Preston Guynn ,

I asked a question - why the inertial frames are not equivalent.

Why the mass of the charged particle arsies with the velocity , this fact has explanations in both classical electrodynamics (the mass as inertia of the electron on self-action of its EM field; first explanation was given by Thomson in 1880th) and in the special relativity (as a cooefficent before the energy).

Both theories predict the same m(v) dependence.

Dear Vladimir Onoochin ,

That was also used by Kaufmann as the main argument to discriminate between Lorentz electrodynamics and Special relativity. Kaufmann never accepted SR.

Dear Stefano Quattrini ,

But the follower of Kaufmann, Bucoherer, seems to consider some correctness of the SR. Of course, one one of them were the enthusiaasts of the SR - in opposite to some theoreticians (Born, Sommerfeld).

One interesting point: assuming the spaceship (without the mirror; to keep the equivalence of the frames) moves with v = const and v ~ c (but less). The frame linked with the spacecraft is inertial. Then all stars move with respoect to the spacecraft. But if the spacecraft is suddenly stopped, what will occur with this frame?

Does it mean that it disappears without any effects? And how the kinetic energy of all stars can disappear?

I think that we cannot chose the inertial frames in the arbitrary way, like a frame of one of twins who fly to the remote stars.

Dear Vladimir Onoochin ,

You are pushing the configurations to limits. But it is not even necessary.

It must be clear that Inertial frames are concepts which fit Physics to a certain extent. They were suitable simplifications that provided valid results in peculiar situations.

But some questions raise in the "general picture"

Have you ever seen a big planet orbiting around a small one (mass)? Have you ever seen a small body (mass) unaffected by the interaction with a large one? The experience and the dynamics tells you that it is always the way around..

There is a behaviour which cannot be "changed": Physics is Dynamical- Hierarchical in deep, only superficially kinematical-relativistic.

Two Inertial systems in a physical configuration is just an ill-posed problem. It involves a reciprocity which does not exist; it should be understood that what one should deal with is a "degree of non-inertiality." according to the hierarchy.

The "relativistic mass" concept is something which was overlooked but it is the only explanation nowadays of the 99% of the "mass" of HADRONS...

The "relativistic mass" is given in that case by hyperkinetics of elementary particles (gluons) moving at a femtometer scale.

Dear Stefano Quattrini ,

>

According to Thomson, AAbraham, Lorentz, the 'relativistic mass' or some increase of inertia of the charged particle is a result of interaction of this particle with own magnetic field. The experiments to verify the dependence m(v) were made with the particles which can be accelerated in the external EM field. So m = \gamma m0 is perfectly described by two very different theories, of Lorentz andd of Einstein.

There are no experiments to check m(v) for neutrons.

Yes, the neutrons can be acccelerated - in the nuclear reactions where the nuclear forces are significant.

I think it it still a problem which is not studiied - if accelerated neutrons demonstrate the dependence m(v) = \gamma m0

Dear Vladimir Onoochin ,

they were supporters of the aether theory. The variation of mass was an interaction with aether I think also for Larmor.

Dear Stefano Quattrini ,

Your mention of Larmor is correct. As far as I know, in the 1900th there was some kind of competition between scientists in Great Britain and Germany. So it seems that Larmor did not accept SR. But unfortunately, he stopped developing the theory of the ether. So Laurent was the only person who tried to justify the theory of the ether.

It is curious that some experimenters who initially tried to justify SR changed their point of view to the ether. But not recently - now SR is like a total doctrine.

Dear Vladimir Onoochin ,

yes, also J.H. Field also quite recently..

http://www.relativity-myths.org.uk/jhfield/pdf/synchmc.pdf

https://inspirehep.net/authors/1010023

Dear Stefano Quattrini ,

Unfortunately, all works on synchronisation are too abstract - they are reminiscent of the scholastic debates of monks in the Middle Ages about the essence of God. The authors never think about how to organize the experiment they propose.

How does Dr. Field intend to accelerate the clock to that speed. What accuracy of the devices should Dr. Field has to make measurements - the clock should fly close to the observer and the observer should have time to measure something in this clock, etc.

Dear Vladimir Onoochin ,

partially yes...

Same place, same time is absolute synchronization...

Distant synchronization is a matter of distinguishing what can be considered scientific or not...

Dear all,

I wanted to inform you that ResearchGate will be removing comments on papers as of May 1st, 2025.

I will be requesting a copy of the 5,000 comments on a paper by Wolfgang Engelhardt, titled Free Fall in Gravitational Theory. I encourage others to do the same, as this might increase the chances of receiving a response.

Below is the message I have sent to ResearchGate:

Subject: Request for Comments on Paper

Dear Colleagues,

I noticed that you will be removing comments on papers, and I would like to request a copy of the comments on the following paper: https://www.researchgate.net/publication/312118218_Free_Fall_in_Gravitational_Theory/comments

There are nearly 5,000 comments on this paper. Could you please compile them into a PDF and send them to me?

Thank you very much for your assistance.

Best regards, Prof. Halim Boutayeb

Dear Vladimir Onoochin ,

Everybody to my opinion agrees that Einstein's very first premise was:

having A and B at rest Lt(A,B) as light-time to connect A to B = Lt(B,A) as light-time to connect B to A, provided that A and B are not accelerated (belong to an inertial frame). As it was written in 1905 ELECTRODYNAMICS OF...

That is the just concept of istotropy of the speed of light, constant for every observer, which should be a prerogative of every inertial frame.

The direct consequence of Lt(B,A) = Lt(A,B) is the applicability of Einstein synchronization procedure and the direct consequence is Lorentz Transformation in Einstein and Poincarè form.

If it is possible to show that there is a condition of non-acceleration such that

Lt(A,B) Lt(B,A), then all the above is invalidated.

In such case the isotropy of the speed of light is a prerogative of certain non-accelerated systems (like ECI frame for example).

It is not difficult to get it from some calculations of Sagnac effect, is that in general Lt(A,B) Lt(B,A), independently on the synchronization procedures used, provided that A and B move in ECI or in isotropic frame.

While the Lorentz Transformation predicts that

(a) Lt(A,B)=Lt(B,A) = H/c - gamma vH/c2

in general, and also according to General Relativity, (a) never occurs since considering H/c as the light time at rest in ECIF, then by synchronizing the clocks in ECIF one would necesssarily get

Lt(A,B) = H/c-vH/c2(sqrt(1-v/c)/sqrt(1+v/c))

Lt(B,A) = H/c+vH/c2(sqrt(1+v/c)/sqrt(1-v/c))

The above can be found in the simplest case in circular motion but is valid for any trajectory irrespective of the curvature since the formula is independent of the radius of curvature.

Since (a) is valid only as a first approximation, the LT in Einstein's form can be valid only as a first-order approximation.

Basically the equivalence of inertial frames is just a comfortable approximation..

Dear Stefano Quattrini ,

As I understand, you are trying to justify that the inertial frames must be equivalent.

But let me remind you some historical facts.

The theories of electrodynamics in XIX century were developed to explain the experimental facts. As a result, only Lorentz's theory of the stationary ether was able to explain all existing experimental facts. In this theory, the speed of light is isotropic only when we measure this isotropy in the frame of the ether. But the galilean transformations of the Maxwell equations from the frame connected with the Earth to the ether frame give some additional terms. Poincare noted that this non-invariance of the Maxwell equations under the galilean transformation should give violation of third Newton's law (his paper of 1900). So Lorentz developed the coordinate transformations which seems to provide the invariance of the Maxwell equations - but Lorentz stressed that these transformations are 'fictitious', they are fulfilled only for the EM fields in a body uniformly moving relatively to the ether.

So in his theory, in its final form, the frames are not equivalent. Despite his theory was able to explain all experimental facts.

In Einstein's theory the equivalence of the frames, i.e. the invariance of the Maxwell equations under the LT, is the fact which 'opened the door' for this theory to be accepted by the mainstream.

And the equivalence of inertial frames is not a comfortable approximation. If this equivalence is broken, it means that the special relativity is not absolutely correct.

Dear Vladimir Onoochin ,

I guess I expressed myself improperly since I was misunderstood as I can understand.

I am putting on the table the fact that in a Physical problems, in general, we cannot work with two equivalent inertial frames, since isotropy of light can be a property measured at rest with ECI frame or Celestial bodies central frame or Galaxy inertial frame of reference or at rest with CMBR if sufficiently far from celestial bodies.