"Bilge" <dubious@[EMAIL PROTECTED]
> wrote in message
news:slrnf6uv6q.van.dubious@[EMAIL PROTECTED]
> 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.
>
I already did, so the "ambiguous verbiage" above was not covering over,
but
framing the background to, the core point: The relative velocities between
points in a rotating body are given (if v << c) by v = -R cross omega,
where
R is the separation to the other point. Therefore, it is really rotating
since that makes for a way to distinguish it from bodies in other states
of
rotation (or not at all) without recourse to inertial issues. That
shouldn't
have been hard to gather.
There is no way to completely avoid so-called ambiguous verbiage, since
there are arguments about how to frame the issue. I can't help that. BTW,
could we talk about quantum mechanics, general relativity, etc., in all
respects, without any use of "ambiguous verbiage"? Give me the honest
answer.
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