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Length contraction

  1. Dec 21, 2005 #1
    If the length of an object could contract under length contraction, what about fundamental particles, like electrons, quarks, protons, etc? After all, an object is made up of a lattice/group of particles.
  2. jcsd
  3. Dec 21, 2005 #2


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    They all contract as observed by an observer moving relative to them.

    The length-contraction/time-dilation is an artifact of that observer's space-time reference system. In their own frame of reference the "electrons, quarks, protons, etc" are not being squashed!

  4. Dec 21, 2005 #3
    Yes, that's what I wanted to ask. In our frame, we see length of objects being contracted. So, how about particles like protons, electrons etc? How would the travelling particles look like in our frame? After all, objects are made of particles. So, length contraction needs to be explained in terms of particles.

    Secondly, consider a hydrogen atom, having an electron orbiting around a proton. This hydrogen atom travels close to speed of light, from what we observe. How does this change the wavefunction of the orbiting electron and also the electron's position expectation value?
  5. Dec 21, 2005 #4


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    It does not really change the wave function. It is the x- and t-coordinates that change. You could calculate the wave function in the rest frame and then transform the result to your frame.
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