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Red shift and observable light

  1. Aug 8, 2011 #1
    Since light emitted farther away from our point in the universe is more and more red shifted, would this mean that at a certain time we wouldn't be able to observe light further than a fixed distance since it's been red shifted beyond the electromagnetic spectrum?
     
    Last edited by a moderator: Aug 8, 2011
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  3. Aug 8, 2011 #2

    bcrowell

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    Yes. That's the edge of the observable universe. Every year, it gets several light-years farther out from us (not just 1 light-year, since space is expanding while the light is in transit).
     
  4. Aug 8, 2011 #3

    Chronos

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    Redshifted galaxies will become increasingly redshifted over time. They will never suddenly 'blink' out of view. Redshift is a continuous, not discrete, function.
     
  5. Aug 13, 2011 #4
    @Chronos Eventually it will be redshifted out of the electromagnetic spectrum though right?
     
  6. Aug 13, 2011 #5

    phinds

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    Ben, I guess I have another misunderstanding that I need you to clear up. I thought the edge of the observable universe was the place at which objects exist from which emitted light has had time to reach us based on their position and their speed of recession from us and that we couldn't see beyond that point because the photons from those objects is now traveling away from us due to recession faster than they are traveling towards us due to their local speed. Clearly my concept IS tied up with red-shift so I'm having difficulty formulating my question well (another sign that I'm obviously confused). I guess at heart my belief is that the edge of the OU is based on time, not redshift and my question is an amorphous "HELP --- please get me unconfused"

    Thanks.
     
  7. Aug 13, 2011 #6

    Chronos

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    The CMB will eventually move so far into the 'red' it will be cease to be detectable, but, never leave the EM spectrum.
     
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