3 ms·

How far away would one have to be before human radio signals would simply blend in with the background noise?

• topspin 5y ago
  This[1] page claims that cold war military radar systems would be prominent for "hundreds" of light years, as opposed to earlier, lower power signals. Since these have only been running for approximately 60 years the diameter of the sphere in which these signals exist is only about 0.1% of our galaxy. So the real limit for the foreseeable future is the speed of light. [1] https://www.sciencefocus.com/space/how-far-from-earth-could-aliens-detect-our-radio-signals/ https://www.sciencefocus.com/space/how-far-from-earth-could-...
  • clankyclanker 5y ago
    Those Cold War systems have since been replaced with much more efficient systems that don’t just spew signals into space, so there’s only a ten or twenty year window during which another civilization could have looked to see those signals. Since then, we’ve become much quieter because signals that can be detected hundreds of light years away are expensive and not necessary for a specie that lives within an 8 minute light radius.
    • fogihujy 5y ago
      Right, so if another species does what we do, then we'd be lucky if we were inside the 200 ly radius of them at a time where they sent enough signals for us to notice?