Sir Roger Penrose is one of the biggest names in mathematics AND physics. Here he talks about sibling rivalry, Stephen Hawking, having ideas, and toilet paper. Roger Penrose Wikipedia - https://en.wikipedia.org/wiki/Roger_Penrose Roger Penrose books - Amazon - https://amzn.to/2XIpNBo The Order of Merit - https://en.wikipedia.org/wiki/Order_of_Merit The Theory of Everything - 2014 movie about Stephen Hawking - https://www.imdb.com/title/tt2980516/ Penrose Tiling - https://en.wikipedia.org/wiki/Penrose_tiling Penrose Toilet Paper - https://collection.sciencemuseumgroup.org.uk/objects/co439558/pack-of-four-rolls-quilted-toilet-paper-with-penrose-tiling-packaging-toilet-paper The San Franciscos Transit Center with its Penrose Tiling - https://en.wikipedia.org/wiki/Transbay_Transit_Center#/media/File:Salesforce_Transit_Center_main_entrance.jpg With thanks to MSRI - https://www.msri.org Support us on Patreon - https://www.patreon.com/numberphile