I've read that, since the universe is expanding at an increasing rate, light that leaves our galaxy now will never reach far away galaxies. That even though a galaxy is moving away from us slower than the speed of light right now, before the light reaches there from our perspective, the increasing expansion will cause that far away galaxy to be moving away from us faster than the speed of light, and the light will never reach it.
However, it's also my understanding that light doesn't "experience" time (I can't think of a better way to phrase that). So from light's "perspective", it's emitted and absorbed at the same time. So the expansion of the universe that happens during the light's transit from our perspective shouldn't affect it.
I'm obviously misunderstanding something, since the light can't both get there and not get there.
I'm not a physics student, I only have a layman understanding and I'm trying to piece things together. Is the answer simply that the first part of my question is wrong; that the light will in fact reach the other galaxy if that galaxy isn't currently moving away from us faster than the speed of light?
Edit: I'm trying to figure out how it works when a photon leaves our galaxy and heads towards another galaxy, where the two galaxies are moving apart slower than c when the photon leaves, but the expansion of the universe causes the two galaxies to be moving apart faster than c at some point during the photon's transit, from our perspective.
As far as I understand it, a photon only has a transit time when viewed from a relativistic perspective.
Best Answer
Here's an example in layman's terms. It's not 100% accurate, but it should give you a good idea of how it could be.
Imagine a balloon that has only been slightly inflated. Now draw two dots on the balloon. An ant at one dot starts walking towards the other at a constant speed. However, at the same time we start inflating the balloon. Assuming our balloon can keep expanding forever and never pops even as the ant moves towards the second dot that dot is getting farther away because of the balloon's expansion. If we inflate it fast enough the ant will never reach the dot...
Note that in this example the dots aren't even moving on the balloon, yet the expansion could prevent the ant from ever reaching the second dot.