Getting your head around the implications of the many worlds theory can be an almost incomprehensible task. Subscribe for regular science videos: http://bit.ly/RiSubscRibe In this short clip from the Q&A following his talk on quantum mechanics, theoretical physicist Sean Carroll explores how we can conceive of the branches of the universe and how they could all fit. Watch the full talk: https://youtu.be/5hVmeOCJjOU Sean M Carroll is a theoretical physicist, specialising in quantum mechanics, gravitation, cosmology, statistical mechanics, and foundations of physics, with occasional dabblings elsewhere. His official titles are Research Professor of Physics at Caltech and Research Professor at the Santa Fe Institute. He lives in Los Angeles with his wife, writer Jennifer Ouellette. 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