Richdog said:
Quite possibly, but don't forget about what you just said about how old the universe is. It's likely that other civilisations may not even be passed a sort of prehistoric age yet. Others may of died out 2 billion years ago.
There are two factors that attribute to the likelyhood of an alien race visiting our planet.
1.) The aliens would have to own extremely sophisticated technology, with the ability to survive on a spacecraft for many many years, have the ability to travel at the speed of light, or have somehow created another form of interstellar travel.
All possible, but occuring within a decent distance from Earth? Highly unlikely.
2.) The alien race that visit us must be within the same timescale as us. There is a good chance that a few planets within 10 light years of Earth, can harbor life. But they would need to be on a similar evolutionary scale as us. That's two civilisations existing in the same era amongst billions and billions of years. Again, the odds are massive.
It's possible, because the theory is there. But the actual odds of it happening are colossally stacked against us. The distances are so vast, the time scales are so huge, it overshadows the feasibility IMO.
).
(And yes, they are real). Occasionally indisputable proof was captured on video of a UFO. Bright lights flitting around the sky with more maneuverability and speed than any aircraft humans had ever built. What these people didn't know, and what I mentioned above, was that there was a twelve year lag between what the government could build and what the public knew about. These 'UFO-gazers' were simply catching a glimpse of next generation U.S. military aircraft being developed out at Area 51. Of course intelligence officials would never correct the mistake. It was obviously preferable that the world read about another UFO sighting than to have people learn about the U.S. military's true flight capabilities.