Is It Irrational to Believe in Aliens?

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!

[via pbs]