Re: Why Einstein is the founder of special relativity
- From: "Juan R." <juanrgonzaleza@xxxxxxxxxxxxxxxxxxxx>
- Date: Fri, 23 Sep 2005 19:57:50 +0000 (UTC)
Martin Ouwehand wrote:
> this alludes to the fact that Lorentz didn't use the "correct" transformation
> law for the charge density and the current, while those found by Poincaré
> are such that the Maxwell equations after the transformation are indeed
> the same as in the ether frame.
i post before only part of the quote by Lorentz. The total is
"These considerations published by myself in 1904, have stimulated
Poincaré to write his article on the dynamics of electron where he
has given my name to the just mentioned transformation. I have to note
as regards this that a similar transformation have been already given
in an article by Voigt published in 1887 and I have not taken all
possible benefit from it. Indeed I have not given the most appropriate
transformation for some physical quantities encountered in
the formulae. This was done by Poincare and later by Einstein and
Minkowski[...] I had not thought of the straight path leading to them,
since I considered there WAS an essential difference between the
reference systems x, y, z, t and x', y', z', t'. In one of them were
used - such was my reasoning - coordinate axes with a definite
position in ether and what could be termed true time; in the other, on
the contrary, one simply dealt with subsidiary quantities introduced
with the aid of a mathematical trick. Thus, for instance, the variable
t' could not be called time in the same sense as the variable t. Given
such reasoning, I did not think of describing phenomena in the
reference system x', y', z', t' in precisely the SAME WAY, as in the
reference system x, y, z, t[...] I later saw from the article by
Poincare that, if I had acted in a more systematic manner, I could have
achieved an even more significant simplification. Having not noticed
this, I was not able to achieve total invariance of the equations; my
formulae remained cluttered up with excess terms, that should have
vanished. These terms were too small to influence phenomena noticeably,
and by this fact I could explain their independence of the Earth's
motion, revealed by observations, but I did not establish the
relativity principle as a rigorous and universal truth. On the
contrary, Poincare achieved total invariance of the equations of
electrodynamics and formulated the relativity postulate - a term
first introduced by him[...] I may add that, while thus correcting THE
DEFECTS OF MY work [after noted by Einstein -i already cited- that SR
basically follows from Lorentz relativity once corrected Lorentz error
with the concept of time], he never reproached me for them. I am unable
to present here all the beautiful results obtained by Poincare.
Nevertheless let me stress some of them. First, he DID NOT restrict
himself by demonstration that the RELATIVISTIC transformations left the
form of electromagnetic equations unchangeable [i.e. by use of real
time t']. He explained this success of transformations by the
opportunity to present these equations as a CONSEQUENCE of the least
action principle [a physical principle] and by the fact that the
FUNDAMENTAL equation expressing this principle and the OPERATIONS used
in derivation of the FIELD equations are IDENTICAL in SYSTEMS x, y, z,
t and x', y', z', t'[...] There are some NEW notions in this part of
the article, I should especially mark them. Poincare notes, for
example, that in consideration of quantities x, y, z, tsqr(-1) as
COORDINATES of a point in FOUR-dimensional space the relativistic
transformations reduces to rotations in this space. He also comes to
idea to add to the three components X, Y, Z of the force a quantity T =
Xa + Yb + Zc, which is nothing more than the work of the force at a
unit of time, and which may be treated as a fourth component of the
force in some sense. When dealing with the force acting at a unit of
volume of a body the RELATIVISTIC transformations change quantities X,
Y, Z, Tsqr(-1) in a similar way to quantities x, y, z, tsqr(-1). I
remind on these ideas by Poincare because they are closed to methods
LATER used by Minkowski and other
scientists to easing mathematical actions in the theory of relativity."
Lorentz says that error is he tought that local time was a mathematical
tool.
Lorentz clearly stipulates that was Poincaré who corrected this and
obtained full invariance by nothing that equations in both frames were
IDENTICAL ones. Lorentz also said that about Einstein work.
"The main reason of my failure was I always thought that only quantity
t could be treated as a true time and that my local time t' was
considered only as an auxiliary mathematical value. In the Einstein
theory, just opposite, t' is playing the same role as t. If we want to
describe phenomena as dependent on x', y', z', t', then we should
operate with these variables in just the same way as with x, y, z, t"
But the first to show this was Poincare
Also Poincaré proved the invariance of ds of the 4D, and it follows
that t and x cannot be absolute. Poincaré used other notation but
ds^2 = (cdt)^2 - (dx)^2
If ds is an invariant, t is not. Remember Poincaré words "time is
relative" I and other cited here.
I already CITED to Poincaré saying that Lorentz 'local time' was a
real time measured by a clock. Poincaré (1900):
"I assume observers, situated at different points, to compare their
clocks with the aid of light signals [...] The local time tau is the
time READ from the CLOCKS thus controlled."
Poincaré is correcting Lorentz error, and Lorentz noted this. AFTER
Einstein used the same operational definition of time as 'that'
measured by clocks.
> To me, for Poincaré in his 1905-1906 articles, as for Lorentz in his
> 1904 article, the Lorentz transformation is an abstract transformation,
> a mathematical help to show that the Lorentz contraction will be enough
> to explain null results like the Michelson experience to all orders in
> v/c.
for Poincaré the Lorentz transformation was not a mathematical tool
was the basis of a NEW mechanics that he developed: four-velocity,
four-force, new simultaneity, PoR, equations of motion, etc.
> ] I think that Poincaré changed his view partially in 1908-1909, etc.
>
> in the 1908-1909 articles, Poincaré at least expounds a theory of
> space-time based on measurements made by obsverers, something that
> is missing in the 1905-1906 papers. It is definitely not the same as
> Einstein's. For instance in his 1908 article (available from
> http://www.soso.ch/wissen/hist/SRT/srt.htm -- BTW thank you Homo Lykos
> for the link !), I understand from his arguments around pages 565-566
> that he uses the following transformation:
>
> x' = (x - v * t) / sqrt(1 - v^2/c^2) (Lorentz contraction)
> t' = t - (v * x) / (c^2 - v^2) ("local time")
>
> (x', t') is what is actually measured by an observer in motion with res=
pect
> to the ether, (x, t) are the coordinates in the ether frame (beware tha=
t
> in his formula for the local time, he expresses x in term of x', result=
ing
> in a slightly different formula). With the help of this transformation,=
he
> is able to explain the null result of the Michelson experience: the tim=
e
> of travel of a light pulse along a given distance doesn't depend on the
> direction. But the transformation rule for the speed of light (last
> equation on page 566 -- BTW there is a misprint: t should be replaced
> by tau) is:
>
> c' = c * sqrt(1 - v^2/c^2)
>
> which doesn't respect the principle of relativity (by measuring the spe=
ed
> of light in different frames, it's possible to tell which is moving fas=
test
> whith respect to the ether.)
also in posterior years Einstein changed his mind and aknowledge to
Lorentz that SR needs of an aether -I already cited this- If you reject
Poincaré in the basis of posterior work you would also reject Einstein
in the same basis.
Do not forget also that in posterior years Einsten said that c was NOT
a constant for properly studying gravitation (which was already being
studied by Poincaré so early as 1906). Then why if Poincaré was
studying gravitation AND relativity and was not sure about constancy of
c in an unified theory in 1908-09, and Einstein when in posterior years
studied gravity and initially though that c was not a constant that is
not a basis for critizing Einstein.
After Einstein changed AGAIN his view and now c is also constant in GR.
But what if Einstein has passed away in 1910-12? then now we had said
that Einstein thought that c was not constant, remember that Poincaré
died prematurely due to got cancer in 1909.
Other example, Einstein originally obtained GR without the 'trace
term', after receiving copy of Hilbert work submitted the 'final'
version of GR with the 1/2 'trace term'. In posterior years (1919) said
that WAS incorrect and substituted by a (1/4) [Tilman Sauer of the
Einstein Papers Project in arXiv:physics/0405066]. See the new version
of my document for details on this. If in posterior years Einstein said
the correct term was 1/4, why are not those posterior works used
against Einstein?
Again i see a double attitude when people omits many important data.
- Pauli early words are used against Poincaré but Pauli 1955 words
claiming that Poincaré obtained SR ignored.
- Lorentz words supporting Poincaré priority ignored but others
writings used in favor of Einstein.
- Poincaré posterior works used against Poincaré priority, but
Einstein posterior works (e.g. return to aether, non constancy of c)
ignored againt Einstein.
- It is argued that Einstein obtained SR from two postulates but in
posterior years own Einstein aknowledged that is not true (i already
cited additional hypothesis), etc.
- Each time that Poincaré is ambiguous, this is used against Poincaré
but ambiguity of Einstein writtings ignored. For example in Einstein
1905 SR article "If we place x'=x-vt, it is clear that a point at rest
in the system k must have a system of values x', y, z, independent of
time." At the best this is ambigous (a point at rest in moving frame
k?). By less that this Poincaré is attacked.
- Poincaré obtains the character of group but is claimed that do not
understand situation. Einstein claim that LT form a group (probably
read it in Poincaré works that claimed newer read but colleagues said
the contrary -i already cited-) but after do NOT use that character of
group (which implies that do not understand).
- Poincare states that c, light velocity is a universal constant.
Einstein says that c, the velocity of light in empty space, is an
universal constant, and people claim that Poincare said 'constant' but
mean 'non-constant'!
- Einstein: "light (as required by the principle of the constancy of
the velocity of light, in combination with the principle of relativity)
is also propagated with velocity c when measured in the moving system."
Next Einstein writes "But the ray moves relatively to the initial point
of k, when measured in the stationary system, with the velocity c-v"
- I have seen people attacking Lorentz and Poincaré and their ideas of
electron. Einstein write "A rigid body which, measured in a state of
rest, has the form of a sphere, therefore has in a state of
motion--viewed from the stationary system--the form of an ellipsoid of
revolution".
- A guy wrote here time ago that Poincaré had worked 'only' EM whereas
Einstein work was more general, including gravitation. But Poincare was
working in gravitation in 1906!!!!
- Minkowski and others clearly sipulated that v is always LESS than c.
Einstien wrote "For v=c all moving objects--viewed from the
'stationary' system--shrivel up into plane figures. For velocities
greater than that of light our deliberations become meaningless" But
did explcitely says that v = c was meaningless? Again wrote "Thus, when
v=c, W becomes infinite. Velocities greater than that of light have--as
in our previous results--no possibility of existence." But Einstein
said nothing about meaningless of v=c. SR is today explained in books
says that v < c.
That c is a limiting velocity was already said by Poincare -i already
cited-.
- Einstein: "It follows, further, that the velocity of light c cannot
be altered by composition with a velocity less than that of light."
Then, is Einstein claiming that when v is equal to c the velocity of
light c is altered?
- Einstein: "a spherical surface moving with the velocity of light
[...] We may therefore say that this surface permanently encloses the
same light complex [...] The spherical surface--viewed in the moving
system--is an ellipsoidal surface"
- Etc.
You may use the same criterion for all authors.
For instance, you claim that Poincaré wrote "[with the help of the
Lorentz transformation], two systems, one at rest, the other moving,
become exact copies of each other" whereas, if Poincaré had discoverd
SR, he would have said something like "the observations of a given
system in two different frames are related through the Lorentz
transformation".
Einstein said in 1948 (extracted from arXiv physics/0405075)
"With the AID of the Lorentz transformation the special relativity
principle CAN BE formulated as follows: the laws of Nature are
invariant with respect to the Lorentz transformation (i. e. a law of
Nature must not change, if it would be referred to a new inertial
reference system obtained with the AID of Lorentz transformation for x,
y, z, t)."
Compare with above Lorentz quote
"On the contrary, Poincare achieved total invariance of the equations
of electrodynamics and formulated the relativity postulate - a term
first introduced by him[...] First, he DID NOT restrict himself by
demonstration that the RELATIVISTIC transformations left the form of
electromagnetic equations unchangeable [i.e. by use of real time t'].
He explained this success of transformations by the opportunity to
present these equations as a CONSEQUENCE of the least action principle
[a physical principle] and by the fact that the FUNDAMENTAL equation
expressing this principle and the OPERATIONS used in derivation of the
FIELD equations are IDENTICAL in SYSTEMS x, y, z, t and x', y', z',
t'[...]"
where Lorentz recognizes that was Poincaré who showed that laws of
NATURE were invariant to the LT, due to "PoR + least action principle
of physics".
> ] but does not imply that his writtings of 1902, 1904-1906 are absent
> ] from study.
>
> you seem to be saying that after discovering Special Relativity in 1905=
,
> he changed his mind... It is easy to see that what is missing in his 19=
08
> article is time dilatation: do you know of an earlier reference where
> Poincaré actually mentions it *in words* and says something like "Hey=
!
> motion has an influence on the *rate* of clocks !" ?
I already cited his definition of 'local time' as clock rate. Since
Lorentz local time (Poincare's t') is different of t, rates of clocks
are different.
I and many others authors!!!! I have recopiled in the new version of my
previous document on history of relativity a lot of authors claiming
that SR was not obtained by Einstein. For example Pauli 1955 (who i
already cited here several times)
Now read my recent post Sep 21 on 'what is the history of...' thread
for another NEW support of 'my' thesis Poincare did basically all the
work
Jean Mawhin claims
"His books on Maxwell theory contain the germs of special relativity
and led him to analyze, CORRECT, and name the Lorentz transformations."
"[...] the mathematician Poincaré reached relativistic kinematics via
Maxwell's electromagnetic theory[...]"
Juan R.
Center for CANONICAL |SCIENCE)
.
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- Why Einstein is the founder of special relativity
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