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arXiv:0912.5394

A quantum solution to the arrow-of-time dilemma: reply

Lorenzo Maccone

Published Dec 30, 2009• 3 citations
arXivHTMLPDF

Abstract

I acknowledge a flaw in the paper "A quantum solution to the arrow of time dilemma": as pointed out by Jennings and Rudolph, (classical) mutual information is not an appropriate measure of information. This can be traced back to the quantum description underlying my analysis, where quantum mutual information is the appropriate measure of information. The core argument of my paper (summarized in its abstract) is not affected by this flaw. Nonetheless, I point out that such argument may not be adequate to account for all phenomena: it seems necessary to separately postulate a low entropy initial state.

DOI
10.48550/arxiv.0912.5394

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I acknowledge a flaw in the paper "A quantum solution to the arrow of time dilemma": as pointed out by Jennings and Rudolph, (classical) mutual information is not an appropriate measure of information. This can be traced back to the quantum description underlying my analysis, where quantum mutual information is the appropriate measure of information. The core argument of my paper (summarized in its abstract) is not affected by this flaw. Nonetheless, I point out that such argument may not be adequate to account for all phenomena: it seems necessary to separately postulate a low entropy initial state.
A recent Letter by Maccone presents a solution to the arrow-of-time dilemma based on existing laws of quantum mechanics. He argues that all phenomena where the entropy decreases must not leave any information (in the observer's memory) of their having happened, the observer being a part of the whole system. He concludes that quantum mechanics is necessary to his argument, which he thinks does not otherwise work in classical mechanics. This Comment and the previously published Comment of Jennings, Rudolph describes flaws in Maccone's arguments. However, the main argument (observer's memory erasing) previously formulated in the works by one of us (O.K.) and repeated by Maccone is correct under conditions described in this Comment. Moreover, this argument can be used for resolving a reduction paradox (Schrodinger Cat paradox) in quantum mechanics. In part fourth time arrows synchronization (decohorence) is discussed. In part fifth time arrows synchronization (decohorence) in quantum gravity is discussed. This Comment consists of five parts. The first one is written by Oleg Kupervasser and Dimitri Laikov. The second, third, fourth and fifth ones are written by Oleg Kupervasser only.