Posted: Nov 13, 2010 8:34 pm
Yes, hackenslash made a good point. Consider a civilization just half the diameter of our own galaxy away from us, about 50k light years. They can't possibly know we are technologically advanced for at least another 50,000 years. By that time we'll be 50,000 years more advanced than they can see. Neanderthals were still alive.
Same for us looking for them. If they've been developing a technological civilization the last 40,000 years, then even if we had a telescope to see insects on the surface of their planet, we wouldn't see a technological civilization for another 10,000 years. From the perspective of the nearest galaxy, sapiens is not even within a million years of forming a separate lineage from the other primates yet.
The Fermi question is less about where than when.
Same for us looking for them. If they've been developing a technological civilization the last 40,000 years, then even if we had a telescope to see insects on the surface of their planet, we wouldn't see a technological civilization for another 10,000 years. From the perspective of the nearest galaxy, sapiens is not even within a million years of forming a separate lineage from the other primates yet.
The Fermi question is less about where than when.