The Fermi Paradox has been where the aliens could be for years. No answers yet.
Where are they?
The Fermi paradox says that scale of the universe and simple probability indicate that intelligent life should be common in our galaxy and beyond. But, as far as we can tell, it’s not.
All life seeks to expand. We did this by colonizing new habitats on Earth. Many of us hope that in the future, we’ll go on to colonize our own galaxy, and, subsequently, the surrounding star system. Using technology that’s is almost within our reach, it would probably take us about five to fifty million years to colonize this galaxy. That seems kind of slow, but it’s a short time on the cosmological scale. If we could do it, why isn’t there evidence that someone else did it too?
We should also note that we got to the moon and then, inexplicably, stopped and went back home. If other civilizations stalled in similar ways, they might not have travelled far. But at least we’ve sent probes out, like Voyagers 1 & 2. The least adventurous forms of intelligent life out there would also have left some evidence of their existence.