On 2007-06-12, Neil Bates <neil_delver@[EMAIL PROTECTED]
> wrote:
> Thoroughgoing Machian GR says that *all* motion is relative, even
> accelerated motion. Hence, a "spinning" wheel can be thought of at rest,
> with the centrifugal forces on it being created by motion of the matter
> beyond it. (Actually, not in the same sense as when charges start to
> accelerate at a distance, for then there would be a time delay..) But
assume
> that at least linear motion is relative and real to that extent. Then,
since
> relative linear motions are "real" they can be used to make distinctions
> between situations. Consider that a rotating body has actual relative
> velocity vectors of parts of itself relative to any given other part!
(For
> example, each other point (if v << c) moves at v = -R cross omega,
> where R is the connecting separation and not r of a circle etc.)
> The magnitudes depend on omega, which is thus real per that
consideration
> (which does not invoke any mechanical or inertial effects.) I know,
> rotation itself redefines that perhaps, but just taking the bare idea of
> "relative velocity" and applying it to rotation, yields this result.
> A paradox of understanding? A decent refutation of pan-relativism?
> What say you?
I say, write down an equation that replaces all of the ambiguous
verbiage in the above with something that states clearly and concisely
whatever physical content the above is supposed to contain.
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