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If QM requires a constant universal time, does this rule out closed time-like curves?
The part about "isolated from [...] the rest of the universe" may be what's relevant, but I can't tell what he's talking about just from the isolated quote. Unfortunately the article is paywalled, so it's going to be difficult for anyone here to puzzle out what he really means.I was re-reading an article from New Scientist 10 June 2006; Marcus Chown's "Do the Cosmic Twist" and I recalled that I had been puzzled by the following first time round:
"The trouble is, quantum theory requires time to be "universal" - there should never be closed loops of time isolated from the time in the rest of the universe".
No.Thanks, Ben. Is there any way I can make the article available on this forum without infringing copyright?
The various developments of quantum field theory in curved space-time have left the false impression that general relativity and quantum mechanics are compatible as long as one considers the length scales well above the Planck length [p. 2]
From http://arxiv.org/abs/gr-qc/0407033 :It turns out that certain predictions of classical general relativity such as closed time-like curves and event horizons are in conflict with a quantum mechanical description of space-time itself. In particular, a quantum mechanical description of any system requires a universal time. In practice, universal time is defined by means of synchronization of atomic clocks, but such synchronization is not possible in space-times with event horizons or closed time-like curves. [p. 2]
They describe the conventional wisdom, and say the conventional wisdom is wrong. However, they don't seem to give any explanation of what they think is wrong with the conventional wisdom.The various developments of quantum field theory in curved space-time have left the false impression that gen- eral relativity and quantum mechanics are compatible. Actually though certain predictions of classical general relativity such as closed time-like curves and event hori- zons are in conflict with a quantum mechanical descrip- tion of space-time itself. In particular, a quantum me- chanical description of any system requires a universal time. In practice, universal time is defined by means of synchronization of atomic clocks, but such synchroniza- tion is not possible in space-times with event horizons or closed time-like curves.
Uh oh. My kook alarms were already going off, but now they're really, really going off.On the other hand, he doesn't believe in black holes!
But: http://www.nature.com/news/2005/050328/full/news050328-8.htmlThere is no suggestion in the article that either Mazur or Chapline doubt the existence of black holes.