- #1
Jarek 31
- 158
- 31
- TL;DR Summary
- (Why) Can we be certain that spacetime is orientable?
Einstein's general relativity theory assumes that spacetime is a manifold with intrinsic curvature proportional to stress-energy tensor.
But manifolds, in principle, can be non-orientable, like Möbius strip or Klein bottle:
So could spacetime be non-orientable?
If not, is that because of impossibility of getting such stress-energy tensor configuration, or are there some other reasons?
If yes, could e.g. traveling through such Klein-bottle-like wormhole perform P or T symmetry on such object?
I have found 3 peer-reviewed articles optimistic about such possibility (should they be so?):
Nonorientable spacetime tunneling: https://journals.aps.org/prd/abstract/10.1103/PhysRevD.59.064026
Observing other universes through ringholes and Klein-bottle holes: https://aip.scitation.org/doi/abs/10.1063/1.4734422?download=true&journalCode=apc
The orientability of spacetime: https://iopscience.iop.org/article/10.1088/0264-9381/19/17/308
But manifolds, in principle, can be non-orientable, like Möbius strip or Klein bottle:
So could spacetime be non-orientable?
If not, is that because of impossibility of getting such stress-energy tensor configuration, or are there some other reasons?
If yes, could e.g. traveling through such Klein-bottle-like wormhole perform P or T symmetry on such object?
I have found 3 peer-reviewed articles optimistic about such possibility (should they be so?):
Nonorientable spacetime tunneling: https://journals.aps.org/prd/abstract/10.1103/PhysRevD.59.064026
Observing other universes through ringholes and Klein-bottle holes: https://aip.scitation.org/doi/abs/10.1063/1.4734422?download=true&journalCode=apc
The orientability of spacetime: https://iopscience.iop.org/article/10.1088/0264-9381/19/17/308