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How WMAP satellite surveyed all over observable universe

  1. May 12, 2012 #1

    what i want to know is how much area of universe (in light years if possible) is surveyed by WMAP .when you say CMB permeates entire universe based on data from these satellites orbiting earth how much of universe is actually surveyed by WMAP ?

    if you survey around where we are now in this universe you'd see more matter than anything else..so how physicist say all those quoted above

    the farthest we seen of universe is with hubbles' Ultra deep field image / how can WMAP satellite detect the temperature of thermal radiation over HUDF with incredible accuracy
  2. jcsd
  3. May 12, 2012 #2
    I think it surveyed the Cosmic Microwave Background Radiation to get that image, which shouldn't be too hard, as we have constant exposure to it.
  4. May 12, 2012 #3
    hi whoian

    CMB is said to permeates all over universe ?Does WMAP surveyed all universe :eek:

    also the other facts quoted above 4% thing ?

    any idea
  5. May 12, 2012 #4


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  6. May 12, 2012 #5


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    The radiation that WMAP detected has propagated through the entire observable universe before reaching us. As time passes we detect radiation that was emitted further away from us initially at the time of recombination when it was emitted.
  7. May 13, 2012 #6


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    If you "look", you only see matter which interacts with photons. Dark matter and dark energy don't do that, therefore we cannot see them directly.

    The CMB observed by WMAP comes from regions (in every direction of space) which are ~45 billion light years away from us now. This is larger than 13.7 billion, as space expanded between these positions and us in the last 13.7 billion years.
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