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Universe frame of reference

  1. May 12, 2015 #1
    Dear PF Forum,

    Again the same question about preferred frame of reference. I have read several threads in Physics forum, but I think this question belong to cosmology. And I have searched in Google and in PF forum threads, so, I'll ask some confirmation here.
    1. Does the universe have a preferred frame of reference?
    2. Some says it's CMB. Is it true?
    3. Is it aether all over again?
    4. If this is true, does the universe have coordinates?
    5. How does every atom, matter, energy and time in B rocket knows that it changes its inertial frame of reference?

    Thanks for any idea

  2. jcsd
  3. May 12, 2015 #2


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    2017 Award

    Staff: Mentor

    The universe is not a sentient entity. So far, all experiments confirmed that the laws of physics are the same in all reference frames up to the experimental precision.
    No, coordinates are a human invention. We can invent a coordinate system, based on an arbitrary reference frame (like the earth-based one used in your quote).
    Acceleration is detectable.
  4. May 12, 2015 #3


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    Gold Member

    Still, I would say it does in a way. The assumption is that the (very) large scale distribution of matter is approximately comoving, which means there is a shared "cosmological" time and this comoving matter defines a frame of reference, the CMB frame, with respect to which anyone can measure its own velocity.
    But this is no aether : what defines this frame is the matter in the universe, not some substance in between.
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