Implications of Time-reversal asymmetric quantum physics

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Discussion Overview

The discussion revolves around the implications of time-reversal asymmetry in relativistic physics, particularly in the context of quantum mechanics and its conflicts with General Relativity (GR). Participants explore theoretical implications, potential successor theories, and the relationship between quantum mechanics and GR.

Discussion Character

  • Exploratory, Technical explanation, Debate/contested

Main Points Raised

  • Some participants question the implications of quantum mechanics being not time-reversal symmetric to a high degree of statistical significance.
  • Others argue that GR conflicts with quantum mechanics, suggesting the need for a successor theory that reconciles both frameworks, similar to the relationship between Maxwell's equations and Quantum Electrodynamics (QED).
  • One participant mentions specific conflicts, including infinite probabilities in the quantization of gravity, and seeks to identify additional conflicts between GR and quantum mechanics.
  • There is a discussion about CP violation and its relation to time-reversal asymmetry, with some suggesting it accounts for baryon asymmetry and matter-antimatter asymmetry, contingent on future experimental results.
  • A participant raises a question about the implications of time-reversal invariance on the stress-energy tensor (Tμν) in GR, speculating whether it could require complex values if particle physics is not time-reversal invariant.

Areas of Agreement / Disagreement

Participants express multiple competing views regarding the implications of time-reversal asymmetry and the relationship between GR and quantum mechanics. The discussion remains unresolved with no consensus on the nature of these implications or the existence of a successor theory.

Contextual Notes

Limitations include the dependence on definitions of time-reversal symmetry and the unresolved status of certain mathematical aspects related to the quantization of gravity and the implications for the stress-energy tensor.

Schneibster
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So what is the implication of time-reversal asymmetry in relativistic physics, now that we know that quantum mechanics is not time-reversal symmetric to 14 standard deviations?
 
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Schneibster said:
So what is the implication of time-reversal asymmetry in relativistic physics, now that we know that quantum mechanics is not time-reversal symmetric to 14 standard deviations?

GR is known to be in conflict with several aspects of quantum mechanics. Some successor theory (to one or both) is needed. The majority view is that GR is classical, successful, approximate theory with the same relation to some successor as Maxwell's equations are to QED.
 
PAllen said:
GR is known to be in conflict with several aspects of quantum mechanics.
This one makes two I know of, one old one added to one I just found out about; the old one is the infinite probabilities when attempting to accomplish the first quantization of gravity. Are there yet others?

This is actually pretty definitive, I've had some conversations back when it wasn't clear that CP violation necessarily proved T reversal asymmetry, with some folks who thought I was nutty for saying it did and that it accounted for baryon asymmetry. I'm now hearing that once all the CKM and PMNS matrix mixing angles are figured out, we expect to see that it exactly accounts for the matter-antimatter asymmetry, and that the statistics have bent toward this determination as more BaBar results have come in- correct me if I'm wrong.

PAllen said:
Some successor theory (to one or both) is needed. The majority view is that GR is classical, successful, approximate theory with the same relation to some successor as Maxwell's equations are to QED.
That makes sense. Still, it's not any of the obvious low-order quantum theories.
 
General Relativity does not know about the details of particle physics, its only contact with matter is via the stress energy tensor. If particle physics is not time reversal invariant, does that have something to say about Tμν? Does Tμν have to be complex or something?
 

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