发信人: EPS.bbs@bbs.ntu.edu.tw (猫咬猪), 看板: astronomy
标  题: Re: 什麽是马赫原理?
发信站: 台大计中椰林风情站 (Tue Apr 22 14:15:51 2003)
转信站: Lion!news.nsysu!news.civil.ncku!netnews.csie.nctu!ctu-peer!news.nctu!ne

==> graddivcurl@bbs.ee.ntu.edu.tw (为所应为) 提到:
> ※ 引述《EPS.bbs@crux.chem.nsysu.edu.tw (观测如作战)》之铭言：
> : 不论如何,广义相对论与马赫原理在某种程度上似乎是被暧昧地连结在
> : 一起,广意相对论是某能成为马赫原理的终极解答? 到目前为止我还没听过
> : 有人说是或不是的,大家都看得到那个暧昧但有趣的连结,但没人有真正的
> : 答案....
> While most of my GR books are in Taiwan, I still may say something about it,
> based on my memory & Ohanian & Ruffini's text.
> In a wider sense, Mach's principle only states that matter acts on the
> geometry (Ohanian & Ruffini's text).
> There are several viewpoints (or interpretations) about Mach's Principle.
> In Tolman's text on Relativity, Thermodynamics, and Cosmology, he states that
> the dependence of gravitational field and Metric on the distribution of matter
> and energy is mediated via Principle of Mach. Einstein (in his text on the
> meaning of relativity) formulated Mach's principle as: "The spacetime
> geometry is entirely determined by the energy-momentum tensor of matter".
> Also, Wheeler formulated Mach's principle as the following:
> "The inertial properties of an object are determined by the energy-momentum
> throughout all space". His more precise formulation of Mach's Principle
> is given below: "The spacetime geometry is uniquely determined by the
> energy-momentum and by the initial conditions on the geometry."

I would rather say, all these statements are linked to Mach's
principle but not exactly Mach's principle itself.

For example, the energy-momentum tensor, will change its form when
an observer is moving at constant speed relative to the matter associated
with the tensor.  However, what Mach's principal really states is about
inertia, and therefore acceleration.

Personally I am convinced that these statements about space-time in
GR by various people are all linked to Mach's principle but the link
is vague.

Anyway, it interesting to see all these.
--
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