Re: So... Lerentz Contractions are *physical* not observered?

On Jul 8, 2:45 am, "Martin Hogbin" <goatREMOVETHIS...@xxxxxxxxxx>
wrote:
"Dono" <s...@xxxxxxxxxxx> wrote in messagenews:1183846337.585684.30840@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
On Jul 7, 11:16 am, "Martin Hogbin" <goatREMOVETHIS...@xxxxxxxxxx>
wrote:
"Dono" <s...@xxxxxxxxxxx> wrote in messagenews:1183824772.376166.322850@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
On Jul 7, 9:11 am, "Martin Hogbin" <goatREMOVETHIS...@xxxxxxxxxx>
wrote:

It seem you are just confused about terminology. Lorentz' 1904
paper described contraction and time dilation. The term 'LET'
is generally used here to mean that complete theory (length
contraction and time dilation) that is exactly equivalent to SR.

Actually this is exactly what I told Tom. He disagreed, claiming that
there is only one LET.

That is correct. As I said before the term 'LET' is not used
in the learned journals. The subject has probably been
discussed on this newsgroup more than anywhere else and
here 'LET' is exclusively used (by those who have any
understanding of the subject) to mean the complete theory,
consisting of both length and time effects, that is described
in Lorentz' 1904 paper.

Why don't you read the whole exchange rather
than jumping in the middle and throwing accusations "you are wrong".

Well I have done and it starts like this:

[Roberts]
Certainly. In LET, motion relative to the ether causes objects to
contract

[Dono]
Nonsense, Tom

The "object contraction" from Lorentz 1904 paper has been falsified by
several experiments:


Meaning that LET has been rendered FALSE 100 years ago. Beacuse the
"objectcontraction" described by Lorentz in his 1904 paper has been
rendered FALSE 100 years ago.
See here, the official Trouton biography:

http://www.phys.ucl.ac.uk/department/history/BFox1.html#Fox140


If you do read the exchange from the beginning, you will see that this
is exactly the nature of my disagreement with Tom, I claim that LET is
not based on the "object contraction" of the Lorentz 1904 paper,

Perhaps you should have said: 'I claim that LET is not based _solely_
on the "object contraction" if you wanted to make your meaning clear.

A.If LET is based on "object contraction" then, by vitue of "object
contraction" having been falsified experimentall, LET is false.
This is fine with me, as long as Tom (and his followers) stop
repeating the mantra "LET is indistinguishable from SR".

B.The only other possiblity is that LET is NOT based on "object
contraction" at all. This would save LET but render it a totally
uninteresting theory, a sort of SR with one frame arbitrarily labeled
as a "preferred frame. I think that this is what Selleri, Schmeltzer,
etc are really doing. See here:

http://oldserver.ba.infn.it/~selleri/


LET has a clearly understood meaning on this newsgroup, as described
above.


This is fine, all I am saying is that you have a choice between:

A. LET is a false theory
B. LET is an irrelevant theory.

Which one do you pick?



A theory which has only length contraction with no time effects
has been falsified but this theory has never been called LET
by anyone but yourself.

Again, you do not read and you throw accusations around. I pointed out
quite clearly to Tom that the Lorentz theory (LT) of 1904 is not the
same thing as LET,

You are clearly using LET with a different meaning from everyone else
here. LET _is_ the Lorentz' 1904 theory on this group. I am not aware
of a more definitive description elsewhere.


http://oldserver.ba.infn.it/~selleri/


Perhaps we should call
length contraction only FET.

Yes, this is exactly what I was telling Tom. I was calling it LT to
differentiate it from LET.

Not quite. You were calling what we call 'LET', 'LT' ,and what I have
just called 'FET' ,'LET'. No wonder you confused everyone

In the end it looks like we all agree on the physics.

1 Lorentz-FitzGerald contraction alone is not sufficient to explain
all the experimental evidence.

So, it cannot be use as a foundation for LET.


2 The complete theory of length and time transformation outlined
in Lorentz' 1904 paper is sufficient to explain all* experimental
results and is experimentally and mathematically equivalent
to SR.


But in his 1904 paper, Lorentz MIXES "object contraction" with his
newly (and not quite correctly) derived transforms. So, his 1904 paper
is hopelessly muddled and, contrary to what Tom (and his followrs)
claim, it is not possible to found an unfalsifiable, SR-equivalent
theory based on it.






As I am perfectly sure that Tom knows all of the above, any
disagreement can only have been due to misunderstandings.


Well, Tom has been conspicously silent since my last challenge,
hopefully he's been reading the theory of the papers I cited and he's
rethinking his statements.

You seem to be making up your own terminology and
expecting everyone else to understand it. If have never
seen the term 'projective contraction' used before but I
presume you are referring to the concept of the projection
of a 4-dimensional object onto 3-dimensional space.

No, it is meant to mean the projection of coordinates from one frame
of reference into another one, you know, using the lorentz transform
for spatial coordinates to illustrate what we know in SR under the
name of "length contraction".

'Transformation of coordinates' would be the standard term.

Fine. I have seen others using the term "projective"in order to
describe the transformations, frankly I couldn't care less, it is a
nit.




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