Originally posted by whodey
Should we seek them out or hide from them?
Here is what Stephen Hawking said about the idea.
He seems to think it would be like Columbus meeting the Indians, so we should be wary.
An unlikely scenario in the extreme, since nothing has been detected anywhere 'near' Earth and so an advanced civilization would statistically be thousands of light years away, maybe even in Andromeda galaxy rather than our own Milky Way.
Another issue I don't see people bringing up:
Suppose we knew how long the average civilization lasts at a high techno level, like ours today or stronger.
So suppose we figure out we have a smaller and smaller chance of that civilization being around some number of years in the future.
So for Earth, just going out on a limb here, say that number is 500 years or so, hell lets go all out and say 1000 years.
So we have radio for 1000 years and our signals therefore in 1000 years will cover a sphere 2000 ly across. So suppose at the thousand year mark, our civilization poops out, stops transmitting. We would then have an outgoing wavefront of radio/TV electromagnetic signals 1000 light years deep going out into the galaxy.
Ok, now supppose there is another civilization say 10,000 light years away from us in our own galaxy.
Suppose further that civilization does its own 1000 year cycle but 3000 years ago from our time frame. So ITS 1000 light year deep wavefront charges out into the galaxy and what happens? Both of our signals meet life forms incapable of recieveing signals, us say 3000 to 4000 years from now when the alien signal would get here. And from us our 1000 ly thick wavefront will pass them by with them never having a radio capaple of picking us up. So it's like ships passing in the night but in a fog bank, neither one of us will ever know the presence of the other civilization. So extend that to opposite ends of our own galaxy, say 100,000 light years apart. Now aliens may be separated in time by nearly that amount of time and our signals bounce around in the galaxy theirs reaching us when we were say, back in the stone age or maybe 100,000 years in OUR future when we maybe have advanced past the need for radio waves and therefore are radio silent for another reason.
Maybe most of any possible alien signal does the same, the result, we can listen for 1000 years and maybe encounter absolutely nothing.