016 17:35:03 -0800stinkfootSo, the unknowable kicks in
http://www.metafilter.com/161308/So%2Dthe%2Dunknowable%2Dkicks%2Din
<a href="https://plus.google.com/117663015413546257905/posts/VdJyWda2hrj">Logic hacking</a> - "Writing shorter and shorter computer programs for which it's unknowable whether these programs run forever, or stop... the winner of the <a href="https://johncarlosbaez.wordpress.com/2016/05/21/the-busy-beaver-game/">Busy Beaver Game</a> for N-state Turing machines becomes unknowable using ordinary math - somewhere between N = 5 and N = 1919." <a href="https://plus.google.com/117663015413546257905/posts/8eYTjrpiGte">Interview with a Mathematical Physicist</a>: <a href="https://plus.google.com/117663015413546257905/posts/JFF1nW6uxcD">John Baez</a>
<ul><li><a href="https://www.physicsforums.com/insights/interview-mathematical-physicist-john-baez-part-1/">Part 1</a> - "Here's the first part of an interview. I used it as an excuse to say what I've been doing all these years. I also talk about my uncle Albert Baez, who got me interested in physics in the first place - and <a href="https://johncarlosbaez.wordpress.com/2016/06/11/azimuth-news-part-5/">what I'm working on</a> right now. I hope it's interesting even if you care more about math and physics. There's a lot here about quantum gravity, category theory and some of my hobbies, like the octonions."</li>
<li><a href="https://www.physicsforums.com/insights/interview-mathematical-physicist-john-baez-part-2/">From crackpots to climate change</a> - "Here's part two of my interview on Physics Forums. I talk about the early days of the internet, before the world-web caught on. First we started discussing physics on 'usenet newsgroups' like sci.physics - but then a flood of crackpots invaded... That's what led me to create the Crackpot Index. But spending lots of time on newsgroups was still worthwhile, and it led me to start writing '<a href="http://math.ucr.edu/home/baez/TWF.html">This Week's Finds</a>', which has been called the world's first blog, in 1993. I also talk about my physics and math heroes, what discoveries I'm most looking forward to, and why I switched to thinking about environmental problems. It was a great chance to ponder lots of things, including the far future of the Universe."</li></ul>
also btw...
-<a href="https://plus.google.com/117663015413546257905/posts/gvzrNKQqqnV">1+1 = 0</a>
-<a href="https://plus.google.com/117663015413546257905/posts/4fMBVQUhrDm">Computing the uncomputable</a>
-<a href="https://plus.google.com/117663015413546257905/posts/6jw8M2dxV9g">The inaccessible infinite</a>
-<a href="https://plus.google.com/117663015413546257905/posts/ZSb9MWjdKss">The longest G+ post I'll ever write</a>
-<a href="https://plus.google.com/117663015413546257905/posts/8E9ztrNUir7">The world's most long-winded proof</a>
-<a href="https://www.cs.auckland.ac.nz/~chaitin/summer.html">Paradoxes of randomness</a>
-<a href="http://lemire.me/blog/2016/05/23/the-surprising-cleverness-of-modern-compilers/">The surprising cleverness of modern compilers</a> tag:metafilter.com,2016:site.161308Sat, 30 Jul 2016 11:42:28 -0800kliulessWhat else have we missed about the primes?
http://www.metafilter.com/157880/What%2Delse%2Dhave%2Dwe%2Dmissed%2Dabout%2Dthe%2Dprimes
<a href="https://www.quantamagazine.org/20160313-mathematicians-discover-prime-conspiracy/">Prime numbers, it seems, have decided preferences about the final digits of the primes that immediately follow them.</a> tag:metafilter.com,2016:site.157880Mon, 14 Mar 2016 04:13:49 -0800Proofs and Refutations"may someday help in a more objective assignment of books..."
http://www.metafilter.com/156677/may%2Dsomeday%2Dhelp%2Din%2Da%2Dmore%2Dobjective%2Dassignment%2Dof%2Dbooks
<a href="http://www.theguardian.com/books/2016/jan/27/scientists-reveal-multifractal-structure-of-finnegans-wake-james-joyce">Scientists find evidence of mathematical structures in classic books. <small>[The Guardian]</small></a> <a href="https://en.wikipedia.org/wiki/James_Joyce">James Joyce</a>'s <a href="https://en.wikipedia.org/wiki/Finnegans_Wake">Finnegans Wake</a> has been described as many things, from a masterpiece to unreadable nonsense. But it is also, according to scientists at <a href="http://www.ifj.edu.pl/?lang=en">the Institute of Nuclear Physics in Poland</a>, almost indistinguishable in its structure from a purely mathematical <a href="http://imagej.nih.gov/ij/plugins/fraclac/FLHelp/Multifractals.htm">multifractal</a>. <blockquote>"The absolute record in terms of multifractality turned out to be Finnegans Wake by James Joyce. The results of our analysis of this text are virtually indistinguishable from ideal, purely mathematical multifractals," said Professor Stanisław Drożdż, another author of the paper, which has just been published in the computer science journal Information Sciences.
</blockquote> tag:metafilter.com,2016:site.156677Thu, 28 Jan 2016 16:29:54 -0800FizzThe likelihood that there's interesting or important math is pretty high
http://www.metafilter.com/153893/The%2Dlikelihood%2Dthat%2Dtheres%2Dinteresting%2Dor%2Dimportant%2Dmath%2Dis%2Dpretty%2Dhigh
<a href="http://www.nature.com/news/the-biggest-mystery-in-mathematics-shinichi-mochizuki-and-the-impenetrable-proof-1.18509">Shinichi Mochizuki and the impenetrable proof</a> - "Fesenko has studied Mochizuki's work in detail over the past year, visited him at RIMS again in the autumn of 2014 and says that he has now verified the proof. (The other three mathematicians who say they have corroborated it have also spent considerable time working alongside Mochizuki in Japan.) The overarching theme of inter-universal geometry, as Fesenko describes it, is that one must look at whole numbers in a different light — leaving addition aside and seeing the multiplication structure as something malleable and deformable. Standard multiplication would then be just one particular case of a family of structures, just as a circle is a special case of an ellipse." (<a href="https://www.newscientist.com/article/dn26753-mathematicians-anger-over-his-unread-500-page-proof/">previously</a>: <a href="http://www.metafilter.com/119847/Mathematics-world-abuzz-with-a-proof-of-the-ABC-Conjecture">1</a>,<a href="http://www.metafilter.com/127954/Proof-and-Community-Standards">2</a>; <a href="https://twitter.com/Noahpinion/status/652145064043347968">via</a>) <blockquote>"Looking at it, you feel a bit like you might be reading a paper from the future, or from outer space," [<a href="http://www.metafilter.com/user/21049">mefi's own</a>] number theorist Jordan Ellenberg, of the University of Wisconsin–Madison, wrote <a href="https://quomodocumque.wordpress.com/2012/09/03/mochizuki-on-abc/">on his blog</a> a few days after the paper appeared.</blockquote>
also btw...
-<a href="http://www.nature.com/news/maths-whizz-solves-a-master-s-riddle-1.18441">UCLA mathematician Terence Tao has produced a solution to the Erdős discrepancy problem</a> [<a href="http://arxiv.org/abs/1509.05363">1</a>,<a href="https://terrytao.wordpress.com/2015/09/11/the-erdos-discrepancy-problem-via-the-elliott-conjecture/">2</a>,<a href="https://plus.google.com/+DavidRoberts/posts/edR1nqyTGxX">3</a>]
-<a href="https://www.youtube.com/watch?v=XFDM1ip5HdU">What does it feel like to invent math</a>?<a href="http://www.metafilter.com/135502/An-infinite-number-of-mathematicians-walk-into-a-bar#5366342">*</a> tag:metafilter.com,2015:site.153893Fri, 16 Oct 2015 09:34:05 -0800kliulessLearning common core math with a check written by an upset father
http://www.metafilter.com/153278/Learning%2Dcommon%2Dcore%2Dmath%2Dwith%2Da%2Dcheck%2Dwritten%2Dby%2Dan%2Dupset%2Dfather
When the father of a second grader got annoyed by <a href="http://www.corestandards.org/Math/">common core math</a> tools (namely, <a href="https://www.youtube.com/watch?v=p6RaMGDPfJg">ten frame cards</a>), his annoyance went viral when <a href="http://www.buzzfeed.com/morganshanahan/this-dad-wrote-a-check-to-his-kids-school-in-common-core-mat">he wrote a check to his student's school using common core numbers</a>. Then <a href="http://www.patheos.com/blogs/friendlyatheist/2015/09/21/the-dad-who-wrote-a-check-using-common-core-math-doesnt-know-what-hes-talking-about/">the Friendly Athiest on Patheos used that check to teach how common core math works</a> at the second grade level. tag:metafilter.com,2015:site.153278Wed, 23 Sep 2015 19:24:49 -0800filthy light thiefFamous Fluid Equations Are Incomplete
http://www.metafilter.com/151640/Famous%2DFluid%2DEquations%2DAre%2DIncomplete
<a href="http://www.nytimes.com/2015/07/26/magazine/the-singular-mind-of-terry-tao.html">The Singular Mind of Terry Tao</a> - "<a href="http://thecolbertreport.cc.com/guests/terence-tao/6wtwlg/terence-tao">Imagine</a>, <a href="http://www.smh.com.au/good-weekend/terence-tao-the-mozart-of-maths-20150306-13fwcv.html">he said</a>, that <a href="http://bactra.org/notebooks/tsallis.html">someone awfully clever</a> could <a href="https://en.wikipedia.org/wiki/MONIAC_Computer">construct a machine</a> out of pure water. It would be built not of rods and gears but <a href="http://paulromer.net/why-information-grows/">from a pattern</a> of interacting currents." (<a href="https://twitter.com/Noahpinion/status/624664545995264000">via</a>) <blockquote>Tao has emerged as one of the field's great bridge-builders. At the time of his Fields Medal, he had already made discoveries with more than 30 different collaborators. Since then, he has also become a prolific math blogger with a decidedly non-Gaussian ebullience: He celebrates the work of others, shares favorite tricks, documents his progress and delights at any corrections that follow in the comments. He has organized cooperative online efforts to work on problems. "Terry is what a great 21st-century mathematician looks like," [<a href="http://www.metafilter.com/user/21049">mefi's</a> <a href="http://projects.metafilter.com/4308/How-Not-To-Be-Wrong">own</a>] Jordan Ellenberg, a mathematician at the University of Wisconsin, Madison, who has collaborated with Tao, told me. He is "part of a network, always communicating, always connecting what he is doing with what other people are doing."</blockquote>
<a href="https://plus.google.com/117663015413546257905/posts/EVYdMhSqtWu">also btw</a>...
<a href="https://www.quantamagazine.org/20150721-famous-fluid-equations-are-incomplete/">A 115-year effort to bridge the particle and fluid descriptions of nature has led mathematicians to an unexpected answer</a> - "The evidence suggests that truer equations of fluid dynamics can be found in a little-known, relatively unheralded theory developed by the Dutch mathematician and physicist <a href="https://en.wikipedia.org/wiki/Diederik_Korteweg">Diederik Korteweg</a> in the early 1900s. And yet, for some gases, even the Korteweg equations fall short, and there is no fluid picture at all." tag:metafilter.com,2015:site.151640Wed, 29 Jul 2015 00:34:29 -0800kliulessLoop - Pool on an elliptical table
http://www.metafilter.com/151559/Loop%2DPool%2Don%2Dan%2Delliptical%2Dtable
<a href="http://www.loop-the-game.com">Loop - Pool on an elliptical table.</a> <i>The ellipse has two significant points, called focuses, which have a remarkable geometrical property that is almost always explained using the example of an imaginary pool table.
"If a pool table is the shape of an ellipse, then a ball shot from one focus will always rebound to the other focus no matter in which direction the ball is shot."
That sounded interesting! Wouldn't it be fun, I thought, if I could build one of these imaginary tables?
<a href="http://www.theguardian.com/science/alexs-adventures-in-numberland/2015/jul/16/loop-new-cue-sport-pool-ellipse-elliptical">So I did</a>.</i> tag:metafilter.com,2015:site.151559Sun, 26 Jul 2015 13:54:00 -0800dngHoTT Coq
http://www.metafilter.com/150345/HoTT%2DCoq
<a href="https://www.quantamagazine.org/20150519-will-computers-redefine-the-roots-of-math/">Univalent Foundations Redefines Mathematics</a> - "When a legendary mathematician found a mistake in his own work, he embarked on a computer-aided quest to eliminate human error. To succeed, he has to <a href="http://homotopytypetheory.org/book/">rewrite the century-old rules</a> underlying all of mathematics." (<a href="http://www.metafilter.com/126041/Computerized-Math-Formal-Proofs-andamp-Alternative-Logic">previously</a>) <a href="http://www.ams.org/notices/201309/rnoti-p1164.pdf">Voevodsky's Univalence Axiom in Homotopy Type Theory</a>
<blockquote>One of Voevodsky's goals (<a href="https://intelligence.org/2014/02/21/john-baez-on-research-tactics/">as we understand it</a>) is that, in a not too distant future, mathematicians will be able to verify the correctness of their own papers by working <a href="http://math.andrej.com/2014/01/13/univalent-foundations-subsume-classical-mathematics/">within the system of univalent foundations</a> formalized in a proof assistant and that doing so will become natural even for pure mathematicians (the same way that most mathematicians now typeset their own papers in TeX). We believe that this aspect of the <a href="http://ncatlab.org/nlab/show/univalence+axiom">univalent foundations program</a> distinguishes it from other approaches to foundations by providing a practical utility for the working mathematician.</blockquote>
-<a href="http://www.science4all.org/le-nguyen-hoang/type-theory/">Type Theory: A Modern Computable Paradigm for Math</a>
-<a href="http://www.science4all.org/le-nguyen-hoang/homotopy-type-theory/">Homotopy Type Theory and Higher Inductive Types</a>
-<a href="http://www.science4all.org/le-nguyen-hoang/univalence/">Univalent Foundations of Mathematics</a>
also btw...
-<a href="https://www.youtube.com/watch?v=QNznD9hMEh0">James Simons interview</a>
-<a href="https://mathematicswithoutapologies.wordpress.com/2015/05/13/univalent-foundations-no-comment/">Univalent Foundations: "No Comment."</a> (<a href="http://math-frolic.blogspot.com/2015/05/set-theory-type-theory-hott-univalent.html">via</a>)
-<a href="https://terrytao.wordpress.com/career-advice/there%E2%80%99s-more-to-mathematics-than-rigour-and-proofs/">There's more to mathematics than rigour and proofs</a> tag:metafilter.com,2015:site.150345Tue, 09 Jun 2015 22:40:35 -0800kliuless3Blue1Brown: Reminding the world that math makes sense
http://www.metafilter.com/150242/3Blue1Brown%2DReminding%2Dthe%2Dworld%2Dthat%2Dmath%2Dmakes%2Dsense
<a href="https://www.youtube.com/watch?v=F_0yfvm0UoU">Understanding e to the pi i</a> - "<a href="http://www.3blue1brown.com/s/HowToThinkAboutExponentials.pdf">An intuitive explanation</a> as to why <a href="http://www.bbc.co.uk/programmes/b04hz49f" title="Melvyn Bragg and his guests discuss Euler's number, also known as e. First discovered in the seventeenth century by the Swiss mathematician Jacob Bernoulli when he was studying compound interest, e is now recognised as one of the most important and interesting numbers in mathematics. Roughly equal to 2.718, e is useful in studying many everyday situations, from personal savings to epidemics. It also features in Euler's Identity, sometimes described as the most beautiful equation ever written. With: Colva Roney-Dougal, Reader in Pure Mathematics at the University of St Andrews; June Barrow-Green, Senior Lecturer in the History of Maths at the Open University; and Vicky Neale, Whitehead Lecturer at the Mathematical Institute and Balliol College at the University of Oxford.">e</a> to the <a href="http://www.bbc.co.uk/programmes/p004y291" title="Melvyn Bragg and guests discuss the history of the most detailed number in nature. In the Bible's description of Solomon's temple it comes out as three, Archimedes calculated it to the equivalent of 14 decimal places and today's super computers have defined it with an extraordinary degree of accuracy to its first 1.4 trillion digits. It is the longest number in nature and we only need its first 32 figures to calculate the size of the known universe within the accuracy of one proton. We are talking about Pi, 3.14159 etc, the number which describes the ratio of a circle's diameter to its circumference. How has something so commonplace in nature been such a challenge for maths? And what does the oddly ubiquitous nature of Pi tell us about the hidden complexities of our world? With: Robert Kaplan, co-founder of the Maths Circle at Harvard University; Eleanor Robson, Lecturer in the Department of History and Philosophy of Science at Cambridge University; and Ian Stewart, Professor of Mathematics at the University of Warwick.">pi</a> <a href="http://www.bbc.co.uk/programmes/b00tt6b2" title="Melvyn Bragg and his guests discuss imaginary numbers. In the sixteenth century, a group of mathematicians in Bologna found a solution to a problem that had puzzled generations before them: a completely new kind of number. For more than a century this discovery was greeted with such scepticism that the great French thinker Rene Descartes dismissed it as an 'imaginary' number. The name stuck - but so did the numbers. Long dismissed as useless or even fictitious, the imaginary number i and its properties were first explored seriously in the eighteenth century. Today the imaginary numbers are in daily use by engineers, and are vital to our understanding of phenomena including electricity and radio waves. With: Marcus du Sautoy, Professor of Mathematics at Oxford University; Ian Stewart, Emeritus Professor of Mathematics at the University of Warwick; and Caroline Series, Professor of Mathematics at the University of Warwick.">i</a> equals -1 <a href="https://www.youtube.com/watch?v=1rVHLZm5Aho">without a hint</a> of calculus. This is <a href="https://www.youtube.com/watch?v=zLzLxVeqdQg">not your usual</a> Taylor series nonsense." (<a href="https://twitter.com/stevenstrogatz/status/604653212214292481" title="''A star is born.''">via</a> <a href="https://twitter.com/Noahpinion/status/604679198259580928" title="''Best geek video I've seen all week.''">via</a>; <a href="http://www.reddit.com/r/math/comments/2xzzk0/nontaylorseries_explanation_for_eulers_formula/">reddit</a>; <a href="http://www.metafilter.com/89918/Math-is-beautiful">previously</a>) <a href="https://www.youtube.com/channel/UCYO_jab_esuFRV4b17AJtAw">More videos from 3Blue1Brown</a>: "<a href="http://www.3blue1brown.com/">3Blue1Brown</a> is some combination of math and entertainment, depending on your disposition. The goal is for explanations to be <a href="http://www.3blue1brown.com/about/" title="''When the tool I am building for animations becomes something besides a jumble of Python and Duct tape, I'll make it publicly available so that anyone can use it to easily illustrate their own explanations.''">driven by animations</a>, for difficult problems to be made simple with changes in perspective, and for philosophizing to be limited to the brevity and semantic constraints of silly poetry. Basically, math sits in <a href="https://plus.google.com/117663015413546257905/posts/QAhMH35LThk">an ivory tower it built itself out of</a> jargon and impossibly long sequences of (seemingly) logical steps, and I would like to take it out for a walk to <a href="http://wordplay.blogs.nytimes.com/2015/03/09/%CF%80/">meet everyone</a>." tag:metafilter.com,2015:site.150242Sat, 06 Jun 2015 11:42:18 -0800kliulessArithmeticfilter
http://www.metafilter.com/146474/Arithmeticfilter
<a href="http://www.momonix.com/calc/">Nothing but an endless supply of mental arithmetic problems.</a> Five levels of difficulty, from "10 - 6" to "√370881." You can find slightly more granular training <a href="http://windhoff.net/mental_arithmetic/#Addition">here</a>. See <a href="http://en.wikipedia.org/wiki/Mental_calculation">Wikipedia</a> for a survey of mental methods, or read <a href="http://www-history.mcs.st-and.ac.uk/HistTopics/Mental_arithmetic.html">A.C. Aitken's</a> <a href="http://stepanov.lk.net/mnemo/aitkene.html">explanation</a> of his Art of Calculation. tag:metafilter.com,2015:site.146474Mon, 26 Jan 2015 08:41:53 -0800IridicNo Pentagons
http://www.metafilter.com/146120/No%2DPentagons
<a href="http://gruze.org/tilings/">Imperfect Congruence</a> - <i>It is a curious fact that no edge-to-edge regular polygon tiling of the plane can include a pentagon ... This website explains the basic mathematics of a particular class of tilings of the plane, those involving regular polygons such as triangles or hexagons. As will be shown, certain combinations of regular polygons cannot be extended to a full tiling of the plane without involving additional shapes, such as rhombs. The site contains some commentary on Renaissance research on this subject carried out by two renowned figures, the mathematician-astronomer Johannes Kepler and the artist Albrecht Dürer.</i> Bonus link: <a href="http://plus.maths.org/content/trouble-five">The Trouble with Five</a> (by Craig Kaplan, at Plus magazine - a short, tantalizing article suitable for school-age readers...) tag:metafilter.com,2015:site.146120Wed, 14 Jan 2015 11:58:51 -0800Wolfdog"Science is when you think a lot."
http://www.metafilter.com/145704/Science%2Dis%2Dwhen%2Dyou%2Dthink%2Da%2Dlot
<a href="http://www.ams.org/bookstore/pspdf/mcl-5-prev.pdf">Two enjoyable chapters</a> [PDF, 33 pages] from the book <i><a href="http://www.ams.org/bookstore-getitem/item=MCL-5">Math from Three to Seven</a>: The Story of a Mathematical Circle for Preschoolers.</i> "This book does not purport to show you how to create precocious high achievers. It is just one person's story about things he tried with a half-dozen young children." tag:metafilter.com,2014:site.145704Mon, 29 Dec 2014 10:43:09 -0800Wolfdog√2N
http://www.metafilter.com/143992/2N
<a href="http://www.quantamagazine.org/20141015-at-the-far-ends-of-a-new-universal-law/">At the Far Ends of a New Universal Law</a> <blockquote>The law appeared in full form two decades later, when the mathematicians Craig Tracy and Harold Widom proved that the critical point in the kind of model May used was the peak of a statistical distribution. Then, in 1999, Jinho Baik, Percy Deift and Kurt Johansson discovered that the same statistical distribution also describes variations in sequences of shuffled integers — a completely unrelated mathematical abstraction. Soon the distribution appeared in models of the wriggling perimeter of a bacterial colony and other kinds of random growth. Before long, it was showing up all over physics and mathematics.
"The big question was why," said Satya Majumdar, a statistical physicist at the University of Paris-Sud. "Why does it pop up everywhere?"</blockquote> tag:metafilter.com,2014:site.143992Tue, 28 Oct 2014 12:59:35 -0800the man of twists and turnsTake that, Keanu Reeves.
http://www.metafilter.com/143228/Take%2Dthat%2DKeanu%2DReeves
<a href="http://www.autostraddle.com/rebel-girls-mapping-power-privilege-and-oppression-254794/">Privilege and oppression explained through math</a> - specifically, matrices and Venn diagrams. tag:metafilter.com,2014:site.143228Wed, 01 Oct 2014 10:05:31 -0800divabatCalculus without limits
http://www.metafilter.com/142845/Calculus%2Dwithout%2Dlimits
<a href="https://plus.google.com/u/0/117663015413546257905/posts/14b9fdM62un">Hyperreal numbers: infinities and infinitesimals</a> - "In 1976, <a href="https://www.math.wisc.edu/~keisler/">Jerome Keisler</a>, a student of the famous logician <a href="http://johncarlosbaez.wordpress.com/2013/03/31/probability-theory-and-the-undefinability-of-truth/">Tarski</a>, published this <a href="http://www.vias.org/calculus/">elementary textbook</a> that <a href="http://en.wikipedia.org/wiki/Infinitesimal#History_of_the_infinitesimal">teaches calculus</a> using <a href="http://en.wikipedia.org/wiki/Hyperreal_number">hyperreal numbers</a>. <a href="https://www.math.wisc.edu/~keisler/calc.html">Now it's free</a>, with a Creative Commons copyright!" (pdf—<a href="https://www.math.wisc.edu/~keisler/keislercalc-12-27-13.pdf">25mb</a> :) also btw :P
<ul><li><a href="https://plus.google.com/u/0/117663015413546257905/posts/JHAku2S1KFw">The logic of real and complex numbers</a> - "The cool part is that in some ways the complex numbers are <i>simpler</i> than the real numbers! The <a href="http://johncarlosbaez.wordpress.com/2014/09/08/the-logic-of-real-and-complex-numbers/">ultimate reason</a> is that you can't talk about one complex number being greater than another. This avoids some nonstandard number systems where you have a number that's greater than all the ones you wanted to talk about."</li>
<li><a href="https://plus.google.com/u/0/117663015413546257905/posts/dZcXuyHj7LH">Science, models, and machine learning</a> - "<a href="http://johncarlosbaez.wordpress.com/2014/09/03/science-models-and-machine-learning/">Machine learning</a> is the art of <a href="http://www.newscientist.com/article/mg22329832.700-googles-factchecking-bots-build-vast-knowledge-bank.html?full=true">getting computers to learn, so you don't have to</a> explicitly tell them what to do. People use it in spam filters, search engines that guess what you're trying to find, optical character recognition, <a href="https://medium.com/aspen-ideas/robots-with-their-heads-in-the-clouds-e88ac44def8a">cars that drive themselves</a>, and <a href="https://plus.google.com/u/0/117663015413546257905/posts/SrQe3Bsd9kp">many other</a> things. <a href="http://www.metafilter.com/135046/Things-Dont-Make-Sense-Till-They-Make-Sense-to-a-Stupid-Robot">But how does it work?</a>"</li>
<li><a href="http://infoproc.blogspot.com/2014/08/neural-networks-and-deep-learning-2.html">Neural Networks and Deep Learning</a> - "Inspired by the topics discussed in this <a href="http://infoproc.blogspot.com/2014/08/neural-networks-and-deep-learning.html">earlier post</a>, I've been reading <a href="http://neuralnetworksanddeeplearning.com/">Michael Nielsen's online book</a> on neural nets and deep learning."</li>
<li><a href="http://vserver1.cscs.lsa.umich.edu/~crshalizi/weblog/cat_statcomp.html">Introduction to Statistical Computing</a> - "At an intersection of <a href="http://vserver1.cscs.lsa.umich.edu/~crshalizi/weblog/cat_enigmas_of_chance.html">Enigmas of Chance</a> and <a href="http://vserver1.cscs.lsa.umich.edu/~crshalizi/weblog/cat_corrupting_the_young.html">Corrupting the Young</a>."</li>
<li><a href="http://www.math.columbia.edu/~woit/wordpress/?p=7172">Higher Algebra & Topos Theory</a> - "<a href="http://www.macfound.org/fellows/921/">Mathematician Jacob Lurie</a>, who was honored for redefining models in algebraic geometry, negotiated with his publisher to make his book on <a href="https://plus.google.com/u/0/117663015413546257905/posts/LX52bzbuWgH">math principles</a> available for <a href="http://www.math.harvard.edu/~lurie/">free download</a> on his personal website. While academics sometimes place papers online free, putting a whole book online isn't yet standard practice, according to the 36-year-old Harvard University professor. 'From my point of view, the benefit of writing a book is for people to look at it. I would like as many people as possible to look at it', he said."</li></ul> tag:metafilter.com,2014:site.142845Wed, 17 Sep 2014 17:23:34 -0800kliuless21st Century Wiener
http://www.metafilter.com/140806/21st%2DCentury%2DWiener
<a href="http://www.theatlantic.com/technology/archive/2014/06/norbert-wiener-the-eccentric-genius-whose-time-may-have-finally-come-again/372607/">Norbert Wiener: The Eccentric Genius Whose Time May Have Finally Come (Again)</a> - "The most direct reason for Wiener's fall to relative obscurity was the breakthrough of a young mathematician and engineer named <a href="http://www.metafilter.com/6138/The-passing-of-a-giant">Claude Shannon</a>." <a href="http://tikalon.com/blog/blog.php?article=2014/Norbert_Wiener">Norbert Wiener</a>:
<blockquote>In his 1950 book, "<a href="http://en.wikipedia.org/wiki/The_Human_Use_of_Human_Beings">The Human Use of Human Beings</a>," [<a href="http://21stcenturywiener.org/wp-content/uploads/2013/11/The-Human-Use-of-Human-Beings-by-N.-Wiener.pdf">PDF</a>] Wiener <a href="http://www.forbes.com/sites/christopherhelman/2014/07/02/dean-kamen-thinks-his-new-stirling-engine-could-power-the-world/print/">envisioned</a> a <a href="https://medium.com/@AdamThierer/muddling-through-how-we-learn-to-cope-with-technological-change-6282d0d342a6">utopia</a> in which <a href="http://www.bloombergview.com/articles/2014-07-07/larry-page-s-slacker-utopia">automation</a> would relieve humanity of <a href="http://marginalrevolution.com/marginalrevolution/2014/07/the-decline-of-drudgery-and-the-paradox-of-hard-work.html">manual</a> <a href="http://crookedtimber.org/2014/07/10/in-search-of-search-theory/">labor</a> to allow more <a href="http://continuations.com/post/91111911845/more-on-basic-income-and-robots">creative</a> pursuits. Sixty years later, we have much automation, but <a href="http://www.economist.com/blogs/freeexchange/2014/07/thomas-piketty-history-money">income</a> <a href="http://boingboing.net/2014/06/24/thomas-pikettys-capital-in-t.html">inequality</a> rather than utopia. Wiener died in Stockholm, Sweden, at age 69.
The crater, <a href="http://en.wikipedia.org/wiki/Wiener_%28crater%29">Wiener</a>, on the far side of the Moon is named after him. I've always believed in "Wiener's Law of Libraries," "<a href="http://en.wikiquote.org/wiki/Norbert_Wiener">There are no answers, only cross references</a>". The IEEE is sponsoring a conference, <a href="http://21stcenturywiener.org/">Norbert Wiener in the 21st Century</a>, commemorating Norbert Wiener. </blockquote>
also btw...
<ul><li><a href="http://www.nytimes.com/2013/05/21/science/mit-scholars-1949-essay-on-machine-age-is-found.html?pagewanted=all">In 1949, He Imagined an Age of Robots</a>: " 'The Machine Age' (<a href="http://libraries.mit.edu/archives/mithistory/pdf/MC0022_MachineAgeV3_1949.pdf">pdf</a>) an essay written for <i>The New York Times</i> by Norbert Wiener, a visionary mathematician, languished for six decades in the M.I.T. archives, and now excerpts are being published."</li>
<li><a href="http://infoproc.blogspot.com/2014/06/theoreticians-as-professional-outsiders.html">Theoreticians as Professional Outsiders</a>: The Modeling Strategies of John von Neumann and Norbert Wiener (<a href="http://www.ehudlamm.com/outsiders.pdf">pdf</a>)</li>
<blockquote>Both von Neumann and Wiener were outsiders to biology. Both were inspired by biology and both proposed models and generalizations that proved inspirational for biologists. Around the same time in the 1940s von Neumann developed the notion of self reproducing automata and Wiener suggested an explication of teleology using the notion of negative feedback. These efforts were similar in spirit. Both von Neumann and Wiener used mathematical ideas to attack foundational issues in biology, and the concepts they articulated had lasting effect. But there were significant differences as well. Von Neumann presented a how-possibly model, which sparked interest by mathematicians and computer scientists, while Wiener collaborated more directly with biologists, and his proposal influenced the philosophy of biology. The two cases illustrate different strategies by which mathematicians, the "professional outsiders" of science, can choose to guide their engagement with biological questions and with the biological community, and <a href="http://www.metafilter.com/137105/John-Baez-on-the-maths-of-connecting-everyone-and-everything-on-earth">illustrate different kinds of generalizations</a> that mathematization can contribute to biology. The different strategies employed by von Neumann and Wiener and the types of models they constructed may have affected the fate of von Neumann's and Wiener's ideas – as well as the reputation, in biology, of von Neumann and Wiener themselves.</blockquote>
<li><a href="http://www.nytimes.com/2014/07/08/science/a-billionaire-mathematicians-life-of-ferocious-curiosity.html">A Billionaire Mathematician's Life of Ferocious Curiosity</a>: "Dr. Simons received his doctorate at 23; advanced code breaking for the National Security Agency at 26; led a university math department at 30; won geometry's top prize at 37; <a href="http://infoproc.blogspot.com/2014/07/james-simons-mathematics-common-sense.html">founded Renaissance Technologies</a>, one of the world's most successful hedge funds, at 44; and began setting up <a href="http://www.simonsfoundation.org/quanta/">charitable foundations</a> at 56."</li>
<li><a href="http://infoproc.blogspot.com/2014/07/physics-and-horizons-of-truth.html">Physics and the Horizons of Truth</a>: "mathematics without something like the 'axiom of infinity' might be well-defined..." [<a href="http://infoproc.blogspot.com/2013/06/horizons-of-truth.html">Horizons of Truth</a>: Kurt Gödel and the Foundations of Mathematics (<a href="http://f3.tiera.ru/2/M_Mathematics/MA_Algebra/MAml_Mathematical%20logic/Baaz%20M.,%20et%20al.%20(eds.)%20Kurt%20Goedel%20and%20the%20foundations%20of%20mathematics.%20Horizons%20of%20truth%20(CUP,%202011)(ISBN%200521761441)(O)(541s)_MAml_.pdf">pdf</a>)]</li>
<li><a href="https://www.youtube.com/watch?v=uh6GCY9i6tY">Sentences you never thought you'd hear in Congress</a>: "Madame Speaker, I would like to talk about <a href="http://www.metafilter.com/134338/binding-the-andat">twin prime numbers</a>..."</li></ul> tag:metafilter.com,2014:site.140806Fri, 11 Jul 2014 07:11:08 -0800kliulessMath or Maths?
http://www.metafilter.com/138740/Math%2Dor%2DMaths
<a href="http://www.numberphile.com/videos/math_maths.html">Math or Maths?</a> A few minutes with Dr Lynne Murphy (an American linguist in England) should clear this right up. Via <a href="http://www.numberphile.com/index.html">Numberphile</a>. tag:metafilter.com,2014:site.138740Wed, 30 Apr 2014 17:39:24 -0800R. MuttA SAT Attack on the Erdos Discrepancy Conjecture
http://www.metafilter.com/138247/A%2DSAT%2DAttack%2Don%2Dthe%2DErdos%2DDiscrepancy%2DConjecture
<a href="http://io9.com/computers-are-providing-solutions-to-math-problems-that-1525261141">Computers are providing solutions to math problems that we can't check</a> - "A computer has solved the longstanding <a href="http://arxiv.org/abs/1402.2184">Erdős discrepancy</a> problem! Trouble is, we have no idea what it's talking about — because the solution, which is <a href="http://www.newscientist.com/article/dn25068-wikipediasize-maths-proof-too-big-for-humans-to-check.html">as long as all of Wikipedia</a>'s pages combined, is far too <a href="http://mathbabe.org/2013/07/30/the-stacks-project-gets-ever-awesomer-with-new-viz/">voluminous</a> for us <a href="http://oliviacaramello.com/Unification/Unification.htm">puny humans</a> to confirm." (<a href="http://marginalrevolution.com/marginalrevolution/2014/04/are-computer-coming-up-with-answers-we-cannot-understand.html">via</a>; <a href="http://www.metafilter.com/126041/Computerized-Math-Formal-Proofs-andamp-Alternative-Logic">previously</a> ;) tag:metafilter.com,2014:site.138247Sat, 12 Apr 2014 08:55:27 -0800kliulessthere is no soundtrack
http://www.metafilter.com/137347/there%2Dis%2Dno%2Dsoundtrack
<a href="https://www.simonsfoundation.org/quanta/20140224-a-fluid-new-path-in-grand-math-challenge/">Finite time blowup for an averaged three-dimensional Navier-Stokes equation</a> - "[<a href="http://terrytao.wordpress.com/">Terence Tao</a>] has shown that in an alternative abstract universe closely related to the one described by the <a href="http://en.wikipedia.org/wiki/Navier%E2%80%93Stokes_equations">Navier-Stokes</a> equations, it is possible for a body of fluid to form a sort of computer, which can build a self-replicating fluid robot that, <a href="http://www.drseussart.com/details/illustration/littlecats.html">like the Cat in the Hat</a>, keeps transferring its energy to smaller and smaller copies of itself until the fluid '<a href="http://terrytao.wordpress.com/2014/02/04/finite-time-blowup-for-an-averaged-three-dimensional-navier-stokes-equation/">blows up</a>.' " [<a href="http://terrytao.wordpress.com/2014/02/25/conserved-quantities-for-the-euler-equations/">1</a>,<a href="http://terrytao.wordpress.com/2014/03/02/noethers-theorem-and-the-conservation-laws-for-the-euler-equations/">2</a>,<a href="http://terrytao.wordpress.com/2014/03/06/conserved-quantities-for-the-surface-quasi-geostrophic-equation/">3</a>] (<a href="http://www.metafilter.com/55295/Another-Clay-Institute-Millenium-Prize-Problem-Solved">previously</a>) tag:metafilter.com,2014:site.137347Sun, 09 Mar 2014 13:49:39 -0800kliulessJohn Baez on the maths of connecting everyone (and everything) on earth
http://www.metafilter.com/137105/John%2DBaez%2Don%2Dthe%2Dmaths%2Dof%2Dconnecting%2Deveryone%2Dand%2Deverything%2Don%2Dearth
<a href="http://johncarlosbaez.wordpress.com/2014/02/22/network-theory-overview/">Network Theory Overview</a> - "<a href="http://johncarlosbaez.wordpress.com/2014/02/07/network-theory-talks-at-oxford/">The idea</a>: nature and the world of human technology are <a href="http://johncarlosbaez.wordpress.com/2013/04/23/network-theory-part-29/">full of networks</a>! People like to draw diagrams of networks. Mathematical physicists know that in principle these diagrams can be understood using <a href="http://math.ucr.edu/home/baez/irvine/">category theory</a>. But why should <a href="http://www.perimeterinstitute.ca/videos/energy-and-environment-what-physicists-can-do">physicists have all the fun</a>? This is the century of <i><a href="https://plus.google.com/117663015413546257905/posts/e6stQjMvm3y">understanding living systems and adapting to life on a finite planet</a></i>. Math isn't the main thing we need, but it's got to be <a href="https://plus.google.com/117663015413546257905/posts/5gt7pfibYMg">part of the solution</a>... <a href="http://johncarlosbaez.wordpress.com/2014/03/02/network-theory-i/">so one thing we should do</a> is develop a unified and powerful <a href="http://math.ucr.edu/home/baez/networks/">theory of networks</a>." (<a href="https://plus.google.com/117663015413546257905/posts/SmWyn8HcDyW">via</a> ;) tag:metafilter.com,2014:site.137105Sun, 02 Mar 2014 09:06:38 -0800kliulessWondering What to Get with That Gift Card?
http://www.metafilter.com/135164/Wondering%2DWhat%2Dto%2DGet%2Dwith%2DThat%2DGift%2DCard
It's a bit late for the holiday, but math(s) comedian Helen Arney <a href="http://www.bbc.co.uk/programmes/p01ns0wj">sings about her Christmas wish</a> -- the largest known Mersenne Prime, <a href="http://en.wikipedia.org/wiki/Mersenne_prime">Mersenne 48</a>. The song appeared on a recent edition of the BBC4 radio show/podcast <a href="http://www.bbc.co.uk/programmes/b006qshd">More or Less</a> which deals with numbers and especially statistics. Arney performs as part of <a href="http://festivalofthespokennerd.com/">The Festival of the Spoken Nerd</a> in the UK.
Bonus Helen Arney -- <a href="http://www.youtube.com/watch?v=5JOAoiX1LHA&feature=c4-overview-vl&list=PLUQzg8K3BcJLmneP2TwqoEJvqr2_NvFIX">"The Google Song"</a> from Numberphile [<a href="http://www.metafilter.com/123329/Numberphile-videos-about-numbers-and-stuff">previously</a>] tag:metafilter.com,2013:site.135164Sat, 28 Dec 2013 07:20:05 -0800GenjiandProustbinding the andat
http://www.metafilter.com/134338/binding%2Dthe%2Dandat
<a href="http://www.wired.com/wiredscience/2013/11/prime/all/">Closing in on the twin prime conjecture</a> (<a href="https://www.simonsfoundation.org/quanta/20131119-together-and-alone-closing-the-prime-gap/">Quanta</a>) - "Just months after <a href="http://www.metafilter.com/128049/Quite-a-day-for-analytic-number-theory">Zhang</a> announced his result, <a href="http://arxiv.org/abs/1311.4600">Maynard</a> has presented an independent proof that pushes the gap down to 600. A <a href="http://terrytao.wordpress.com/tag/polymath8/">new Polymath project</a> is in the planning stages, to try to combine the collaboration's techniques with Maynard's approach to push this bound even lower." <a href="https://plus.google.com/u/0/117663015413546257905/posts/LxR23RdyvuF">also btw</a> :P (<a href="https://plus.google.com/u/0/117663015413546257905/posts/jd5K4jBKRYP">for fun</a>!)
-<a href="https://plus.google.com/u/0/117663015413546257905/posts/Z4cUWGQp8Ar">Schröder–Hipparchus numbers</a> (<a href="http://golem.ph.utexas.edu/category/2013/04/permutations_polynomials_and_p.html">The Hipparchus Operad</a>)
-<a href="https://plus.google.com/u/0/117663015413546257905/posts/WoXqXCzkc9S">Quasi</a>-<a href="http://golem.ph.utexas.edu/category/2013/06/quasicrystals_and_the_riemann.html">crystals</a> (<a href="https://plus.google.com/u/0/117663015413546257905/posts/j4Xxg44n1t6">quantum physics and number theory</a>)
-<a href="https://www.simonsfoundation.org/quanta/20131126-to-settle-infinity-question-a-new-law-of-logic/">To Settle Infinity Question, a New Law of Mathematics</a>
oh and <a href="https://www.simonsfoundation.org/quanta/20131107-physicists-eye-quantum-gravity-interface/">perhaps</a> more practically...
-<a href="http://www.thephysicsmill.com/2013/10/13/causal-dynamical-triangulations/">Quantum Geometry: Causal Dynamical Triangulations</a> (<a href="https://plus.google.com/u/0/117663015413546257905/posts/ATg9EwD5CJy">via</a>)
-<a href="https://plus.google.com/u/0/117663015413546257905/posts/9HeN1sSQztA">Quantropy</a>
-<a href="https://plus.google.com/u/0/117663015413546257905/posts/51Gd5adQZNM">Petri nets</a> (<a href="http://johncarlosbaez.wordpress.com/2013/04/19/petri-net-programming-part-3/">programming</a> <a href="http://www.metafilter.com/134300/ASCII-fluid-simulator">water</a>)
-<a href="http://johncarlosbaez.wordpress.com/2013/04/23/network-theory-part-29/">Network theory</a>
-<a href="https://plus.google.com/u/0/117663015413546257905/posts/SrQe3Bsd9kp">The network of mathematics</a>
-<a href="http://math.ucr.edu/home/baez/irvine/">The Foundations of Applied Mathematics</a> (<a href="https://plus.google.com/u/0/117663015413546257905/posts/LX52bzbuWgH">topos theory</a>)
-<a href="http://www.wired.com/wiredscience/2013/10/topology-data-sets/all/">Topological Data Analysis</a> tag:metafilter.com,2013:site.134338Sun, 01 Dec 2013 16:19:50 -0800kliuless