eli5 So if the universe is constantly expanding and there is no void then what happens to light? Does it just get to the furthest expansion and wait for it to expand more? Does the expansion of the universe “stretch” light enough where it loses too much energy and stops?

Question

Basically, where does light end up? I know that there is no void and that the universe is all that there is and it is constantly expanding, but what happens to light? Wouldn’t it reach the edge? Does cosmological redshift eventually cause the light to stop after long enough?

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Answer 1

The universe is expanding faster than the speed of light so it can never reach the edge. In fact the universe is expanding at an accelerated rate meaning its gaining speed. That being said there is still a lot we dont know.