this post was submitted on 13 Aug 2023
541 points (93.6% liked)

Memes

45897 readers
1330 users here now

Rules:

  1. Be civil and nice.
  2. Try not to excessively repost, as a rule of thumb, wait at least 2 months to do it if you have to.

founded 5 years ago
MODERATORS
 
you are viewing a single comment's thread
view the rest of the comments
[–] [email protected] 4 points 1 year ago (1 children)

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?

[–] [email protected] 9 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

[–] [email protected] 2 points 1 year ago (1 children)

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

[–] [email protected] 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

[–] [email protected] 1 points 1 year ago

Here is an alternative Piped link(s): https://piped.video/1n_otIs6z6E

Piped is a privacy-respecting open-source alternative frontend to YouTube.

I'm open-source, check me out at GitHub.