Obtuse Triangular Billiards

Richard Schwartz

Brown University

Brandeis University

Thursday, February 9, 2006

Talk at 4:30 p.m. in 317 Goldsmith Hall

Tea at 4:00 p.m. in 300 Goldsmith Hall

Abstract: The triangular billiards problem, which goes back about 200 years, asks if every triangular shaped billiard table has a periodic billiard path. Until recently, almost nothing was known about this problem. In particular, it was not known if there was any epsilon>0 such that all obtuse triangles with big angle less than 90+epsilon degrees had a periodic billiard path. I will describe my computer-aided (but rigorous) proof that a triangle has a periodic billiard path if all its angles are less than 100 degrees. During the talk, I hope to demonstrate McBilliards, a graphical user interface which lets the user survey the proof and also experiment with triangular billiards.

Home Web page: Alexandru I. Suciu Posted: January 19, 2006
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