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?

In: 14

Answer 1

As far as know there is no “edge” of the universe. It seems We’re either in an infinite plane or a hyper sphere. Either way light will travel forever until it hits something.

Fun fact. Everyway you point is towards where the big bang happened.

[pbs spacetime]
(https://youtu.be/BOLHtIWLkHg)