On Monday, July 24, 2023 at 8:52:24 PM UTC+1, Tom Roberts wrote:
> On 7/24/23 1:01 PM, erkd...@gmail.com wrote:
> > A =valid= general theory of relativity is a separate, completely
> > different theory to SR.
> Yes. That's what we have.

Not unless we've recently changed the theory's characterisation.
Einstein wrote SR-compliance directly into some of the
theory's critical definitions.
If those definitions have changed, then we have a different variant,
and potentially a different theory.

> > Einstein's //attempt// at a general theory (presented in 1915, in
> > print by 1916) was designed to try to incorporate SR into GR as a
> > fully-contained set of physics theory, so that GR1916 was a full
> > superset of SR physics, and and that's geometrically impossible.

> No, it isn't. SR is the LOCAL LIMIT of GR. That is geometrically and
> physically possible, even necessary:
> * Geometrically, every geometry has tangent spaces, and for GR
> those tangent spaces obey SR.

Firstly, flat empty tangent spaces don't have an interior physics (with
regard to matter), because it's a precondition of their //being// flat
empty spaces that they don't //contain// any matter.

Do you not understand how perverse it is to try to derive the properties
of matter from the special properties of a space that only has those
properties if, by definition, no matter is present? It's unphysics!

Suppose that a marketing student wanted to come up with a set of
equations describing how people move about in a shopping centre, and
they chose a shopping centre, but specified that it was only to be studied
between 2am and 3am, when it was guaranteed that there would be
nobody in the building not even cleaners.
Suppose that they then came up with some idiotic formula for how
shoppers behave, that doesn't work if ==even one=== shopper is present.
They could say, well, the shopping centre may contain five thousand
people when it's open, or five hundred. It's variable.
But if you only zoom in far enough, until you are looking at individual
atoms, ==there are no customers there==. "Zero customers" is always a
limiting case of the behaviours of "some customers", and if you zoom in
enough there are always ==no== customers, everywhere, and everywhen,
guaranteed, at every point in the shopping centre continuum. .
So even though the laws for zero customers are never right, they are
universally correct! :)

You'd think that the researcher was completely crazy, yes?

That's the stunt that Einstein pulled.
Einstein was not insane. But he knew that he was substantially brighter
than most of his audience, so he could bullshit them and get away with it.
That would buy him lots of time, during which he might be able to come up
with a better argument, that might actually make sense.

Of course,he never quite did manage to come up with a proof of the validity
of SR. The nearest he got was energy-conservation arguments, and those
got wrecked by the idea of gravitational waves, because g-waves weren't
part of his energy-accounting. That was one of his arguments for why we
knew that g-waves didn't exist, because if they //did// exist, his whole
system was going to have to be redesigned.

> * Physically it is essential, because SR is among the best-tested
> and most-validated theories we have (within its domain, of
> course). Far more so than GR.

Okay. So at that point, we abandon logic, geometry and mathematics,
and say, "General relativity //ought// to reduce to SR physics, because //we
like// SR physics."

I suppose that at least that's an honest answer.
But it's kinda "faith based", don't you think?
"Lots of people believe in this, and like it, so it's probably true."

Kind reduces GR architecture from deterministc geometry to a branch of
the social sciences.

> > That's why Einstein's GR1916 (sez me) is not a valid general theory
> > of relativity.
> NONSENSE! GR has been validated many times in many different ways, and
> has not been refuted.

GR1916 is refuted in the very paper that this thread is supposed to be about.
Did you not read it?

* SR relationships make gravitomagnetism impossible, and without GM,
we can't have a general theory of relativity.
* So a valid general theory logically can't use the SR relationships.
* GR1916 //does// use the SR relationships, so it is not a valid general
theory of relativity.

A refutation in three sentences.
Here you go:
https://www.researchgate.net/publication/372245510_Principles_of_Gravitomagnetism_I_-_Unavoidability
> NOTE: You use "invalid" where you should use "inconsistent". In physics,
> "valid" means "supported by experiments and refuted by none

In general language, if a theory is internally inconsistent, then it is also
not a valid theory (for failing to meet the minimum theoretical criteria
expected of a working theory).

> Your
> complaints are about the inconsistency between flat-space SR and
> curved-space GR.

Yes.

> But the tangent spaces of any curved manifold are
> equivalent to flat spaces, and SR holds in the tangent spaces of any
> manifold in GR.

SR //might// arguably apply to the tangent spaces as a special case,
in an entirely abstract sense. But it will =not= apply when you have a space
containing two fundamental massed particles with relative motion, and
with the attendant gravitational and gravitomagnetic distortions, because
that's a different geometry. The "empty tangent space" case does not
describe the geometry of real particles interacting.

it's pretty pointless coming up with a set of equations to describe the
behaviour of matter, if these =only= apply in the =absence= of matter,
don't you think? If SR can't apply to actual moving bodies, and we have to
derive a whole new relativistic theory based on gravitomagnetism, with
different equations, to handle what happens when =real= matter moves
under general theory, then who the hell cares about what's supposedly
happening in little vanishingly-small empty spaces when nobody is
looking?
The "empty tangent-space" case is only of any interest whatosever if
the rules, laws and relationships that we derive from it can also be
applied to real physics. But i a working ganeral theory, geometrically,
they can't.

Within the context of a working general theory, suggesting an "SR of
the tangent spaces" makes about as much sense as calculating the
aerodynamics of fairies and goblins and flying unicorns. The starting
assumption that everything else will be based on is already
counterfactual.

And again, flat spacetime on its own doesn't give us SR. Only flat
spacetime //plus relativity// gives us SR, and there's always the distinct
possibility that "relativity" as a concept depends on relativising
//observations//, and might not have to apply when a region is empty,
and no observations can be made there.

it might be that the relativity concept itself becomes "null" (and irrelevant)
in a tangent space, because there is nothing there for the principle to apply
to.

Also, note Einstein's defence against "the hole problem" in general relativity.
Faced with the prospect of coordinate system breakdowns in empty voids
containing no matter, when the surrounding coordinate systems were
extrapolated into a void, Einstein's answer was that coordinate-system
-based arguments were meaningless in empty spaces. Coordinate systems,
said Einstein, has been considered "physical" under SR, but under GR were
completely arbitrary, and had no physical meaning unless a coordinate was
attached to a physical marker.

If we are to apply Einstein's arguments consistently (which is sometimes
difficult!), we can argue that we don't give a stuff what may or may not
hypothetically happen in blank empty tangent spaces, because that's not
matter-physics.
> Your complaints and confusions are all due to your lack of understanding
> of the actual relationship between SR and GR.

No, I think I've gone through the actual relationship between SR and GR in
rather more depth than most folk who promote GR.

The "you don't understand" argument is hackneyed, and too close the the
religious gurur's "You don't understand, if you understood you would believe"

The statement suggests a certain assumed intellectual hierarchy (regarding
who gets to decide who is wrong) that may not be valid.

Any fool can declare "you don't understand!" when someone says something
that they can't comprehend and don't like. I've been told by supposed experts
that I "don't understand" SR, when all I was trying to tell them was that the
Gamow characterisation of SR was faulty. They wouldn't accept it.
How could something they were brought up with, and believed all their
professional lives, be untrue? That might mean - gasp -- that maybe they
weren't as bright as they thought! Preposterous!
When I was trying to explain that the Gamow description was faulty, I think
they took it as a personal insult for me to suggest that the math was on my
side. But it was true.

On Monday, July 24, 2023 at 6:22:00 PM UTC-7, erkd...@gmail.com wrote:
> > Light emitted from the rim of a rotating disk arrives redshifted at the hub,
> > by an amount corresponding to the relativistic time dilation, whereas there
> > is no such effect according to Newtonian physics.
>
> There is, if you do the math properly.

No, every pulse (or wavecrest) traverses the same distance, and we are obviously not accumulating pulses in transit anywhere, so, if there were no relativistic time dilation, the rate of arrival of pulses at the hub would necessarily equal the rate of departure from the rim (in terms of their respective proper times). That is the unequivocal answer in the context of Newtonian physics and Galilean relativity. Agreed?

In contrast, local Lorentz invariance implies that there is relativistic time dilation between the rim and the hub, which results in a "transverse" shift in frequency. (Note that "transverse" in this context simply means a condition for which the optical path length is not changing.) Agreed?

On 7/24/23 8:21 PM, erkd...@gmail.com wrote:
> On Monday, July 24, 2023 at 8:52:24 PM UTC+1, Tom Roberts wrote:
>> On 7/24/23 1:01 PM, erkd...@gmail.com wrote:
>>> A =valid= general theory of relativity is a separate, completely
>>> different theory to SR.
>> Yes. That's what we have.
>
> Not unless we've recently changed the theory's characterisation.
> Einstein wrote SR-compliance directly into some of the theory's
> critical definitions.

The "change" was a recognition that SR is valid only locally. Note this
was inherent in the original formulation, just not recognized as such.

> If those definitions have changed, then we have a different variant,
> and potentially a different theory.

This is not a "variant" or "different theory". SR stands as it did in
1905, it's just that we now know it is not universally applicable. The
same thing happened to Newtonian mechanics, and to quantum mechanics.
Reductions in the domain of a theory are not really a "change", as they
were really there all the time, just not recognized.

> Firstly, flat empty tangent spaces don't have an interior physics
> (with regard to matter), because it's a precondition of their
> //being// flat empty spaces that they don't //contain// any matter.

Again you confuse EXACT with valid. SR is valid locally, including the
standard model (which is the current best theory of matter and its
interactions).

> Do you not understand [...]

No, it is YOU who does not understand.

> [silly analogy that is not even close] That's the stunt that Einstein
> pulled.

Nope. Not even close. SR, in some sense, evolved into GR. Not the other
way around.

> Of course,he never quite did manage to come up with a proof of the
> validity of SR.

Of course not! one cannot "prove" anything about a physical theory. One
can prove theorems about its mathematical formulation, but not about its
VALIDITY (which is whether it agrees with experiment).

> Okay. So at that point, we abandon logic, geometry and mathematics,
> and say, "General relativity //ought// to reduce to SR physics,
> because //we like// SR physics."

NONSENSE! You REALLY need to learn something about the subject before
attempting to write about it.

SR is the local limit of GR, at every point in every manifold of GR.
This is a theorem about the math of GR. From a physics standpoint it is
essential, as SR is among the best-tested theories we have -- if GR did
not have SR as its local limit, it would have been rejected long ago.

Your insistence on exactness is YOUr mistake, confusing physics with
mathematics. Math is exact, physics is not.

> [... further fantasies]

> * SR relationships make gravitomagnetism impossible, and without
> GM, we can't have a general theory of relativity. * So a valid
> general theory logically can't use the SR relationships. * GR1916
> //does// use the SR relationships, so it is not a valid general
> theory of relativity.

Again you confuse EXACT with valid. The gravitomagnetism you obsess
about is in GR, and DISAPPEARS in its local limit. Your fantasies do not
refute GR or show an internal inconsistency.

>> NOTE: You use "invalid" where you should use "inconsistent". In
>> physics, "valid" means "supported by experiments and refuted by
>> none
>
> In general language, if a theory is internally inconsistent, then it
> is also not a valid theory (for failing to meet the minimum
> theoretical criteria expected of a working theory).

This is a physics newsgroup, not "general language". Moreover, you have
not shown any internal inconsistency in GR. You have only shown
inconsistencies in your personal guesses and fantasies.

> [... further long-winded nonsense]

Tom Roberts

On 7/24/23 3:42 PM, Porter Lihov wrote:
> I can't see 𝗮𝗻𝘆 𝘀𝗽𝗲𝗲𝗱 𝗲𝗺𝗯𝗲𝗱𝗱𝗲𝗱 𝗶𝗻 𝘁𝗵𝗼𝘀𝗲 𝗚𝗥
> 𝗲𝗾𝘂𝗮𝘁𝗶𝗼𝗻𝘀.

Sure, because "speed" is related to coordinates, and the fundamental
equations of GR are independent of coordinates.

> And correspondingly, it's like 𝗶𝗺𝗽𝗼𝘀𝘀𝗶𝗯𝗹𝗲 𝘁𝗼
> 𝗱𝗲𝗿𝗶𝘃𝗲 𝗮 𝗹𝗲𝗻𝗴𝘁𝗵 𝗰𝗼𝗻𝘁𝗿𝗮𝗰𝘁𝗶𝗼𝗻 out of them,

Not true. If one applies the equations of GR to a suitable physical
situation, "length contraction" certainly is predicted. Of course it is
much easier to take the limit of the GR equations and apply the
equations of SR. (Any suitable physical situation is likely to need just
the local limit of GR.)

> [... further evidence he does not understand this]

Tom Roberts

On Monday, July 24, 2023 at 6:22:00 PM UTC-7, erkd...@gmail.com wrote:
> > Light emitted from the rim of a rotating disk arrives redshifted at the hub,
> > by an amount corresponding to the relativistic time dilation, whereas there
> > is no such effect according to Newtonian physics.
>
> There is, if you do the math properly.

Every pulse (or wavecrest) traverses the same distance, and we are obviously not accumulating pulses in transit anywhere, so, if there were no relativistic time dilation, the rate of arrival of pulses at the hub would necessarily equal the rate of departure from the rim (in terms of their respective proper times). That is the unequivocal answer in the context of Newtonian physics and Galilean relativity. Agreed?

In contrast, local Lorentz invariance implies relativistic time dilation between the rim and the hub, which results in a "transverse" shift in frequency. (Note that "transverse" in this context simply means a condition for which the optical path length is not changing.) Agreed?

Tom Roberts wrote:

> On 7/24/23 3:42 PM, Porter Lihov wrote:
>> I can't see 𝗮𝗻𝘆 𝘀𝗽𝗲𝗲𝗱 𝗲𝗺𝗯𝗲𝗱𝗱𝗲𝗱 𝗶𝗻 𝘁𝗵𝗼𝘀𝗲 𝗚𝗥 𝗲𝗾𝘂𝗮𝘁𝗶𝗼𝗻𝘀.
>
> Sure, because "speed" is related to coordinates, and the fundamental
> equations of GR are independent of coordinates.
>
>> And correspondingly, it's like 𝗶𝗺𝗽𝗼𝘀𝘀𝗶𝗯𝗹𝗲 𝘁𝗼 𝗱𝗲𝗿𝗶𝘃𝗲 𝗮 𝗹𝗲𝗻𝗴𝘁𝗵
>> 𝗰𝗼𝗻𝘁𝗿𝗮𝗰𝘁𝗶𝗼𝗻 out of them,
>
> Not true. If one applies the equations of GR to a suitable physical
> situation, "length contraction" certainly is predicted. Of course it is
> much easier to take the limit of the GR equations and apply the
> equations of SR. (Any suitable physical situation is likely to need just
> the local limit of GR.)
>
>> [... further evidence he does not understand this] Tom Roberts

ohh my butt, 𝐭𝐡𝐢𝐬_𝐞𝐥𝐞𝐜𝐭𝐫𝐢𝐜𝐢𝐚𝐧 doesn't know the basics in physics. He is
just 𝐦𝐨𝐯𝐢𝐧𝐠_𝐡𝐢𝐬_𝐥𝐢𝐩𝐬. Choose any coordinate you want, there are no speeds
in GR,
except the 𝐬𝐩𝐞𝐞𝐝_𝐨𝐟_𝐥𝐢𝐠𝐡𝐭, which is an 𝐮𝐧𝐢𝐭.

put the money where your mouth is, and show it in math symbols. 𝐘𝐨𝐮_𝐜𝐚𝐧'𝐭.
You are 𝐣𝐮𝐬𝐭_𝐦𝐨𝐯𝐢𝐧𝐠_𝐲𝐨𝐮𝐫_𝐥𝐢𝐩𝐬. Amazing the impertinence from this
𝐞𝐥𝐞𝐜𝐭𝐫𝐢𝐜𝐢𝐚𝐧. Also, you are just 𝐦𝐨𝐫𝐚𝐥𝐥𝐲_𝐬𝐮𝐩𝐩𝐨𝐫𝐭𝐢𝐧𝐠_the nazi ukraine.

On 7/24/23 10:40 PM, Bill wrote:
> On Monday, July 24, 2023 at 6:22:00 PM UTC-7, erkd...@gmail.com
> wrote:
>>> Light emitted from the rim of a rotating disk arrives redshifted
>>> at the hub, by an amount corresponding to the relativistic time
>>> dilation, whereas there is no such effect according to Newtonian
>>> physics.
>>
>> There is, if you do the math properly.

Nope. Why don't you show us your "properly done" math?

> Every pulse (or wavecrest) traverses the same distance, and we are
> obviously not accumulating pulses in transit anywhere, so, if there
> were no relativistic time dilation, the rate of arrival of pulses at
> the hub would necessarily equal the rate of departure from the rim
> (in terms of their respective proper times). That is the unequivocal
> answer in the context of Newtonian physics and Galilean relativity.
> Agreed?

Yes. Of course Newtonian physics and Galilean relativity predict their
respective proper times are equal (i.e. identical clocks on the rim
and at the hub would remain synchronized).

> In contrast, local Lorentz invariance implies relativistic time
> dilation between the rim and the hub, which results in a
> "transverse" shift in frequency. (Note that "transverse" in this
> context simply means a condition for which the optical path length is
> not changing.) Agreed?

Yes. I agree that in this physical situation the optical path length is
not changing, but I disagree with your meaning of the word "transverse"
(unchanging optical path length is a consequence of a transverse
physical situation, not its defining characteristic).

Tom Roberts

On Tuesday, 25 July 2023 at 16:02:07 UTC+2, Tom Roberts wrote:
> On 7/24/23 10:40 PM, Bill wrote:
> > On Monday, July 24, 2023 at 6:22:00 PM UTC-7, erkd...@gmail.com
> > wrote:
> >>> Light emitted from the rim of a rotating disk arrives redshifted
> >>> at the hub, by an amount corresponding to the relativistic time
> >>> dilation, whereas there is no such effect according to Newtonian
> >>> physics.
> >>
> >> There is, if you do the math properly.
> Nope. Why don't you show us your "properly done" math?

Speaking of math - it's always good to remind
that your bunch of idiots had to announce its oldest,
very important part false - as it didn't want to fit
your madness.

On 7/24/23 4:27 PM, erkd...@gmail.com wrote:
> On Monday, July 24, 2023 at 6:19:53 PM UTC+1, Tom Roberts wrote:
>> On 7/24/23 9:07 AM, erkd...@gmail.com wrote:
>>> The unstated implicit third postulate of Einstein's 1905 paper
>>> is the requirement that the presence and relative motion of
>>> matter has zero effect on the lightbeam geometry.
>> Hmmm. In 1905 this "third postulate" was unknown.
>
> Indeed. Because Einstein kept damned quiet about the fact that his
> 1905 derivation and his 1905 theory had a dirty great big
> vulnerability. [...] He would have known about it.

You think that Einstein was clairvoyant????

In 1905 there was no inkling that space could be anything but Euclidean,
and absolutely no expectation that the presence of matter could affect
space. Spacetime was not known.

Various non-Euclidean geometries were known to mathematicians.
Nobody considered them applicable to physics. Space vs. spacetime
was a major stumbling block, and the latter was unknown.

Don't apply revisionist history in applying modern knowledge to ancient
times and expecting people back then to understand things we know today.

> I think his 1905 paper is actually extremely clever in how it tries
> to hide the vulnerability,

I think you know NOTHING AT ALL about Einstein's internal mental
processes. Neither do I. But it is QUITE CLEAR that your claims about
him are simply wrong. The "vulnerability" you claim was COMPLETELY
UNKNOWN in 1905.

>> Today we understand this, and it is part and parcel of GR.
>
> Nah. Your team still don't get it, or they wouldn't be where they
> are. The relationship between flat-spacetime and curved-spacetime
> physics theory is bit subtle. It's kinda getting into philosophy.

No. It is merely the mathematics of limits -- well known.

In _ANY_ Riemannian or semi-Riemannian manifold, with any curvature
whatsoever, one can ALWAYS find Riemann normal coordinates at any point
of the manifold, which are valid to any given accuracy in a suitable
neighborhood of the point. This is inherent in differential geometry. In
GR such coordinates are essentially SR.

Where do you think the "flat earth" nonsense comes from? -- it comes
from idiots fantasizing that the Riemann normal coordinates where they
are standing apply to the entire surface of the earth. Just like you
fantasize that SR would apply throughout the universe. Both are equally
wrong by ignoring the same local vs. global relationships.

>> This does not "invalidate" SR, because we have reduced SR's domain
>> of applicability to exclude situations in which that is
>> important.
>
> The strict range of validity of the 1905 derivaiton is that it
> describes the relativistic physics of observations in empty space.

Back then that was not known to be a limitation. Your revisionist
history stinks.

> Snag is, in empty space, there are no physical observers present and
> nothing to physically observe. Within an empty region, there are no
> observations being made that //need// to be relativised. So the
> theory is null.

You STILL don't get it.

Compared to the earth or sun, one can neglect the mass of an observer,
satellite, or spaceship. Much of physics is figuring out which aspects
of a physical situation can be neglected, in order to reduce the
complexity enough so the equations can be solved and useful results
obtained.

A real-world example: near the surface of the earth, any truly inertial
frame will accelerate downward at 9.8 m/s^2; such a frame must be
limited in size related to one's measurement accuracy, and for an
accuracy >= 1 micron the curvature of the earth can be neglected over
100 meters (at least), which is the size of an LHC cavern. In the LHC
caverns, each event [@] is analyzed individually, and since the relevant
particles travel with speed approaching c relative to the cavern, no
event lasts longer than 333 nanoseconds. During that time a truly
inertial frame initially at rest relative to the apparatus would fall
approximately [#] (1/2)gt^2 which is less than a picometer. Since their
instruments have resolutions more than a million times larger, the
motion of the truly inertial frame can be neglected and each event can
be analyzed using SR, considering the apparatus to be at rest in an
inertial frame.

[@] Here "event" is in the sense of particle physics, not
relativistic geometry. An event at the LHC consists of a
single proton-proton interaction and whatever particles
it produces.

[#] Here the approximation of using Newtonian gravitation
is extremely good.

> Special relativity is a fairy tale.

But a very useful one, as there are many physical situations in which it
is appropriate to use SR as an approximation to GR, when the
approximation is much better than measurement resolutions.

> Within relativity theory, when matter has curvature, and moves, the
> SR equations do not work.

They can work APPROXIMATELY. And in many physical situations that
approximation is MUCH more accurate than measurement resolutions.

Real-world example: In our everyday lives we use Newtonian physics,
because its approximation to GR is VASTLY better than our measurement
resolutions (~ millimeters).

> So special relativity does not apply to real-world matter.

Not true. SR can apply APPROXIMATELY to real-world matter, and in some
physical situations that approximation is much better than measurement
resolutions -- in such cases SR can be used; it is ENORMOUSLY easier to
apply than GR.

Similarly, Newtonian physics can apply APPROXIMATELY to real-world
matter....

> [SR] is not correct foundation theory. It does not and cannot give
> the correct fundamental equations of motion for moving matter. It
> is, to use a taboo word, "wrong".

Again you confuse "not exact" with "wrong". Because of that you
overstate the case.

Besides, at the level of fundamental theories of physics, one uses GR,
not SR.

But as a practical matter, for physical situations in which SR is an
acceptable approximation to GR, one applies SR because it is ENORMOUSLY
simpler to use SR than GR.

> [... repetitious arrogance, ignorance, and nonsense]

> could you please point me to the project page where our GR
> universities are pooling their resources to identify the exact shape
> of the relativistic Doppler equations that have to replace the SR
> predictions? Because I don't see one.

You don't "see one" because YOU HAVE NOT LOOKED.

Experiments that measure Doppler shift are performed on earth. Here on
earth the linear approximation to GR is much more accurate than any
measurement accuracies, and is what is used. In that approximation,
Doppler shift separates into a gravitational term and a
relative-velocity term (i.e. SR). The equations for this are well known
-- look in any GR textbook.

> If you //say// that the community understand the relationship
> between SR and GR, then what evidence can you show us to back that
> up?

Look in any GR textbook for the various approximations to GR.

> It seems very much as if we're stuck.

YOU are indeed stuck, due to your arrogance and ignorance (a deadly
combination in any intellectual endeavor). Physicists are not "stuck" by
this, because we understand it.

>> Today, nobody expects SR to be universally valid --
>
> Its equations have to be either universally ==valid==, or
> universally ==invalid==.

Nope. SR is APPROXIMATELY VALID in many interesting physical situations,
and SR can be used when the approximation induces errors much smaller
than measurement resolutions.

>> SR and GR are compatible geometrically.
>
> SR and a valid general theory are not compatible as ==physics==.

This is just not true. SR is the local limit of GR, and GR is a valid
theory (within its domain). The experimental success of SR means that
any valid general theory MUST reduce to SR in the local limit -- there
are few theories that do so while also obeying essential general
principles (e.g. coordinate independence); they are either GR or
modest generalizations of GR.

> [... repetitious arrogance, ignorance, and nonsense]

Tom Roberts

On Tuesday, July 25, 2023 at 7:02:07 AM UTC-7, Tom Roberts wrote:
> > On Monday, July 24, 2023 at 6:22:00 PM UTC-7, erkd...@gmail.com wrote:
> >>> Light emitted from the rim of a rotating disk arrives redshifted
> >>> at the hub, by an amount corresponding to the relativistic time
> >>> dilation, whereas there is no such effect according to Newtonian
> >>> physics.
> >>
> >> There is, if you do the math properly.
> Nope. Why don't you show us your "properly done" math?

All he's doing is getting confused over the grown-up meaning of "transverse". See below.

> > Note that "transverse" in this context simply means a condition for which
> > the optical path length is not changing.
>
> I disagree with your meaning of the word "transverse" ...

This is the entire source of Eric's eternal confusion. He naively thinks that when people talk about transverse Doppler being a unique feature of special relativity that they are claiming there is no Doppler shift in Galilean relativity for propagation paths that are spatially perpendicular to the direction of motion. That's obviously false in general, because aberration implies that perpendicularity is frame-dependent. It's trivial to describe cases in Newtonian physics with "perpendicular" Doppler shift, and this is what Eric has fixated upon, imagining that he has made some startling discovery that he needs to share with the world.

When grown-ups talk about transverse Doppler in special relativity they are using the word "transverse" in the Lagrangian sense, not necessarily the geometrical sense. In fact, we can describe situations that don't involve any spatial angles at all (with linearly moving mirrors, etc.), but that nevertheless exhibit transverse Doppler shift. Again, in this sense, "transverse" refers to a configuration in which the elements are in motion but the optical path length is not changing. In Galilean/Newtonian physics, Doppler shift is purely the rate of change of the optical path length, whereas in special relativity there is the "transverse" (in the Lagrangian sense) shift due to time dilation, even when the optical path length is not changing.

He also is confused when people suggest that local Lorentz invariance is not exact... which of course is false. Local Lorentz invariance is theoretically exact, and it is empirically exact at least to the precision that it has so far been possible to measure. This is perfectly consistent with the fact that the spatio-temporal relations may have intrinsic curvature.

On Tuesday, July 25, 2023 at 4:40:12 AM UTC+1, Bill wrote:
> On Monday, July 24, 2023 at 6:22:00 PM UTC-7, erkd...@gmail.com wrote:
> > > Light emitted from the rim of a rotating disk arrives redshifted at the hub,
> > > by an amount corresponding to the relativistic time dilation, whereas there
> > > is no such effect according to Newtonian physics.
> >
> > There is, if you do the math properly.
> Every pulse (or wavecrest) traverses the same distance, and we are obviously not accumulating pulses in transit anywhere, so, if there were no relativistic time dilation, the rate of arrival of pulses at the hub would necessarily equal the rate of departure from the rim (in terms of their respective proper times). That is the unequivocal answer in the context of Newtonian physics and Galilean relativity. Agreed?

Not necessarily.
Under Newtonian optics, a ray aimed by the emitter at 90 degrees is seen by the observer to be advancing at the same rate as the emitter, and therefore aimed a little bit forwards. If they aim their detector at the emitter at 90 degrees in the lab, then the ray that they actually //see// was originally aimed a little to the rear, and therefore has a recession redshift component.

Once you've done the trig, the "aberration redshift" at Lab90 degrees comes out as E'/E = 1 - v^2./ c^2 ... a Lorentz-squared redshift.

So in a quick-and-dirty analysis, we see the circling clock to be constantly Lorentz-squared redshifted. Without invoking time-dilation.

In the next step, though, we realise that if we watch the circling clock apparently ticking more slowly, hour after hour, day after day, year after year, then it starts to become absurd that we are seeing an ever-increasing timelag in the clock, without anything in the geometry changing to explain where all these signals might be stacking up in space. Eventually, we have to conclude that the only way we can be seeing the clock to be constantly running more slowly, at a constant distance from us, //indefinitely//, is if it ==really is== running more slowly.

We can also invoke the principle of equivalence and say that in the co-rotating frame where the clock appears stationary to the central observer, and the redshift can;t be blamed on relative motion, there appears to be a radial gravitational field, and the circling clock appears to be lower down in the field than the central observer, and sending its signal "uphill". We can then say that in the co-rotating frame, the stationary clock runs more slowly because it is gravitationally time-dilated.

In an inertial frame the circling clock's redshift is blamed on relative motion, in the co-rotating frame, the stationary clock's redshift is blamed on the apparent gravitational field.

The argument that we can treat the same shift on the centrifuged clock either as a motion shift or as gravitational shift used to be considered to be part of general relativity (see: the 1959 Harwell group's papers on using a centrifuged clock to measure gravitational time dilation). However, in 1960, the community realised that if the motion shifts were described using SR, then the geometry didn't work.

I'm glossing over some details here (whether the the clock's physical resistance to the applied acceleration has a further effect) ... but the mainstream guys tend to gloss over them, too.
So once you have the aberration redshift effect, you also seem to get the circling clocks effect, and duality with gravitational shifts.

Of course, by this point, the thing is not looking much like conventional C19th Newtonian theory, and the word "Newtonian" maybe only really applies to the shift equations and the equations of motion.
If anyone can think of a better word than Newtonian, I'm open to suggestions. I personally think of these as being the "gravitomagnetic equations", but currently, if I use that terminology, nobody will know what the heck I'm talking about.

Eric Baird
https://www.researchgate.net/publication/372245510_Principles_of_Gravitomagnetism_I_-_Unavoidability

On Monday, July 24, 2023 at 10:45:22 AM UTC-7, Maciej Wozniak wrote:
> On Monday, 24 July 2023 at 19:19:53 UTC+2, Tom Roberts wrote:
> > On 7/24/23 9:07 AM, erkd...@gmail.com wrote:
> > > The unstated implicit third postulate of Einstein's 1905 paper is
> > > the requirement that the presence and relative motion of matter has
> > > zero effect on the lightbeam geometry.
> > Hmmm. In 1905 this "third postulate" was unknown.
> Today we know - we're FORCED!!! To THE BEST WAY!!!
> > As I keep saying, you REALLY need to learn
> that we're FORCED!!! To THE BEST WAY!!!

That is a beautiful truth but...
I think it is the opposite. People are forced into their wrong ways
because they have nothing else.

On Tuesday, July 25, 2023 at 5:14:03 PM UTC-7, erkd...@gmail.com wrote:
> > Light emitted from the rim of a rotating disk arrives redshifted at the hub,
> > by an amount corresponding to the relativistic time dilation, whereas there
> > is no such effect according to Newtonian physics.
>
> There is, if you do the math properly.
>
> > Every pulse (or wavecrest) traverses the same distance, and we are obviously
> > not accumulating pulses in transit anywhere, so, if there were no relativistic
> > time dilation, the rate of arrival of pulses at the hub would necessarily equal
> > the rate of departure from the rim (in terms of their respective proper times).
> > That is the unequivocal answer in the context of Newtonian physics and Galilean
> > relativity. Agreed?
>
> Not necessarily. Under Newtonian optics... the circling clock can be constantly
> Lorentz-squared redshifted without invoking time-dilation.

No, for an emitter at the rim and a receiver at the hub of a rotating disk, there cannot possibly be any frequency shift unless there is relativistic time dilation, as explained to you (twice) above... and as you've now finally realized:

> In the next step, though, [I] realise that [what you explained to me is
> undeniably correct, and what I typed was baloney, for which I now apologize.]
> ... the only way we can be seeing the clock to be constantly running more slowly,
> at a constant distance from us... is if it =really is= running more slowly, i.e., time
> dilation.

Right, so you now agree that what I explained to you (and you thrice pompously denied) was in fact perfectly correct. Excellent. This explodes all your beliefs.

> So once you have the aberration redshift effect, you also seem to get the
> circling clocks effect...

No, as explained above, and as you've acknowledged with at least one part of your brain, if there was no time dilation, there could be no frequency shift in that situation. You did not -- and you could not -- derive the frequency shift from any aberration effect. According to Newtonian physics, which of course includes Newtonian aberration, there would be no frequency shift in this situation. You simply made a mistake in your calculations. The frequency shift exists only because of the time dilation entailed by special relativity... which the other part of your brain denies. So you now realize that your beliefs are self-contradictory. Agreed?

> By this point, [what I call Newtonian theory] is not looking much like Newtonian theory,
> and the word "Newtonian" maybe only really applies to the shift equations and the
> equations of motion.

The term "Newtonian physics" should only be applied to Newtonian physics, which does not contain time dilation, and does not contain any frequency shift in any configuration in which the optical path length is not changing. This is what grown-ups call the "transverse" Doppler of special relativity, which is absent from Newtonian theory. Please note that the word "transverse" is being used in the unambiguous Lagrangian sense, not the naive and ambiguous spatial geometrical sense.

> If anyone can think of a better word than Newtonian, I'm open to suggestions.

Sure, if you want to refer to the theory of physics that entails all the well-established effects of special relativity, including the second-order relativistic Doppler effect, the most suitable name is "special relativity". Welcome aboard.