Back in the 50s, during the flying saucer craze, a bunch of nuclear physicists were sitting around the lunch table at Los Alamos, discussing current events.
Curious and speculative creatures that they are, they wondered whether intelligent life existed out there in the universe?
Naturally, the pens and pencils came out, napkins and table clothes were scribbled upon, guesses were posed, assumptions and suppositions quantified, equations formulated, numbers calculated, and the answer turned out to be "Yes".
Not only was the answer yes, there are aliens out there, but yes, there should be a LOT of aliens out there, and they should have visited us by now.
And so one physicist, by the name of Enrico Fermi, aksed the question "Where are they?"
That's Fermi's paradox. Given the age of the universe, the appropriate number of stars and planets that could harbor Life (and not necessarilly our kind of Life), the (supposedly) inevitable evolution of intelligence, and from that a development of technology, then aliens should be all over the fricking place. But they are not. Where are they?
Hundreds of explanation have been offered. Ranging from:
- We Earthlings are too primitive/violent/creepy/icky for contact
- We Earthlings are the first race so far
- The aliens are really, really, really far away
- They are here, in disguise
None of these explanations are completely satisfactory for one reason or another. Let's ignore the fact that the whole issue is question begging anyway. We have only one example (if you are liberal and tolerant enough to grant humanity this) of intelligent life. There's no reason that aliens have to be like us. None whatsoever.
But I've figured out the answer. Ready? Shh. Come close and I'll whisper it to you.
Yeah, that's why they ain't around. Paradox solved. Once you have time travel, you are God. You can do anything you want, go anywhere you want, know anything and everything, change anything and everything. Whoever invents time travel first, gets to be God.
So, sometime in the future, people can travel in time. And all those aliens? We got rid of them all.
Or, more probably, they got rid of us.