On Thursday, 9 December 2021 at 23:32:09 UTC+1, bodk...@gmail.com wrote:
> Richard Hachel <r.ha...@tiscali.fr> wrote:
> > Le 09/12/2021 à 16:56, Odd Bodkin a écrit :
> >> Richard Hachel <r.ha...@tiscali.fr> wrote:
> >>> Le 09/12/2021 à 13:18, Sylvia Else a écrit :
> >>>> On 09-Dec-21 10:26 pm, Richard Hachel wrote:
> >>>>> The train paradox.
> >>>>> Everyone knows this paradox.
> >>>>> A train is running on a 0.8c railway line.
> >>>>> The train measures 500 meters at rest.
> >>>>> In the terrestrial frame of reference, it measures only 300 meters.
> >>>>> We will then place a bridge over which he must pass, but this bridge is
> >>>>> not finished. Lack of 500 meters for the connection.
> >>>>> In the train's frame of reference, the train measures 500 meters, and
> >>>>> the hole 300 meters.
> >>>>> By some means, we make sure that either the train will be able to pass,
> >>>>> or it will not be able to.
> >>>>> We imagine that if at least part of the train touches the rail, it will
> >>>>> be kept on the track (gravitational or electric effect, etc.).
> >>>>
> >>>> You can't just claim that the effects are whatever is required to create
> >>>> your 'paradox'.
> >>>>
> >>>> In both frames the train takes on the order of a microsecond to cross
> >>>> the gap. The train will accelerate downwards due to gravity, falling a
> >>>> negligible distance during that time. So in both frames the train will
> >>>> have no difficult making the crossing.
> >>>>
> >>>> Sylvia.
> >>>
> >>> Do you put dust under the carpet when you clean your house?
> >>> This is what most relativistic theorists have been doing with me for
> >>> decades.
> >>
> >> I’m not sure I’m following you. First of all, talking here is not talking
> >> with a crowd of “relativistic theorists”. Secondly, this is an example of
> >> basic instructional cases that are covered in introductory textbooks. Why
> >> are you fishing here for explanations instead of just reading those?
> >>
> >>> Since they do NOT want to argue with me because I terrify them, they put
> >>> dust under the carpet.
> >>> And when I ask a question, they always do like that.
> >>> It allows them not to show their incompetence.
> >>> At worst, they overwhelm me with insults or contempt.
> >>> But they never answer the questions correctly.
> >>> Never.
> >>> Well almost. Let's be honest, there are people out there who try to do it
> >>> right. But there aren't many.
> >>>
> >>> R.H.
> >>>
> >
> > The problem, as for decades, is that my questions are never answered
> > correctly.
> Well, it could be that they are in fact answered correctly but

But in the meantime in the real world, forbidden by your
moronic religion incorrect GPS clocks keep measuring
t'=t, just like all serious clocks always did.

Richard Hachel <r.hachel@tiscali.fr> wrote:

> Le 09/12/2021 à 20:36, nospam@de-ster.demon.nl (J. J. Lodder) a écrit :
> > Richard Hachel <r.hachel@tiscali.fr> wrote:
> >
> >> Le 09/12/2021 à 12:56, nospam@de-ster.demon.nl (J. J. Lodder) a écrit :
> >>
> >> > <https://en.wikipedia.org/wiki/Ladder_paradox>
> >>
> >> All of this does not answer the question I asked at all.
> >>
> >> > Jan
> >>
> >> What's happens for the train?
> >
> > See <https://en.wikipedia.org/wiki/Ladder_paradox>
> >
> > Jan
>
> There is an anomaly and "dust under the carpet" in this example.
> It shows an elastic and non-rigid train.
> In my example, we are going to attach a huge iron rod to each side of the
> train, so that it does not bend as in the wrong answer to the problem.
> I ask my question again, what will happen?

Wrong question.
Truly rigid rods must by definition have an infinite elastic modulus,
and hence an infinite speed of sound.
The truly rigid rod is an idealisation
that is not compatible with special relativity.

Jan

Richard Hachel <r.hachel@tiscali.fr> wrote:

> Le 09/12/2021 à 23:45, Odd Bodkin a écrit :
> > No, Richard. There is NO SUCH THING as an arbitrarily rigid rod. Such an
> > idea violates the laws of physics.
> >
> > There is a very simple physical explanation why no solid object can be
> > rigid. Any solid body consists of atoms, and a disturbance at one end has
> > to transmit through neighboring atoms, in a chain to the atoms at the other
> > end. This is true whether the "huge rod" is made of iron or diamond,
> > whether it is an inch in diameter or a meter in diameter. That transmission
> > happens at the speed of sound in the solid material, no faster.
> >
> > This means that if you took a GIANT steel rod, four meters in diameter and
> > a hundred meters long, and you abruptly stopped the front end of the rod,
> > the back end of that giant steel rod would CONTINUE MOVING for another 17
> > millisecond before it even received notice that the front end had stopped.
> > If that giant rod is moving at 100 km per second, the back end of the rod
> > will move almost 1700 meters before even starting to slow down.
> >
> > The more rigid the material, the faster the speed of sound. But the speed
> > of sound cannot be infinite, and in fact can never even be close to c. So
> > there is no such thing as perfect rigidity.
> >
> > This is not sweeping dust under the rug. It is simply not allowing a
> > supposition about perfect rigidity that is counter to the laws of physics.
> >
> > This, by the way, is an important lesson explicitly taught in books about
> > relativity, which I gather you have not read. Instead, you have just tried
> > to figure it out on your own, and in the process you make mistakes.
>
> I think it is impossible to get along under such conditions.
> I think the relativsites, who are facing a very big problem (me), cannot
> clearly answer all of my questions.
> I just offer thought experiments, and when you can't answer, I'm told
> about physical impossibilities, or you drown things in a haze of words.
> I think it's manipulation.

You have been answered.
Doing thought experiments inevitably involves idealisations.
If your idealisations conflict with the law of physics
it can't be a surprise that you may obtain results
that violate the laws of physics,

Jan

On Friday, 10 December 2021 at 10:53:10 UTC+1, J. J. Lodder wrote:
> Richard Hachel <r.ha...@tiscali.fr> wrote:
> > Le 09/12/2021 ŕ 23:45, Odd Bodkin a écrit :
> > > No, Richard. There is NO SUCH THING as an arbitrarily rigid rod. Such an
> > > idea violates the laws of physics.
> > >
> > > There is a very simple physical explanation why no solid object can be
> > > rigid. Any solid body consists of atoms, and a disturbance at one end has
> > > to transmit through neighboring atoms, in a chain to the atoms at the other
> > > end. This is true whether the "huge rod" is made of iron or diamond,
> > > whether it is an inch in diameter or a meter in diameter. That transmission
> > > happens at the speed of sound in the solid material, no faster.
> > >
> > > This means that if you took a GIANT steel rod, four meters in diameter and
> > > a hundred meters long, and you abruptly stopped the front end of the rod,
> > > the back end of that giant steel rod would CONTINUE MOVING for another 17
> > > millisecond before it even received notice that the front end had stopped.
> > > If that giant rod is moving at 100 km per second, the back end of the rod
> > > will move almost 1700 meters before even starting to slow down.
> > >
> > > The more rigid the material, the faster the speed of sound. But the speed
> > > of sound cannot be infinite, and in fact can never even be close to c.. So
> > > there is no such thing as perfect rigidity.
> > >
> > > This is not sweeping dust under the rug. It is simply not allowing a
> > > supposition about perfect rigidity that is counter to the laws of physics.
> > >
> > > This, by the way, is an important lesson explicitly taught in books about
> > > relativity, which I gather you have not read. Instead, you have just tried
> > > to figure it out on your own, and in the process you make mistakes.
> >
> > I think it is impossible to get along under such conditions.
> > I think the relativsites, who are facing a very big problem (me), cannot
> > clearly answer all of my questions.
> > I just offer thought experiments, and when you can't answer, I'm told
> > about physical impossibilities, or you drown things in a haze of words.
> > I think it's manipulation.
> You have been answered.
> Doing thought experiments inevitably involves idealisations.
> If your idealisations conflict with the law of physics
> it can't be a surprise that you may obtain results
> that violate the laws of physics,

And if the idealisations of your idiot guru conflict
with the laws common sense, it can't be a surprise
that he's obtaining various idiotic results in his
idiotic gedankens. GPS, however, obeys the laws
of common sense and it can't be a surprise that
the clocks there keep measuring t'=t, just like
all serious clocks always did.

J. J. Lodder wrote:

> Wrong question.
> Truly rigid rods must by definition have an infinite elastic modulus,
> and hence an infinite speed of sound.
> The truly rigid rod is an idealisation that is not compatible with
> special relativity. Jan

idiot. That's exactly what relativity, the *relativity_effects*, expects.
That there are not 100% rigid, that's irrelevant. You are a braindead
idiot.

Maciej Wozniak <maluwozniak@gmail.com> wrote:

> On Friday, 10 December 2021 at 10:53:10 UTC+1, J. J. Lodder wrote:
> > Richard Hachel <r.ha...@tiscali.fr> wrote:
> > > Le 09/12/2021 ? 23:45, Odd Bodkin a écrit :
> > > > No, Richard. There is NO SUCH THING as an arbitrarily rigid rod. Such an
> > > > idea violates the laws of physics.
> > > >
> > > > There is a very simple physical explanation why no solid object can be
> > > > rigid. Any solid body consists of atoms, and a disturbance at one
> > > > end has to transmit through neighboring atoms, in a chain to the
> > > > atoms at the other end. This is true whether the "huge rod" is made
> > > > of iron or diamond, whether it is an inch in diameter or a meter in
> > > > diameter. That transmission happens at the speed of sound in the
> > > > solid material, no faster.
> > > >
> > > > This means that if you took a GIANT steel rod, four meters in
> > > > diameter and a hundred meters long, and you abruptly stopped the
> > > > front end of the rod, the back end of that giant steel rod would
> > > > CONTINUE MOVING for another 17 millisecond before it even received
> > > > notice that the front end had stopped. If that giant rod is moving
> > > > at 100 km per second, the back end of the rod will move almost 1700
> > > > meters before even starting to slow down.
> > > >
> > > > The more rigid the material, the faster the speed of sound. But the
> > > > speed of sound cannot be infinite, and in fact can never even be
> > > > close to c. So there is no such thing as perfect rigidity.
> > > >
> > > > This is not sweeping dust under the rug. It is simply not allowing a
> > > > supposition about perfect rigidity that is counter to the laws of
> > > > physics.
> > > >
> > > > This, by the way, is an important lesson explicitly taught in books
> > > > about relativity, which I gather you have not read. Instead, you
> > > > have just tried to figure it out on your own, and in the process you
> > > > make mistakes.
> > >
> > > I think it is impossible to get along under such conditions. I think
> > > the relativsites, who are facing a very big problem (me), cannot
> > > clearly answer all of my questions. I just offer thought experiments,
> > > and when you can't answer, I'm told about physical impossibilities, or
> > > you drown things in a haze of words.
> > > I think it's manipulation.
> > You have been answered.
> > Doing thought experiments inevitably involves idealisations.
> > If your idealisations conflict with the law of physics
> > it can't be a surprise that you may obtain results
> > that violate the laws of physics,
>
> And if the idealisations of your idiot guru conflict
> with the laws common sense, it can't be a surprise
> that he's obtaining various idiotic results in his
> idiotic gedankens.

If a medium with an infinite speed of sound existed
then ALL of SPR would be false.
No point then in worrying about details like trains or ladders.

BTW, Lorentz, (well before 1905)
in his 'Theory of Electrons' already showed
that such materials cannot exist,
if one assumes that matter is held together
by electromagnetic interactions.
It turned out, much later, that Lorentz was right about that.

> GPS, however, obeys the laws
> of common sense and it can't be a surprise that
> the clocks there keep measuring t'=t, just like
> all serious clocks always did.

Another counter-factual.
Ask the guys who really have serious clocks about it,
like at NIST for example,

Jan

J. J. Lodder wrote:

> If a medium with an infinite speed of sound existed then ALL of SPR
> would be false.
> No point then in worrying about details like trains or ladders.

sounds are irrelevant in relativity. Idiot.

On Friday, 10 December 2021 at 12:27:06 UTC+1, J. J. Lodder wrote:

> > GPS, however, obeys the laws
> > of common sense and it can't be a surprise that
> > the clocks there keep measuring t'=t, just like
> > all serious clocks always did.
> Another counter-factual.
> Ask the guys who really have serious clocks about it,
> like at NIST for example,

Put your pathetic toys straight into your dumb, fanatic
ass, where they belong. As anyone can check in GPS,
they're useless for SERIOUS measurements. Common
sense was warning your idiot guru.

J. J. Lodder wrote:

>> And if the idealisations of your idiot guru conflict with the laws
>> common sense, it can't be a surprise that he's obtaining various
>> idiotic results in his idiotic gedankens.
>
> If a medium with an infinite speed of sound existed then ALL of SPR
> would be false.
> No point then in worrying about details like trains or ladders.

speaking the witch, if 100% rigid, no contractions and extension can
exists (sound 3D). If they DO exists, then those are inherently EM based,
hence MUST obey relativity.

Reese Page <uteb@dlwcrt.ca> wrote:

> J. J. Lodder wrote:
>
> >> And if the idealisations of your idiot guru conflict with the laws
> >> common sense, it can't be a surprise that he's obtaining various
> >> idiotic results in his idiotic gedankens.
> >
> > If a medium with an infinite speed of sound existed then ALL of SPR
> > would be false.
> > No point then in worrying about details like trains or ladders.
>
> speaking the witch, if 100% rigid, no contractions and extension can
> exists (sound 3D).

You misunderstood, no contractions need to happen.
You tap one end, and the other end moves instantaneously.
So instantaneous clock synchronisation etc., so no relativity.

> If they DO exists, then those are inherently EM based,
> hence MUST obey relativity.

Correct, like I said elsethread, so they can't exist,

Jan

J. J. Lodder wrote:

>> speaking the witch, if 100% rigid, no contractions and extension can
>> exists (sound 3D).
>
> You misunderstood, no contractions need to happen.
> You tap one end, and the other end moves instantaneously.
> So instantaneous clock synchronisation etc., so no relativity.

probably not, you were talking about sounds. The same EM approach
applies, since the rigid bindings are pure EM.

>> If they DO exists, then those are inherently EM based,
>> hence MUST obey relativity.
>
> Correct, like I said elsethread, so they can't exist,

Richard Hachel <r.hachel@tiscali.fr> wrote:
> Le 09/12/2021 à 23:45, Odd Bodkin a écrit :
>> No, Richard. There is NO SUCH THING as an arbitrarily rigid rod. Such an
>> idea violates the laws of physics.
>>
>> There is a very simple physical explanation why no solid object can be
>> rigid. Any solid body consists of atoms, and a disturbance at one end has
>> to transmit through neighboring atoms, in a chain to the atoms at the other
>> end. This is true whether the “huge rod” is made of iron or diamond,
>> whether it is an inch in diameter or a meter in diameter. That transmission
>> happens at the speed of sound in the solid material, no faster.
>>
>> This means that if you took a GIANT steel rod, four meters in diameter and
>> a hundred meters long, and you abruptly stopped the front end of the rod,
>> the back end of that giant steel rod would CONTINUE MOVING for another 17
>> millisecond before it even received notice that the front end had stopped.
>> If that giant rod is moving at 100 km per second, the back end of the rod
>> will move almost 1700 meters before even starting to slow down.
>>
>> The more rigid the material, the faster the speed of sound. But the speed
>> of sound cannot be infinite, and in fact can never even be close to c. So
>> there is no such thing as perfect rigidity.
>>
>> This is not sweeping dust under the rug. It is simply not allowing a
>> supposition about perfect rigidity that is counter to the laws of physics.
>>
>> This, by the way, is an important lesson explicitly taught in books about
>> relativity, which I gather you have not read. Instead, you have just tried
>> to figure it out on your own, and in the process you make mistakes.
>
> I think it is impossible to get along under such conditions.
> I think the relativsites, who are facing a very big problem (me), cannot
> clearly answer all of my questions.
> I just offer thought experiments, and when you can't answer, I'm told
> about physical impossibilities, or you drown things in a haze of words.
> I think it's manipulation.

No, it’s not manipulation and it’s not a haze of words. Thought experiments
are fine, but it makes no sense to make a supposition in the thought
experiment that violates laws of physics and then ask what the laws of
physics would predict. That’d be like asking what Newton’s laws of motion
would predict if conservation of momentum do not hold.

It’s fine to idealize in a thought experiment, but not to the extent that
laws of physics would be broken.

This has nothing to do with technical feasibility of trains going half the
speed of light. This has to do with perfect rigidity being counter to
physical laws.

> Gentle, unconscious manipulation that believes it is necessary for the
> good of science.
> But handling all the same.
> And we never answer clearly and openly to the questions I ask. Precise
> questions, often asked with digital applications to make them concrete.
> But digital applications that we avoid even more than my questions,
> because they require an answer, and that we cannot answer me: "go see on
> such site, or listen to such video".
> There, you have to answer me, and it's not easy to cheat, or to dust the
> carpet. I ask very simple questions, often concrete, with very simple
> digital applications.
> I ask for example what is the speed of the rocket? I am not being
> answered.
> I ask if a 300-meter train moving at such a speed will fall into a
> 300-meter hole, I am next told that "physically, it is not possible".
> This is, of course, a thought experiment. I know that there are no trains
> today capable of going at such speeds. That's not what I'm talking about.
>
> R.H.
>

--
Odd Bodkin -- maker of fine toys, tools, tables

On 12/9/2021 2:40 PM, Richard Hachel wrote:
> Le 09/12/2021 à 16:07, Michael Moroney a écrit :
>> The problem with that analysis is that you implicitly assume that
>> there is some sort of infinite speed communication of the front and
>> rear of the train with each other so that the train can 'decide' to
>> fall into the gap if and only if both ends are not supported. Then you
>> point out how in one frame both ends are unsupported and in another
>> they never are both unsupported. Paradox. However, there is no such
>> infinite speed communication. The front of the train can only 'know'
>> about the situation of the rear as it was 500/c seconds ago. Same for
>> the bridge, one end can only 'know' about the situation of the other
>> end as it was 500/c seconds ago.  This is much like the bug/rivet
>> 'paradox' which isn't a paradox if you remember it takes a finite time
>> for the event of the rivet head reaching the wall to reach the tip, so
>> the bug is always squashed.
>
> In the example I gave, which three observers are right, and which three
> are wrong?
>
What three observers?

Richard Hachel wrote:

> The train paradox.
> Everyone knows this paradox.

Actually, it is the first time that I have heard of this name. But in a
textbook a similar thought experiment is done with a pole in a barn.

> A train is running on a 0.8c railway line.
> The train measures 500 meters at rest.
> In the terrestrial frame of reference, it measures only 300 meters.

This does not make sense. The "terrestrial frame of reference" *is* the
rest frame as certainly the rails are not moving relative to that frame.

Therefore, the train’s length is measured *the same* "at rest" and in "the
terrestrial frame of reference".

So you are already starting from a false premise. This does not bode well
for the rest.

> […]
> two incompatible ideas cannot exist together, and all the frames of
> reference are necessarily right for them.

In the actual thought experiment, the ideas are not incompatible, because of
a measurable relativistic effect that is predicted by the Lorentz
transformation and that you are unwilling to accept: the relativity of
simultaneity. It leads to another measurable relativistic effect that you
obviously misunderstand, commonly called “length contraction”.

The length of an object is defined as the spatial distance between the end
points of that object *at the same time*. If events do not happen at the
same time in a reference, then this affects the role of lengths in general,
and the measured lengths outside that frame in particular.

And you have switched the frame of reference in your argument in an
incorrect way – a common mistake made by beginners in discussing special
relativity.

See also:

Fermilab: “Length contraction: the real explanation”
<https://www.youtube.com/watch?v=-Poz_95_0RA>

> Except that you have to find a rotten repository. But which one is it, if
> one is not absurd?

Your mind is a rotten repository of thoughts apparently, and your argument
is absurd, instead.

PointedEars
--
«Nec fasces, nec opes, sola artis sceptra perennant.»
(“Neither high office nor power, only the scepters of science survive.”)

—Tycho Brahe, astronomer (1546-1601): inscription at Hven

ake the Duke University example for instance. a 98% compliance:

Hundreds of vaccinated students test positive for COVID-19 at Duke University (Hundreds of vaccinated students test positive for COVID-19 at Duke University)

More students are infected now, despite 98 percent vaccination, than were infected a year ago, before vaccines were available (Hundreds of vaccinated students test positive for COVID-19 at Duke University)

Hundreds of vaccinated students test positive for COVID-19 at Duke University (Hundreds of vaccinated students test positive for COVID-19 at Duke University)

With 98% compliance rate, it doesn't get any better than that. Yet within a few weeks, a surge in positive tests found 349 covid cases. And 97.4% of them were fully vaxxed

Le 11/12/2021 à 00:40, Thomas 'PointedEars' Lahn a écrit :

> It leads to another measurable relativistic effect that you
> obviously misunderstand, commonly called “length contraction”.

Rest assured, good Doctor Hachel knows these things as well as you do.
I remind you that for example I give the lengths, times, wavelengths
measured by an observer who sees an object pass in his line of sight.
Rest assured, relativists know the three equations I am giving here, and
consider them to be true. It's just the concepts that we don't agree on.
You see, there are a lot of things that I agree with them on. It is true
that there are small notions with which I cannot agree more with them.
But no one can say of me that I don't know SR, or that I am a sun crank
who thinks this whole theory is wrong and useless. I did not say that.
Never.

<http://news2.nemoweb.net/jntp?Ymt0Qv7FVcYcIj5R4dMEfnz5eE8@jntp/Data.Media:2>

<http://news2.nemoweb.net/jntp?Ymt0Qv7FVcYcIj5R4dMEfnz5eE8@jntp/Data.Media:1>

> PointedEars

Clic in this adress to read in http format ---> <http://news2.nemoweb.net/?DataID=Ymt0Qv7FVcYcIj5R4dMEfnz5eE8@jntp>

R.H.

Thomas 'PointedEars' Lahn wrote:

> Richard Hachel wrote:
>> […]
>> two incompatible ideas cannot exist together, and all the frames of
>> reference are necessarily right for them.
>
> In the actual thought experiment, the ideas are not incompatible, because
> of a measurable relativistic effect that is predicted by the Lorentz
> transformation and that you are unwilling to accept: the relativity of
> simultaneity. It leads to another measurable relativistic effect that you
> obviously misunderstand, commonly called “length contraction”.

I should have said “measured” instead of “measurable” because it has already
been done. So it is not just theoretical.
> The length of an object is defined as the spatial distance between the end
> points of that object *at the same time*. If events do not happen at the
> same time in a reference,
^^^^^^^^^
reference _frame_

> then this affects the role of lengths in
> general, and the measured lengths outside that frame in particular.

PointedEars
--
“Nature uses only the longest threads to weave her patterns
so that each small piece of her fabric reveals the organization
of the entire tapestry.”
—Richard Feynman, theoretical physicist, “Messenger Lecture” 1 (1964)

Richard Hachel wrote:

> Le 11/12/2021 à 00:40, Thomas 'PointedEars' Lahn a écrit :
>> It leads to another measurable relativistic effect that you
>> obviously misunderstand, commonly called “length contraction”.
>
> Rest assured, good Doctor Hachel knows these things as well as you do.

You must be kidding. You wrote “terrestrial reference frame” when you meant
the rest frame of the rails and still said that the train would have a
different length than at rest.

Just another piece of evidence that you do NOT know what you are talking
about. It is all just pseudo-scientific word salad.

PointedEars
--
A neutron walks into a bar and inquires how much a drink costs.
The bartender replies, "For you? No charge."

(from: WolframAlpha)

Le 11/12/2021 à 01:25, Thomas 'PointedEars' Lahn a écrit :

> Just another piece of evidence that you do NOT know what you are talking
> about. It is all just pseudo-scientific word salad.

I especially believe that my translator is not very good.

Stay another five minutes with me. The best will come.
>
>
> PointedEars

R.H.

On 12/10/21 5:27 AM, J. J. Lodder wrote:
> BTW, Lorentz, (well before 1905)
> in his 'Theory of Electrons' [...]

Lorentz published _Theory_of_Electrons_ in 1916. But the genesis of his
theory came in 1904.

NOTE: what he meant by "electron" is QUITE DIFFERENT from what we mean
by the word today. He meant a continuous charged fluid, not individual
charged particles of mass 511 keV (etc.).

Also: His theory is experimentally indistinguishable from Special
Relativity, within their common domain (electrodynamics only). SR has a
much wider domain.

Tom Roberts

On Saturday, 11 December 2021 at 00:40:27 UTC+1, Thomas 'PointedEars' Lahn wrote:
> Richard Hachel wrote:
>
> > The train paradox.
> > Everyone knows this paradox.
> Actually, it is the first time that I have heard of this name. But in a
> textbook a similar thought experiment is done with a pole in a barn.
> > A train is running on a 0.8c railway line.
> > The train measures 500 meters at rest.
> > In the terrestrial frame of reference, it measures only 300 meters.
> This does not make sense. The "terrestrial frame of reference" *is* the
> rest frame as certainly the rails are not moving relative to that frame.

In the meantime in the real world, however, forbidden by
your moronic religion GPS clocks keep measuring t'=t,
just like all serious clocks always did.

On 12/11/2021 12:46 AM, Tom Roberts wrote:
> On 12/10/21 5:27 AM, J. J. Lodder wrote:
>> BTW, Lorentz,  (well before 1905)
>> in his 'Theory of Electrons' [...]
>
> Lorentz published _Theory_of_Electrons_ in 1916. But the genesis of his
> theory came in 1904.
>
> NOTE: what he meant by "electron" is QUITE DIFFERENT from what we mean
> by the word today. He meant a continuous charged fluid, not individual
> charged particles of mass 511 keV (etc.).

Interesting that they used a plural word (electrons) to describe a
continuous fluid.

Tom Roberts wrote:

> Also: His theory is experimentally indistinguishable from Special
> Relativity, within their common domain (electrodynamics only). SR has a
> much wider domain.

which one of which is not electrodynamics?? Light is electrodynamics,
implies the space and the spacetime ARE electrodynamics.

Michael Moroney wrote:

>> Lorentz published _Theory_of_Electrons_ in 1916. But the genesis of his
>> theory came in 1904.
>>
>> NOTE: what he meant by "electron" is QUITE DIFFERENT from what we mean
>> by the word today. He meant a continuous charged fluid, not individual
>> charged particles of mass 511 keV (etc.).
>
> Interesting that they used a plural word (electrons) to describe a
> continuous fluid.

which fluid in your area of residence is not being continuous?

Tom Roberts <tjroberts137@sbcglobal.net> wrote:

> On 12/10/21 5:27 AM, J. J. Lodder wrote:
> > BTW, Lorentz, (well before 1905)
> > in his 'Theory of Electrons' [...]
>
> Lorentz published _Theory_of_Electrons_ in 1916. But the genesis of his
> theory came in 1904.

Well, eh, no. The 1916 book was the final textbook form.
Lorentz had started working on it in 1892,
and the first version of it was completed in 1895.

For another data point, Lorentz (with Zeeman)
received the 1902 Nobel prize for his 'theory of electrons'.
Lorentz' work on it was really well before Einstein.
For a though overview of the developments you can look at
<https://en.wikipedia.org/wiki/Lorentz_ether_theory>

> NOTE: what he meant by "electron" is QUITE DIFFERENT from what we mean
> by the word today. He meant a continuous charged fluid, not individual
> charged particles of mass 511 keV (etc.).

Not quite. Lorentz allowed point particles,
with a clever trick to avoid the infinities.
(by focussing on the structure-independent part)
So Lorentz also gave the correct Lorentz force
on point particles, (or very small extended particles)
just like we still use it.

> Also: His theory is experimentally indistinguishable from Special
> Relativity, within their common domain (electrodynamics only). SR has a
> much wider domain.

Not really. Other forces,including gravity, can be included.
(as shown by Poincaré)
The final result is that LET and SR are completely equivalent.

LET is more general however. It can be used as a framework
for building more general theories in which there is an aether.
<https://en.wikipedia.org/wiki/Test_theories_of_special_relativity >
As such it is indispensable when you want to devise experimental tests
for the validity of special relativity,

Jan