Could an observer prove he is in a CTC?

  • Context: Graduate 
  • Thread starter Thread starter Passionflower
  • Start date Start date
  • Tags Tags
    Observer
Click For Summary
SUMMARY

An observer can prove he is in a Closed Timelike Curve (CTC) by utilizing properties of spacetime that are invariant under diffeomorphisms. The existence of CTCs through a specific point P is a diffeomorphism-invariant property, suggesting that it is indeed observable. A practical method to verify this involves sending a cloud of test particles, such as glass bottles with notes, from point P in all directions within P's future light cone. If some particles return close to P simultaneously with their release, it confirms the presence of CTCs.

PREREQUISITES
  • Understanding of Closed Timelike Curves (CTCs)
  • Familiarity with diffeomorphism invariance in general relativity
  • Knowledge of light cones and their significance in spacetime
  • Basic concepts of particle physics and experimental methods
NEXT STEPS
  • Research the implications of diffeomorphism invariance in general relativity
  • Explore experimental setups for testing CTCs using test particles
  • Study the mathematical framework of Closed Timelike Curves
  • Investigate the philosophical implications of time travel in physics
USEFUL FOR

Physicists, cosmologists, and anyone interested in the theoretical aspects of time travel and the nature of spacetime.

Passionflower
Messages
1,543
Reaction score
0
I think an interesting question is: could an observer prove he is in a CTC?

Intuitively I would think the answer is no.

But I am interested in proofs, conjectures or opinions.
 
Physics news on Phys.org
In general, I would expect that any property of spacetime that is invariant under diffeomorphisms would be observable. Since the fact that CTCs exist through a given point P is invariant under diffeomorphisms is diff-invariant, I would think that the answer to your question would be yes.

As a method of checking, I suppose you could sent out a cloud of test particles from P in all directions in P's future light cone. Let's say that these test particles consist of glass bottles with notes inside addressed to yourself. If some of them arrive very close to P, just as you're sending them, then P has CTCs through it.
 

Similar threads

  • · Replies 7 ·
Replies
7
Views
2K
  • · Replies 18 ·
Replies
18
Views
4K
  • · Replies 11 ·
Replies
11
Views
2K
  • · Replies 35 ·
2
Replies
35
Views
4K
  • · Replies 5 ·
Replies
5
Views
1K
  • · Replies 43 ·
2
Replies
43
Views
4K
  • · Replies 6 ·
Replies
6
Views
1K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 25 ·
Replies
25
Views
5K
  • · Replies 21 ·
Replies
21
Views
2K