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Cosmic microwave background radiation

  1. Oct 14, 2009 #1
    The fact (simplified) is that our planet is rotating arount the Sun, also our solar system is rotating... Is there available information on direction of CMBR in relation to our planet or to our solar system? THX

    foun answer myself

    Re: does the cosmos have direction?


    There is no sense of "universal direction" at all. You are welcome to use the plane of the Earth's rotation to define the perpendicular direction "up." You're also welcome to use the plane of the Earth's orbit, which is 23.5 degrees different. Or the plane of Sun's orbit around the Galaxy, which is again different. Or the plane of the Galaxy.

    You get the idea. There's no preferred direction. There's also nothing different about radio waves, etc. that could be used to
    specify one.

    Let's start all over again. Is CMBR in one direction or many?
    Last edited: Oct 14, 2009
  2. jcsd
  3. Oct 14, 2009 #2


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    Yes. An asymetry is detectable in the CMBR.

    This doesn't appear to have anything to do with your previous question, though. Perhaps you could elaborate on what you are asking and how you are trying to connect the two.
  4. Oct 15, 2009 #3
    There is an asymmetry in frequency. Also there should be some reflections, but shouldn't CMBR have one general direction?
  5. Oct 15, 2009 #4


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    The CMB is extremely homogenous in every respect and in every direction. Reflections are irrelevant, they cancel out. Why would you expect it to have directionality?
  6. Oct 15, 2009 #5
    I expect it to have directionality probably because I don't have enough information. Just asking is there some detailed information, links, numbers...

    Last edited: Oct 16, 2009
  7. Oct 16, 2009 #6


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    Last edited by a moderator: May 4, 2017
  8. Oct 16, 2009 #7
    Thanks mr. Chronos, the answer was there, and it is:
    By measuring the amount of the dipole anisotropy (the bluest part of the sky is .0033 K hotter than average), we can determine the magnitude of the earth's motion with respect to the CMB: the earth is moving at a speed of 370 km/s in the direction of the constellation Virgo.
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