I read the entry about the Ehrenfest rotating disk paradox on Wikipedia, but the entry does not actually answer my question about what happens to the circumference of the disk in the "resolution of the paradox" section.(adsbygoogle = window.adsbygoogle || []).push({});

All I want to know is what happens to the circumference of the rotating disk when observed from the non-rotating (lab frame) inertial reference frame? Is the circumference smaller than 2 pi r due to the Lorentz contraction? I have seen some relativity textbooks stating that the Lorentz contraction makes the circumference smaller by the factor 1/gamma, so that C = 1/gamma x 2 pi r.

Thanks in advance for your answers.

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# Rotating Disk

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