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arXiv 0709.0724cond-mat.stat-mech
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从时间对称微观动力学到时间非对称宏观行为:综述

From Time-symmetric Microscopic Dynamics to Time-asymmetric Macroscopic Behavior: An Overview

Joel L. Lebowitz

摘要:

在{ \it单个宏观}系统中观察到热力学第二定律所体现的时间不对称行为。它可以被理解为自然产生于时间对称的微观定律,当考虑到a)微观尺度和宏观尺度之间的巨大差异,b)早期宇宙的低熵状态,以及c)我们所观察到的是来自这样一个初始状态的系统的行为-而不是所有可能的系统。基于这些成分对第二定律起源的解释可以追溯到麦克斯韦、汤姆森,特别是玻尔兹曼。常见的替代解释,例如那些基于概率分布(系综)的遍历或混合特性的解释,已经存在于只有几个自由度的混沌动力系统中,或者基于不可能有一个真正的孤立系的解释,要么是不必要的,误导的或误导的。然而,宏观演化的特定特征,如扩散方程,确实依赖于孤立宏观系统轨迹的动力学不稳定性(确定性混沌)。这些经典概念在量子世界的延伸在许多方面都是相当直接的。然而,它也带来了一些新的问题。这些问题将得到讨论,但不会得到解决。

英文摘要:

Time-asymmetric behavior as embodied in the second law of thermodynamics is observed in {\it individual macroscopic} systems. It can be understood as arising naturally from time-symmetric microscopic laws when account is taken of a) the great disparity between microscopic and macroscopic scales, b) a low entropy state of the early universe, and c) the fact that what we observe is the behavior of systems coming from such an initial state--not all possible systems. The explanation of the origin of the second law based on these ingredients goes back to Maxwell, Thomson and particularly Boltzmann. Common alternate explanations, such as those based on the ergodic or mixing properties of probability distributions (ensembles) already present for chaotic dynamical systems having only a few degrees of freedom or on the impossibility of having a truly isolated system, are either unnecessary, misguided or misleading. Specific features of macroscopic evolution, such as the diffusion equation, do however depend on the dynamical instability (deterministic chaos) of trajectories of isolated macroscopic systems. The extensions of these classical notions to the quantum world is in many ways fairly direct. It does however also bring in some new problems. These will be discussed but not resolved.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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