The apparent shape of a relativistically moving sphere

  title={The apparent shape of a relativistically moving sphere},
  author={Roger Penrose},
  journal={Mathematical Proceedings of the Cambridge Philosophical Society},
  pages={137 - 139}
  • R. Penrose
  • Published 1 January 1959
  • Physics, Art
  • Mathematical Proceedings of the Cambridge Philosophical Society
It would be natural to assume that, according to the special theory of relativity, an object moving with a speed comparable with that of light should appear to be flattened in the direction of motion on account of its FitzGerald-Lorentz contraction. It will be shown here, however, that this is by no means generally the case. It turns out, in particular, that the appearance of a sphere, no matter how it is moving, is always such as to present a circular outline to any observer. Thus an… 

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