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Anywhere where it's all black ?

  1. Jan 10, 2009 #1
    Hello to all !,

    given our current physics and cosmology theories and understanding of the universe, could there be an 'open space' location from where we could not see any light, as faint as can be, coming from distant galaxies or light source ?... pitch black all around us...


    regards,

    VE

    Edit: actually, if the answer is yes, than can we expand the 'blackness' to any and all currently measurable radiation ?
     
    Last edited: Jan 10, 2009
  2. jcsd
  3. Jan 10, 2009 #2

    mathman

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    Short answer - no. As long as there are no obstacles to light or radiation, it will continue to travel. For example, the cmb can be detected in all directions.
     
  4. Jan 10, 2009 #3
    Thank's for the reply,

    so then, am I right in stating that, given what we presently know, we can safely say that empty space does not exist ?


    VE
     
  5. Jan 10, 2009 #4

    turbo

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    Space that is "empty" of EM radiation cannot exist within our understanding of the universe. There will always be EM suffusing it, no matter where you are. Even if you dug a deep cave in the Earth and hid in that, particles (neutrinos) would be zipping through you day and night. No place to hide.
     
  6. Jan 10, 2009 #5

    Chalnoth

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    Certainly not now. Evolve the universe forward some 10^100 years or so, and it will be effectively completely empty (note: the actual timeframe depends upon the exact nature of physics which we don't yet understand, but the fact that it will happen we can be reasonably confident about). See here:
    http://en.wikipedia.org/wiki/Future_of_an_expanding_universe
     
  7. Jan 10, 2009 #6

    epenguin

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    Is this true? Doesn't there have to be a temperature difference as well as existence of radiation? If I, my instruments are at the same temperature as some other place there is no energy exchange between us, I can receive no signals or information from it even though there still is EM radiation? Nor send any. If there are places not like that, I could notice its presence by its absence IYKWIM. Sounds crazy at first, but doesn't every info we get depend on on a temperature difference? - a star or tungsten filament emits radiation which, maybe after reflection reaches us.
     
    Last edited: Jan 10, 2009
  8. Jan 10, 2009 #7

    Chalnoth

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    Right, which is why there won't be any regions in the universe that are entirely empty until the universe itself is.
     
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