Professor Ron Graham discusses the famed Happy Ending Problem and Ramsey Theory. More Ron Graham Videos: http://bit.ly/Ron_Graham More links & stuff in full description below ↓↓↓ An extra little bit at: https://www.youtube.com/watch?v=hnIBiIcuudU Graham's Number: https://www.youtube.com/watch?v=XTeJ64KD5cg Support us on Patreon: http://www.patreon.com/numberphile NUMBERPHILE Website: http://www.numberphile.com/ Numberphile on Facebook: http://www.facebook.com/numberphile Numberphile tweets: https://twitter.com/numberphile Subscribe: http://bit.ly/Numberphile_Sub Numberphile is supported by the Mathematical Sciences Research Institute (MSRI): http://bit.ly/MSRINumberphile Videos by Brady Haran Brady's videos subreddit: http://www.reddit.com/r/BradyHaran/ Brady's latest videos across all channels: http://www.bradyharanblog.com/ Sign up for (occasional) emails: http://eepurl.com/YdjL9 Numberphile T-Shirts: null Other merchandise: https://store.dftba.com/collections/numberphile