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Here's a small paragraph from Carl Sagan's "Cosmos" describing what a person travelling near the speed of light would observe (as a thought experiment):

"...As your speed increases, you begin to see around the corner of passing objects. While you are rigidly facing forward, things that are behind you appear within your forward field of vision. ....ultimately everything is squeezed into a tiny circular window, which just stays ahead of you."

Can someone please explain in an intuitive way why we would end up seeing objects behind us as being in front of us? And why would it be circular? I wasn't expecting anything to be squeezed as well, since I thought that length contraction applies only from the point of view of an observer in the "stationary" reference frame when describing someone moving near the speed of light.

Would really appreciate some enlightenment on this issue.

Some related questions: Approaching speed of light: why do objects appear further away in front of me?, How realistic is the game A Slower Speed of Light?, Length contraction in Gamow's "Mr. Tompkin in Wonderland", Understanding the Headlight/Beaming effect. Another cool relativistic vision effect is Terrell rotation.

Quillo
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Clara
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    This is called relativistic beaming. Does the amswer here help? https://physics.stackexchange.com/q/359886/123208 – PM 2Ring Mar 23 '22 at 22:42
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    Be carefull, there is no "stationary" reference frame, every inertial frame is equivalent. I am not sure if this is the answer, but from Lorentz transformations the length of every object moving at $v$ (or equivalently the length of any object if we are moving at $v$ wrt that object) is contracted as $\Delta l = \frac{\Delta l_0}{\sqrt{1-\frac{v^2}{c^2}}}$ in the direction of motion. If $v$ approaches $c$ the distance between every two points in the universe would approach zero. Then it would make sense to be able to look at everything as if it was in front of us. – Andrea Mar 23 '22 at 22:56
  • @Andrea your equation should have the rhs multiplied by $1/\gamma$ not $\gamma$ otherwise $l$ will be larger than $l_0$. – joseph h Mar 24 '22 at 03:24
  • @PM2Ring thank you!! It does help with the Abberation explanation. However, that means IF one moves at the speed of light, then object overhead will appear on the horizon, so in order for objects behind us to appear on our horizon, don't we have to move faster than the speed of light? – Clara Mar 24 '22 at 07:25
  • @Andrea I see. Thank you for the reply, but it is still a bit difficult to imagine this way because then everything has a length of zero as well, so I'd imagine we only observe complete darkness and nothing else... – Clara Mar 24 '22 at 07:28
  • @josephh yes my bad, can't fix it now though... Clara to be honest I am not even sure this explanation makes sense, it was just a hint ^^ – Andrea Mar 24 '22 at 16:54
  • Related: resource recommendations for "relativistic vision" https://physics.stackexchange.com/a/239470/226902 – Quillo Feb 08 '23 at 23:04

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