Are closed timelike curves physicaly possible?

Question

Are closed timelike curves physicaly possible?

Answer 1

If you think of time as being a 4th dimension, and if it is possible to warp space into a closed loop, then there should logically be no reason why you couldn't warp the time dimension in the same way. This doesn't mean that any dimension can be warped into a closed loop. But what theoretically works for space, may also work for time.

Answer 2

Who knows? None have been observed. No supported theory indicates that they are possible. No reason to suspect they exist. But nothing specifically excludes them. Room for speculation and possibly a new theory.