On Thursday, March 31, 2022 at 10:37:59 PM UTC-7, Thomas Heger wrote:
> Am 31.03.2022 um 09:14 schrieb JanPB:
> > On Wednesday, March 30, 2022 at 11:04:11 PM UTC-7, Thomas Heger wrote:
> >> 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,
> >
> > They are not different units in the Gaussian system.
> >
> >> like pressure
> >> and weigth,
> >
> > N/A. Learn about X if you want to discuss X (esp. if you want to
> > criticise X).
> >
> >> 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.
> >
> > No. You simply don't understand how this works. Some people, when
> > they don't understand something, tend to blame everyone but themselves
> > for this. I cannot fix this problem for you.
> I understand, that magnetic field and electric field have different
> effects, hence are different things, even if related.
>
> So: I cannot subtract 1 amp from 1 Volt, because that does not make much
> more sense then subtraction weigth from pressure.

You don't subtract 1 A from 1 V.

> Both fields are related, but actually different things.
>
> Now Einstein used magnetic field strength in the z-direction callen 'N'
> and subtracted an electric field strength called 'Y' from that (times a
> real valued factor v/c).

It's not Einstein, and it's not even Lorentz (who started it), it's simply
the mathematics of Maxwell's equations.

> I have asked the question, how this equation is related to physical reality.
>
> Now you replied, that electric and magnetic 'force' have the same units

Not force but force per charge.

> in the cgs system (these units are called 'dyne') and therefore might be
> subtracted.
>
> To me this is total nonsense. Actually the term 'force' was already
> wrong, because actually meant was 'field strength'.

Well, this is basic physics. Although units can be a notoriously confusing
subject. Just ask a mathematician what the units of Riemann curvature are :-)

> That 19th century physics didn't know better would not count as an excuse.

It did know better, this part is exactly the same today.

> >>> 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,
> >
> > So why it doesn't bother you when Lorentz does exactly the same?
> Lorentz and his books and papers were not my topic.

But then you cannot write notes singling out Einstein. If you want your
notes to have any meaning, you have to find out the actual layout of
the land so to speak.

> If Einstein wanted to incorporate some parts from Lorentz' works into
> his own paper, he had to write quotes (what he didn't).

No. That's not how science papers work in general. Authors of course
may do this sort of thing but the appropriateness of it in a particular
instance is 100% the author's discretion. In cases where this sort of
thing is truly misleading, the reviewers will point it out.

> occasionally means the cross from the cross product and not the letter x.
> >>>>> 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.
> >
> > The transformed E and B fields were derived by Lorentz, not Maxwell.
> > Einstein only re-derived them to demonstrate the power of his new approach.
> ???
>
> Actually Maxwell was the guy, who developed the equations, that were
> named after him, not Hendrik Lorentz half a century later.

Lookslike we are talking past each other. I was referring to the transformed
E and B fields which are Lorentz's work.

> >> So, he had apparently other sources, but didn't consider it necessary to
> >> inform the reader, which his sources were.
> >
> > It's obvious what his sources were: Lorentz's big paper from the
> > previous year.
> 'Obvious' is an illegal phrase in theoretical physics.

No, it's a standard procedure. It is simply not required to state the
obvious things. In a math research paper about PDEs the author is
not going to say what derivative is. Etc.

> >>>>> 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?
> >
> > No. This is a research paper, not a textbook. The reader knows exactly
> > where the previous stuff comes from.
> 'Textbook' is not meant as equivalent to 'book printed on paper'.
>
> I prefer the simple phrase 'text', which is applicable to any kind of
> written material, on whatever medium.

Either way, it was perfectly standard for Einstein not to mention it.

> >>>> 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.
> >
> > Einstein just wrote Maxwell's equations.
> 'Maxwell's equation's' (as we know them today) were actually not
> written by Maxwell himself.

True but irrelevant. He simply wrote Maxwell's equations as they
were known at the time of publication (Lorentz did the same in his paper).

> The origional 20 quaternion equations of Maxwell were altered by a guy
> named Heaviside after Maxwell died.
>
> Such equations should therefore bear the name 'Heaviside equations'.

No.

> Now you argue, that this is actually obvious to the intended audience of
> professional physicists.
>
> Therefore you should be able to tell me the source and provide a
> reference to the quoted material.

No. It would be obvious to you if you were a part of the intended audience.

> >> I have read, the Hertz Ansatz used total derivatives, while Einstein
> >> wrote partial differential equation.
> >
> > This is irrelevant.
> Not at all.
>
> If the 'Hertz ansatz' is actually quoted correctly, than everything is
> ok, otherwise not.

Irrelevant.

--
Jan