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Understanding Einstein's simple derivation of the LorentzTransformation



 
 
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  #21  
Old July 25th 11, 01:22 PM posted to sci.physics.relativity,sci.physics,sci.math,sci.astro
Tom Adams
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Posts: 9
Default Understanding Einstein's simple derivation of the Lorentz Transformation

On Jul 24, 8:38*pm, Tom Roberts wrote:
Marvin the Martian wrote:
Einstein did NOT derive the Lorentz transformation. *
Lorentz derived the Lorentz transformation.


I disagree. Lorentz obtained the transform equation via an ansatz, without
justification or explanation. He did not even display them in the form we use
today until after 1905. Einstein derived them from his two postulates, and
displayed them in the form used today. I believe Einstein was instrumental in
christening them "Lorentz transformations". The earlier paper by Voigt that
displayed an equivalent transform was not (re-)discovered until the name
"Lorentz transform" was well established.

Tom Roberts


Poincare christened it the Lorentz transformation before 1950. It was
not in it final form then. Poincare christened the "relativity
principle" before 1905, so he, in effect, christened the theory of
realtivity. But Einstein published the final form of the Lorentz
Transformation first, and he dispensed with aether. Poincare was
close to showing that aether could be a undetectible convention in
print by mid 1905 but a bit too late, and he never rejected it because
he thought light needed a medium.
  #22  
Old July 25th 11, 01:38 PM posted to sci.physics.relativity,sci.physics,sci.math,sci.astro
Androcles[_45_]
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Posts: 31
Default Understanding Einstein's simple derivation of the Lorentz Transformation


"Marvin the Martian" wrote in message
...
| On Sun, 24 Jul 2011 23:07:33 -0700, K_h wrote:
|
| "Marvin the Martian" wrote in message
| ...
| On Sun, 24 Jul 2011 20:44:53 -0500, Sam Wormley wrote:
|
| On 7/24/11 4:19 PM, Marvin the Martian wrote:
| Damn it!!
|
| Einstein did NOT derive the Lorentz transformation.
|
| Wanna bet, Marvin!
|
| The Lorentz transformation was originally the result of attempts by
| Lorentz and others to explain how the speed of light was observed to
| be independent of the reference frame, and to understand the
| symmetries of the laws of electromagnetism. Albert Einstein later
| re-derived the transformation from his postulates of special
| relativity. The Lorentz transformation supersedes the Galilean
| transformation of Newtonian physics, which assumes an absolute space
| and time (see Galilean relativity). See:
| http://www.fourmilab.ch/etexts/einstein/specrel/www/
|
| He didn't "re-derive" ****.
|
| Einstein derived the equations (called the Lorentz transformations) from
| the two postulates of special relativity. Historically, though, he was
| not the first to write down those transformations.
|
|
| He showed how his "postulates" are consistent with the Lorentz
| transformation. The Lorentz transformation predates SR - Einstein's
| paper
|
| Einstein showed that the Lorentz transformations are a consequence of
| the two postulates. All physical laws are the same in all reference
| frames and that includes Maxwell's laws.
|
| No. The two "postulates" are a direct result of Maxwell's equations
| (which are NOT laws, btw) and the Lorentz transformation. Einstein was
| confused.


You are ****ing INSANE!

You haven't got a ****ing clue what an equation is, let alone Maxwell's,
you ignorant bull****ting *******. **** off back to your Martian
sanatorium.




  #23  
Old July 25th 11, 01:42 PM posted to sci.physics.relativity,sci.physics,sci.math,sci.astro
Tom Adams
external usenet poster
 
Posts: 9
Default Understanding Einstein's simple derivation of the Lorentz Transformation

On Jul 24, 8:38*pm, Tom Roberts wrote:
Marvin the Martian wrote:
Einstein did NOT derive the Lorentz transformation. *
Lorentz derived the Lorentz transformation.


I disagree. Lorentz obtained the transform equation via an ansatz, without
justification or explanation. He did not even display them in the form we use
today until after 1905. Einstein derived them from his two postulates, and
displayed them in the form used today. I believe Einstein was instrumental in
christening them "Lorentz transformations". The earlier paper by Voigt that
displayed an equivalent transform was not (re-)discovered until the name
"Lorentz transform" was well established.

Tom Roberts


The wiki says the Voigt tranform is not equivalent, that it has a
different value for time dialation:

http://en.wikipedia.org/wiki/Woldemar_Voigt

Poincare christened the Lorentz Transform (when it was not quite in
its final form)
  #24  
Old July 25th 11, 01:46 PM posted to sci.physics.relativity,sci.physics,sci.math,sci.astro
Tom Adams
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Posts: 9
Default Understanding Einstein's simple derivation of the Lorentz Transformation

On Jul 25, 1:39*am, Tom Roberts wrote:
Marvin the Martian wrote:
On Sun, 24 Jul 2011 19:38:57 -0500, Tom Roberts wrote:
Marvin the Martian wrote:
Einstein did NOT derive the Lorentz transformation. Lorentz derived the
Lorentz transformation.
I disagree. Lorentz obtained the transform equation via an ansatz,
without justification or explanation.


No, the Lorentz transform holds Maxwell's equations invariant.


Your "no" is just plain wrong -- go read his 1904 paper. He pulled his "change
of variables" out of the air with no explanation or justification, as I said.

Yes, the Lorentz transforms do hold the ME invariant, but that was first shown
by Poincaré, not Lorentz. Indeed, Lorentz made a mistake in his 1904 paper, and
the equations he presented are not invariant (his error relates to the
transformation of charge density, not the transformation of coordinates). That
paper is the basic reason they carry his name (1904 preceding 1905).

* * * * (Einstein only discussed the vacuum Maxwell-Hertz equations, and
* * * * *thus did not have this issue.)

He did not even display them in
the form we use today until after 1905.


Irrelevant if they are in the form of a matrix or not.


None of the early papers display them as a matrix. That came much later as group
theory was applied. Matrix notation is almost essential to display them in their
full 4-d splendor.

But yes, this is more a side comment, not a major point.

Einstein derived them from his
two postulates, and displayed them in the form used today.


Bull****. The Lorentz transformation was DESIGNED to hold Maxwell's
equations invariant under change of velocity. The first "postulate" is
thus circular logic. So is the second, since the velocity of all
electromagnetic radiation is a constant according to MWE.


Strong words from someone who clearly does not understand either the issues or
the history.

Einstein's contribution was showing that Maxwell's equations and the PoR are not
inconsistent. The PoR is NOT AT ALL "circular logic", because Maxwell's theory
has a unique aether frame, and the PoR does not apply -- in Maxwell's theory the
speed of light is c only in the aether frame, and is most definitely NOT the
same in all frames. The inconsistency between Maxwell's theory (which violates
the PoR) and classical mechanics (which includes the PoR) was the central
conundrum of theoretical physics just before 1905. Especially because
experiments showed that electrical, optical, and magnetic phenomena did obey
some sort of relativity, but Maxwell's theory did not. Note that today's
non-quantum theory of electromagnetism is called "Classical Electrodynamics" and
not "Maxwell's theory" -- it merely retains Maxwell's equations as a part of the
theory, in a way completely unanticipated by Maxwell.

IOW: you are applying today's understanding of electrodynamics, not the context
of 1905. The Maxwell's equations of Classical Electrodynamics are most
definitely NOT Maxwell's theory; Classical Electrodynamics was developed
specifically with SR in mind, and a subset of equations from Maxwell's theory
was rescued from oblivion and carry his name.

* * * * Einstein, of course, made many other major contributions to
* * * * theoretical physics....

You don't seem to understand that before 1905 the coordinate transformations
between Cartesian coordinates of relatively moving frames were strictly the
province of MECHANICS, not electrodynamics. Einstein was breaking new ground
when he melded them together in his 1905 paper. For instance, that's why his
entire first part does not discuss electrodynamics at all, just coordinate and
velocity relationships, i.e. MECHANICS.

Tom Roberts


"Apparently Poincaré was unaware of Larmor's contributions, because he
only mentioned Lorentz and therefore used for the first time the name
"Lorentz transformation"."

http://en.wikipedia.org/wiki/History...ransformations

  #25  
Old July 25th 11, 01:50 PM posted to sci.physics.relativity,sci.physics,sci.math,sci.astro
Tom Adams
external usenet poster
 
Posts: 9
Default Understanding Einstein's simple derivation of the Lorentz Transformation

On Jul 25, 7:59*am, Marvin the Martian wrote:
On Sun, 24 Jul 2011 23:07:33 -0700, K_h wrote:
"Marvin the Martian" wrote in message
m...
On Sun, 24 Jul 2011 20:44:53 -0500, Sam Wormley wrote:


On 7/24/11 4:19 PM, Marvin the Martian wrote:
Damn it!!


Einstein did NOT derive the Lorentz transformation.


* *Wanna bet, Marvin!


The Lorentz transformation was originally the result of attempts by
Lorentz and others to explain how the speed of light was observed to
be independent of the reference frame, and to understand the
symmetries of the laws of electromagnetism. Albert Einstein later
re-derived the transformation from his postulates of special
relativity. The Lorentz transformation supersedes the Galilean
transformation of Newtonian physics, which assumes an absolute space
and time (see Galilean relativity). See:
http://www.fourmilab.ch/etexts/einstein/specrel/www/


He didn't "re-derive" ****.


Einstein derived the equations (called the Lorentz transformations) from
the two postulates of special relativity. *Historically, though, he was
not the first to write down those transformations.


He showed how his "postulates" are consistent with the Lorentz
transformation. The Lorentz transformation predates SR - Einstein's
paper


Einstein showed that the Lorentz transformations are a consequence of
the two postulates. *All physical laws are the same in all reference
frames and that includes Maxwell's laws.


No. The two "postulates" are a direct result of Maxwell's equations
(which are NOT laws, btw) and the Lorentz transformation. Einstein was
confused.

Since the Lorentz transformation is the mathematical transform under
which maxwell's equations are invariant, and SR is nothing more than
the Lorentz transformation itself, this his first "postulate" is
stupid. The


There is nothing stupid about it and relativity is more than just one
set of transformations. *Relativistic invariance applies to gobs of
other things beyond Maxwell's equations *... e.g. the uncertainty
principle, matter waves, the color force, gravity waves, and so on.


The math IS the theory. All the rest is non-science and subjective.

You're impressed that a transformation that was designed to keep
Maxwell's equations invariant... keeps Maxwell's equations invariant.
That, I find amusing.

There is nothing at all about SR that has any relevance at all the
Heisenberg Uncertainty Principle or quantum mechanics. Where the hell did
THAT come from? Einstein didn't even believe or understand QM, he had an
irrational belief and a stupid preconceived bias AGAINST Quantum
mechanics (and a few other things, like Lemaitre's Big Bang Theory).

transform has been verified by experiment and thus isn't a postulate at
all, it is a theory.


Correct, the theory of relativity has been experimentally proven beyond
a reasonable doubt. *The term "postulate" is just a linguistic remnant;
a way of speaking now and no longer a reference to a speculative idea.


Actually, length contraction has never been shown experimentally. Don't
overstate the case. The consistency of the speed of light and time
dilation has been shown experimentally.

I guess you don't know what a postulate is. It has nothing to do with a
speculative idea.

The second postulate about the speed of light being constant is also a
direct result of Maxwell's equations.


It is a trivial result of relativity but not a direct result of
Maxwell's equations.


The hell it isn't. Once you solve Maxwell's equations for the wave
equation, the speed of the wave, c, falls right out.

*If Maxwell's equations are used with the Galilean
transformations then, in many reference frames, the speed of light is
not the same in all directions.


Maxwell's equations are not invariant under a Galilean transformation,
which leads to the conclusion that the physics of electromagnetism would
have to be dependent upon the frame of the observer, which is an absurd
result.

Once you solve for the correct transformation, you see that the speed of
light is a constant wrt all observers.

Einstein's contributed three things:

* He used circular logic to claim that the laws of physics under the
proper invariant transformation are invariant.

* That the speed of light is constant, which he took to be a postulate
instead of looking at Maxwell's equations, which show that the speed of
the electromagnetic wave is a constant.

* He wrote a paper that said "Hey!! What Lorentz and Fitzgerald Said!"

Of his three contributions to SR, the first two are silly and the last
one useful, as even Lorentz didn't understand the significance of the
Lorentz-Fitzgerald transformation. Einstein showed the significance of
the Lorentz-Fitzgerald transformation - THAT was his contribution.- Hide quoted text -

- Show quoted text -


Maxwell never answered the question "constant with respect to what?".
So, he did not realize that constant was meaningless or at least had a
free variable buried in it. Einstein, in effect, figured this out
early in his teens.
  #26  
Old July 25th 11, 02:22 PM posted to sci.physics.relativity,sci.physics,sci.math,sci.astro
Marvin the Martian
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Posts: 655
Default Understanding Einstein's simple derivation of the LorentzTransformation

On Mon, 25 Jul 2011 05:50:37 -0700, Tom Adams wrote:


Maxwell never answered the question "constant with respect to what?".
So, he did not realize that constant was meaningless or at least had a
free variable buried in it. Einstein, in effect, figured this out early
in his teens.


Why would Maxwell even need to answer? Maxwell knew that Maxwell's
equations were not invariant under a Galilean transformation, so the
question is meaningless. He also knew that they were a well proven
theory.

I'm sure that he was puzzled by it, but a good scientist knows what he
doesn't know and doesn't pretend to know everything.
  #27  
Old July 25th 11, 02:36 PM posted to sci.physics.relativity,sci.physics,sci.math,sci.astro
Marvin the Martian
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Posts: 655
Default Understanding Einstein's simple derivation of the LorentzTransformation

On Mon, 25 Jul 2011 05:15:02 -0700, Tom Adams wrote:

On Jul 24, 5:19Â*pm, Marvin the Martian wrote:
Damn it!!

Einstein did NOT derive the Lorentz transformation.

Lorentz derived the Lorentz transformation.


The wiki on the history of the Lorentz tranformation indicates that
Einstein was the first to publish a paper with the Lorentz
transformation in its final from. Poincare had a draft of a paper with
the final form mid 1905.


Define "form", as if this mattered.

Poincare named an number of similar equations "Lorentz Tranformation"
starting around 1901, but Einstein was the first to publish the final
form.

Poincare was close to a theory that made it impossible to detect the
aether wind, but he still thought light needed a medium. The unique
thing Einstein did in 1905 was to be the first to completely reject the
existence of aether.


  #28  
Old July 25th 11, 02:36 PM posted to sci.physics.relativity,sci.physics,sci.math,sci.astro
Androcles[_45_]
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Posts: 31
Default Understanding Einstein's simple derivation of the Lorentz Transformation


"Marvin the Martian" wrote in message
...
| On Mon, 25 Jul 2011 05:50:37 -0700, Tom Adams wrote:
|
|
| Maxwell never answered the question "constant with respect to what?".
| So, he did not realize that constant was meaningless or at least had a
| free variable buried in it. Einstein, in effect, figured this out early
| in his teens.
|
| Why would Maxwell even need to answer? Maxwell knew that Maxwell's
| equations were not invariant under a Galilean transformation, so the
| question is meaningless. He also knew that they were a well proven
| theory.
|
| I'm sure that he was puzzled by it, but a good scientist knows what he
| doesn't know and doesn't pretend to know everything.
|
That rules you out then, doesn't it?


  #29  
Old July 25th 11, 03:08 PM posted to sci.physics.relativity,sci.physics,sci.math,sci.astro
Tom Adams
external usenet poster
 
Posts: 9
Default Understanding Einstein's simple derivation of the Lorentz Transformation

On Jul 25, 9:36*am, Marvin the Martian wrote:
On Mon, 25 Jul 2011 05:15:02 -0700, Tom Adams wrote:
On Jul 24, 5:19*pm, Marvin the Martian wrote:
Damn it!!


Einstein did NOT derive the Lorentz transformation.


Lorentz derived the Lorentz transformation.


The wiki on the history of the Lorentz tranformation indicates that
Einstein was the first to publish a paper with the Lorentz
transformation in its final from. *Poincare had a draft of a paper with
the final form mid 1905.


Define "form", as if this mattered.


Lorentz did not have the math completely correct.

Poincare got the math right. His publication of the transform
predated Einstein by a few months (I incorrectly stated otherwise.)
Poincare was also aware that it made the aether concept superfluous,
but he continued to think that light needed a medium.





Poincare named an number of similar equations "Lorentz Tranformation"
starting around 1901, but Einstein was the first to publish the final
form.


Poincare was close to a theory that made it impossible to detect the
aether wind, but he still thought light needed a medium. *The unique
thing Einstein did in 1905 was to be the first to completely reject the
existence of aether.- Hide quoted text -


- Show quoted text -


  #30  
Old July 25th 11, 04:00 PM posted to sci.physics.relativity,sci.physics,sci.math,sci.astro
Marvin the Martian
external usenet poster
 
Posts: 655
Default Understanding Einstein's simple derivation of the LorentzTransformation

On Mon, 25 Jul 2011 07:08:38 -0700, Tom Adams wrote:

On Jul 25, 9:36Â*am, Marvin the Martian wrote:
On Mon, 25 Jul 2011 05:15:02 -0700, Tom Adams wrote:
On Jul 24, 5:19Â*pm, Marvin the Martian wrote:
Damn it!!


Einstein did NOT derive the Lorentz transformation.


Lorentz derived the Lorentz transformation.


The wiki on the history of the Lorentz tranformation indicates that
Einstein was the first to publish a paper with the Lorentz
transformation in its final from. Â*Poincare had a draft of a paper
with the final form mid 1905.


Define "form", as if this mattered.


Lorentz did not have the math completely correct.

Poincare got the math right. His publication of the transform predated
Einstein by a few months (I incorrectly stated otherwise.) Poincare was
also aware that it made the aether concept superfluous, but he continued
to think that light needed a medium.


Thank you. I don't disagree with that.
 




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