Will light get reflected at edge of space

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Discussion Overview

The discussion centers around the concept of light behavior at the "edge of space" or the universe, specifically whether light could be reflected back and how this might affect our perception of the universe's size and mass. The scope includes theoretical considerations and speculative reasoning about the universe's structure and light propagation.

Discussion Character

  • Exploratory, Debate/contested, Conceptual clarification

Main Points Raised

  • One participant proposes that if light were to reflect at the edge of the universe, we might see reflections of stars at different times and locations, suggesting that this could lead to a misinterpretation of the universe's size and mass.
  • Another participant asserts that there is no "edge of the universe" for light to reflect off of, challenging the initial premise.
  • A different viewpoint mentions the theoretical possibility of a universe with periodic boundary conditions, which could allow for multiple images of distant galaxies, though this is considered unlikely and unsupported by evidence.
  • One participant introduces the idea of being at the temporal edge of the universe, noting that while we cannot see reflections from the future, light travels into our future after passing Earth.
  • A reiteration of the absence of an "edge of the universe" is presented, with a question about the dependence on boundary conditions.

Areas of Agreement / Disagreement

Participants express disagreement regarding the existence of an edge to the universe and the implications of light reflection. Multiple competing views remain, particularly concerning the nature of the universe's boundaries and the behavior of light.

Contextual Notes

Some claims rely on assumptions about the universe's structure and boundary conditions, which remain unresolved. The discussion includes speculative elements that are not universally accepted.

DRBU012
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What happens when light gets to the edge of space or universe, does it get reflected back.
Assuming that light gets reflected back at the edge of universe. We are seeing the reflections of the same star galaxy, at different points of time, at different location. Since the reflected photons travel a greater distance than the photons of the real object, the reflected photons would be of lower frequency when compared to the light from the actual object.
So if we eliminate all the reflections from actual direct light of stars (luminous objects), would the size and mass of the universe that we intepret as of now, be smaller than what we perceive.
 
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There is no "edge of the universe" for light to reflect off of.
 
There is no edge. One possibility that has been considered in the literature (Highly unlikely in my opinion) is that of a universe with periodic boundary conditions in which case it would be possible to travel all around the universe back to your starting position without ever taking a turn (kinda like circumnavigating the globe). That possibility could create multiple images of distant galaxies. But alas, there is no evidence that our universe has periodic boundaries.
 
We are at the temporal edge of the universe - the oldest place in all of the heavens. You cannot get more distant from the Big Bang than here. Do you see any weird reflections? Once a light beam whizzes by earth, it travels into our future. We can't see reflections from the future, only the past.
 
jtbell said:
There is no "edge of the universe" for light to reflect off of.

doesn't that depend on whether or not there are boundary conditions?
 

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