Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

How far away could we detect ourselves?

  1. Feb 14, 2009 #1
    If we were an alien species withe a SETI program, with exactly the same technological capabilities, how far away could we be and still detect an Earth signal that would register as intelligent life? (ignore the travel time, assume all signals have had enough time to get as far as they can, obviously if the first signal we emitted was a year ago the answer would be one light year) If the answer is longer than when we emitted the signal, when would that signal be detected by this race?
  2. jcsd
  3. Feb 14, 2009 #2


    User Avatar
    Homework Helper

    This is off the cuff form memory of something I heard in a talk time ago, the point was that at radio frequencies our chatter outshines the Sun, and it could be detected at the other end of the galaxy with roughly our present level technology.
  4. Feb 14, 2009 #3
    I am asking because I thought I heard somewhere that all our signals were lost in the noise not too many light years away, less than a few hundred.
  5. Feb 14, 2009 #4


    User Avatar
    Science Advisor

    The most powerfull signal we've ever sent was a special http://archive.seti.org/seti/seti-background/arecibo.php" [Broken], and would be detectable by a SETI program like our own from the other end fo the gallaxy.
    Last edited by a moderator: May 4, 2017
  6. Feb 14, 2009 #5
    Depends on the bread. :) And it's petroleum. And I don't think a one time event counts. The chances of our SETI program picking up a one time event are slim to none. I am talking about repeated events, normal traffic.
    Last edited: Feb 14, 2009
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook