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PERIMETER INSTITUTE RECORDED SEMINAR ARCHIVE

Origin of the anthropocentric flow of time?
Speaker(s): Joan Vaccaro
Abstract: The underlying motivation for rejecting Everett's many-worlds interpretation of quantum mechanics and instead exploring single-world interpretations is to make physical theory concordant with human experience. From this perspective, the wave function collapse and Bohm-de Broglie interpretations are anthropocentric in origin. But this does not lessen their importance. Indeed accounting for our human experience of the physical world is a key element of any physical theory. This is no less true for the theory of time where accounting for the anthropocentric notion of a unidirectional flow of time is a challenge. In this talk we examine a peculiar time asymmetry that may shed some light on this problem.The matter-antimatter arrow of time, which is associated with the weak force in neutral Kaon decay, has been an enigma for 40 years. While other arrows (cosmological, electromagnetic, thermodynamic and psychological) have been linked together, the matter-antimatter arrow stands alone. It is often regarded as having a negligible effect on time in our daily lives. The main reason for this view appears to be the relatively small violation of the Charge-Parity conjugation invariance (CP) involved. However the smallness of the violation is not necessarily an obstacle to the manifestation of macroscopic effects. For example, a small difference in a quantum-state fidelity for a single particle leads to a difference which grows exponentially with the number of particles. So provided sufficient numbers of particles are involved such a violation could yield significant effects.We examine the effect of the violation of CP invariance on the dynamics of a large system such as the universe. Provided the CPT theorem holds, the CP violation is equivalent to a violation of time reversal invariance (T). We impose the constraint that the violation should equivalent in both directions of time (past and future) with respect to the present. This implies that if H is the Hamiltonian for one direction of time, then THT the Hamiltonian for the opposite direction. We will see that any given quantum state a> that represents the present of our part of the universe is closer to its evolved state a+> in the future compared to its retro evolved state a-> in the past. In other words, our present state is more likely to be extended (slightly) into the future than the past. We will see that the end result is a never-ending extension of the present into the future. Moreover for a collection of a million neutral kaons, the fidelity between the present state and a slightly future-evolved state is a billion times larger than the fidelity between the present and an equivalent retro-evolved state. In this context, the seemingly insignificant kaons appear to be responsible for our anthropocentric view of moving through time.
Date: 29/09/2008 - 5:00 pm
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