"<a href=""https://www.youtube.com/watch?v=Gfr50f6ZBvo&amp;t=1h29m01s"">1:29:01</a> I'm a little bit surprised by Dennis' logic there. 1) our current methods of detecting life are very limited and we've yet to only find a few dozen earth-like exoplanets out of potentially billions", 2) even our own mark on the galaxy is so very small (200 years of radiowave propagation is still a tiny speck of Milky Way), 3) there might be some unavoidable conclusions in physics and technological development that would quickly obsolete radios or anything as crazy as a Dyson sphere. so instead of Great Filter the issue could just as well be a Great Booster, even if intelligent alien life could be detectable with classical instruments during some part of their evolution that window isn't necessarily so long. I'm sure sending probes would still be useful for study purposes but would there be anything to gain by engaging with some primitive lifeforms? "cultural exchange" is a popular scifi trope but once you have AI to generate anything you want the idea of novel cultural products could lose a lot of it's appeal.