Tweet at us! @pbsspacetime Facebook: facebook.com/pbsspacetime Email us! pbsspacetime [at] gmail [dot] com Support us on Patreon! http://www.patreon.com/pbsspacetime Help translate our videos! null Aliens! Could humans really be alone in this expansive universe? And if we're not, how come we've never made contact with other intelligent life? Everyone's thought about it; especially members of the scientific community. Join Gabe as he presents some of the most popular theories that scientists use to rationalize their support or skepticism of the existence of aliens. We may never know the answer to this age old question, but a little scientific thinking never hurt anybody! Extra Credit: http://en.wikipedia.org/wiki/Fermi_paradox http://en.wikipedia.org/wiki/Drake_equation http://www.nickbostrom.com/extraterrestrial.pdf ---------------------------------------­------------------------------ Comments: D. Moritz https://www.youtube.com/watch?v=McsgRggUjE4 Gaëtan DO VAN LANH via Google+ https://www.youtube.com/watch?v=McsgRggUjE4 The Gentleman Physicist https://www.youtube.com/watch?v=McsgRggUjE4 Nicholas Feeley https://www.youtube.com/watch?v=McsgRggUjE4 James Morgan https://www.youtube.com/watch?v=McsgRggUjE4 ---------------------------------------­------------------------------ New SpaceTime episodes every Wednesday! Want to ask some sort of crazy question about Space?: Tweet at us! @pbsspacetime Facebook: facebook.com/pbsspacetime Email us! pbsspacetime [at] gmail [dot] com Hosted by Gabe Perez-Giz Made by Kornhaber Brown (www.kornhaberbrown.com)