Very interesting point that extraterrestrials may not be emitting anything we can detect, either. Oh well.
It doesn’t really make any sense that they would be using radio. Space is radio signal noisy.
I always had the vision of us scanning the horizon with binoculars looking for smoke signals while the aliens are transmitting digital radio.
The Star Trek universe had a race of beings on a planet orbiting Alpha Centauri, which was roughly at the same technological stage we are, except that at some point, they developed a paranoid streak, so all their communication and entertainment was through landline, and most of their civilization was underground, thus explaining why we never saw or heard of them. Except for the underground thing, we’re pretty close to that as well. A lot of the news and entertainment we consume these days travels across the internet instead of the air, and what little we still push through the air is of such low wattage that it may not be making it past the ionosphere.
I wonder if this guy has any idea how much of a signal an air search radar puts out? Every time a carrier battle group goes to active scanning this planet lights up in the radio spectrum quite nicely.