Le 23/02/2023 à 21:57, Richard Hachel a écrit :
> Le 23/02/2023 à 20:33, "Paul B. Andersen" a écrit :
>> Den 23.02.2023 08:46, skrev Thomas Heger:
>>> Am 21.02.2023 um 21:48 schrieb Paul B. Andersen:
>>>>
>>>> The equation is in the beginning of
>>>> § 7. Theory of Doppler’s Principle and of Aberration
>>>>
>>>> If you read on, you will find:
>>>>   ".. an observer is moving with velocity v relatively to
>>>>    an infinitely distant source of light of frequency ν (nu),
>>>>    in such a way that the connecting line “source-observer”
>>>>    makes the angle φ with the velocity of the observer referred
>>>>    to a system of co-ordinates which is at rest relatively to
>>>>    the source of light,.."
>>>>
>>>> You demonstrate that you do not understand what this means
>>>> in your "annotation".
>>>>   "To define velocity in respect to infinity would be a very
>>>>    bad idea, because ‘Infinitely distant' is remaining infinitely
>>>>    distant, even if you move in respect to infinity. Velocity
>>>>    is defined as v=dx/dt. And because that 'x' in dx is not
>>>>    changing (stays always 'infinity'), v will remain zero, however
>>>>    you move. Therefore, your velocity in respect to infinity is always
>>>>    zero."
>>>>
>>>> This is nonsense!
>>
>>>
>>> Why is this nonsense? ?
>>
>> This was explained in the part you snipped.
>> Do you not read what you are responding to?
>>
>>>> The source is stationary in K at infinity.
>>>> The observer is moving at the velocity v⃗ in K, in such a way
>>>> that the connecting line “source-observer” makes the angle φ with
>>>> the velocity.
>>>>
>>>> Look.
>>>> A star with parallax - say < 1"- can be considered to be
>>>> infinitely far away, and stationary in the solar frame.(K)
>>>> And you are saying that the velocity of the Earth in the solar
>>>> frame is always zero because the star is so far away! 😂
>>
>> Please bother to read the following this time!
>>
>> Let us be concrete:
>> Let the source be a star in the ecliptic plane.
>> At the time of observation, the direction to the star is
>> such that the Sun, Earth and star are on the same line.
>> Your velocity in the Solar frame is ≈ 30 km/s, the direction
>> is perpendicular to said line.
>>
>> Note that the distance to the star is irrelevant, it is
>> only the direction that matters. So it might as well
>> be considered to be infinitely far away.
>>
>> So: (see Einstein's words above)
>> The connecting line “source-observer” makes the angle φ = 90⁰
>> with the velocity of the observer (you) referred to a system
>> of co-ordinates (the solar system) which is at rest relatively
>> to the source of light.
>>
>> Do you now understand that your velocity is perfectly well defined
>> even if the distance to the star is unknown (considered to be infinite)?
>> It is indeed nonsensical to claim otherwise.
>>
>> From the above, we can calculate at what angle φ' you will see the star:
>>
>> Einstein's equation for aberration:
>> cosφ′ = (cosφ − v/c)/(1 − cosφ·v/c)
>>
>> φ = 90⁰, cosφ = 0, v/c = 30000/3e8 = 1e-4
>>
>> cosφ′ = -1e-4, φ′≈ (π/2 - 1e-4) radians = 90⁰-20.6"
>>
>> To see the star, you have to point your telescope
>> 20.6 arcseconds in front of the line Sun-Earth-star.
>
> What you say is entirely true, except that you say it was calculated by
> Einstein.
>
> We must stop putting Einstein all over the place, it becomes ridiculous.
>
> This is false, the calculation is derived by itself from the Poincaré-Lorentz
> transformations.
>
> Just take these transformations as I gave them myself, making them more
> "physically obvious", and you get right away:
>
> <http://news2.nemoweb.net/jntp?f39m55jBy0YQroBCrPBwVVIN-m4@jntp/Data.Media:1>
>
> As we see, the angle has no relation to the distance from the star.
>
> On the other hand, if we know the distance of the star in the solar reference
> frame, we can know when its light was emitted (To=d/c),
> but we can also know what its position will be in the reference frame of the
> terrestrial observer (the star will be further away and its light emitted
> earlier).
>
> It's extremely simple and very obvious if you understand how transformations
> work (it's high school level).
>
>> To see the star, you have to point your telescope
>> 20.6 arcseconds in front of the line Sun-Earth-star.
>
> Absolutly.
>
> R.H.

View by Nemo

<http://news2.nemoweb.net/?DataID=dAuhdCA-MTa4mn1f0yVPqbUk3qU@jntp>

R.H.

Am 23.02.2023 um 09:28 schrieb JanPB:
> On Thursday, February 23, 2023 at 8:39:15 AM UTC+1, Thomas Heger wrote:
>> Am 21.02.2023 um 10:44 schrieb JanPB:
>>> On Monday, February 20, 2023 at 9:25:33 PM UTC+1, Thomas Heger wrote:
>>>> Am 18.02.2023 um 11:36 schrieb J. J. Lodder:
>>>>> Thomas Heger <ttt...@web.de> wrote:
>>>>>
>>>>>> Am 18.02.2023 um 10:48 schrieb JanPB:
>>>>>>> On Saturday, February 18, 2023 at 10:02:00 AM UTC+1, Thomas Heger wrote:
>>>>>>>> Hi NG
>>>>>>>>
>>>>>>>> now I have finished my latest version after rewriting almost all
>>>>>>>> annotations from previous versions.
>>>>>>>>
>>>>>>>> The idea behind writing aannotations is this:
>>>>>>>>
>>>>>>>> take a certain text (here: 'On the electrodynamics of moving bodies' by
>>>>>>>> A. Einstein from 1905) and write annotations into it, similar to how a
>>>>>>>> professor writes annotations into the homework of a student.
>>>>>>>
>>>>>>> It only makes sense if it's truly a teacher-pupil relationship. In other
>>>>>>> words, it only makes sense if the person making the annotations
>>>>>>> understands the content.
>>>>>>
>>>>>>
>>>>>> This is actually true.
>>>>>>
>>>>>> Iow: you can only learn to swim by swimming.
>>>>>>
>>>>>> This is why the method works really great: you are forced to understand
>>>>>> every single word in the text, every equation, every picture or reference...
>>>>>
>>>>> Your problem in a nutshell.
>>>>> The point is not 'understanding the words'.
>>>>> You need to get the contents.
>>>>> (and of course any modern undergraduate textbook
>>>>> is far more suitable for that)
>>>>>
>>>> Actually I'm not dealing with the methaphysical content of Einstein's text.
>>>>
>>>> My annotations are mainly about formal issues
>>>
>>> They are either irrelevant or incorrect.
>> Well, this is theoretical physics and that is based on perfectionism in
>> formal and mathematical aspects.
>
> No, this is most definitely not how this works. Perfectionism is in fact
> detrimental to understanding in scientific writing. This is well-known.

In this case I have written about the authors and the text they write.

From theoretical physicists I would actually expect great precison,
because there is not correction of thoughts by contradicting experiments.

Other physicists, which conduct experiments could behave a little
carelessly and adjust their results stepwise to fit to experiments.

But theoretical physicsts depend on valid proofs, which need to be
absolutely perfect.

Any small deviation from the best way possible whould render all their
efforts useless, because nothing would follow from an error.

>> I have, for instance, complained about the reuse vor variable names.
>
> Yes, this is standard and a great aid to exposition. But it presumes
> a certain degree of competence on the part of the writer and the reader.

sure, but I'm the reader and complained about unidentifiable variable names.

Only one reason was the reuse of symbols for other purposes.

Another stumbling block was Einsteins habbit, to use the same symbols
for different types of mathematical objects.

For instance we have:
numbers
scalar quantities
vectors
functions

which are different types of objects.

But Einstein used vectors like e.g. velocity as if they were magnitudes
of the velocity vector.

He also treated v/c as a scalar, while it is actually a vector.

He also used tau as time measure and also as name of a function and
subesequently switched back and forth between such meanings.
This made
tau(x,y,z,t) hard to interpret, because it could be:

tau* (x,y,z,t) (where tau ist a time measure and (x,y,z,t) a four vector)

or

tau(x,y,z,t) (where tau is a function and (x,y,z,t) its argument).

This ambiguity could easily be avoided by using different fonts for
different types of objects.

For instance functions could be written in bold capital letters and
vectors in small bold letters.

Also the use of subscripts was inconstistent.

I would personally use _x as subscript, if a quantity belongs to the x-axis.

E.g. the x-componentent of the electric field strength vector could be
called E_x.

But instead of that Einstein used the variable name 'X', even if that X
was already in use as name of the x-axis of K.

He also treated that 'X' as a vector, even if components of vectors are
numerical values.

Even worse was the geometrical treatment of the 'length' of the field
strength vector.

>> E.g. x' was used for different purposes or P or A.
>
> Again, this is standard and a great aid to exposition.

It was actually very hard to keep track of Einsteins variables.

I counted eight different uses of the tall letter 'A'.

E.g. One rather strange use of 'A' was his unitary sign 'A', used as
internal reference. But there was no 'B' (let alone 'C'), even if
numbers at equations were already invented.

....
>> I also wanted usual names like 'p' for pressure, because if other names
>> than common ones were used, then all variables need proper definitions.
>>
>> But actually none of the variables were defined, what made the intended
>> meaning very difficult to identify.
>
> Everything is defined to a sufficient degree in that paper.

There are certain conventions among physicist to name certain quantities.

For instance v is a usually a velocity or t a time value.

But Einstein used unconventional names, too, like ny for frequency, P
for presssure or W for energy.

Therefore all variables need to be defined properly and explicitly,
because you cannot know, which other variable names are also unconventional.
....

TH

Den 23.02.2023 21:57, skrev Richard Hachel:
> Le 23/02/2023 à 20:33, "Paul B. Andersen" a écrit :
>>
>> Let us be concrete:
>> Let the source be a star in the ecliptic plane.
>> At the time of observation, the direction to the star is
>> such that the Sun, Earth and star are on the same line.
>> Your velocity in the Solar frame is ≈ 30 km/s, the direction
>> is perpendicular to said line.
>>
>> Note that the distance to the star is irrelevant, it is
>> only the direction that matters. So it might as well
>> be considered to be infinitely far away.
>>
>> So: (see Einstein's words above)
>>   The connecting line “source-observer” makes the angle φ = 90⁰
>>   with the velocity of the observer (you) referred to a system
>>   of co-ordinates (the solar system) which is at rest relatively
>>   to the source of light.
>>
>> Do you now understand that your velocity is perfectly well defined
>> even if the distance to the star is unknown (considered to be infinite)?
>> It is indeed nonsensical to claim otherwise.
>>
>>  From the above, we can calculate at what angle φ' you will see the star:
>>
>> Einstein's equation for aberration:
>>    cosφ′ = (cosφ − v/c)/(1 − cosφ·v/c)
>>
>>    φ = 90⁰,  cosφ = 0, v/c = 30000/3e8 = 1e-4
>>
>>    cosφ′ = -1e-4, φ′≈ (π/2 - 1e-4) radians = 90⁰-20.6"
>>
>> To see the star, you have to point your telescope
>> 20.6 arcseconds in front of the line Sun-Earth-star.

>
> What you say is entirely true, except that you say it was calculated by
> Einstein.
>

So it was NOT calculated by Einstein, but it WAS calculated by YOU? :-D

>
> Just take these transformations as I gave them myself, making them more
> "physically obvious", and you get right away:
>
> <http://news2.nemoweb.net/jntp?f39m55jBy0YQroBCrPBwVVIN-m4@jntp/Data.Media:1>
>
> R.H.

--
Paul

https://paulba.no/

Le 24/02/2023 à 14:39, "Paul B. Andersen" a écrit :
> Den 23.02.2023 21:57, skrev Richard Hachel:
>> Le 23/02/2023 à 20:33, "Paul B. Andersen" a écrit :
>>>
>>> Let us be concrete:
>>> Let the source be a star in the ecliptic plane.
>>> At the time of observation, the direction to the star is
>>> such that the Sun, Earth and star are on the same line.
>>> Your velocity in the Solar frame is ≈ 30 km/s, the direction
>>> is perpendicular to said line.
>>>
>>> Note that the distance to the star is irrelevant, it is
>>> only the direction that matters. So it might as well
>>> be considered to be infinitely far away.
>>>
>>> So: (see Einstein's words above)
>>>   The connecting line “source-observer” makes the angle φ = 90⁰
>>>   with the velocity of the observer (you) referred to a system
>>>   of co-ordinates (the solar system) which is at rest relatively
>>>   to the source of light.
>>>
>>> Do you now understand that your velocity is perfectly well defined
>>> even if the distance to the star is unknown (considered to be infinite)?
>>> It is indeed nonsensical to claim otherwise.
>>>
>>>  From the above, we can calculate at what angle φ' you will see the star:
>>>
>>> Einstein's equation for aberration:
>>>    cosφ′ = (cosφ − v/c)/(1 − cosφ·v/c)
>>>
>>>    φ = 90⁰,  cosφ = 0, v/c = 30000/3e8 = 1e-4
>>>
>>>    cosφ′ = -1e-4, φ′≈ (π/2 - 1e-4) radians = 90⁰-20.6"
>>>
>>> To see the star, you have to point your telescope
>>> 20.6 arcseconds in front of the line Sun-Earth-star.
>
>>
>> What you say is entirely true, except that you say it was calculated by
>> Einstein.
>>
>
> So it was NOT calculated by Einstein, but it WAS calculated by YOU? :-D
>
>>
>> Just take these transformations as I gave them myself, making them more
>> "physically obvious", and you get right away:
>>
>> <http://news2.nemoweb.net/jntp?f39m55jBy0YQroBCrPBwVVIN-m4@jntp/Data.Media:1>
>>
>> R.H.

I remind you that I have always said that there were things that did not
fit in the theory of relativity.

The most difficult thing was not to say what, but why.

As for the invariance of the observable speed of light, I found it alone,
as well as the Lorentz transformations, as well as the general addition
equation of speeds, as well as the explanation of Langevin's paradox
(infinitely better for me but it seems that I am fat and arrogant), as
well as all that must be done to understand accelerated media (almost
everything that relativists say about it is false because their
mathematical space-time is not physical).

So yes, otherwise, I find the same thing as you, with the very simple
formulas that I gave yesterday in this post.

R.H.

--
"Mais ne nous trompons pas :
il n'y a pas de violence qu'avec des armes : il y a des situations de
violence."
Abbé Pierre"<http://news2.nemoweb.net/?DataID=f_7j6f7WjvnmIDjy8lqakhqKZVw@jntp>

M.D. Richard "Hachel" Lengrand wrote:
> I am fat and arrogant

You are. Also ignorant and an imbecile.

Le 24/02/2023 à 16:29, le très excellent Python (Jean-Pierre Messager
pour les intimes) a écrit de moi, bien qu'il soit incapable de comprendre
ce que c'est qu'une vitesse réelle, une vitesse observable et une vitesse
apparente dans la pensée hachelienne, qu'il me trouve fat et arrogant:

> You are. Also ignorant and an imbecile.

Mais parlez donc, beau sire!

Faites qu'on vous admire.

D'un point de vue plus pratique, que pensez-vous de ça?

<http://news2.nemoweb.net/jntp?fC_zg0U-o2x_RDBpAXaog5CaJAY@jntp/Data.Media:1>

De ça?

<http://news2.nemoweb.net/jntp?fC_zg0U-o2x_RDBpAXaog5CaJAY@jntp/Data.Media:2>

Ou de ça?

<http://news2.nemoweb.net/jntp?fC_zg0U-o2x_RDBpAXaog5CaJAY@jntp/Data.Media:3>

R.H.
<http://news2.nemoweb.net/?DataID=fC_zg0U-o2x_RDBpAXaog5CaJAY@jntp>

Am 23.02.2023 um 09:52 schrieb JanPB:
> On Thursday, February 23, 2023 at 8:46:44 AM UTC+1, Thomas Heger wrote:
>> Am 21.02.2023 um 21:48 schrieb Paul B. Andersen:
>>> Den 20.02.2023 21:49, skrev Thomas Heger:
>>>> Am 20.02.2023 um 10:30 schrieb JanPB:
>>>>> On Sunday, February 19, 2023 at 9:36:25 PM UTC+1, Paul B. Andersen
>>>>> wrote:
>>>>>> Den 18.02.2023 11:17, skrev Thomas Heger:
>>>>>>>
>>>>>>> This is why the method works really great: you are forced to
>>>>>>> understand
>>>>>>> every single word in the text, every equation, every picture or
>>>>>>> reference...
>>>
>>>>>> Let's see an example of how Thomas is "forced to understand
>>>>>> every single word in the text".
>>>>>>
>>>>>> In § 7. Theory of Doppler’s Principle and of Aberration
>>>>>> Einstein starts with defining an em-wave:
>>>>>>
>>>>>> "In the system K, very far from the origin of co-ordinates,
>>>>>> let there be a source of electrodynamic waves, which in
>>>>>> a part of space containing the origin of co-ordinates may
>>>>>> be represented to a sufficient degree of approximation
>>>>>> by the equations
>>>>>> X = X₀ sin Φ, L = L₀ sin Φ,
>>>>>> Y = Y₀ sin Φ, M = M₀ sin Φ,
>>>>>> Z = Z₀ sin Φ, N = N₀ sin Φ,
>>>>>> where
>>>>>> Φ = ω {t − (lx + my + nz)/c } .
>>>>>>
>>>>>> Here (X₀, Y₀, Z₀) and (L₀, M₀, N₀) are the vectors defining
>>>>>> the amplitude of the wave-train, and l, m, n the direction-cosines
>>>>>> of the wave-normals."
>>>>>>
>>>>>> Thomas has two "annotations" for the equation of
>>>>>> the phase Φ(t,x,y,z):
>>>>>>
>>>>>> "Phi is the product of a time interval and a frequency term.
>>>>>> If you multiply frequency and a duration, you get the number
>>>>>> of waves in a certain interval plus a phase angle. Such
>>>>>> dimensionless numbers are useful for the equations above,
>>>>>> where they describe the sinusoidal behaviour of the waves.
>>>>>> The 'time-interval' t is not time per se (as in our dates
>>>>>> and times of our clocks), because the start of the wave was
>>>>>> certainly not synchronized with the birth of Christ.
>>>>>> Instead t starts with a zero of the sinusoidal wave, while
>>>>>> the small term 1/c(lx + my + nz) could eventually be meant
>>>>>> as phase shift."
>>>
>>> Here you demonstrate:
>>> - You don't know that Φ is the phase of the wave.
>>> Or rather: you don't know what the phase of a wave is.
>>> - You don't understand that (t,x,y,z) are the coordinates
>>> of an event.
>>> - You don't understand that the phase is a function
>>> Φ(t,x,y,z) of these coordinates. Φ = ω{t-(lx + my + nz)/c}
>>>
>>> And this is despite the fact that I (an probably several others)
>>> have explained this to you before:
>>>
>>> |03.04.2021 Paul B. Andersen wrote:
>>> |> Look at this:
>>> |> https://paulba.no/pdf/AberrationDoppler.pdf
>>> |>
>>> |> I am not expecting you to understand anything of it,
>>> |> the point is that equation (1) and (2) are the equations
>>> |> for the electric field in an EM wave moving in the positive
>>> |> z direction. Equation (2) is the phase of the wave.
>>> |> Equation (6) is the same equation as:
>>> |> Φ = ω{t − (lx+my+nz)/c}
>>> |> with the slight difference that this is the phase
>>> |> of a wave propagating in a general direction.
>>> |>
>>> |> Anybody with the slightest knowledge of physics
>>> |> will immediately recognize these equations, and will know
>>> |> that the wavelength is 2πc/ω. (λ = c/f)
>>>
>>> |06.04.2021 Paul B. Andersen wrote:
>>> |> Thomas, in all elementary physics books you will find
>>> |> a chapter with the name "Wave motion" or similar.
>>> |>
>>> |> I looked in the first physic book I ever read,
>>> |> Margenau et al: Physics, from 1953.
>>> |> Here I find as the equation for a wave (any wave):
>>> |>
>>> |> y = A⋅sin(2π(t/P-x/λ))
>>> |>
>>> |> where P is the period, P = 1/f, and λ is the wavelength
>>> |>
>>> |> The argument of a sinus is always a phase,(an angle in radians), so:
>>> |> Φ(t,x) = 2π(t/P-x/λ)
>>> |>
>>> |> This equation can be written on several equivalent forms:
>>> |>
>>> |> Einstein's equation was:
>>> |> Φ = ω{t − (lx+my+nz)/c}
>>> |> In the case where the wave is moving along the x-axis,
>>> |> the direction cosines are l = 1, m = 0 and n = 0,
>>> |> and the equation for the phase can be written:
>>> |> Φ(t,x) = ω(t - x/c) = (ω⋅t - (ω/c)⋅x)
>>> |>
>>> |> inserting ω = 2πf yields:
>>> |> Φ(t,x) = (2πf⋅t − (2πf/c)⋅x) = 2π(f⋅t - (f/c)⋅x)
>>> |>
>>> |> inserting λ = c/f yields:
>>> |> Φ(t,x) = 2π(f⋅t − (1/λ)⋅x)
>>> |>
>>> |> You don't have to be a physicist to know this,
>>> |> it is _very_ elementary physics, and it was
>>> |> known as such _long_ before 1905.
>>>
>>> If you don't understand these equations, you are not
>>> competent to read the paper where the equations occur.
>>>
>>>
>>>>>
>>>>> What he writes here is incredibly naive, this is high school wave motion
>>>>> stuff here he is trying to discuss.
>>>
>>> You said you were "forced to understand every single word in the text"
>>> But you keep demonstrating that you understand nothing of the text:
>>>
>>>>
>>>> Actually not.
>>>>
>>>> I think mainly like a programmer, who writes a code-review or
>>>> something similar.
>>>> I read a text and find a symbol like 'x', for instance.
>>>>
>>>> Now x is not a variable and much less a physical quantity. Thaat 'x'
>>>> is simply a short text, which consists from a single ACII character 'x'.
>>>>
>>>> That is is taken as the name of a variable.
>>>>
>>>> Variables store something. The 'x' is a 'handle' by which that storage
>>>> is addressed.
>>>>
>>>> Now I ask the question, what shall be stored at that storage.
>>>>
>>>> So, I scimmed the text for possible meanings of 'x'.
>>>>
>>>> The first occurance of 'x' denotes a scalar part of a postition vector
>>>> in coordinate system K.
>>>>
>>>> So, ok, 'x' stores scalars, which mean a number, by which the unit
>>>> vector of that coordinate system shall be multiplied.
>>>>
>>>> All together they build a vector (x,y,z), which belongs to system K.
>>>>
>>>> That is nice and no problem at all.
>>>>
>>>> But any further occurances of 'x' are therefore meant as scalar part
>>>> of position vector (x,y,z) from system K.
>>>
>>> This reminds me of a Dilbert story.
>>> I can't find the cartoon, but the story goes like this:
>>>
>>> Teacher solving equations on the blackboard, saying:
>>> " .. and then x = 5"
>>>
>>> Dilbert raising his hand, saying:
>>> "Wait a darn minute! Yesterday you said x = 3!"
>>>
>>>>
>>>> Similar with l, m, and n, which also occur in that equation.
>>>>
>>>> These are 'direction cosines' and belong to angles of the incoming ray
>>>> at the position of the observer.
>>>>
>>>> This is also nice and no problem at all.
>>>>
>>>> But what does the author want to say with this equation, if the
>>>> position in K is not defined and the postion of the observer or a ray
>>>> arriving there were not under consideration?
>>>
>>> This is defined:
>>>
>>> The equation is in the beginning of
>>> § 7. Theory of Doppler’s Principle and of Aberration
>>>
>>> If you read on, you will find:
>>> ".. an observer is moving with velocity v relatively to
>>> an infinitely distant source of light of frequency ν (nu),
>>> in such a way that the connecting line “source-observer”
>>> makes the angle φ with the velocity of the observer referred
>>> to a system of co-ordinates which is at rest relatively to
>>> the source of light,.."
>>>
>>> You demonstrate that you do not understand what this means
>>> in your "annotation".
>>> "To define velocity in respect to infinity would be a very
>>> bad idea, because ‘Infinitely distant' is remaining infinitely
>>> distant, even if you move in respect to infinity. Velocity
>>> is defined as v=dx/dt. And because that 'x' in dx is not
>>> changing (stays always 'infinity'), v will remain zero, however
>>> you move. Therefore, your velocity in respect to infinity is always
>>> zero."
>>>
>>> This is nonsense!
>> Why is this nonsense??
>>
>> Infinity is not a location, but infinitly far away.
>>
>> A signal from infinity would need infinite time to reach us, hence would
>> never be here.
>
> This is the very basis of scientific (and mathematical)
> modelling. In contexts like this, infinity refers to a limit of arbitrarily
> large distance with the signal (the plane wave) already presumed
> omnipresent.

On Monday, February 20, 2023 at 9:30:10 PM UTC+1, Thomas Heger wrote:
> Am 18.02.2023 um 11:52 schrieb JanPB:
> > On Saturday, February 18, 2023 at 11:17:06 AM UTC+1, Thomas Heger wrote:
> >> Am 18.02.2023 um 10:48 schrieb JanPB:
> >>> On Saturday, February 18, 2023 at 10:02:00 AM UTC+1, Thomas Heger wrote:
> >>>> Hi NG
> >>>>
> >>>> now I have finished my latest version after rewriting almost all
> >>>> annotations from previous versions.
> >>>>
> >>>> The idea behind writing aannotations is this:
> >>>>
> >>>> take a certain text (here: 'On the electrodynamics of moving bodies' by
> >>>> A. Einstein from 1905) and write annotations into it, similar to how a
> >>>> professor writes annotations into the homework of a student.
> >>>
> >>> It only makes sense if it's truly a teacher-pupil relationship. In other words,
> >>> it only makes sense if the person making the annotations understands
> >>> the content.
> >> This is actually true.
> >>
> >> Iow: you can only learn to swim by swimming.
> >
> > My point was that that's not what you are doing. What you are doing is
> > like trying to learn playing piano by exclusively studying the fabric of
> > the tuxedo (because piano players tend to wear tuxedo for recitals).
> I wrote annotations into the English version of Einstein's text.
>
> That is something legal and my hobby.
>
> If you like to critizise my annotations, than feel free to do so.
>
> Simply take any of my comments, quote that and show, where my commentens
> were wrong.

I may do that for other readers. It most likely not work for you because
it never does (you must know the basics before you can follow the
explanations or refutations).

> Anything else like telling me what I need to do and what I should read
> or learn, that is not related to the subject.
>
> I surely apprecheate other comments, too, but mainly I'm interested in
> comments about my annotations.

There can be no comments made about your annotations because they
are all not even wrong. Again, it's as if someone started seriously debating
a music critic who focuses exclusively on the clothes the conductor wears.

--
Jan

On Saturday, February 25, 2023 at 12:07:15 PM UTC+1, Thomas Heger wrote:
> Am 23.02.2023 um 09:52 schrieb JanPB:
> > On Thursday, February 23, 2023 at 8:46:44 AM UTC+1, Thomas Heger wrote:
> >> Am 21.02.2023 um 21:48 schrieb Paul B. Andersen:
> >>> Den 20.02.2023 21:49, skrev Thomas Heger:
> >>>> Am 20.02.2023 um 10:30 schrieb JanPB:
> >>>>> On Sunday, February 19, 2023 at 9:36:25 PM UTC+1, Paul B. Andersen
> >>>>> wrote:
> >>>>>> Den 18.02.2023 11:17, skrev Thomas Heger:
> >>>>>>>
> >>>>>>> This is why the method works really great: you are forced to
> >>>>>>> understand
> >>>>>>> every single word in the text, every equation, every picture or
> >>>>>>> reference...
> >>>
> >>>>>> Let's see an example of how Thomas is "forced to understand
> >>>>>> every single word in the text".
> >>>>>>
> >>>>>> In § 7. Theory of Doppler’s Principle and of Aberration
> >>>>>> Einstein starts with defining an em-wave:
> >>>>>>
> >>>>>> "In the system K, very far from the origin of co-ordinates,
> >>>>>> let there be a source of electrodynamic waves, which in
> >>>>>> a part of space containing the origin of co-ordinates may
> >>>>>> be represented to a sufficient degree of approximation
> >>>>>> by the equations
> >>>>>> X = X₀ sin Φ, L = L₀ sin Φ,
> >>>>>> Y = Y₀ sin Φ, M = M₀ sin Φ,
> >>>>>> Z = Z₀ sin Φ, N = N₀ sin Φ,
> >>>>>> where
> >>>>>> Φ = ω {t − (lx + my + nz)/c } .
> >>>>>>
> >>>>>> Here (X₀, Y₀, Z₀) and (L₀, M₀, N₀) are the vectors defining
> >>>>>> the amplitude of the wave-train, and l, m, n the direction-cosines
> >>>>>> of the wave-normals."
> >>>>>>
> >>>>>> Thomas has two "annotations" for the equation of
> >>>>>> the phase Φ(t,x,y,z):
> >>>>>>
> >>>>>> "Phi is the product of a time interval and a frequency term.
> >>>>>> If you multiply frequency and a duration, you get the number
> >>>>>> of waves in a certain interval plus a phase angle. Such
> >>>>>> dimensionless numbers are useful for the equations above,
> >>>>>> where they describe the sinusoidal behaviour of the waves.
> >>>>>> The 'time-interval' t is not time per se (as in our dates
> >>>>>> and times of our clocks), because the start of the wave was
> >>>>>> certainly not synchronized with the birth of Christ.
> >>>>>> Instead t starts with a zero of the sinusoidal wave, while
> >>>>>> the small term 1/c(lx + my + nz) could eventually be meant
> >>>>>> as phase shift."
> >>>
> >>> Here you demonstrate:
> >>> - You don't know that Φ is the phase of the wave.
> >>> Or rather: you don't know what the phase of a wave is.
> >>> - You don't understand that (t,x,y,z) are the coordinates
> >>> of an event.
> >>> - You don't understand that the phase is a function
> >>> Φ(t,x,y,z) of these coordinates. Φ = ω{t-(lx + my + nz)/c}
> >>>
> >>> And this is despite the fact that I (an probably several others)
> >>> have explained this to you before:
> >>>
> >>> |03.04.2021 Paul B. Andersen wrote:
> >>> |> Look at this:
> >>> |> https://paulba.no/pdf/AberrationDoppler.pdf
> >>> |>
> >>> |> I am not expecting you to understand anything of it,
> >>> |> the point is that equation (1) and (2) are the equations
> >>> |> for the electric field in an EM wave moving in the positive
> >>> |> z direction. Equation (2) is the phase of the wave.
> >>> |> Equation (6) is the same equation as:
> >>> |> Φ = ω{t − (lx+my+nz)/c}
> >>> |> with the slight difference that this is the phase
> >>> |> of a wave propagating in a general direction.
> >>> |>
> >>> |> Anybody with the slightest knowledge of physics
> >>> |> will immediately recognize these equations, and will know
> >>> |> that the wavelength is 2πc/ω. (λ = c/f)
> >>>
> >>> |06.04.2021 Paul B. Andersen wrote:
> >>> |> Thomas, in all elementary physics books you will find
> >>> |> a chapter with the name "Wave motion" or similar.
> >>> |>
> >>> |> I looked in the first physic book I ever read,
> >>> |> Margenau et al: Physics, from 1953.
> >>> |> Here I find as the equation for a wave (any wave):
> >>> |>
> >>> |> y = A⋅sin(2π(t/P-x/λ))
> >>> |>
> >>> |> where P is the period, P = 1/f, and λ is the wavelength
> >>> |>
> >>> |> The argument of a sinus is always a phase,(an angle in radians), so:
> >>> |> Φ(t,x) = 2π(t/P-x/λ)
> >>> |>
> >>> |> This equation can be written on several equivalent forms:
> >>> |>
> >>> |> Einstein's equation was:
> >>> |> Φ = ω{t − (lx+my+nz)/c}
> >>> |> In the case where the wave is moving along the x-axis,
> >>> |> the direction cosines are l = 1, m = 0 and n = 0,
> >>> |> and the equation for the phase can be written:
> >>> |> Φ(t,x) = ω(t - x/c) = (ω⋅t - (ω/c)⋅x)
> >>> |>
> >>> |> inserting ω = 2πf yields:
> >>> |> Φ(t,x) = (2πf⋅t − (2πf/c)⋅x) = 2π(f⋅t - (f/c)⋅x)
> >>> |>
> >>> |> inserting λ = c/f yields:
> >>> |> Φ(t,x) = 2π(f⋅t − (1/λ)⋅x)
> >>> |>
> >>> |> You don't have to be a physicist to know this,
> >>> |> it is _very_ elementary physics, and it was
> >>> |> known as such _long_ before 1905.
> >>>
> >>> If you don't understand these equations, you are not
> >>> competent to read the paper where the equations occur.
> >>>
> >>>
> >>>>>
> >>>>> What he writes here is incredibly naive, this is high school wave motion
> >>>>> stuff here he is trying to discuss.
> >>>
> >>> You said you were "forced to understand every single word in the text"
> >>> But you keep demonstrating that you understand nothing of the text:
> >>>
> >>>>
> >>>> Actually not.
> >>>>
> >>>> I think mainly like a programmer, who writes a code-review or
> >>>> something similar.
> >>>> I read a text and find a symbol like 'x', for instance.
> >>>>
> >>>> Now x is not a variable and much less a physical quantity. Thaat 'x'
> >>>> is simply a short text, which consists from a single ACII character 'x'.
> >>>>
> >>>> That is is taken as the name of a variable.
> >>>>
> >>>> Variables store something. The 'x' is a 'handle' by which that storage
> >>>> is addressed.
> >>>>
> >>>> Now I ask the question, what shall be stored at that storage.
> >>>>
> >>>> So, I scimmed the text for possible meanings of 'x'.
> >>>>
> >>>> The first occurance of 'x' denotes a scalar part of a postition vector
> >>>> in coordinate system K.
> >>>>
> >>>> So, ok, 'x' stores scalars, which mean a number, by which the unit
> >>>> vector of that coordinate system shall be multiplied.
> >>>>
> >>>> All together they build a vector (x,y,z), which belongs to system K.
> >>>>
> >>>> That is nice and no problem at all.
> >>>>
> >>>> But any further occurances of 'x' are therefore meant as scalar part
> >>>> of position vector (x,y,z) from system K.
> >>>
> >>> This reminds me of a Dilbert story.
> >>> I can't find the cartoon, but the story goes like this:
> >>>
> >>> Teacher solving equations on the blackboard, saying:
> >>> " .. and then x = 5"
> >>>
> >>> Dilbert raising his hand, saying:
> >>> "Wait a darn minute! Yesterday you said x = 3!"
> >>>
> >>>>
> >>>> Similar with l, m, and n, which also occur in that equation.
> >>>>
> >>>> These are 'direction cosines' and belong to angles of the incoming ray
> >>>> at the position of the observer.
> >>>>
> >>>> This is also nice and no problem at all.
> >>>>
> >>>> But what does the author want to say with this equation, if the
> >>>> position in K is not defined and the postion of the observer or a ray
> >>>> arriving there were not under consideration?
> >>>
> >>> This is defined:
> >>>
> >>> The equation is in the beginning of
> >>> § 7. Theory of Doppler’s Principle and of Aberration
> >>>
> >>> If you read on, you will find:
> >>> ".. an observer is moving with velocity v relatively to
> >>> an infinitely distant source of light of frequency ν (nu),
> >>> in such a way that the connecting line “source-observer”
> >>> makes the angle φ with the velocity of the observer referred
> >>> to a system of co-ordinates which is at rest relatively to
> >>> the source of light,.."
> >>>
> >>> You demonstrate that you do not understand what this means
> >>> in your "annotation".
> >>> "To define velocity in respect to infinity would be a very
> >>> bad idea, because ‘Infinitely distant' is remaining infinitely
> >>> distant, even if you move in respect to infinity. Velocity
> >>> is defined as v=dx/dt. And because that 'x' in dx is not
> >>> changing (stays always 'infinity'), v will remain zero, however
> >>> you move. Therefore, your velocity in respect to infinity is always
> >>> zero."
> >>>
> >>> This is nonsense!
> >> Why is this nonsense??
> >>
> >> Infinity is not a location, but infinitly far away.
> >>
> >> A signal from infinity would need infinite time to reach us, hence would
> >> never be here.
> >
> > This is the very basis of scientific (and mathematical)
> > modelling. In contexts like this, infinity refers to a limit of arbitrarily
> > large distance with the signal (the plane wave) already presumed
> > omnipresent.
> You could equally allow elves as scientific influence!

Am 25.02.2023 um 12:57 schrieb JanPB:
> On Saturday, February 25, 2023 at 12:07:15 PM UTC+1, Thomas Heger wrote:

>>>>> You demonstrate that you do not understand what this means
>>>>> in your "annotation".
>>>>> "To define velocity in respect to infinity would be a very
>>>>> bad idea, because ‘Infinitely distant' is remaining infinitely
>>>>> distant, even if you move in respect to infinity. Velocity
>>>>> is defined as v=dx/dt. And because that 'x' in dx is not
>>>>> changing (stays always 'infinity'), v will remain zero, however
>>>>> you move. Therefore, your velocity in respect to infinity is always
>>>>> zero."
>>>>>
>>>>> This is nonsense!
>>>> Why is this nonsense??
>>>>
>>>> Infinity is not a location, but infinitly far away.
>>>>
>>>> A signal from infinity would need infinite time to reach us, hence would
>>>> never be here.
>>>
>>> This is the very basis of scientific (and mathematical)
>>> modelling. In contexts like this, infinity refers to a limit of arbitrarily
>>> large distance with the signal (the plane wave) already presumed
>>> omnipresent.
>> You could equally allow elves as scientific influence!
>
> No, this is a very basic (high school level) method of scientific modelling.
> It's the same in any E&M textbook when deriving laws of reflection and
> refraction, Brewster's angle, etc. In optics rays originating at infinity are
> one of the standard tools to evaluate aberrations of a lens being optimised.
>
>> Infinity is further away than any numerical distance (or: inf >> x for
>> all x element of R).
>>
>> You must not call 'resonably far away' 'infinity'.
>
> This sort of thing is very basic, straight from ancient Greece.

'Ancient Greece' is not quite the era, which you may call 'contemporary'.

(You may equally quote the Pharao Ramses III.)

Today 'infinity' has a certain meaning and that is not what the ancient
thought about that topic.

Simply think about inf (short for infinity, because I'm too lazy to look
up nun-Ascii-characters) like this:

inf = 1/0

or:

inf - x = inf

inf + x = inf

or:

inf > x for all x element of R

Any x is finite and 'in' means 'not', hence inf means 'not finite'.

>> Also 'plane waves' themselves are unphysical local approximations.
>
> Again, this doesn't matter. Netwon's calculus is similarly an
> unphysical approximation.

???

That calculus is a mathematical method and was actually developed by
Leibnitz.

>> A real plane wave would require an infinetely long emitting antenna,
>> which we can safely exclude.
>
> This is irrelevant. You miss the entire point of this setup.

Sure, I wanted to exclude elves, infinity as a location and infinitely
long antennas.

What's the problem with that?

>> In the real world we have Huygen's principle and waves expand
>> spherically from the emitting points.
>
> Yes, correct (assuming an isotropic medium), but irrelevant.

If all waves are spherical to some extend, than how do you justify
non-spherical plane waves?

I meant, that planes waves are only an approximation for real world
waves and do not exist in reality.

>> The plane waves are possible approximations for an area, where the
>> diameter of the area is small in comparison to the distance of the emitter.
>
> Again, irrelevant.
>
>> But 'small area' would hinder fast relative motion in respect to that
>> area, because soon the area would be left, where the approximation is valid.
>
> Irrelevant.

Not quite.

Einstein's SRT belongs to theoretical physics, hence cannot allow
approximations.

This is so, because theoretical physics is based on mathematically
correct derivations of the result from valid axioms.

This would leave little space for approximation, if any at all.

>
>> From this would follow, that Einstein could only treat the situation at
>> the spherical shell of the wave, where the wave normal hits
>> perpendicular to to that shell.
>
> Irrelevanty and an unnecessary complication.

Not quite.

Einstein should have written, which situation he considered and how he
wanted his variables to be interpreted.

But he wrote an equation, which would not fit to the possible physical
case of a point (x, y, z) at the surface of a spherical wave.

So, instead of that point, which was actually meant?

A possible point to consider would be the observer himself, who moves
along the x-axis with velocity v.

But in this case the point would be simply (x, 0, 0) with x= v*t.

So, what else could he have meant with (x, y, z) if neither the observer
nor an arbitrary point at the surface?

Here you may read and read and read and cannot find an answer, because
Einstein simply didn't say what he meant with (x, y, z) and with the
angle to which the cosines l, m and n belong.

I regarded this as an error, because the author is obliged to tell the
reader, what he meant with his symbols like (x, y, z).

>> In this case the direction cosinus l, m and n would be l=1, m and n
>> would be zero.
>>
>> That is sofar ok and would make sense, but would exclude, what Einstein
>> had written.
>
> It's not "what Einstein had written", it's the standard approach. Any other author
> in any other paper would have written exactly the same if some aspects of waves
> originating at an unspecified faraway distance were required.

Well, no.

What any other author would have written is not relevant, but what
Einstein had actually written.

You cannot count what is not there. So, possibly many other authors
would do similar, possibly not.

But that is not relevant, because only what is actually written can be
counted, not what is not written.

>> I have complained about this and you failed to defend Einstein's arguments.
>
> These are not "Einstein arguments", they are standard arguments for at least
> 100 years before Einstein. Also, I did not "fail to defend" those arguments
> because there is nothing to "defend" here.

Ooops

'Standard arguments for at least a hundred years' are not quotable.

Quotable are only specific authors, possibly Wikipedia or similar, (even
if wikipedia is not quotable for other reasons).

....

TH

El sábado, 18 de febrero de 2023 a las 6:02:00 UTC-3, Thomas Heger escribió:
> Hi NG
>
> So, here comes my latest annotated version of SRT:
>
> https://drive.google.com/file/d/1D2m4RV7StviWik2JiB1_Huk_7PR5Sxvi/view?usp=sharing
>
> You need to download the pdf-file, because this is stored as google doc
> and google will not show the annotations online.
>
>
> Hope you like it...
>
> TH

The same nonsensical "review" of Einstein's paper.

The paper "On the Electrodynamics of Moving Bodies" was received by the Annalen der Physik on June 30, 1905 and reviewed and published on September 26, 1905 ("Annalen der Physik, 17 (1905), pp. 891-921").

As every scientific paper, the reviewing and publication of a paper by a journal, follows a very strict process. In the case of Einstein, his work has been reviewed and commented by thousands of physicists (and, of course, crackpots like yourself). 118 years after its publication, this paper continues to be flawless (except for the last sentence of section 4, where he considers the Earth to be spherical, which it is not).

Are all published scientific papers flawless? Of course not!!!
After publication, readers of those papers can detect errors and send comments to the journal, which can publish those comments and the authors can publish corrections to those found errors.

If the found errors are huge, the journal can retract the original publication.

One of the most notable errors in a published paper was the infamous Wakefield et al paper published by The Lancet (one of the top ten scientific journals) "Ileal-lymphoid-nodular hyperplasia, non-specific colitis, and pervasive developmental disorder in children" which suggested that some vaccines children receive to prevent measles, mumps, and rubella could produce autism.

You can read the retracted version here (https://www.thelancet.com/pdfs/journals/lancet/PIIS0140-6736(97)11096-0.pdf).

It took a few years to discredit that paper as a complete disgrace, after their own authors started to reject the paper and the journal retracted it. The main author, Wakefield, lost his medical license and was fired from the hospital.

In this case the reviewing process got results.

On Sunday, 26 February 2023 at 14:50:48 UTC+1, Paparios wrote:
> El sábado, 18 de febrero de 2023 a las 6:02:00 UTC-3, Thomas Heger escribió:
> > Hi NG
> >
> > So, here comes my latest annotated version of SRT:
> >
> > https://drive.google.com/file/d/1D2m4RV7StviWik2JiB1_Huk_7PR5Sxvi/view?usp=sharing
> >
> > You need to download the pdf-file, because this is stored as google doc
> > and google will not show the annotations online.
> >
> >
> > Hope you like it...
> >
> > TH
>
> The same nonsensical "review" of Einstein's paper.
>
> The paper "On the Electrodynamics of Moving Bodies" was received by the Annalen der Physik on June 30, 1905 and reviewed and published on September 26, 1905 ("Annalen der Physik, 17 (1905), pp. 891-921").
>
> As every scientific paper, the reviewing and publication of a paper by a journal, follows a very strict process. In the case of Einstein, his work has been reviewed and commented by thousands of physicists (and, of course, crackpots like yourself). 118 years after its publication, this paper continues to be flawless (except for the last sentence of section 4, where he considers the Earth to be spherical, which it is not).
>
> Are all published scientific papers flawless? Of course not!!!

And the mumble of your idiot guru, for instance,
was obviously inconsistent.

Paparios <mrios@ing.puc.cl> wrote:

> El sábado, 18 de febrero de 2023 a las 6:02:00 UTC-3, Thomas Heger escribió:
> > Hi NG
> >
> > So, here comes my latest annotated version of SRT:
> >
> > https://drive.google.com/file/d/1D2m4RV7StviWik2JiB1_Huk_7PR5Sxvi/view?usp=s
haring
> >
> > You need to download the pdf-file, because this is stored as google doc
> > and google will not show the annotations online.
> >
> >
> > Hope you like it...
> >
> > TH
>
> The same nonsensical "review" of Einstein's paper.
>
> The paper "On the Electrodynamics of Moving Bodies" was received by the
> Annalen der Physik on June 30, 1905 and reviewed and published on
> September 26, 1905 ("Annalen der Physik, 17 (1905), pp. 891-921").
>
> As every scientific paper, the reviewing and publication of a paper by a
> journal, follows a very strict process. In the case of Einstein, his work
> has been reviewed and commented by thousands of physicists (and, of
> course, crackpots like yourself). 118 years after its publication, this
> paper continues to be flawless (except for the last sentence of section 4,
> where he considers the Earth to be spherical, which it is not).

The error is yours. The last sentence of §4 reads:
=========
Thence we conclude that a balance-clock at the equator must go more
slowly, by a very small amount, than a precisely similar clock situated
at one of the poles under otherwise identical conditions.
========
This is perfectly correct.

The problem may be with your understanding of German. (or English)
§4 starts with: Wir betrachten eine starre Kugel....
(E. We envisage a rigid sphere....)

This means in English: 'consider, as in 'Consider a spherical cow'.
Considering spherical cows doesn't imply
that cows (or the earth) are actually spherical.

You just consider them to be spherical
because that is good enough model for the purpose at hand.
This is standard scientific practice,
Jan

On Sunday, February 26, 2023 at 8:19:52 AM UTC+1, Thomas Heger wrote:
> Am 25.02.2023 um 12:57 schrieb JanPB:
> > On Saturday, February 25, 2023 at 12:07:15 PM UTC+1, Thomas Heger wrote:
>
> >>>>> You demonstrate that you do not understand what this means
> >>>>> in your "annotation".
> >>>>> "To define velocity in respect to infinity would be a very
> >>>>> bad idea, because ‘Infinitely distant' is remaining infinitely
> >>>>> distant, even if you move in respect to infinity. Velocity
> >>>>> is defined as v=dx/dt. And because that 'x' in dx is not
> >>>>> changing (stays always 'infinity'), v will remain zero, however
> >>>>> you move. Therefore, your velocity in respect to infinity is always
> >>>>> zero."
> >>>>>
> >>>>> This is nonsense!
> >>>> Why is this nonsense??
> >>>>
> >>>> Infinity is not a location, but infinitly far away.
> >>>>
> >>>> A signal from infinity would need infinite time to reach us, hence would
> >>>> never be here.
> >>>
> >>> This is the very basis of scientific (and mathematical)
> >>> modelling. In contexts like this, infinity refers to a limit of arbitrarily
> >>> large distance with the signal (the plane wave) already presumed
> >>> omnipresent.
> >> You could equally allow elves as scientific influence!
> >
> > No, this is a very basic (high school level) method of scientific modelling.
> > It's the same in any E&M textbook when deriving laws of reflection and
> > refraction, Brewster's angle, etc. In optics rays originating at infinity are
> > one of the standard tools to evaluate aberrations of a lens being optimised.
> >
> >> Infinity is further away than any numerical distance (or: inf >> x for
> >> all x element of R).
> >>
> >> You must not call 'resonably far away' 'infinity'.
> >
> > This sort of thing is very basic, straight from ancient Greece.
> 'Ancient Greece' is not quite the era, which you may call 'contemporary'.
>
> (You may equally quote the Pharao Ramses III.)
>
> Today 'infinity' has a certain meaning and that is not what the ancient
> thought about that topic.

I was simply pointing out that idealisation (like infinity in this case or
infinitely thin lines in ancient Greece) are an ancient hat. It's nothing
new or suspicious.

> Simply think about inf (short for infinity, because I'm too lazy to look
> up nun-Ascii-characters) like this:
>
> inf = 1/0

This is false.

> or:
>
> inf - x = inf
>
> inf + x = inf

These are a bit better in some sense.

> or:
>
> inf > x for all x element of R

You can define "inf" that way, yes.

> Any x is finite and 'in' means 'not', hence inf means 'not finite'.
> >> Also 'plane waves' themselves are unphysical local approximations.
> >
> > Again, this doesn't matter. Netwon's calculus is similarly an
> > unphysical approximation.
> ???
>
> That calculus is a mathematical method and was actually developed by
> Leibnitz.

Leibniz (no "t", although the misspelling is ancient).
Infinitesimal calculus uses the same modelling method: it treats limits
of expressions involving quantities which can be arbitrarily small. One
can do analogous things with quantities that are arbitrarily large.

If you are puzzled by any of this, you have a lot of work ahead of you.
It's a lot of fun doing this work but set aside a few years, preferably
with a good tutor to save time and make the process more efficient.

> >> A real plane wave would require an infinetely long emitting antenna,
> >> which we can safely exclude.
> >
> > This is irrelevant. You miss the entire point of this setup.
> Sure, I wanted to exclude elves, infinity as a location and infinitely
> long antennas.

Again, you are barking a nonexistent tree. Plane waves are, and
have been for a very long time, a standard tool. Every time you
take a photograph, you use a lens designed by this sort of process.

> What's the problem with that?

It's an irrelevancy. You are spinning wheels.

> >> In the real world we have Huygen's principle and waves expand
> >> spherically from the emitting points.
> >
> > Yes, correct (assuming an isotropic medium), but irrelevant.
> If all waves are spherical to some extend, than how do you justify
> non-spherical plane waves?

Plane waves are not spherical. Their wave fronts (surfaces of constant
phase) are planes, not spheres.

Perfect plane waves don't exist, just like geometric lines don't exist
or light rays don't exist. They are very useful models because they
can be made to approximate reality _as well as we please_ while
keeping things simple.

As you probably know, even the simplest spherical EM wave is
quite a complicated expression compared to the plane wave
expression which approximates it arbitrarily closely. That's how
models are commonly used in science.

Again, look at any E&M book.

> I meant, that planes waves are only an approximation for real world
> waves and do not exist in reality.

Yes, exactly. Neither do light rays, planes or lines of geometry, etc. etc.

> >> The plane waves are possible approximations for an area, where the
> >> diameter of the area is small in comparison to the distance of the emitter.
> >
> > Again, irrelevant.
> >
> >> But 'small area' would hinder fast relative motion in respect to that
> >> area, because soon the area would be left, where the approximation is valid.
> >
> > Irrelevant.
> Not quite.
>
> Einstein's SRT belongs to theoretical physics, hence cannot allow
> approximations.

These are not approximations in the sense you use the term. These are
approximations like derivatives or densities in calculus: they can be made
arbitrarily close to reality. That's why lines and planes (infinitely thin) of
space geometry work. And they work, in a very immediate sense, *exactly*:
bridges and airplanes are built using them.

> >> From this would follow, that Einstein could only treat the situation at
> >> the spherical shell of the wave, where the wave normal hits
> >> perpendicular to to that shell.
> >
> > Irrelevanty and an unnecessary complication.
> Not quite.
>
> Einstein should have written, which situation he considered and how he
> wanted his variables to be interpreted.
>
> But he wrote an equation, which would not fit to the possible physical
> case of a point (x, y, z) at the surface of a spherical wave.

Nonsense.

> So, instead of that point, which was actually meant?
>
> A possible point to consider would be the observer himself, who moves
> along the x-axis with velocity v.

No, both the stationary and the moving observer are at an arbitrary (fixed)
point (x, y, z). As they instantaneously pass one another, they measure
the frequency and the amplitude. Einstein derives the relevant formulas
comparing the observers' measurements.

> But in this case the point would be simply (x, 0, 0) with x= v*t.
>
> So, what else could he have meant with (x, y, z) if neither the observer
> nor an arbitrary point at the surface?
>
> Here you may read and read and read and cannot find an answer, because
> Einstein simply didn't say what he meant with (x, y, z) and with the
> angle to which the cosines l, m and n belong.

Hire a starving physics grad student from the nearest university to explain
this to you face to face. It's incredibly slow and inefficient to do this
over a text-based forum like this.

Bottom line is all of your objections are specious and/or irrelevant.

--
Jan

On 2/25/2023 6:07 AM, Thomas Heger wrote:
> Am 23.02.2023 um 09:52 schrieb JanPB:
>> On Thursday, February 23, 2023 at 8:46:44 AM UTC+1, Thomas Heger wrote:

>>> Infinity is not a location, but infinitly far away.
>>>
>>> A signal from infinity would need infinite time to reach us, hence would
>>> never be here.
>>
>> This is the very basis of scientific (and mathematical)
>> modelling. In contexts like this, infinity refers to a limit of
>> arbitrarily
>> large distance with the signal (the plane wave) already presumed
>> omnipresent.

> Infinity is further away than any numerical distance (or: inf >> x for
> all x element of R).

And...?
>
> You must not call 'resonably far away' 'infinity'.

And nobody does. "Reasonably far away" means "reasonably close to what
happens at an infinite distance". And this is normal limit theory applied.>
>
> Also 'plane waves' themselves are unphysical local approximations.

They are quite physical. They'll propagate just fine if they happen to
exist.
>
> A real plane wave would require an infinetely long emitting antenna,
> which we can safely exclude.

So they (all physicists using a plane wave model) use a "reasonably far
away" source to be reasonably close to a plane wave.
>
> In the real world we have Huygen's principle and waves expand
> spherically from the emitting points.
>
> The plane waves are possible approximations for an area, where the
> diameter of the area is small in comparison to the distance of the emitter.

Which is what Einstein was doing...
>
> But 'small area' would hinder fast relative motion in respect to that
> area, because soon the area would be left, where the approximation is
> valid.

Why did you say something so dumb?

>
> From this would follow, that Einstein could only treat the situation at
> the spherical shell of the wave, where the wave normal hits
> perpendicular to to that shell.

If it looks too much like the shell of a spherical wave front, the
"reasonably far away" source isn't "reasonably far away" enough, a more
distant source is needed.

But in such a paper, details of the plane wave's source are irrelevant.
"Assume there is a plane wave such that..." is perfectly fine.

Remember, you are not the intended audience. Other physicists who were
perfectly OK with the existence of plane waves were.

> I have complained about this and you failed to defend Einstein's arguments.

It's not "Einstein's arguments", it is what EVERY scientist and engineer
needing the simple math of a plane wave uses! So this "error" of yours
belongs in the "Heger doesn't understand standard usage" pile of
'notations'.

I assume you believe Achilles can never pass the tortoise in a race.

>> It's an idealisation which represents reality arbitrarily closely, this
>> method has been in use since ancient Greece.

Exactly.
>>
>>> Also velocity in respect to infinitity is always zero, because
>>> inf- x= inf
>>>
>>> for all x element of R.

Nobody is using the source of the plane wave as the origin!
Einstein defines the origin he uses in S and S', and the math and
physics are just fine!
>>
>> No, this is not how this works. How can you be so unaware of the
>> very basics of scientific methodologies? In optics, for example
>> (lens design), rays from infinity are considered all the time when
>> evaluating the aberrations. Plane waves from infinity are used to
>> derive Snell's law from Maxwell's equations, etc.
>
>
> ??????
>
> No idea, what you are trying to say.

So all of this is way over your head. You admit to being unqualified to
criticize this paper.
>
> Infinity is mathematically already defined, hence physicists cannot
> redefine it otherwise.

Nobody is "redefining infinity". They are just using a plane wave, or at
least a wave that is reasonably close to a plane wave by being
"reasonably far away". (and "reasonably far away" isn't infinity!)

This is such a STUPID criticism!

On 18-Feb-23 8:01 pm, Thomas Heger wrote:
> Hi NG
>
> now I have finished my latest version after rewriting almost all
> annotations from previous versions.
>
> The idea behind writing aannotations is this:
>
> take a certain text (here: 'On the electrodynamics of moving bodies' by
> A. Einstein from 1905) and write annotations into it, similar to how a
> professor writes annotations into the homework of a student.
>
> It was actually meant as a learning tool and aimed to find ALL errors in
> a text and to write into the annotations, why that is an error.
>
> I wrote more than 400 annotations and most of them aare bout errors in
> Einstein's text.
>
> The errors stem from a great varfiety of topics, like:
>
> formal errors
> missing quotes
> unclear formulations
> wrong or reused variables
> illogic resoning
> wrong math
> and so forth...
>
> Many of my arguments were discussed in this forum extensively.  Then I
> had, if possible, taken hints and corrections by members of this board
> and integrated them into this version, too.
>
> A different class of improvements of this lates version came from my
> attempt to identify the possibly sources, which Einstein had used (but
> not quoted).
>
> As I speak, of course, German, I could read the works of Heinrich Hertz
> und could identify possible sources.
>
> French is not that possible, but I can understand a little. So,
> Poincare's 'Sur le dynamic de la electron' was another possible source.
>
> (Dutch is impossible for me, hence I had to leave Hendrik Lorentz away.)
>
> Also language, spelling and formats were improved in this version
> (besides of rethinking and checking the annotations themselves).
>
>
> So, here comes my latest annotated version of SRT:
>
> https://drive.google.com/file/d/1D2m4RV7StviWik2JiB1_Huk_7PR5Sxvi/view?usp=sharing
>
> You need to download the pdf-file, because this is stored as google doc
> and google will not show the annotations online.
>
>
> Hope you like it...
>
> TH

Oh God. Not this again.

Sylvia.

Sylvia Else wrote:

> On 18-Feb-23 8:01 pm, Thomas Heger wrote:
>> You need to download the pdf-file, because this is stored as google doc
>> and google will not show the annotations online. Hope you like it... TH
>
> Oh God. Not this again.

2 Full Minutes Of U.S. Politicians Threatening To Blow Up Nord Stream
Pipelines
https://%62%69%74%63%68%75%74%65.com/video/RMxr1H0ciIN2

no sane person on this planet will ever taking for good, the cacamerican
lying bitches, inbreed *_terrorists_* and liars, global scale. It was
clear along the *_death_vaccination_*, demanded and imposed along
continents. You repulsive cacamericans subhuman excrements. You are still
immigrants on that territory.

Am 27.02.2023 um 07:48 schrieb Volney:
> On 2/25/2023 6:07 AM, Thomas Heger wrote:
>> Am 23.02.2023 um 09:52 schrieb JanPB:
>>> On Thursday, February 23, 2023 at 8:46:44 AM UTC+1, Thomas Heger wrote:
>
>>>> Infinity is not a location, but infinitly far away.
>>>>
>>>> A signal from infinity would need infinite time to reach us, hence
>>>> would
>>>> never be here.
>>>
>>> This is the very basis of scientific (and mathematical)
>>> modelling. In contexts like this, infinity refers to a limit of
>>> arbitrarily
>>> large distance with the signal (the plane wave) already presumed
>>> omnipresent.
>
>> Infinity is further away than any numerical distance (or: inf >> x for
>> all x element of R).
>
> And...?
>>
>> You must not call 'resonably far away' 'infinity'.
>
> And nobody does. "Reasonably far away" means "reasonably close to what
> happens at an infinite distance". And this is normal limit theory applied.>
>>
>> Also 'plane waves' themselves are unphysical local approximations.
>
> They are quite physical. They'll propagate just fine if they happen to
> exist.
>>
>> A real plane wave would require an infinetely long emitting antenna,
>> which we can safely exclude.
>
> So they (all physicists using a plane wave model) use a "reasonably far
> away" source to be reasonably close to a plane wave.
>>
>> In the real world we have Huygen's principle and waves expand
>> spherically from the emitting points.
>>
>> The plane waves are possible approximations for an area, where the
>> diameter of the area is small in comparison to the distance of the
>> emitter.
>
> Which is what Einstein was doing...
>>
>> But 'small area' would hinder fast relative motion in respect to that
>> area, because soon the area would be left, where the approximation is
>> valid.
>
> Why did you say something so dumb?
>
>>
>> From this would follow, that Einstein could only treat the situation
>> at the spherical shell of the wave, where the wave normal hits
>> perpendicular to to that shell.
>
> If it looks too much like the shell of a spherical wave front, the
> "reasonably far away" source isn't "reasonably far away" enough, a more
> distant source is needed.
>
> But in such a paper, details of the plane wave's source are irrelevant.
> "Assume there is a plane wave such that..." is perfectly fine.
>
> Remember, you are not the intended audience. Other physicists who were
> perfectly OK with the existence of plane waves were.
>
>> I have complained about this and you failed to defend Einstein's
>> arguments.
>
> It's not "Einstein's arguments", it is what EVERY scientist and engineer
> needing the simple math of a plane wave uses! So this "error" of yours
> belongs in the "Heger doesn't understand standard usage" pile of
> 'notations'.

Einstein mentioned on page 16: '...if an observer is moving with
velocity v relatively to an infinitely distant source of light '.

I have complained about this statement, because velocity v in respect to
infinity is always zero.

It was therefor a VERY !!!! bad idea to make such a statement.

Also planes waves are not real world waves, but local approximations to
spherical waves from distant sources.

That approximation is actually ok, but not in the context, which
Einstein used.

The validity of this approximation would require, that the realm of
observation is not moved around with considerable velocity (what
Einstein actually wanted to do).

....

>>>> Also velocity in respect to infinitity is always zero, because
>>>> inf- x= inf
>>>>
>>>> for all x element of R.
>
> Nobody is using the source of the plane wave as the origin!
> Einstein defines the origin he uses in S and S', and the math and
> physics are just fine!

Sorry, but I cannot follow your arguments.

Waves have a source and that source was actually mentioned (see above).

Now plane waves are really plane and extend infinitely sideways without
any curvature.

But such waves do not exist, because they are physically impossible.

What in fact exists is a plane wave as local approximation for a limited
realm, which that wave hits.

>>> No, this is not how this works. How can you be so unaware of the
>>> very basics of scientific methodologies? In optics, for example
>>> (lens design), rays from infinity are considered all the time when
>>> evaluating the aberrations. Plane waves from infinity are used to
>>> derive Snell's law from Maxwell's equations, etc.
>>
>>
>> ??????
>>
>> No idea, what you are trying to say.
>
> So all of this is way over your head. You admit to being unqualified to
> criticize this paper.

Actually the statement above is hard to interpret, which has nothing to
do with physics, but with unidentifiable intensions of the author.

I had complained, that real plane waves do not exist, hence could not be
used in Einstein's setting.

It is actually possible to use plane waves as approximations in many
practical applications, e.g. in lens design.

But lenses have no infinite extensions, like the space, where Einstein
wanted to move around with his observer.

....

TH

Am 26.02.2023 um 20:38 schrieb J. J. Lodder:

>>> So, here comes my latest annotated version of SRT:
>>>
>>> https://drive.google.com/file/d/1D2m4RV7StviWik2JiB1_Huk_7PR5Sxvi/view?usp=s
> haring
>>>
>>> You need to download the pdf-file, because this is stored as google doc
>>> and google will not show the annotations online.
>>>
>>>
>>> Hope you like it...
>>>
>>> TH
>>
>> The same nonsensical "review" of Einstein's paper.
>>
>> The paper "On the Electrodynamics of Moving Bodies" was received by the
>> Annalen der Physik on June 30, 1905 and reviewed and published on
>> September 26, 1905 ("Annalen der Physik, 17 (1905), pp. 891-921").
>>
>> As every scientific paper, the reviewing and publication of a paper by a
>> journal, follows a very strict process. In the case of Einstein, his work
>> has been reviewed and commented by thousands of physicists (and, of
>> course, crackpots like yourself). 118 years after its publication, this
>> paper continues to be flawless (except for the last sentence of section 4,
>> where he considers the Earth to be spherical, which it is not).

The text was analysed by me. That was a project started by a dispute
with the local regular 'Dono', who spit out insults, because I had
complained about errors in this text.

I had regarded Einstein's text simply as 'bad science' and didn't care
too much about it.

But these constant insults annoyed me, hence I wanted to make my
critique a little more explicit.

I found later the topic interesting and the method I have used as quite
a good learning tool. So I have finished my project now and wanted to
let you know about my result.

> The error is yours. The last sentence of §4 reads:
> =========
> Thence we conclude that a balance-clock at the equator must go more
> slowly, by a very small amount, than a precisely similar clock situated
> at one of the poles under otherwise identical conditions.
> ========
> This is perfectly correct.
>
> The problem may be with your understanding of German. (or English)
> §4 starts with: Wir betrachten eine starre Kugel....
> (E. We envisage a rigid sphere....)

A sphere the two-dimensional is the surface of a ball, hence has no
thickness.

'Kugel' means actually 'ball', what is a massive, solid object.

Two dimensional objects have no material content, hence cannot be
treated similar to 3d-objects. Especially the sphere is not rigid,
because the material is so strong, but because it is an imagined object
and you cannot bent imaginations.

> This means in English: 'consider, as in 'Consider a spherical cow'.
> Considering spherical cows doesn't imply
> that cows (or the earth) are actually spherical.
>
> You just consider them to be spherical
> because that is good enough model for the purpose at hand.
> This is standard scientific practice,

No scientist would ever call a cow 'spherical'.

You could, however, approximate cows by balls in a few special cases.

E.g. I could imagine a possible use of such a model for certain
situations, where e.g. a herd of cattle is forced into a cage.

But usually cows behave too different to balls, that such a modell would
be regarded as useless.

TH
>
>
>

Am 27.02.2023 um 22:34 schrieb Sylvia Else:
> On 18-Feb-23 8:01 pm, Thomas Heger wrote:
>> Hi NG
>>
>> now I have finished my latest version after rewriting almost all
>> annotations from previous versions.
>>
>> The idea behind writing aannotations is this:
>>
>> take a certain text (here: 'On the electrodynamics of moving bodies'
>> by A. Einstein from 1905) and write annotations into it, similar to
>> how a professor writes annotations into the homework of a student.
>>
>> It was actually meant as a learning tool and aimed to find ALL errors
>> in a text and to write into the annotations, why that is an error.
>>
>> I wrote more than 400 annotations and most of them aare bout errors in
>> Einstein's text.
>>
>> The errors stem from a great varfiety of topics, like:
>>
>> formal errors
>> missing quotes
>> unclear formulations
>> wrong or reused variables
>> illogic resoning
>> wrong math
>> and so forth...
>>
>> Many of my arguments were discussed in this forum extensively. Then I
>> had, if possible, taken hints and corrections by members of this board
>> and integrated them into this version, too.
>>
>> A different class of improvements of this lates version came from my
>> attempt to identify the possibly sources, which Einstein had used (but
>> not quoted).
>>
>> As I speak, of course, German, I could read the works of Heinrich
>> Hertz und could identify possible sources.
>>
>> French is not that possible, but I can understand a little. So,
>> Poincare's 'Sur le dynamic de la electron' was another possible source.
>>
>> (Dutch is impossible for me, hence I had to leave Hendrik Lorentz away.)
>>
>> Also language, spelling and formats were improved in this version
>> (besides of rethinking and checking the annotations themselves).
>>
>>
>> So, here comes my latest annotated version of SRT:
>>
>> https://drive.google.com/file/d/1D2m4RV7StviWik2JiB1_Huk_7PR5Sxvi/view?usp=sharing
>>
>>
>> You need to download the pdf-file, because this is stored as google
>> doc and google will not show the annotations online.
>>
>>
>> Hope you like it...
>>
>> TH
>
> Oh God. Not this again.
>

Why not?

This is the relativity forum of the Usenet and my critique would
certainly fit to the subject of this board.

TH

On 28-Feb-23 6:30 pm, Thomas Heger wrote:
> Am 27.02.2023 um 22:34 schrieb Sylvia Else:
>> On 18-Feb-23 8:01 pm, Thomas Heger wrote:
>>> Hi NG
>>>
>>> now I have finished my latest version after rewriting almost all
>>> annotations from previous versions.
>>>
>>> The idea behind writing aannotations is this:
>>>
>>> take a certain text (here: 'On the electrodynamics of moving bodies'
>>> by A. Einstein from 1905) and write annotations into it, similar to
>>> how a professor writes annotations into the homework of a student.
>>>
>>> It was actually meant as a learning tool and aimed to find ALL errors
>>> in a text and to write into the annotations, why that is an error.
>>>
>>> I wrote more than 400 annotations and most of them aare bout errors in
>>> Einstein's text.
>>>
>>> The errors stem from a great varfiety of topics, like:
>>>
>>> formal errors
>>> missing quotes
>>> unclear formulations
>>> wrong or reused variables
>>> illogic resoning
>>> wrong math
>>> and so forth...
>>>
>>> Many of my arguments were discussed in this forum extensively.  Then I
>>> had, if possible, taken hints and corrections by members of this board
>>> and integrated them into this version, too.
>>>
>>> A different class of improvements of this lates version came from my
>>> attempt to identify the possibly sources, which Einstein had used (but
>>> not quoted).
>>>
>>> As I speak, of course, German, I could read the works of Heinrich
>>> Hertz und could identify possible sources.
>>>
>>> French is not that possible, but I can understand a little. So,
>>> Poincare's 'Sur le dynamic de la electron' was another possible source.
>>>
>>> (Dutch is impossible for me, hence I had to leave Hendrik Lorentz away.)
>>>
>>> Also language, spelling and formats were improved in this version
>>> (besides of rethinking and checking the annotations themselves).
>>>
>>>
>>> So, here comes my latest annotated version of SRT:
>>>
>>> https://drive.google.com/file/d/1D2m4RV7StviWik2JiB1_Huk_7PR5Sxvi/view?usp=sharing
>>>
>>>
>>> You need to download the pdf-file, because this is stored as google
>>> doc and google will not show the annotations online.
>>>
>>>
>>> Hope you like it...
>>>
>>> TH
>>
>> Oh God. Not this again.
>>
>
> Why not?
>
>
> This is the relativity forum of the Usenet and my critique would
> certainly fit to the subject of this board.
>

How many times do you need to show that you have no understanding of
what Einstein wrote?

Sylvia.

On 2023-02-28 08:43:55 +0000, Sylvia Else said:

> On 28-Feb-23 6:30 pm, Thomas Heger wrote:
...

> How many times do you need to show that you have no understanding of
> what Einstein wrote?

There is the risk that we forget him when we focus to those idiots
that have recently posted here.

Mikko

Le 28/02/2023 à 09:43, Sylvia Else a écrit :
>
> How many times do you need to show that you have no understanding of
> what Einstein wrote?
>
> Sylvia.

Uh... Do you really think that I understand everything that Einstein wrote
(or badly copied)?

No, I do not understand.

Minkowski block, I don't understand.

Contraction of distances and expansions of durations, I don't understand
the equations.

Bearholes, wormholes, white fountains and time travel, I don't understand.

Proper time of accelerated objects, I don't understand.

Relativistic instantaneous velocities of accelerated objects, I don't have
the same equations.

They tell me that I'm stupid and that I don't understand anything.

It's better, so everyone can sleep peacefully.

R.H.

On Tuesday, February 28, 2023 at 8:12:04 AM UTC+1, Thomas Heger wrote:
> Am 27.02.2023 um 07:48 schrieb Volney:
> > On 2/25/2023 6:07 AM, Thomas Heger wrote:
> >> Am 23.02.2023 um 09:52 schrieb JanPB:
> >>> On Thursday, February 23, 2023 at 8:46:44 AM UTC+1, Thomas Heger wrote:
> >
> >>>> Infinity is not a location, but infinitly far away.
> >>>>
> >>>> A signal from infinity would need infinite time to reach us, hence
> >>>> would
> >>>> never be here.
> >>>
> >>> This is the very basis of scientific (and mathematical)
> >>> modelling. In contexts like this, infinity refers to a limit of
> >>> arbitrarily
> >>> large distance with the signal (the plane wave) already presumed
> >>> omnipresent.
> >
> >> Infinity is further away than any numerical distance (or: inf >> x for
> >> all x element of R).
> >
> > And...?
> >>
> >> You must not call 'resonably far away' 'infinity'.
> >
> > And nobody does. "Reasonably far away" means "reasonably close to what
> > happens at an infinite distance". And this is normal limit theory applied.>
> >>
> >> Also 'plane waves' themselves are unphysical local approximations.
> >
> > They are quite physical. They'll propagate just fine if they happen to
> > exist.
> >>
> >> A real plane wave would require an infinetely long emitting antenna,
> >> which we can safely exclude.
> >
> > So they (all physicists using a plane wave model) use a "reasonably far
> > away" source to be reasonably close to a plane wave.
> >>
> >> In the real world we have Huygen's principle and waves expand
> >> spherically from the emitting points.
> >>
> >> The plane waves are possible approximations for an area, where the
> >> diameter of the area is small in comparison to the distance of the
> >> emitter.
> >
> > Which is what Einstein was doing...
> >>
> >> But 'small area' would hinder fast relative motion in respect to that
> >> area, because soon the area would be left, where the approximation is
> >> valid.
> >
> > Why did you say something so dumb?
> >
> >>
> >> From this would follow, that Einstein could only treat the situation
> >> at the spherical shell of the wave, where the wave normal hits
> >> perpendicular to to that shell.
> >
> > If it looks too much like the shell of a spherical wave front, the
> > "reasonably far away" source isn't "reasonably far away" enough, a more
> > distant source is needed.
> >
> > But in such a paper, details of the plane wave's source are irrelevant.
> > "Assume there is a plane wave such that..." is perfectly fine.
> >
> > Remember, you are not the intended audience. Other physicists who were
> > perfectly OK with the existence of plane waves were.
> >
> >> I have complained about this and you failed to defend Einstein's
> >> arguments.
> >
> > It's not "Einstein's arguments", it is what EVERY scientist and engineer
> > needing the simple math of a plane wave uses! So this "error" of yours
> > belongs in the "Heger doesn't understand standard usage" pile of
> > 'notations'.
> Einstein mentioned on page 16: '...if an observer is moving with
> velocity v relatively to an infinitely distant source of light '.
>
> I have complained about this statement, because velocity v in respect to
> infinity is always zero.

This is false. Think about it. And think what we've been telling you about
the meaning of infinitely far as a limit of arbitrary large distance.

> It was therefor a VERY !!!! bad idea to make such a statement.

No, it was a very standard idea.

> Also planes waves are not real world waves, but local approximations to
> spherical waves from distant sources.

Yes.

> That approximation is actually ok, but not in the context, which
> Einstein used.

It's very appropriate (also standard).

> The validity of this approximation would require, that the realm of
> observation is not moved around with considerable velocity (what
> Einstein actually wanted to do).

No, completely incorrect.

> >>>> Also velocity in respect to infinitity is always zero, because
> >>>> inf- x= inf
> >>>>
> >>>> for all x element of R.
> >
> > Nobody is using the source of the plane wave as the origin!
> > Einstein defines the origin he uses in S and S', and the math and
> > physics are just fine!
> Sorry, but I cannot follow your arguments.
>
> Waves have a source and that source was actually mentioned (see above).

The wave is given as a plane wave. Wave planes have no sources, they are
unphysical and they are limits of physical waves with sources at finite
distances. Physics and mathematics are full of models of that kind,
the principle;e of using such models goes back to ancient Greece.

> Now plane waves are really plane and extend infinitely sideways without
> any curvature.
>
> But such waves do not exist, because they are physically impossible.

This is irrelevant in the context of the scientific method. What you demand
is some sort of Mediaeval Scholastics. It may have its domain of validity but
it's not science.

> What in fact exists is a plane wave as local approximation for a limited
> realm, which that wave hits.

Correct but irrelevant here.

> >>> No, this is not how this works. How can you be so unaware of the
> >>> very basics of scientific methodologies? In optics, for example
> >>> (lens design), rays from infinity are considered all the time when
> >>> evaluating the aberrations. Plane waves from infinity are used to
> >>> derive Snell's law from Maxwell's equations, etc.
> >>
> >>
> >> ??????
> >>
> >> No idea, what you are trying to say.
> >
> > So all of this is way over your head. You admit to being unqualified to
> > criticize this paper.
> Actually the statement above is hard to interpret, which has nothing to
> do with physics, but with unidentifiable intensions of the author.

I simply said that if one takes a plane wave and puts it in the Maxwell's
equations, the resulting constraints on the wave will imply that at a
media boundary the light rays must refract according to Snell's law.
This is shown in any book on E&M.

> I had complained, that real plane waves do not exist, hence could not be
> used in Einstein's setting.

This is incorrect. And it's not "Einstein", it's everybody and his mother.
Just look inside any textbook on E&M, radiation, etc.

> It is actually possible to use plane waves as approximations in many
> practical applications, e.g. in lens design.
>
> But lenses have no infinite extensions, like the space, where Einstein
> wanted to move around with his observer.

The point I made was in response to your complaints about "putting"
the source "at infinity". I simply responded that this was a standard
application of a standard limiting process, as in geometry, calculus,
and other countless applications in physics and mathematics, like
in lens design where aberrations are calculated by considering light
sources at infinity (and at finite distances as well).

--
Jan

On 2/28/2023 2:12 AM, Thomas Heger wrote:
> Am 27.02.2023 um 07:48 schrieb Volney:
>> On 2/25/2023 6:07 AM, Thomas Heger wrote:
>>> Am 23.02.2023 um 09:52 schrieb JanPB:
>>>> On Thursday, February 23, 2023 at 8:46:44 AM UTC+1, Thomas Heger wrote:
>>
>>>>> Infinity is not a location, but infinitly far away.
>>>>>
>>>>> A signal from infinity would need infinite time to reach us, hence
>>>>> would
>>>>> never be here.
>>>>
>>>> This is the very basis of scientific (and mathematical)
>>>> modelling. In contexts like this, infinity refers to a limit of
>>>> arbitrarily
>>>> large distance with the signal (the plane wave) already presumed
>>>> omnipresent.
>>
>>> Infinity is further away than any numerical distance (or: inf >> x for
>>> all x element of R).
>>
>> And...?
>>>
>>> You must not call 'resonably far away' 'infinity'.
>>
>> And nobody does. "Reasonably far away" means "reasonably close to what
>> happens at an infinite distance". And this is normal limit theory
>> applied.>
>>>
>>> Also 'plane waves' themselves are unphysical local approximations.
>>
>> They are quite physical. They'll propagate just fine if they happen to
>> exist.
>>>
>>> A real plane wave would require an infinetely long emitting antenna,
>>> which we can safely exclude.
>>
>> So they (all physicists using a plane wave model) use a "reasonably far
>> away" source to be reasonably close to a plane wave.
>>>
>>> In the real world we have Huygen's principle and waves expand
>>> spherically from the emitting points.
>>>
>>> The plane waves are possible approximations for an area, where the
>>> diameter of the area is small in comparison to the distance of the
>>> emitter.
>>
>> Which is what Einstein was doing...
>>>
>>> But 'small area' would hinder fast relative motion in respect to that
>>> area, because soon the area would be left, where the approximation is
>>> valid.
>>
>> Why did you say something so dumb?
>>
>>>
>>>  From this would follow, that Einstein could only treat the situation
>>> at the spherical shell of the wave, where the wave normal hits
>>> perpendicular to to that shell.
>>
>> If it looks too much like the shell of a spherical wave front, the
>> "reasonably far away" source isn't "reasonably far away" enough, a more
>> distant source is needed.
>>
>> But in such a paper, details of the plane wave's source are irrelevant.
>> "Assume there is a plane wave such that..." is perfectly fine.
>>
>> Remember, you are not the intended audience. Other physicists who were
>> perfectly OK with the existence of plane waves were.
>>
>>> I have complained about this and you failed to defend Einstein's
>>> arguments.
>>
>> It's not "Einstein's arguments", it is what EVERY scientist and engineer
>> needing the simple math of a plane wave uses! So this "error" of yours
>> belongs in the "Heger doesn't understand standard usage" pile of
>> 'notations'.
>
>
> Einstein mentioned on page 16: '...if an observer is moving with
> velocity v relatively to an infinitely distant source of light '.

And he previously stated: "In the system K, very far from the origin of
co-ordinates, let there be a source of electrodynamic waves, which in a
part of space containing the origin of co-ordinates may be represented
to a sufficient degree of approximation by the equations [plane wave
equation]". His intended audience (not you) knows he's about to use
plane waves for something, he's stating the source is far enough that
the approximation of a plane wave is less than some small error range.
At the time scientists typically discarded higher powers of some
polynomial or Taylor expansion.
>
> I have complained about this statement, because velocity v in respect to
> infinity is always zero.
>
> It was therefor a VERY !!!! bad idea to make such a statement.

He states the "very far from the origin" is in the system K. The wave
equations he lists are that of a stationary source in K.
>
> Also planes waves are not real world waves, but local approximations to
> spherical waves from distant sources.

Once again, SUCH APPROXIMATIONS ARE USED ALL THE TIME. Plane waves are
very convenient to work with. Especially with optics. Even cameras with
a focal distance setting have an "infinity" setting.
> That approximation is actually ok, but not in the context, which
> Einstein used.

It's just as valid there as anywhere else. The general attitude with
plane waves in a science or engineering work is that they exist for the
example, if, how or whether they can be formed is irrelevant. If they
exist they propagate just fine.
>
> The validity of this approximation would require, that the realm of
> observation is not moved around with considerable velocity (what
> Einstein actually wanted to do).

Sure it can! It just has to be far enough away. Einstein writes of the
distant source: "may be represented to a SUFFICIENT degree of
approximation". Not sufficient? Use a more distant source! His target
audience (again, not you) considers that statement as "boilerplate" to
define usage of a plane wave.
>
>
> ...
>
>>>>> Also velocity in respect to infinitity is always zero, because
>>>>> inf- x= inf
>>>>>
>>>>> for all x element of R.
>>
>> Nobody is using the source of the plane wave as the origin!
>> Einstein defines the origin he uses in S and S', and the math and
>> physics are just fine!
>
>
> Sorry, but I cannot follow your arguments.
>
> Waves have a source and that source was actually mentioned (see above).

Irrelevant. He defined the origin of the system K, and even stated that
the source of the plane wave is "very far from the origin of
co-ordinates". I have no idea why you want to use its source as origin
when the origin of system K was already defined.
>
> Now plane waves are really plane and extend infinitely sideways without
> any curvature.
>
> But such waves do not exist, because they are physically impossible.

So what? He stated "may be represented to a sufficient degree of
approximation". Again, this is done all the freaking time!
>
> What in fact exists is a plane wave as local approximation for a limited
> realm, which that wave hits.

"May be represented to a sufficient degree of approximation".
>
>>>> No, this is not how this works. How can you be so unaware of the
>>>> very basics of scientific methodologies? In optics, for example
>>>> (lens design), rays from infinity are considered all the time when
>>>> evaluating the aberrations. Plane waves from infinity are used to
>>>> derive Snell's law from Maxwell's equations, etc.
>>>
>>>
>>> ??????
>>>
>>> No idea, what you are trying to say.
>>
>> So all of this is way over your head. You admit to being unqualified to
>> criticize this paper.
>
>
> Actually the statement above is hard to interpret, which has nothing to
> do with physics, but with unidentifiable intensions of the author.

Maybe hard to interpret for you, but any scientist or engineer sees it
as a simple statement how plane waves are used as an ideal source to
work with.
>
> I had complained, that real plane waves do not exist, hence could not be
> used in Einstein's setting.

"May be represented to a sufficient degree of approximation".
>
> It is actually possible to use plane waves as approximations in many
> practical applications, e.g. in lens design.

And SR.
>
> But lenses have no infinite extensions, like the space, where Einstein
> wanted to move around with his observer.

Irrelevant. For a larger distance, you need a more distant source. If
you are fine with an "infinite extension" for the domain of SR, then you
should be fine with an infinitely distant source. And for the zillionth
time, his target audience, other scientists, weren't going to nitpick
over plane waves, they used them as well.