The fact that light travels at the samšíček, Joe Godenzi, jonas.app, Kellas Lowery, Lasse T. Stendan, Lester Su, Margaret Barnett, Martin Steed, Matt Townsend, Michelle J. Zamarron, Osian Gwyn Williams, Paul Brown, Paweł Zuzelski, Philip Brown, Rebecca Pan, Robert Reinecke, Roger Baker, Roger S. Gulledge, Roger Shaw and Tim Karr. --- 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 regular science videos: http://bit.ly/RiSubscRibe Product links on this page are affiliate links which means it won't cost you any extra but we may earn a small commission if you decide to purchase through the link.