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New
The latest blog posts to take off on Hacker News. 95 posts.
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How Advanced Is the NSA's Cryptanalysis, and Can We Resist It?
The latest Snowden document is the US intelligence ‘black budget.’ There’s a lot of information in the few pages the Washington Post decided to publish, including an introduction by Director of National Intelligence James Clapper. In it, he drops a tantalizing hint: ‘Also, we are investing in groundbreaking…
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Understanding the FFT Algorithm
The Fast Fourier Transform (FFT) is one of the most important algorithms in signal processing and data analysis. I've used it for years, but having no formal computer science background, It occurred to me this week that I've never thought to ask how the FFT computes the discrete Fourier transform so quickly. I dusted…
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What is algebra?
NOVEMBER 20, 2011. We hear a lot about the importance that all children master algebra before they graduate from high school. But what exactly is algebra, and is it really as important as everyone …
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I hate the Pumping Lemma
I hate the Pumping Lemma for regular languages. It’s a complicated way to express an idea that is fundamentally very simple, and it isn’t even a very good way to prove that a language is not regula…
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Rotating Images
How to rotate an image, and a need trick to rotate a bitmap an arbitrary amount in a simple paint package.
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The Factoring Cryptopocalypse
The key detail to understand about the work in the Joux papers is that it is limited to solving discrete logarithm problems over fields of small characteristic . As interesting as the work is, mathematically, it should not be a great surprise to cryptographers: We've known for over a decade that small-characteristic…
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Gödel, Turing and Cantor: The Math
This is mathematical section of the parent essay Gödel Incompleteness for Startups Gödel Numbering A formal system is just a collection of axioms and rules. Just like we did before we can record ax…
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Computer scientists develop 'mathematical jigsaw puzzles' to encrypt software
The "software obfuscation" system encrypts software so that it only allows someone to use a program as intended while preventing any deciphering of the code behind it.
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A back-projection algorithm to extract 3D volume from shadows
If you'd rather read python than english you can go straight to the code on github: https://github.com/jminardi/volume-from-shadow
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Ten Signs a Claimed Mathematical Breakthrough is Wrong
Yesterday several people asked my opinion of a preprint claiming to solve the Graph Isomorphism problem in deterministic polynomial time. I responded: If I read all such papers, then I wouldn’t hav…
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Link between quantum physics and game theory found
A deep link between two seemingly unconnected areas of modern science - quantum physics and game theory - is described by researchers from the Universities of Bristol and Geneva in a paper published in Nature Communications.
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Let's Play Ancient Greek Geometry
Today I’m releasing Let’s Play: Ancient Greek Geometry . It’s a Compass and Straightedge tool/puzzle game written in JavaScript. I’ve always thought Geometric Construction felt like a puzzle, so to me this pairing was quite natural. Compass and Straight edge is a technique for constructing shapes out of circles…
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Algorithms Every Data Scientist Should Know: Reservoir Sampling
Cloudera Blog is your source for expert guidance on the latest data and AI trends, technology innovation, best practices, success stories, and more.
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Two dozen mathematicians wrote a 600 page book in 6 months on GitHub
Since spring, and even before that, I have participated in a great collaborative effort on writing a book on Homotopy Type Theory. It is finally finished and ready for public consumption. You can get the book freely at http://homotopytypetheory.org/book/ . Mike Shulman has written about the contents of the book , so I…
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Ultimate Tic Tac Toe
Once at a picnic, I saw mathematicians crowding around the last game I would have expected: Tic-tac-toe.
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Shakespeare.txt.jpg: A JPEG compression experiment
Experimenting with JPEG compressing text.
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Feynman vs. The Abacus
A Japanese man came into the restaurant. I had seen him before, wandering around; he was trying to sell abacuses. He started to talk to the waiters, and challenged them: He said he could add numbers faster than any of them could do.
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Elsevier journals: has anything changed?
Greg Martin, a number theorist at UBC (the University of British Columbia in Vancouver) doesn’t think so, so he has decided to resign from the editorial board of Elsevier’s Journal of N…
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How far can you overhang blocks?
How hungover can you get? Kids blocks and Calculus!