With a focus on string theory, quantum mechanics, and cosmology, Sir Roger Penrose looks at how physicists are just as susceptible to flights of fantasy, fashion and blind faith as anyone else. Watch the Q&A and special announcement of the Penrose Institute: https://youtu.be/iH4XJHJ8AOw Subscribe for regular science videos: http://bit.ly/RiSubscRibe Can the following of fashion, blind faith, or flights of fantasy have anything seriously to do with the scientific quest to understand the universe? Surely not - but Roger Penrose argues that researchers working at the extreme frontiers of physics are as susceptible to these forces as anyone else, and that fashion, faith, and fantasy, while sometimes highly productive in physics, may be leading today's researchers astray in three of that field's most important areas—string theory, quantum mechanics, and cosmology. Roger Penrose is a renowned mathematical physicist, mathematician and philosopher of science. He is the recipient of many awards, including the Copley Medal, the Albert Einstein Medal and the Eddington Medal. Subscribe for regular science videos: http://bit.ly/RiSubscRibe The Ri is on Twitter: http://twitter.com/ri_science and Facebook: http://www.facebook.com/royalinstitution and Tumblr: http://ri-science.tumblr.com/ Our editorial policy: http://www.rigb.org/home/editorial-policy Subscribe for the latest science videos: http://bit.ly/RiNewsletter