Why We are Alone in the Galaxy | Marc Defant | TEDxUSF
15:19
Where Are All The Aliens? | Tim O'Brien | TEDxOldham
17:59
What if Everything You Know is Wrong: Bob McDonald at TEDxVictoria 2013
16:06
Cosmology and the arrow of time: Sean Carroll at TEDxCaltech
11:26
Why the majority is always wrong | Paul Rulkens | TEDxMaastricht
17:58
The Exploration and Colonization of Mars: Why Mars? Why Humans? | Dr. Joel Levine | TEDxRVA
15:57
Are We Alone? When Will Earthlings Find ET? | Dan Werthimer | TEDxSFState
24:02
Is Time Travel, Especially Into the Past Possible? | Matt Szydagis | TEDxSchenectady
19:26