Re: Definition of LET and SR (was: Re: MMX, Contraction and Constancy)

Harry <[EMAIL PROTECTED]> wrote in message
news:[EMAIL PROTECTED]
>
> "greywolf42" <[EMAIL PROTECTED]> wrote in message
> news:[EMAIL PROTECTED]
> > Harry <[EMAIL PROTECTED]> wrote in message
> > news:[EMAIL PROTECTED]

{snip higher levels}

> > > Barry, the PoR is *not* about the reality of nature, nor is it about
> > > causes. It is only a law about laws: that the laws of nature do not
> > > depend on (inertial) velocity.
> >
> > Precisely my point.  The PoR and LET have no connection.
> >
> > > It was the purpose of Lorentz to make the laws of nature independent
> > > of velocity, because experiments suggested that such is the case.
> >
> > According to Lorentz, that was not Lorentz' *purpose.*
>
> You may be right that it was not his starting purpose;

Then the statement about Lorentz' purpose was incorrect on its face.

> nevertheless the consequences from his theory are the Lorentz
> transformations, which have that result, eventhough it was not yet
> apparent to him.

No, the Lorentz transformations are not a consequence of Lorentz' 1904
paper.  To get the LT, one also needs to assume the PoR -- which does not
exist in Lorentz' paper.

> In his intro, after citing Poincare's objections to the LET approach,

Poincare's objection was not to LET (which was not identified until this
paper in 1904).  Poincare's 1900 objection was to Lorentz' 1899 cause-free
mathematical correlation.  LET was Lorentz' *response* to Poincare's
objection.

> he {Lorentz} wrote:
> "Surely, this course of inventing special hypotheses for each new
> experimental result is somewhat articficial. It would be more
> satisfactory, if it were possible to show, by means of certain fundamental
> assumptions, and without neglecting terms of one order of magnitude or
> another, that many electromagnetic actions are entirely independent of the
> motion of the system."
>
> But he did not stay there, for he wrote further on that he supposed that
> his theory of translations also applies to forces between uncharged
> particles, which obviously goes beyond electromagnetism.

It goes beyond pure Maxwellian EM, for Lorentz' paper includes a physical
model of the electron.  However, Lorentz' postulates are tied to the 'motion
of the system' -- not just the EM field.

> Even more, he supposed that
> the same about EM mass applies to all masses; and the length contraction
> already was supposed to apply equally to all matter.

Somewhat garbled, but Lorentz did postulate that the effect of moving an
electron through an EM field was the same as the effect of moving an
uncharged particle through the same field.  You'll note that this additional
assumption is no longer needed -- if we simply acknowledge that modern
physics presumes that all matter particles are built from fundamentally
charged particles.

But after all that, I don't see what point you are trying to make.

> > One cannot infer *why* any individual did something, based solely upon a
> > modern interpretation of something that was later tagged with the
> > individual's name (or for any other later change).  One must read the
> > documents to see what the individual *said* was the reason.
> >
> > > And it was Poincare who gave the name "Lorentz transformations" to the
> > > transformations that he wrote down in their final form.
> >
> > Correct.  But the reciprocal transformations that Poincare invented are
> > not contained in Lorentz' work -- even if Poincare based them on
> > Lorentz' work.
>
> True; they nevertheless follow directly from the above cited assumptions,
> although Lorentz had not noticed it himself yet.

But they *don't* follow from the above assumptions.  One needs to add the
PoR, before one gets to what Poinacare called the 'Lorentz transformations.'

> > > In no way did he intend to suggest that the mathematical symmetry
> > > corresponds to lack of a physical cause for the physical effects that
> > > these equations describe; only the impossibility to determine the
> > > velocity relative to that cause.
> >
> > Again, you are guessing as to someone's *intent.*  Which is fallacious
> > rumormongering.  Simply read the written articles.
>
> I did not guess, so to cite him again, for the nth time (Lorentz 1906):
> "Einstein simply postulates what we have deduced, with some difficulty and
> not altogether satisfactorily, from the fundamental equations of the
> electromagnetic field".

Your quote says nothing about the *intent* of Lorentz, in 1904, to write his
paper.  What his later conclusions might be are irrelevant.

Why not stick to physics (which you do reasonably well), instead of
attempting to invoke authority (which you do poorly)?

--
greywolf42
ubi dubium ibi libertas
{remove planet for return e-mail}