Category Archives: pictures

Post without words #7

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Making tessellations

I just received my copy of Tessalation!, a great new book written by Emily Grosvenor and beautifully illustrated by Maima Widya Adiputri, which I helped fund on Kickstarter. It’s about a girl named Tessa who goes exploring in her backyard … Continue reading

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Apollonian gaskets and Descartes’ Theorem II

In a few previous posts I wrote about “kissing sets” of four mutually tangent circles, and the fact that their signed bends satisfy Descartes’ Theorem, (Remember that the signed bend of a circle is like the curvature , except that … Continue reading

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Factorization diagram cards!

I’ve designed a set of factorization diagram cards and had them actually printed. This is one of the first times in my life when I have caused Actual Physical Objects to be created (other than using a printer I guess) … Continue reading

Posted in arithmetic, counting, pattern, pictures, primes, teaching, video | Tagged , , | 4 Comments

Tiny Polka Dot

I’m really excited about Tiny Polka Dot, a Kickstarter project producing a deck of colorful, mathy cards especially for young children—along with a list of games to play with the cards. I have a four-year-old and I’m sure he is … Continue reading

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Apollonian gaskets and Descartes’ Theorem

In my previous post, I explained a recursive procedure for drawing Apollonian gaskets. Given any three mutually tangent circles, there are exactly two other circles which are mutually tangent to all three (forming what we called a “kissing set”). This … Continue reading

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Apollonian gaskets

In my last post I showed off this tantalizing picture: This pattern of infinitely nested circles is called an Apollonian gasket. Over the next post or two I’ll explain some cool math behind actually constructing them. Mostly I will state … Continue reading

Posted in geometry, pattern, pictures, recursion | Tagged , , , | 3 Comments