5 ms·

There's one simple metric for SETI progress that I would like to see and have always had trouble finding. What is the radius within which SETI can exclude the

There's one simple metric for SETI progress that I would like to see and have always had trouble finding. What is the radius within which SETI can exclude the existence of a civilization currently using Earth-like electromagnetic communications technology and how many star systems are believed to lie within that radius ? How will proposed SETI efforts expand that radius ? I think this is kind of a key metric that could tell us a lot about how widespread technological civilizations might be in the galaxy.

Dominisi 7y ago
The issue with using general "Earth-like electromagnetic communications technology" is the inverse square law. Our own communications aren't distinguishable from the cosmic background radiation even at our closest neighbor. The only way we would find something is if they pointed a VERY powerful noise source directly at us, or us at them. And even then, we are looking at maybe a 100 lightyear bubble (~600 main sequence stars).
- tgflynn 7y ago
  > The only way we would find something is if they pointed a VERY powerful noise source directly at us, or us at them. Do you mean we could detect ordinary technological EM radiation if we pointed a sufficiently high-gain antenna at the transmitting planet ? Otherwise if SETI assumes someone is sending an interstellar signal on purpose, I would question its value, because there's no strong reason to think anyone is doing that. I realize we did it once, but an argument can be made (and has been) that it was a fairly stupid thing to do.