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Question about Cosmic Background Radiation

  1. Feb 18, 2014 #1
    I was wondering what experiments or observations have shown that the cosmic microwave background radiation exists outside our galaxy in intergalactic space. Have we detected it emanating from sources outside the galaxy? I know we've detected it here on Earth.
  2. jcsd
  3. Feb 18, 2014 #2


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    Upon its discovery, circa 1965, the CMB was observed come from every direction with the same intensity, without diurnal or seasonal variations. On this basis, scientists concluded the signal had to originate outside our Galaxy. Further study showed it had a perfect blackbody spectrum, ruling out diffuse star light as the source.
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