Are closed time like curves an inherent feature of rotating universe models?

In summary, there is a possible connection between the rotation of the universe and the existence of closed time-like curves (CTCs), which allow for time travel. However, it is a complex and uncertain relationship, as the vorticity of the universe is a local property while CTCs are a global feature. Some rotating universes do maintain causality, but there is currently no evidence of a non-rotating universe violating causality. Further research is needed to understand the exact relationship between rotation and the possibility of CTCs.
  • #1
Galteeth
69
1
This is a follow up to my previous question, as they appear that in both the Godel Metric and the Van Stockum dust

Perhaps a better way to put this is, could there be a model where you had rotation (maybe around a non-symmetrical axis?) and not get these CTCs?
 
Physics news on Phys.org
  • #2
On this old page by a guy who did his PhD thesis on rotating universes in GR, in the section "Time Traveling and Rotation of the Universes" he writes:
The rotation of the universe, i.e., the vorticity, is a local property. The closed time-like curve is a global feature. Accordingly the connection may be obscure. We don't have any concept of a universe rotating as a whole: The picture is complicated very much by the non-existence of a suitable global reference system; by the presence of shear and expansion; by the space-time curvature; and by the infinity of the universe.

There are rotating universes that do preserve causality. I am not aware of any non-rotating universe that violates causality.
He doesn't elaborate on that statement though (his name is Egils Sviestins, and http://www.isif.org/fusion07CD/Fusion07/pdfs/Fusion2007_1143.pdf [Broken] seems to give an email for someone of that name, you could try contacting him). Also, in the later section "Is Time Traveling Possible in our Universe?" he writes:
In order to be able to travel to the past, three conditions should be fulfilled:

1. Einstein's General Relativity is a valid description of the universe.
2. The Universe has a suitable structure probably incorporating sufficiently fast rotation.
3. The practical difficulties can be overcome.
So it may have something to do with the rate of rotation, but the previous quote suggests that the exact connection between the type of rotation and the possibility of CTCs isn't easy to state.
 
Last edited by a moderator:
  • #3


Closed time-like curves (CTCs) are not an inherent feature of all rotating universe models. They only appear in specific solutions to Einstein's field equations, such as the Godel metric and Van Stockum dust. These solutions involve certain assumptions and simplifications that may not accurately reflect the complexities of our universe. Therefore, it is possible that there could be a rotating universe model without CTCs, depending on the specific parameters and assumptions used in the model.

Furthermore, the presence of CTCs in a universe model does not necessarily mean that time travel or causality violations are possible. The concept of CTCs is still a subject of debate and further research is needed to fully understand their implications. Some physicists argue that CTCs could be a mathematical artifact rather than a physical reality.

In summary, while CTCs may appear in some rotating universe models, they are not an inherent feature of all rotating universe models and their existence does not necessarily imply the possibility of time travel. More research is needed to fully understand the role of CTCs in our understanding of the universe.
 

1. What are closed time-like curves (CTCs)?

CTCs are hypothetical paths in spacetime that allow an object to return to its own past. This means that an object following a CTC would encounter its own previous state at some point in its journey.

2. How do rotating universe models incorporate CTCs?

Some rotating universe models, such as the Gödel universe, allow for the existence of CTCs. These models involve a rotating spacetime, which can create a closed loop in time and allow for the possibility of CTCs.

3. Are CTCs a well-established concept in physics?

No, the existence of CTCs is still a topic of debate and controversy in the physics community. While some theoretical models suggest their possibility, there is currently no empirical evidence to support their existence.

4. What implications would CTCs have if they were proven to exist?

If CTCs were proven to exist, it would challenge our understanding of causality and the arrow of time. It would also have implications for the possibility of time travel and the potential for paradoxes.

5. Is there any current research or experimentation being done on CTCs?

Yes, there are ongoing studies and theoretical discussions about CTCs in the fields of theoretical physics and cosmology. However, due to the theoretical nature of CTCs, it is difficult to conduct tangible experiments to test their existence.

Similar threads

  • Special and General Relativity
Replies
5
Views
2K
  • Special and General Relativity
Replies
7
Views
1K
  • Special and General Relativity
Replies
5
Views
2K
Replies
72
Views
5K
  • Classical Physics
Replies
7
Views
665
  • Special and General Relativity
Replies
13
Views
1K
  • Special and General Relativity
Replies
6
Views
898
  • Special and General Relativity
Replies
11
Views
1K
  • Special and General Relativity
Replies
1
Views
948
  • Beyond the Standard Models
8
Replies
264
Views
14K
Back
Top