this post was submitted on 08 Sep 2023
384 points (96.8% liked)
Asklemmy
43945 readers
1063 users here now
A loosely moderated place to ask open-ended questions
Search asklemmy ๐
If your post meets the following criteria, it's welcome here!
- Open-ended question
- Not offensive: at this point, we do not have the bandwidth to moderate overtly political discussions. Assume best intent and be excellent to each other.
- Not regarding using or support for Lemmy: context, see the list of support communities and tools for finding communities below
- Not ad nauseam inducing: please make sure it is a question that would be new to most members
- An actual topic of discussion
Looking for support?
Looking for a community?
- Lemmyverse: community search
- sub.rehab: maps old subreddits to fediverse options, marks official as such
- !lemmy411@lemmy.ca: a community for finding communities
~Icon~ ~by~ ~@Double_A@discuss.tchncs.de~
founded 5 years ago
MODERATORS
you are viewing a single comment's thread
view the rest of the comments
view the rest of the comments
Here's something I just ran into looking stuff up for my comment: GN-z11 is one of the farthest galaxies we've ever seen. Thanks to the expansion of the universe, at a distance of over 30 billion light-years, it has to be moving away from us at over twice the speed of light.
What the fuck does that mean, temporally? Like, forget the speed of light, time dilation has to do with space and relative speeds. If I'm moving at near the speed of light relative to you, then my clock will physically tick more slowly. What happens if I'm moving over twice the speed of light? Is the real life GN-z11 in our reference frame moving backwards in time at over twice the rate we're moving forward?
From my understanding, this is caused by the universe itself expanding between the 2 objects, not that the object itself is moving that speed relative to us. It's still completely insane to think about, either way.
I can't find any reference that says it's moving away from us at twice the speed of light, which would violate Relativity. The fact that it is further away from us in light years than the age of the universe in years, is due to the fact that the space itself is expanding.
The thing is, it's moving that fast because of the expansion of space. โ30 billion light-years over โ14 billion years equates to over twice the speed of light. Does that mean there's no crazy relativistic time dilation, and time is moving normally for them in our frame of reference, since they aren't physically moving, it's space that's expanding? That's just as wild to my brain
Relativity only applies to local reference frames and not to the recession rates of cosmologically distant objects.