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Groups > sci.physics.relativity > #581481
| From | Thomas Heger <ttt_heg@web.de> |
|---|---|
| Newsgroups | sci.physics.relativity |
| Subject | Re: Annotated version of SRT |
| Date | 2022-03-31 08:04 +0200 |
| Message-ID | <jakuinFdpk5U1@mid.individual.net> (permalink) |
| References | (5 earlier) <2bdf54d6-0e96-4d0f-90fc-5a07a87810b4n@googlegroups.com> <jafmn1FdgsuU1@mid.individual.net> <6ca88e7e-8ad2-4b05-a152-c519063dec5dn@googlegroups.com> <jaie83FthliU1@mid.individual.net> <44d26ee9-6af6-46d7-bfa0-487493f14570n@googlegroups.com> |
Am 30.03.2022 um 20:08 schrieb JanPB:
>>>>>> But I have not dealt with these equations, because I disliked Einstein's
>>>>>> subtraction of magnetic field strength from electric field strength, anyhow.
>>>>>
>>>>> It's nothing peculiar to Einstein, it's the Gaussian system of units.
>>>> I have actually problems with subtracting electric field strength from
>>>> magnetic field strength.
>>>>
>>>> This is like subtracting 1 V from 1 A.
>>>>
>>>> To me this doesn't make any sense at all.
>>>
>>> That's your problem then. If you want to resolve this, you must
>>> learn how various systems of units work.
>> No.
>>
>> In the cgs system electric field strength and magnetic field strength
>> have the same unit of force, because the fields were equated with the
>> process of measuring them.
>>
>> These measuring devices contained deformable springs, which measure a force.
>>
>> Such springs are contained in many analog measuring devices, like a
>> pressure gauge, a cithen balance or a volt-meter.
>>
>> All of them measure something by a reference to a deformable spring.
>>
>> But you cannot subtract Volts from psi, just because both were measured
>> with a deformable spring.
>>
>> To do so would require a physical justification, which was entirely
>> missing in Einstein's text.
>
> No, this is how units of systems work (Gaussian, in this case).
I have given you already the example, that many anolg measuring devices
work with deformable springs, which emasure ultimatively a force.
But still you must not add or subtract different units, like pressure
and weigth, for instance, even if a pressure gauge and a kitchen scale
work with a spring.
It is fantastically stupid nonsese to even advocate such use of values.
> But you haven't answered my question why exactly the same
> addition or subtraction does not bother you when it's written
> in the Lorentz force law:
>
> F/q = E + (v/c) x B
Actually it did bother me, that Einstein tried to subtract electric from
magnetic field strength, but I have not written a comment to all
occurances of the same topic.
Einstein had not used the 'x' of the cross product correctly, but in one
case, where it does not belong, while leaving it away in an equation
(related to your equation from above), where it would belong.
>>> The values of the fields measured by the k observer.
>>> Ultimately they are the way they are because Maxwell's equations
>>> are the way they are.
>>
>> I wouldn't count that as an explanation.
>
> That's where the formula comes from. Can't you derive it for
> yourself?
Actually I have read a book of Maxwell and was not able to find the
equations Einstein used.
So, he had apparently other sources, but didn't consider it necessary to
inform the reader, which his sources were.
>>> He only wanted to show that his method yields the same formulas
>>> for the transformed fields as those obtained by Lorentz. He also
>>> does it more elegantly by being able to get rid of the extra multiplicative
>>> factor by quick geometric considerations while Lorentz works quite
>>> hard on that one detail in his 1904 paper.
>> Here a quote from some text written by Lorentz would be required.
>
> If it was a textbook, yes. In a research paper devoted to a topic everyone
> is talking about - no. It's excessive pedantry in most contexts of this type
> and considered a defect by some.
Don't you think it would be nice to know, WHICH textbook Einstein used?
>> If he actually wanted to do, what you assume he wanted to do, he had to
>> write that himself.
>
> Not needed, he was writing for the professional audience. Another author
> might have said it. Point is, this is a non-issue. Even less than non-issue.
I think, it is in fact an issue!
Actually Einstein mentioned Heinrich Hertz and his adaptation of
Maxwell's equation.
As far as I can tell, Herth did that and developed an own form of
Maxwell's equations. But Hertz died young and his version got more or
less lost.
Now it is hard to say, to what Einstein actually referred with his
equations.
I have read, the Hertz Ansatz used total derivatives, while Einstein
wrote partial differential equation.
Now: what guarantees, that at least Hertz was quoted correctly?
>>>>>> I also found it totally illogic to aplly the geometric relations from
>>>>>> the kinematic part to the 'length' of the field strength vector.
>>>>>
>>>>> These are Lorentz's formulas from his 1904 paper (or earlier,
>>>>> I forget). It's not any more or less illogical than Maxwell's
>>>>> equations. Einstein uses the same "geometric relations" as
>>>>> Lorentz in 1904 to derive those formulas.
>>>> But you cannot apply geometric relations to field strength vectors,
>>>> because the 'length' of the vectors is arbitrary.
>>>
>>> Measured values of those fields are not arbitrary.
>> Sure. But 'length of the field strength vector' is arbitrary, because it
>> is only a geometric representation of field strength.
>>
>> To apply the methods of the kinematic part to the length of the field
>> strength vector is imho nonsense.
>
> This is simple mathematics: there are fields E and B at every point
> in space and at every instant, as measured by K. In other words,
> there are two vector functions: E(x, y, z, t) and B(x, y, z, t).
The term 'space' is undefined, if no reference system is provided.
That is actually the main point of relativity itself: space is 'relative'.
Therefore you cannot refer to coordinates without an anchor, to where
you base these coordinates on.
Space itself does not provide any 'anchor' hence you cannot use
coordinates without a reference point.
This, btw, is also the case for time, because time also requires a
reference point, from which we measure time intervals.
So: 'instant of time' and 'position in space' are illegal constructs, if
you have no reference system.
> Those E and B functions satisfy Maxwell's equations. Meanwhile,
> the observer k assigns the quadruple of numbers (ksi, eta, zeta, tau)
> to every point in space and a time instant. If both K and k consider
> the same event, its corresponding descriptive quadruples (x, y, z, t)
> and (ksi, eta, zeta, tau) are related by a certain linear map called
> "Lorentz transformation". When you apply this transformation, you'll
> discover that the only way to maintain Maxwell's equations is by
> altering E and B according to the formulas you object to (despite
> the fact that identical formulas have been used in the Lorentz force
> formula which never bothered you for some reason).
k and K were coordinate systems. The observers had different names in
Einsteins text. I would prefer to use 'A' as name of the stationary
observer located at the zero spot of K.
The system k moves along the X-axis of K with velocity v into the
positive x-direction.
The system k has also an observer located at its center, for which I
would chose the name 'B'.
This system is also stationary, but only in respect to B, while A moves.
The Lorentz tranformations should now convert observation from K to k or
vice versa.
To do so, also the fields stationary in k and moving in K or vice versa
had to be transformed, too.
To do this we had to read Henry Poincaré, who developed such
transformations and named them after Hendrik Lorentz.
> The entire POINT of Einstein's paper (as originally intended by Einstein) was
> to show that one can sensibly justify the claim that those transformed
> E and B fields would be exactly as physical (according to k) as the
> original E and B were (according to K). This e.g. resolves the
> magnet-and-coil question Einstein mentions in the introduction.
Einstein actual intentions were not my topic. I have only studied a
certain text, into which I wrote annotations.
...
>>>> If the field strength is actually changing with velocity, this would be
>>>> a physical problem, not a geometrical one.
>>>
>>> But the fields do change with the observer, this had been known for
>>> a long time. ...
>>
>> Why then wrote Einstein the opposite?
>
> He didn't write the opposite.
Actually he did:
he wrote on page 14 (roughly in the middle)
X'=X
That 'X' means 'electric field strenth in the x-direction'.
The ' sign ('prime') means 'moving'.
Therefore Einstein assumed, that the electric field strength would not
change upon movement.
But that is apparently wrong, at least Mmaxwell wrote so in 1864.
...
TH
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Annotated version of SRT Thomas Heger <ttt_heg@web.de> - 2022-03-27 08:48 +0200
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Re: Annotated version of SRT Vance Rera <rerv@trscnat.ag> - 2022-04-03 20:38 +0000
Re: Annotated version of SRT JanPB <filmart@gmail.com> - 2022-03-30 11:08 -0700
Re: Annotated version of SRT Thomas Heger <ttt_heg@web.de> - 2022-03-31 08:04 +0200
Re: Annotated version of SRT JanPB <filmart@gmail.com> - 2022-03-31 00:14 -0700
Re: Annotated version of SRT Maciej Wozniak <maluwozniak@gmail.com> - 2022-03-31 00:26 -0700
Re: Annotated version of SRT Thomas Heger <ttt_heg@web.de> - 2022-04-01 07:05 +0200
Re: Annotated version of SRT JanPB <filmart@gmail.com> - 2022-04-01 00:25 -0700
Re: Annotated version of SRT Thomas Heger <ttt_heg@web.de> - 2022-04-02 08:18 +0200
Re: Annotated version of SRT Thomas Heger <ttt_heg@web.de> - 2022-04-01 07:37 +0200
Re: Annotated version of SRT JanPB <filmart@gmail.com> - 2022-04-01 00:39 -0700
Re: Annotated version of SRT Thomas Heger <ttt_heg@web.de> - 2022-04-02 08:38 +0200
Re: Annotated version of SRT Richie Cruze <rcru@bstntap.jp> - 2022-04-02 18:17 +0000
Re: Annotated version of SRT Michael Moroney <moroney@world.std.spaamtrap.com> - 2022-04-02 14:57 -0400
Re: Annotated version of SRT Richie Cruze <rcru@bstntap.jp> - 2022-04-02 19:07 +0000
Re: Annotated version of SRT Michael Moroney <moroney@world.std.spaamtrap.com> - 2022-04-02 15:22 -0400
Re: Annotated version of SRT Richie Cruze <rcru@bstntap.jp> - 2022-04-02 19:33 +0000
Re: Annotated version of SRT JanPB <filmart@gmail.com> - 2022-04-02 12:30 -0700
Re: Annotated version of SRT Richie Cruze <rcru@bstntap.jp> - 2022-04-02 19:53 +0000
Re: Annotated version of SRT JanPB <filmart@gmail.com> - 2022-04-03 00:38 -0700
Re: Annotated version of SRT Elmer Joss <josl@nntdca.mx> - 2022-04-03 08:50 +0000
Re: Annotated version of SRT JanPB <filmart@gmail.com> - 2022-04-03 13:07 -0700
Re: Annotated version of SRT Vance Rera <rerv@trscnat.ag> - 2022-04-03 20:24 +0000
Re: Annotated version of SRT JanPB <filmart@gmail.com> - 2022-04-03 15:34 -0700
Re: Annotated version of SRT Vance Rera <rerv@trscnat.ag> - 2022-04-04 00:25 +0000
Re: Annotated version of SRT JanPB <filmart@gmail.com> - 2022-04-03 19:33 -0700
Re: Annotated nazi excrement JanPB failed the eugenicist IQ-test Hagan Koon <koh@nisnaha.mx> - 2022-04-04 12:30 +0000
Re: Annotated nazi excrement JanPB failed the eugenicist IQ-test JanPB <filmart@gmail.com> - 2022-04-04 12:23 -0700
Re: Annotated nazi excrement JanPB failed the eugenicist IQ-test Lamar Main <lana@rtcpans.in> - 2022-04-04 21:04 +0000
Re: Annotated nazi excrement JanPB failed the eugenicist IQ-test Paul Alsing <pnalsing@gmail.com> - 2022-04-04 17:41 -0700
Re: Annotated nazi excrement JanPB failed the eugenicist IQ-test Michael Moroney <moroney@world.std.spaamtrap.com> - 2022-04-04 21:09 -0400
Re: Annotated nazi excrement JanPB failed the eugenicist IQ-test whodat <whodaat@void.nowgre.com> - 2022-04-05 00:17 -0500
Re: Annotated nazi excrement JanPB failed the eugenicist IQ-test JanPB <filmart@gmail.com> - 2022-04-04 23:03 -0700
Re: Annotated nazi excrement JanPB failed the eugenicist IQ-test Michael Moroney <moroney@world.std.spaamtrap.com> - 2022-04-05 02:10 -0400
Re: Annotated nazi excrement JanPB failed the eugenicist IQ-test Lamar Main <lana@rtcpans.in> - 2022-04-05 09:35 +0000
Re: Annotated nazi excrement JanPB failed the eugenicist IQ-test JanPB <filmart@gmail.com> - 2022-04-05 03:13 -0700
Re: Annotated nazi excrement JanPB failed the eugenicist IQ-test Lamar Main <lana@rtcpans.in> - 2022-04-05 09:33 +0000
Re: Annotated nazi excrement JanPB failed the eugenicist IQ-test JanPB <filmart@gmail.com> - 2022-04-04 16:00 -0700
Re: Annotated nazi excrement JanPB failed the eugenicist IQ-test Lamar Main <lana@rtcpans.in> - 2022-04-05 09:54 +0000
Re: Annotated version of SRT Thomas Heger <ttt_heg@web.de> - 2022-04-05 08:09 +0200
Re: Annotated version of SRT Thomas Heger <ttt_heg@web.de> - 2022-04-03 08:07 +0200
Re: Annotated version of SRT JanPB <filmart@gmail.com> - 2022-04-03 00:43 -0700
Re: Annotated version of SRT Odd Bodkin <bodkinodd@gmail.com> - 2022-04-03 12:38 +0000
Re: Annotated version of SRT Thomas Heger <ttt_heg@web.de> - 2022-04-04 07:14 +0200
Re: Annotated version of SRT JanPB <filmart@gmail.com> - 2022-04-04 01:44 -0700
Re: Annotated version of SRT Thomas Heger <ttt_heg@web.de> - 2022-04-05 08:16 +0200
Re: Annotated version of SRT Odd Bodkin <bodkinodd@gmail.com> - 2022-04-04 13:55 +0000
Re: Annotated version of SRT Thomas Heger <ttt_heg@web.de> - 2022-04-05 08:25 +0200
Re: Annotated version of SRT Michael Moroney <moroney@world.std.spaamtrap.com> - 2022-04-05 02:46 -0400
Re: Annotated version of SRT Odd Bodkin <bodkinodd@gmail.com> - 2022-04-05 14:56 +0000
Re: Annotated version of SRT Michael Moroney <moroney@world.std.spaamtrap.com> - 2022-04-03 15:42 -0400
Re: Annotated version of SRT Thomas Heger <ttt_heg@web.de> - 2022-04-04 07:20 +0200
Re: Annotated version of SRT nospam@de-ster.demon.nl (J. J. Lodder) - 2022-04-04 13:10 +0200
Re: Annotated version of SRT Odd Bodkin <bodkinodd@gmail.com> - 2022-04-04 13:55 +0000
Re: Annotated version of SRT Thomas Heger <ttt_heg@web.de> - 2022-04-05 08:35 +0200
Re: Annotated version of SRT nospam@de-ster.demon.nl (J. J. Lodder) - 2022-04-05 10:28 +0200
Re: Annotated version of SRT Maciej Wozniak <maluwozniak@gmail.com> - 2022-04-05 03:15 -0700
Re: Annotated version of SRT Odd Bodkin <bodkinodd@gmail.com> - 2022-04-05 14:56 +0000
Re: Annotated version of SRT Michael Moroney <moroney@world.std.spaamtrap.com> - 2022-04-05 14:03 -0400
Re: Annotated version of SRT Odd Bodkin <bodkinodd@gmail.com> - 2022-04-05 18:06 +0000
Re: Annotated version of SRT Michael Moroney <moroney@world.std.spaamtrap.com> - 2022-04-05 13:58 -0400
Re: Annotated version of SRT Michael Moroney <moroney@world.std.spaamtrap.com> - 2022-04-04 21:02 -0400
Re: Annotated version of SRT "Paul B. Andersen" <paul.b.andersen@paulba.no> - 2022-04-03 22:31 +0200
Re: Annotated version of SRT nospam@de-ster.demon.nl (J. J. Lodder) - 2022-04-04 13:10 +0200
Re: Annotated version of SRT Mikko <mikko.levanto@iki.fi> - 2022-03-29 10:26 +0300
Re: Annotated version of SRT Mikko <mikko.levanto@iki.fi> - 2022-03-29 10:01 +0300
Re: Annotated version of SRT Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2022-03-30 07:16 +0200
Re: Annotated version of SRT Paparios <mrios@ing.puc.cl> - 2022-03-27 06:41 -0700
Re: Annotated version of SRT "Dono." <eggy20011951@gmail.com> - 2022-03-27 08:31 -0700
Re: Annotated version of SRT Michael Moroney <moroney@world.std.spaamtrap.com> - 2022-03-27 11:43 -0400
Re: Annotated version of SRT Thomas Heger <ttt_heg@web.de> - 2022-03-27 19:28 +0200
Re: Annotated version of SRT Michael Moroney <moroney@world.std.spaamtrap.com> - 2022-03-29 13:52 -0400
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