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Measure the speed of earth in universe

  1. Jun 26, 2012 #1
    suppose an electrostatic sphere and an very sensitive magnetometer are placed in a space that has magnetic field outside been screened ideally. Can we know the speed of the earth transverse in the universe by dealing with the data obtained?
     
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  3. Jun 26, 2012 #2

    sophiecentaur

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    I thought it was established that there is no real meaning to 'speed in the universe'. All motion is relative. Michleson and Morley (1887) did a famous experiment to determine our speed through the 'aether' and detected nothing. Afaik, no one has proved otherwise.
     
  4. Jun 26, 2012 #3

    phinds

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    It is already known that we are moving with respect to the CMB, which is about as close as one could reasonably get to any definition of "speed in the universe", and that speed is pretty well known. In any event it is of no consequence that I am aware of.
     
  5. Jun 26, 2012 #4

    sophiecentaur

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    Which direction?
     
  6. Jun 26, 2012 #5

    sophiecentaur

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    370km/s in the direction of Leo, apparently, is what the doppler shift indicates. But what does that actually mean? See this link from some while ago, on PF.
     
  7. Jun 26, 2012 #6
    Hi welcome to physicsforums! :smile:

    Such experiments were done in the late 19the century and no effect was found at all. That led to the conclusion that the relativity principle must also be valid for electromagnetic effects - thus no "absolute velocity" can be measured. And from that emerged the Lorentz transformations and special relativity.
     
  8. Jun 26, 2012 #7

    phinds

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    As I said, I don't think it has any significance. I mean, it is a physical fact, but it has no practical consequences.
     
    Last edited: Jun 26, 2012
  9. Jun 26, 2012 #8

    sophiecentaur

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    I agree.
     
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