if a single source of light quite small, was placed somewhere inside a completely reflective sphere, quite large, what would the reflections look like from the light source's point of view within that sphere?


extra-credit: what would it look like over the course of time with movement starting from the moment the light turned on?

Found this question has been asked over in MathOverflow, sum clue?

  • $\begingroup$ I don't think this question can actually be answered since if it were to be, it would only be speculation. And there is nothing to support that the universe reflects light in this way. $\endgroup$ – Calc1DropOut Apr 8 '14 at 6:46
  • $\begingroup$ Let alone that the universe is seemingly elliptical to astronomers. $\endgroup$ – Calc1DropOut Apr 8 '14 at 6:55
  • 1
    $\begingroup$ ya, i expect even a 3d computer model would take like 15 billion years or so to even calculate a snapshot image let alone a moving one. nonetheless, entertain the idea of how many times the light might bounce inside of the sphere before hitting your eye again, in relation to that same light taking another longer or shorter path before reaching your eye and so on. same exercise if you like from within an elliptical sphere or maybe a touroid but that's getting too fun! $\endgroup$ – irth Apr 8 '14 at 6:57

The simple answer to your headline question is: No.

That kind of correlation between different angles has been investigated, and no significant correlation beyond 1 degree (first acoustic peak), e.g. large-scale circular structures in the CMB, has been found.

Details about the investigation of non-trivial topologies within the limits of recombination, see this Planck paper.

Closer-by structures (like galaxy clusters) visible by telescopic observations are correlated to gravitational lensing of the CMB, as described in this Planck paper, or by the integrated Sachs-Wolfe effect, as described in this Planck paper, since galaxy clusters tend to be correlated with dark matter halos.

Repeating pattens (from mirroring) would be evident from 3d maps (like this one for the local 300 Mpc environment) of the mass distribution or telescopic observations.

Multiple images of distant objects are well-known, e.g. as Einstein crosses, or Einstein rings, caused by gravitational lensing. This can include mirroring in extreme cases; it's well-known how this would look like.

  • $\begingroup$ Thanks Gerald, I'll digest that Planck paper but still wondering if the visuals from this experiment would reflect the visuals we are observing through telescopes. $\endgroup$ – irth Apr 8 '14 at 20:55

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