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Why does the cosmic microwave background make a noise

  1. Sep 13, 2012 #1
    For about the 7th time I've been told the story of how Penzias and Wilson discovered a noise the source of which they could not detect. It turned out to be the CMB. Well, why should the cmb make a noise? It's just photons in the microwave spectrum.
  2. jcsd
  3. Sep 13, 2012 #2


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    When you turn on an AM/FM radio, what you're picking up is just photons in the radio spectrum. All they did was build a 'radio' for microwave photons.
  4. Sep 13, 2012 #3
    Thanks, I understand
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