How do reflections work? Aren't changes in direction caused by acceleration? Also aren't photons affected by the gravity of black holes? How does that work?

[–] xionzui@lemmy.world 8 points 1 year ago* (last edited 1 year ago) (1 children)

Reflections involve the material absorbing and re-emitting photons back the other direction.

The curvature of light from gravity is actually space-time itself being curved by mass. The light continues on a straight path through a curved space-time. It looks like it changes direction from the outside, but that’s just the shape of the universe in that area.

That’s why we feel gravity. The space-time around earth is curved inward, so going forward in time would actually mean falling towards the center if we were stationary in space. The ground is constantly accelerating us upwards. Light does not get accelerated that way, so it follows the curvature.

If you want to get really deep into the reflection topic: https://youtu.be/rYLzxcU6ROM

[–] yewler@lemmygrad.ml 1 points 1 year ago (1 children)

Heyo that's dope! Definitely adding that video to my watch later. Thanks for explaining that.

[–] xionzui@lemmy.world 1 points 1 year ago (1 children)

It is! I also found this video later that I think does a better job of explaining reflection: https://youtu.be/1n_otIs6z6E

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