>>12581353Well there are the arguments about dyson spheres, how fast you can colonize the galaxy, how life tends to expand etc. etc. that if valid, at the very least makes it very unlikely we could hope to detect any sign of intelligent ET in our galaxy or nearby ones, since if there was any it should be very obvious and we should've noticed by now. The observable universe is however very huge, and it wasn't very clear to me how big part of the universe we can pretty much rule out for having intelligent ET, or the kind we have any decent chance of finding anyway. So it didn't seem to rule out finding technosignatures very far away. But recently Robin Hanson has posted on this subject on his Overcoming Bias blog and seems to have come to the conclusion that we should see expansive alien civilizations either as very huge regions or not at all, and that looking for smaller areas of expansionist aliens very far away that we could have missed is pretty much pointless. Very disappointing.
