Do string theory and loop quantum gravity consider retro-causality or quantum entanglement? Did the universe start with the Big Bang? Jim Baggott answers audience questions following his talk. Subscribe for regular science videos: http://bit.ly/RiSubscRibe Watch the talk: https://youtu.be/dW7J49UTns8 Jim Baggott is an award-winning science writer. He trained as a scientist, completing a doctorate in chemical physics at the University of Oxford in the early 80s, before embarking on post-doctoral research studies at Oxford and at Stanford University in California. This Q&A was filmed at the Ri on 12 February 2019. --- A very special thank you to our Patreon supporters who help make these videos happen, especially: Darren Jones, Dave Ostler, David Lindo, Elizabeth Greasley, Greg Nagel, Ivan Korolev, Lester Su, Osian Gwyn Williams, Radu Tizu, Rebecca Pan, Robert Hillier, Roger Baker, Sergei Solovev and Will Knott. --- The Ri is on Patreon: https://www.patreon.com/TheRoyalInstitution and 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