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Magnetic moment of the electron and spin

  1. Oct 30, 2012 #1
    Quote from wikipedia about the electron's spin
    But in optics and other fields we learned that speeds exceeding c are possible, if they do not propagate information. So is the concept of a classical electron with definite radius still physically correct in the sense that it's surface is actually allowed to move faster than c?
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  3. Oct 30, 2012 #2


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    Can you give a textbook reference for that ?
  4. Oct 30, 2012 #3
  5. Oct 30, 2012 #4


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  6. Oct 30, 2012 #5
    The effect is probably best known in the case of anomalous dispersion in which even the group velocity may exceed the speed of light in vacuo. Although the speed of information doesn't.
    Last edited: Oct 30, 2012
  7. Oct 30, 2012 #6


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    No, not at all. The electron does not have a surface. It's a pointlike particle, which means that, along with all other particles considered elementary, its size is smaller than anything we have been able to probe.

    Secondly, despite having angular momentum, an electron does not rotate.
  8. Oct 31, 2012 #7
    I recognize that statement.It is given on wikipedia which is interesting.It was uhlenbeck who came up to lorentz with the idea of electron having a spin .But lorentz showed him that if this would be the case then the surface would have to rotating that much fast,which was impossible on classical grounds.But nevertheless his idea was well received (along with goudsmith) by heisenberg who said that this idea will remove all the problems of pauli theory.Sorry,I don't remember the reference of it.If I will find ,i will post it.
  9. Oct 31, 2012 #8
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