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Radio communication from the galaxy's far side?

  1. Sep 25, 2012 #1
    Is it at all possible for radio communication to travel from the obscured part of our galaxy to Earth? If so, about how long would it take to reach us?

    I have an idea for fiction where we're able to receive communications from the far side of the Milky Way, but we can't figure out how to communicate back, and the pursuit of trying to communicate back divides people and so forth. However if it's completely impossible in the realm of physics to receive communications from the far side of the galaxy, I'll have to rethink the idea.

    Note: I have little to no scientific background. Sorry, I'm working on it, though I have math-related disabilities.
     
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  3. Sep 25, 2012 #2

    mfb

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    We are ~25000 light years away from the galactic center, if the sender has the same distance (but in the opposite direction) it takes ~50000 years per direction.

    I don't know about the absorption, but if you want 1-way communication, you can use a different technology level: Assume that the sender emits a real powerful signal, and we cannot reach a comparable intensity yet.
     
  4. Sep 25, 2012 #3

    Ryan_m_b

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    The hydrogen line is regarded as being a good candidate for interstellar communication but as has been pointed out any message is going to take tens of thousands of years to get there and an equal time to get back.
     
  5. Sep 25, 2012 #4

    phyzguy

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    The dust in the galactic plane scatters radiation, but the amount of scattering is proportional to the fourth power of the frequency. This means short wavelengths like light are heavily absorbed, but longer wavelengths like radio propagate through the dust without being significantly absorbed or scattered. So yes, radio waves can travel to Earth from the far side of the galaxy. As others have said, it will take 25,000-50,000 years, depending on where it is coming from.
     
  6. Sep 25, 2012 #5
    Thanks for the answers so far, very heartening to know this is in the realm of possibility. 50,000 years in the grand scheme of things isn't too terribly long.

    This is a little above me but thanks, I understand the underlying concept. I was also lead to an article about the Pioneer Plaque which sort of blew my mind a second time. I never asked how we could communicate to outside intelligent life about where we're located, but that exact question occurred to me earlier today. Question answered.

    That's great. I thought that was impossible. But to my understanding viewing the obscured part of our galaxy is impossible, right?
     
  7. Sep 26, 2012 #6

    mfb

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    In terms of evolution of the universe and life, it is short. In terms of human technology, it is extremely long.
    50000 years ago, our ancestors used stone tools and invented gods for thunder and lightning, as they had no idea how to explain it otherwise.
    We can receive radio signals for less than 100 years now, and laser signals for less than 50 years (if we look at the right frequency and in the right direction).
    Every 10 to 20 years, new telescopes are so much more powerful that the older ones are not competitive any more. At the same time, computing power increases by a factor of ~30-1000.
     
  8. Sep 26, 2012 #7

    phinds

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    If by viewing, you mean looking with your eyes, then yes. If by viewing, you mean using instruments in other frequencies, then not necessarily.
     
  9. Sep 26, 2012 #8

    phyzguy

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    Right. For example, infrared telescopes are capable of seeing through the dust and imaging the starts at the galactic center. This could count as "viewing".
     
  10. Sep 26, 2012 #9

    Ryan_m_b

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    Just to add to this our species is only 200ky old.
     
  11. Sep 26, 2012 #10

    phinds

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    I think astronomers would take issue with "could".
     
  12. Sep 26, 2012 #11

    Drakkith

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    I'd say so. I know I count it as "viewing".
     
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