If there is intelligent life why can't we detect it?

Discussion in 'Astronomy, Exobiology, & Cosmology' started by trevor borocz johnson, Dec 7, 2015.

  1. trevor borocz johnson Registered Senior Member

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    If there is intelligent life in a solar system within ten thousand miles, and they have been using the stratosphere to communicate radio waves for long enough that they have started to reach us, why aren't we able to point telescopes at their source and focus in on the broadcast after all radio waves are energy can't they be focused like any other energy?
     
    danshawen likes this.
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  3. Dywyddyr Penguinaciously duckalicious. Valued Senior Member

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    Within 10 thousand miles?
    Less than 5% of the way to the Moon.
    Do you have any idea what you're talking about?
     
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  5. exchemist Valued Senior Member

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    Rhetorical?
     
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  7. origin In a democracy you deserve the leaders you elect. Valued Senior Member

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    Ignoring all of the inaccurate clutter in your OP the reason that we have not detected any radio waves from another civilzation (assuming one exists and is broadcasting) is that the signals would be way too weak to detect with our current technology.
     
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  8. trevor borocz johnson Registered Senior Member

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    10,000 light years*
     
  9. spidergoat Liddle' Dick Tater Valued Senior Member

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    You can't just focus on something 10,000 light years away and get an instant result. You would have to wait 10,000 years.
     
  10. trevor borocz johnson Registered Senior Member

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    ok, but say the alien culture has been using radio signals for the past 20,000 years, we would be able to pick up the signal from ten thousand years ago right now here on earth? maybe its because of their advanced culture to ours they don't glorify celebrities with t.v. or radio. Or use some other advanced technology that doesn't use radio waves.
     
    Last edited: Dec 7, 2015
  11. Russ_Watters Not a Trump supporter... Valued Senior Member

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    The Aricebo message was sent toward M13, which is 25,000 light years away.
    https://en.m.wikipedia.org/wiki/Arecibo_message

    That's about the limit of our detection range, but only under highly unusual circumstances. For normal broadcast signals, the detection range is much shorter. So yes, there could be other intelligent life relatively nearby and we might not know.
     
  12. danshawen Valued Senior Member

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    The path loss for any distance greater than about 10 light years is -341.5 dB see:

    http://www.qsl.net/pa2ohh/jsffield.htm

    Arecibo is a 305 meter antenna has a microwave gain of about 50, so any signal attenuated 300 dB more than the gain of the antenna is still a very long way into the region of noise. Unless the signal was spot beamed by ET directly at us with a gain profile suitable to offset such a large path loss, it would make recovery of any such signal(s) unlikely in the extreme. There are limits to the sensitivity and selectivity of radio telescopes.

    The Byrd radio telescope at Greenbank, a 100m dish, is the largest steerable radio telescope (and also largest movable object) in the world, refurbished after a windstorm wrecked the supporting structure of the original telescope by the late, great COMSAT corporation of which I was an employee for 22 years.

    https://en.wikipedia.org/wiki/Green_Bank_Telescope

    Budget cuts in 2013 threatened to close the facility, but I didn't see a follow up article saying it had closed, so I guess it is still funded.

    The gain of this antenna will not be as great as for Arecibo, obviously, but it has sufficient selectivity and sensitivity to its designed purpose, which is radioastronomy, not searching for signals from ET.
     
  13. billvon Valued Senior Member

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    We can! We regularly receive radio waves from the space station, which contains intelligent life and is within 10,000 miles (250 miles, actually.)
     
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  14. DaveC426913 Valued Senior Member

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    Trevor, what are you asking? Are you asking if we should have received messages, or are you asking if, since we haven't we should deduce there are isn't anyone out there?
     
  15. trevor borocz johnson Registered Senior Member

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    I'm just trying to get answers to what we are already trying to do and how's it working. I have an invention I'm working on that could be an improvement to technology and I want to know how the current efforts are going to pick up radio waves?
     
  16. Daecon Kiwi fruit Valued Senior Member

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    What invention would this be?
     
  17. Fraggle Rocker Staff Member

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    Ten thousand miles? You must be joking. As was already noted, the Moon is two hundred thousand miles from Earth!

    Venus is the nearest planet to Earth, and when the two are at their closest, they are still twenty-five million miles apart.

    The distance to the nearest star is measured in light-years. One LY = six trillion miles.

    Worse yet, the nearest star that might have a planet whose environment could support life is about ten light years away.
     
  18. exchemist Valued Senior Member

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    Here we go..........
     
  19. Sarkus Hippomonstrosesquippedalo phobe Valued Senior Member

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    I'll wait to see the CAD of the paper cups and string ensemble before passing judgement.

    Please Register or Log in to view the hidden image!

     
  20. exchemist Valued Senior Member

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    No, his style is more Dr Strangelove - the underground cavern and nuclear bomb sort of scale. Maybe we could string a cable between the Earth and Mars.............
     
  21. billvon Valued Senior Member

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    You had to go and ask, didn't you . . . .
     
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  22. Little Bang Registered Member

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    I think life in the Universe is like fire flies in the night, you never see two at exactly the same time.
     
  23. Little Bang Registered Member

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    Intelligent life.
     

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