Originally Posted by OccultHawk

Well we do know that we haven't seen or heard a peep.



If the Drake equation is correct there should be about 20,000 potentially observable civilizations in the Milky Way.

As far as other galaxies go we can see back for billions of years. There could be radio waves or other sorts of indicators of intelligence that's moving at light speed and still a million years away, yes. But the fact there's absolute silence (to our ears, admittedly) means, obviously, that there's no civilization that we've been able to detect from any time window.

Sagan would be disappointed but maybe not really that surprised. He described humanity as alligators with nuclear weapons.

And TH mentioned Hawking. Hawking is extraordinarily pessimistic about our ability to survive. He also thinks "finding" alien life would likely end up being very bad news. He has suggested that if there are other civilizations more advanced they probably have to good sense to stay as hidden as possible. He thinks putting information on the Voyager about how to find us was stupid. More and more our methods of electromagnetic means of communication are from point to point on earth and not broadcasting through space at light speed. Some theoretical physicists hypothesize that moving inward is the natural progression for intelligent species and explain it that way. But to me, none of these explanations satisfies the paradox. Not even one single outlier. You can't get around that conveniently.