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发表于 2010-5-1 23:37:15
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本帖最后由 lagi1 于 2010-5-1 23:41 编辑
不可能整套中国“易理”都是由“引力”这个特殊题目所主宰。
老外已经有些研究指出,混沌系统出现“自由度塌缩”可能是很有一般性的现象。
也就是说,世间上过万亿兆件的昏乱事件,有很多都可以用很少的几个参数形容、预测得到。
因为这是一种热力学现象,所以这万亿兆件事件之间的相互关系,不一定要由引力来主导,可以是其它的物理相互所用力。
http://theoryofchanges.com/index.php?option=com_content&view=article&id=99:dimensionality-loss&catid=41:nls-theories&Itemid=59
Chaos and Irreversibility
In 1986 Professor William G. Hoover, Dr. Brad L. Holian and I discovered that the phase-space probability density of dynamically-thermostated stationary nonequilibrium systems collapses onto a fractal attractor. The dimension of such a fractal is smaller than the dimension of the equilibrium phase space. The dimensionality loss is related to the rate of irreversible entropy production, and is a consequence of the Second Law of thermodynamics. It explains, for example, why such systems have an "arrow of time" and behave irreversibly in spite of their time-reversible equations of motion.
To generate a nonequilibrium flow, an external perturbation is needed. It drives the system away from equilibrium. However, such a perturbation performs work on the system and would raise the temperature without a suitable thermostat or ergostat. It removes the excessive heat and establishes a stationary state. However, the time-reversible thermostats, which we used in 1986 and which are currently the standard procedure, have led to an interesting controversy in the literature questioning their physical significance.
Recently, we have been able to show that the dimensionality loss mentioned above may exceed by far the dimensions contributed by the thermostatted degrees of freedom for a system far from equilibrium. We have also demonstrated that it is possible to replace the time-reversible dynamical thermostats by stochastic thermostats and to construct Lyapunov spectra for such systems, which share the desired properties with their time-reversible counterparts. This shows that dynamical thermostats are not merely convenient numerical tools but may be a first stepping stone towards a theory of nonequilibrium stationary states. |
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