PBS Member Stations rely on viewers like you. To support your local station, go to: http://to.pbs.org/DonateSPACE ↓ More info below ↓ Sign Up on Patreon to get access to the Space Time Discord! https://www.patreon.com/pbsspacetime Check out the Space Time Merch Store https://pbsspacetime.com/ Why does it appear, that humanity is the lone intelligence in the universe? The answer might be that planet Earth is more unique than we've previously assumed. The rare earth hypothesis posits exactly this - that a range of factors made Earth exceptionally unusual and uniquely able to produce intelligent life. In upcoming episodes we’ll be exploring the anthropic principle and its two main versions - the strong and the weak anthropic principles. The strong anthropic principle tells us that the observed universe must be able to produce observers - including the contentious idea that this predicts the existence of universes beyond our own. But in today's episode we’re going to focus on the weak anthropic principle. It says that we must find ourselves in a part of the universe capable of supporting us. For example, in a planetary biosphere rather than floating in the void between the galaxies. This may seems tautological, but accounting for this observer selection bias is important to understanding why the universe looks the way it does from our perspective. And the weak anthropic principle is much more useful than that. When combined with the apparent absence of alien civilizations, it may tell us why intelligent life is incredibly rare in our universe. Hosted by Matt O'Dowd Written by Matt O'Dowd Graphics by Leonardo Scholzer & Adriano Leal Directed by: Andrew Kornhaber Executive Producers: Eric Brown & Andrew Kornhaber End Credits Music by J.R.S. Schattenberg: https://www.youtube.com/channel/UCRl6-nb4iOnsij-vnpAjp0Q Special Thanks to Our Patreon Supporters BIg Bang Supporters: Alexander Tamas David Barnholdt David Nicklas Fabrice Eap John S Juan Benet matt miller Morgan Hough Quasar Supporters Mark Heising Mark Rosenthal Vinnie Falco Hypernova chuck zegar Danton Spivey Donal Botkin Edmund Fokschaner Hank S joe pearce John Hofmann John R. Slavik Jordan Young Joseph Salomone Mathew Matthew O'Connor Syed Ansar Gamma Ray Burst A G Adrian Hatch Adrien Molyneux AlecZero Andreas Nautsch Bradley Jenkins Brandon labonte Dan Warren Daniel Lyons David Bethala DFaulk Frederic Simon Geoffrey Short Graydon Goss Greg Smith James Flowers John Funai John Griffith John Michael Kerr John Pollock John Robinson Jonathan Nesfeder Joseph Dillman Josh Thomas Kevin Lee Kevin Warne Kyle Hofer Malte Ubl Nick Virtue Nick Wright Paul Rose Scott Gossett Sean Warniaha Tim Stephani Tonyface Yurii Konovaliuk