Universe expansion is accelerating?

Click For Summary

Discussion Overview

The discussion revolves around the concept of the accelerating expansion of the universe and its implications regarding the speed of light. Participants explore the relationship between the expansion of space and the speed limit imposed by light, questioning how these concepts interact.

Discussion Character

  • Exploratory, Debate/contested, Conceptual clarification

Main Points Raised

  • One participant questions whether the accelerating expansion of the universe implies that it will eventually expand at a constant rate due to the speed limit of light.
  • Another participant clarifies that space itself can expand at an accelerating rate and is not constrained by the speed of light, which only applies to objects moving within space.
  • A third participant challenges the phrasing of "space itself expands," suggesting that it is more accurate to say that objects are simply getting farther apart, referencing "metric expansion."
  • Additionally, a participant mentions that the recession velocity of distant objects can exceed the speed of light, noting that this is not considered proper velocity and thus does not violate the speed limit.

Areas of Agreement / Disagreement

Participants express differing views on the description of space expansion and its implications, indicating that there is no consensus on the terminology or the interpretation of the concepts involved.

Contextual Notes

The discussion includes varying interpretations of the expansion of the universe and the definitions of terms like "recession velocity" and "metric expansion," which may lead to misunderstandings without further clarification.

AlbertoSalomon
Messages
3
Reaction score
0
Hi i have a question, i m a engineer but i have probably a dumb question ¿if the Expansion of the Universe is accelerating, but exist a speed limit "c" this tell me that at one point the universe will expand at a constant rate?
 
Physics news on Phys.org
Its an often-asked question. What happens is that *space* itself expands at an accelerating rate, and is thus not bound by the speed of light. The speed of light is a maximum bound for something that travels *in* space, but space itself can expand at any rate it wants.
 
Actually "*space* itself expands" is a very contentious way of describing it. More correctly, it is simply that things get farther apart. Google "metric expansion" for more details.
 
thanks for your answers
 
You might also be interested to know that even within our Observable Universe, the recession velocity of things the farthest away from us is currently about 3c. No speeding tickets are issued because recession velocity is not proper velocity and speeding tickets only apply to proper velocity
 

Similar threads

  • · Replies 13 ·
Replies
13
Views
1K
  • · Replies 18 ·
Replies
18
Views
3K
  • · Replies 2 ·
Replies
2
Views
3K
  • · Replies 3 ·
Replies
3
Views
775
  • · Replies 23 ·
Replies
23
Views
4K
  • · Replies 1 ·
Replies
1
Views
3K
Replies
18
Views
2K
  • · Replies 7 ·
Replies
7
Views
3K
  • · Replies 4 ·
Replies
4
Views
2K
  • · Replies 10 ·
Replies
10
Views
4K