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A new interpretation of ether

  1. Aug 22, 2009 #1
    Here I try to explain what I read somewhere- that the speed of light has decreased over the last couple of centuries.
    If it is reported that the speed of sound is decreasing in a solid, you may say thatdue to continued vibrations and deformations of the solid, its modulus of elasticity has decreased.
    I think an explanation of the decreasing speed of light could be explained by a new interpretation of ether.
    As space expands, it expands the ether along with it so the polarizability of the ether decreases thus decreasing the speed of light.
    The rotating earth drags the ether so the MM shows null result.
    Completely crankish? Forgive
  2. jcsd
  3. Aug 22, 2009 #2


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    You probably read this in an article by a creationist, since they are the only ones pushing this idea as far as I know (this is one way they try to justify the fact that we can see stars that are much more than 6000 light years away despite the fact that they believe the universe was only created about 6000 years ago). You do see a few scientists speculating about the speed of light having changed over billions of years, but more technically they are talking about a change in the fine structure constant, since it really only makes sense to talk about a "change" in a dimensionless constant (see this article). And the evidence for this is definitely not widely-accepted.
  4. Aug 22, 2009 #3


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    The speed of light has not decreased measurably over the last couple of centuries. The fine structure constant depends on the speed of light. We can tell if the fine structure constant has changed by looking at the spectra of distant stars and galaxies. The light we get from a galaxy carries information about the galaxy at the time the light left. Since some of these galaxies are billions of light years away, we get information about the state of these galaxies as they were billions of years ago. The only hint of a possible change in the fine structure constant seen amounts to about change of 1 part in 100,000 over billions of years. If this were due to a change in the speed of light, the change over 200 years would be not measurable.

    Ether dragging has already been suggested as a reason for the MM experiment's null result. It was discarded because it was not compatible with the observation of stellar aberration. With ether and no drag you would get stellar aberration but a postive result from the MM experiment. Ether drag would give you a null MM result, but not the observed stellar aberration. What we get it both a null result and stellar aberration.
  5. Aug 22, 2009 #4

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    Also, independent of dc/dt, if ether were dragged along with the earth, it was shown by Airy in the 19th century that the predictions for stellar aberration would be different than what was observed.
  6. Aug 22, 2009 #5


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    It makes no physical sense to talk about the value of ANY dimensionful universal constant changing. The value of a dimensionful universal constant is simply an artifact of the units used to express it. The only universal constants with physical significance are the dimensionless ones.

    If c were double today what it was yesterday without a change in any of the dimensionless fundamental constants then we would not even be able to measure the difference with our most sophisticated instruments. On the other hand, if c were kept constant but the fine structure constant were doubled we would measure c to have changed by a factor of 2.
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