What's this weird tree of fractions in that strange book Kepler wrote in 1619, "The Harmony of the World"? It may be a rather deep piece of mathematics! (continued)pic.twitter.com/gsfKEEftLR
You can add location information to your Tweets, such as your city or precise location, from the web and via third-party applications. You always have the option to delete your Tweet location history. Learn more
Yes! My tweets never mentioned PSL(2,Z) - I figured most people would prefer not hearing about that. But this series of tweets is actually my answer to @SamuelGWalters tweet-puzzle asking for two elements of SL(2,Z) that generate a free submonoid of that group.
So delighted to learn, though, that this marvelous and ubiquitous structure was already familiar to Kepler -- in 1619! Amazing. How did you happen to notice this extraordinary detail? Are you a Kepler scholar?
Twitter may be over capacity or experiencing a momentary hiccup. Try again or visit Twitter Status for more information.