To date, there has been zero evidence of extraterrestrial life. There has not been one verifiable, uncontestable shred of evidence in favor of their existence. However, logic would indicate that otherworldly civilizations would be everywhere. This is known as the Fermi paradox. We are, of course, looking for them. Organizations such as SETI, the Search for Extraterrestrial Intelligence, listen to radio signals from far-off stars in the hopes that one of them might be artificial. Nothing yet. Contact with aliens will have tremendous ramifications for mankind. Even if microscopic bacteria are discovered somewhere other than Earth, it will be the single biggest scientific discovery of the past half-millenium. An advanced alien civilization will challenge mankind's beliefs about himself, his universe and his god. Discuss. My own opinion is that aliens almost certainly do exist, but contact will always be impossible, at least in the forseeable future, due to the unimaginably large expanses of interstellar space.

The Universe if infinite, there fore we can state that there are an infinite number of worlds, however since every world is not inhabited it can be said that there are a finite number of inhabited worlds. any finite number averaged against infinity is zero so the entire population of the universe can be said to be zero. Thus everyone you meet is just a passing delusion of your derganged mind