Could Space-Time Curvature Enable Time Loops?

  • Context: Undergrad 
  • Thread starter Thread starter petrushkagoogol
  • Start date Start date
  • Tags Tags
    Klein Space-time
Click For Summary

Discussion Overview

The discussion explores the theoretical possibility of time loops in the context of space-time curvature, specifically considering models like the Klein bottle and the implications of having multiple time dimensions. It includes theoretical considerations and references to specific spacetimes that may allow for closed timelike curves.

Discussion Character

  • Exploratory
  • Debate/contested
  • Technical explanation

Main Points Raised

  • One participant suggests that if space-time is curved like a Klein bottle, it might allow for events to loop back in time.
  • Another participant emphasizes the conditional nature of this idea, stating that it is a significant assumption and advises caution until evidence is presented.
  • A different viewpoint proposes that time loops could theoretically exist with more than one time dimension, although this is not observed in reality.
  • Some participants note that closed timelike curves can exist in spacetimes with the standard metric signature, citing examples such as Godel spacetime and the interior of Kerr spacetime.
  • One participant expresses interest in the examples provided and acknowledges their potential relevance to the discussion.

Areas of Agreement / Disagreement

Participants express differing views on the necessity of complex topologies like the Klein bottle for time loops, with some arguing that simpler models could suffice. The discussion remains unresolved regarding the implications of these theories and the existence of time loops.

Contextual Notes

The discussion highlights the dependence on theoretical models and the lack of empirical evidence for multiple time dimensions or the specific topologies mentioned. There are unresolved assumptions regarding the nature of time and space-time curvature.

petrushkagoogol
Messages
28
Reaction score
4
If space-time is curved like a klein bottle, is it theoretically possible that events could loop back in time ? :wink:
 
Space news on Phys.org
That is a big "if". Assuming it is like a Klein bottle, then it will loop back in every dimension. I wouldn't think too hard about it till there is some evidence.
 
Well in principle there could be a time loop just by having more time dimensions than one.
No need for anything as complicated as a Klein bottle topology.
However in reality we only observe one dimension of time and there is no reason to suspect more.
 
rootone said:
in principle there could be a time loop just by having more time dimensions than one.

This is not necessary; there are spacetimes with the usual metric signature (one timelike and three spacelike dimensions) which have closed timelike curves. The Godel spacetime is one; the deep interior (inside the inner horizon) of Kerr spacetime is another.
 
PeterDonis said:
This is not necessary; there are spacetimes with the usual metric signature (one timelike and three spacelike dimensions) which have closed timelike curves. The Godel spacetime is one; the deep interior (inside the inner horizon) of Kerr spacetime is another.
Thanks, I suspected this could be the case, I'll look into the examples you mentioned.
 

Similar threads

Undergrad The curvature of space and curvature of spacetime
  • · Replies 21 ·
Replies
21
Views
3K
Undergrad Two-dimensional negative curvature space
  • · Replies 2 ·
Replies
2
Views
3K
Undergrad Research on conservation of spacetime curvature
  • · Replies 6 ·
Replies
6
Views
2K
Undergrad Is the expansion of the universe affecting time or just space?
  • · Replies 22 ·
Replies
22
Views
3K
Undergrad Does dark-energy require a source of energy?
  • · Replies 2 ·
Replies
2
Views
3K
Undergrad Why is the observed local region of space flat?
  • · Replies 25 ·
Replies
25
Views
4K
Undergrad Cosmological principle about space and time
  • · Replies 20 ·
Replies
20
Views
2K
High School What is the relationship between expansion and curvature?
  • · Replies 20 ·
Replies
20
Views
4K
Undergrad Curvature of space in large regions: zero or not?
  • · Replies 9 ·
Replies
9
Views
2K
Undergrad Is it possible to apply Gauss' law to a Klein bottle?
  • · Replies 1 ·
Replies
1
Views
2K