This is YBC 7289, a Babylonian tablet from 1800 BC – 1600 BC showing the sides and diagonals of a square with a very accurate sexagesimal approximation to the square root of two, "the greatest known computational accuracy ... in the ancient world". Now a Good Article on Wikipedia, https://en.wikipedia.org/wiki/YBC_7289

The view from my desk. Actually my office has lots of windows with a nice view of a well-used plaza, outdoor coffee shop, trees, and distant mountains. But to see that, I have to get up and go over to one of the windows. If I stay at my desk and look up at the window, I see this interesting geometric pattern instead.

Matsya And The Great Deluge, street art from Fort Bragg illustrating an ancient Indian folk tale. For a more complete view of this piece and more information about it, see https://www.fortbraggalleywayart.org/the-fish-mural.html

It feels like I haven't been taking and posting enough photos. So here's a cell phone shot from yesterday that I took to illustrate the Wikipedia article https://en.wikipedia.org/wiki/Mendocino_Beacon

The Beacon hasn't actually lived there for nearly 20 years, but their old sign still hangs on the building.

Amazon trained a sexism-fighting, resume-screening AI with sexist hiring data, so the bot became sexist: https://boingboing.net/2018/10/11/garbage-conclusions-out.html

A Problem Fit for a Princess: https://www.mathteacherscircle.org/news/mtc-magazine/sa2017/apollonian-gaskets/

A post on the history of the Apollonian Gasket, a fractal formed by tangent circles, inspired by its use as the logo of the San Joaquin Math Teachers’ Circle.

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- https://www.ics.uci.edu/~eppstein/

I'm a computer scientist at the University of California, Irvine, interested in algorithms, data structures, discrete geometry, and graph theory.

Joined Apr 2017