The apparent shape of a relativistically moving sphere

@article{Penrose1959TheAS,
  title={The apparent shape of a relativistically moving sphere},
  author={Roger Penrose},
  journal={Mathematical Proceedings of the Cambridge Philosophical Society},
  year={1959},
  volume={55},
  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… 

On the apparent visual forms of relativistically moving objects

SummaryThe question of the apparent visual shape of an object moving at relativistic speeds, as perceived by a single observer, is analysed afresh. It is shown by qualitative arguments that the

The visual appearance of rapidly moving objects

I would like to draw the attention of physicists to a recent paper by James Terrell in which he does away with an old prejudice held by practically all of us. We all believed that, according to

The appearance, apparent speed, and removal of optical effects for relativistically moving objects

Because various parts of an object are different distances from an observer, and light takes a finite time to reach the observer, the appearance of a relativistically moving object will be very

The appearance of the objects rolling at relativistic speeds

In the late 1950s Terrell and Penrose produced a series of papers dealing with the appearance of the rapidly moving bodies while in rectilinear motion as photographed by a simple, pinhole camera. A

Relativistic Aberration for Accelerating Observers

We investigate the effects of the aberration of light for a uniformly accelerating observer. The observer we consider is initially at rest with respect to a luminous spherical object--a star,

Visual Appearance of Extended objects in Special Relativity

The Lorentz transformation is a spontaneous measurement. We first highlight the difference between “measuring” and “seeing”, where the latter considers the time light rays (emitted by each point on

The Geometry of Special Relativity

  • N. Dragon
  • Physics
    Sidney Coleman's Lectures on Relativity
  • 2021
Simple geometric properties of spacetime and free particles underlie the theory of relativity just as Euclidean geometry follows from simple properties of points and straight lines. The vacuum, the

The distortion of a body's visible shape at relativistic speeds

The problem of obtaining the apparent equation of motion and shape of a moving body from its arbitrary given equation of motion in special relativity is considered. Also the inverse problem of

Projection of relativistically moving objects on a two-dimensional plane, the `train' paradox and the visibility of the Lorentz contraction

Although many papers have appeared on the theory of photographing relativistically moving objects, pioneered by the classic work of Penrose and Terrell, three problems remain outstanding. (1) There

Gamow’s cyclist: a new look at relativistic measurements for a binocular observer

TLDR
A rigorous re-analysis of the cyclist, this time in three dimensions, is undertaken for a binocular observer, accounting for both the distortion in apparent position and the relativistic colour and intensity shifts undergone by a fast-moving object.
...

References

SHOWING 1-5 OF 5 REFERENCES

Relativity, Gravitation and World-Structure

Geometry of Two-Component Spinors.

  • O. Veblen
  • Mathematics
    Proceedings of the National Academy of Sciences of the United States of America
  • 1933

It seems not to have been noticed before, and is therefore worth publishing separately. Consider the usual formulation of Riemannian geometry in terms of vectors

    Expanding universes (Cambridge

    • 1956