h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

SETI is a lot of fun but what if we find eti and they turn out to be a plannet of hungry big things with 2 mouths that come here looking for food and find only humans and other good things to eat. We may have to eat them! and all that searching for nothing.

One problem that SETI must be thinking about is "Do they have a radio, Do they care?" As a world we have had technology for the most shortest time imaginable. On a cosmic scale, if there was life on an other planet that evolved from the same "big bang" that created us, they would be at the same level of technology as us. 200 years ago we did not have a radio, neither did they. So if they live on the other side of the galaxy then a signal sent by "them" would reach us in around a thousand years or so. But if they live on the other side of the universe, we will over take our signal to them when we go look for interesting curios. Lets hope they are friendly and understanding when we meet them.

The fact that they might have sprung forth from the same big bang, doesn't mean their evolution is at the same point as hours. We might be a bit slow in comparison to them. After all, billions of years have passed since that event; what is a million years on such a huge timescale?

So they might have evolved to our "intellectual standard", say, a million years ago. They may have been sending signals that will soon reach us, and when we investigate, we find them long gone.
Or maybe they are just now evolving into the cave-dwelling apes we once were. In that case, they may be ready to understand our signals in about 100.000 years from now.