I've sometime wondered if intelligent alien species produce a large amount of radio frequency emissions. In 1961, one of man's defining characteristics was radio broadcasting with powerful transmitters that operated with omnidirectional antennas that radiated in all directions, including into space. Today though, that is slowly going away in favor of data transmitted by fiber-optics and low-power microwave transmissions sent with directional antennas between satellites and ground receivers. This radiation would be much harder to detect at interstellar distances. Some day broadcast radio and TV will go the way of long-distance shortwave transmissions (who isn't a cable-cutter anymore?), and the emissions from each will drop massively. We'll only have been a bright radio frequency emitter for maybe 150 years, the tiniest almost immeasurable fraction of time out of the age of the universe. We can probably assume the same for other technological civilizations, the only ones that leak radiation would be those trying to be found. Would they want to be found? Many people have suggested that we don't want to be found for fear of what aliens might do to us. That would leave infrared radiation (waste heat) from a large industrial society that might be detected. That would be hard to find, and it assumes that aliens have industry on a massive scale, which produce enough waste heat to be distinguishable from their sun. We can't assume that. Alien civilizations could be very hard to detect unless they are trying to be found. They might be hiding all around us.
We'll only have been a bright radio frequency emitter for maybe 150 years, the tiniest almost immeasurable fraction of time out of the age of the universe.
Very interesting point! I never considered this before. It's almost kind of sad to imagine a bright flare up of radio transmissions in the dark void of space that then falls silent. It's interesting to consider that at least in our timeline of development such transmissions probably peaked during the cold war. The decline of radio transmissions could either indicate progress towards better communication methods or perhaps that the civilization destroyed itself. Not that we're out of the woods yet!
Alien civilizations could be very hard to detect unless they are trying to be found. They might be hiding all around us.
I like these points. Civilizations about where we are are putting out limited signals for a limited time. Before and after it could possibly diminish, making discovery less likely.
What I'm curious about is if we could even unify enough to make a decision on whether or not to be discoverable. It may be that we diminish our signals/emissions incidentally so the decision gets passively made. I wish we could get to a point where we unify enough to actively make that decision.
That is certainly true, but if they are very far behind us, they don't have the technology for radio transmissions yet, so we won't find them via radio telescope any more than we will find aliens who no longer use powerful broadcast transmitters. There's probably just a few hundred-year window where communication in this form will be attractive to a species
I've sometime wondered if intelligent alien species produce a large amount of radio frequency emissions. In 1961, one of man's defining characteristics was radio broadcasting with powerful transmitters that operated with omnidirectional antennas that radiated in all directions, including into space. Today though, that is slowly going away in favor of data transmitted by fiber-optics and low-power microwave transmissions sent with directional antennas between satellites and ground receivers. This radiation would be much harder to detect at interstellar distances. Some day broadcast radio and TV will go the way of long-distance shortwave transmissions (who isn't a cable-cutter anymore?), and the emissions from each will drop massively. We'll only have been a bright radio frequency emitter for maybe 150 years, the tiniest almost immeasurable fraction of time out of the age of the universe. We can probably assume the same for other technological civilizations, the only ones that leak radiation would be those trying to be found. Would they want to be found? Many people have suggested that we don't want to be found for fear of what aliens might do to us. That would leave infrared radiation (waste heat) from a large industrial society that might be detected. That would be hard to find, and it assumes that aliens have industry on a massive scale, which produce enough waste heat to be distinguishable from their sun. We can't assume that. Alien civilizations could be very hard to detect unless they are trying to be found. They might be hiding all around us.
Very interesting point! I never considered this before. It's almost kind of sad to imagine a bright flare up of radio transmissions in the dark void of space that then falls silent. It's interesting to consider that at least in our timeline of development such transmissions probably peaked during the cold war. The decline of radio transmissions could either indicate progress towards better communication methods or perhaps that the civilization destroyed itself. Not that we're out of the woods yet!
Of even among us! 👽
I like these points. Civilizations about where we are are putting out limited signals for a limited time. Before and after it could possibly diminish, making discovery less likely. What I'm curious about is if we could even unify enough to make a decision on whether or not to be discoverable. It may be that we diminish our signals/emissions incidentally so the decision gets passively made. I wish we could get to a point where we unify enough to actively make that decision.
This premise assumes all alien civilizations are more advanced than we are.
That is certainly true, but if they are very far behind us, they don't have the technology for radio transmissions yet, so we won't find them via radio telescope any more than we will find aliens who no longer use powerful broadcast transmitters. There's probably just a few hundred-year window where communication in this form will be attractive to a species
Very interesting.