Tag Archives: graph

Now on mathstodon.xyz

Christian Lawson-Perfect and Colin Wright have set up an instance of Mastodon—a decentralized, open-source Twitter clone—as a place for mathy folks to be social. It’s appropriately named mathstodon.xyz, and because it’s open-source they were able to easily hack in support. … Continue reading

Posted in meta, proof | Tagged , , , , , , | 3 Comments

Post without words #15

Image | Posted on by | Tagged , , , , | 8 Comments

Post without words #14

(click here for a bigger version)

Posted in pattern, pictures, posts without words | Tagged , , , , | 14 Comments

Network reliability

Over on my other blog I’ve started writing about an interesting but apparently nontrivial problem, which some readers of this blog may find interesting as well. Suppose you have a network of computers with some one-directional wires between them. Each … Continue reading

Posted in links, probability | Tagged , , , | 2 Comments

Mystery curve, animated

As a follow-on to my previous post, here’s an animation (17MB) showing how the “mystery curve” arises as a sum of circular motions: Recall that the equation for the curve is . The big blue circle corresponds to the term—it … Continue reading

Posted in complex numbers, geometry, programming | Tagged , , , , , , , | 6 Comments

Random cyclic curves

Princeton Press just sent me a review copy of a new book by Frank Farris called Creating Symmetry: The Artful Mathematics of Wallpaper Patterns. It looks amazing and I’m super excited to read it. Apparently John Cook has been reading … Continue reading

Posted in complex numbers, geometry, programming | Tagged , , , , , | 24 Comments

17×17 4-coloring with no monochromatic rectangles

Quick, what’s special about the following picture? As just announced by Bill Gasarch, this is a grid which has been four-colored (that is, each point in the grid has been assigned one of four colors) in such a way that … Continue reading

Posted in open problems, pattern, people, pictures | Tagged , , , , , | 5 Comments