The Principle of Relativity is the proposition that the laws of Nature are the same for all unaccelerated frames of reference. It was proposed by Galileo, not Einstein. Galileo presented it in the form of “thought experiments”.

The constancy of the speed of light in a vacuum is a consequence of Maxwell’s electromagnetic theory. Since it is a “law of Nature” Galileo’s Principle should apply to it. Thus Einstein arrived at Special Relativity. He arrived at it and presented it, through “thought experiments”.

Since then, the theory has been amply verified by real experiments. The role of “thought experiments” in Special Relativity is today is pedagogical. They are an aid to understanding, not an essential component of the theory. I cannot see how they render the theory “metaphysical”.

Vikram sees "the observer” in the theory as a “metaphysical entity”. I disagree. In the real world we all know what an “observer” is − a real human being perceiving things. When I encounter “the observer” while reading about relativity, I take that to mean a physicist equipped with any instruments he may require to receive and send signals, to measure and record distances and times − not at all a metaphysical entity!

If the employment of “thought experiments” in formulating and understanding a physical theory renders that theory “metaphysical”, then all theoretical physics is metaphysical. Because no theory can exist in the absence of thought.

No! SR is a limiting case that is useful in making predictions when gravity does not have to be considered. Compare it to the ideal gas law, not exact but close enough for many purposes, and a starting point for further research.

You can add one more (6th) criteria to your list. Special and General Relativity are Observer dependent. If you remove the observer from the theory, theory can collapse. Observer is a metaphysical entity. Relativity theory does not provide any analysis of the Observer. Who is the Observer? Is he/she the human body? Or the two eyes? Or other senses? Or the mind? Or the soul behind the mind? Frequently relativity theory mentions “the rest frame of the observer.” If the observer is the body then his body parts like hands feet may not have the same rest frame. If two eyes, then both eyes will be in the different rest frame. If the mind, then every idea in the mind may have a different rest frame. So the theory has not properly defined who the observer is.

Vikram, this I suggest is a valid concern. But physics seems dependent on phenomenological events-

The Principle of Relativity is the proposition that the laws of Nature are the same for all unaccelerated frames of reference. It was proposed by Galileo, not Einstein. Galileo presented it in the form of “thought experiments”.

The constancy of the speed of light in a vacuum is a consequence of Maxwell’s electromagnetic theory. Since it is a “law of Nature” Galileo’s Principle should apply to it. Thus Einstein arrived at Special Relativity. He arrived at it and presented it, through “thought experiments”.

Since then, the theory has been amply verified by real experiments. The role of “thought experiments” in Special Relativity is today is pedagogical. They are an aid to understanding, not an essential component of the theory. I cannot see how they render the theory “metaphysical”.

Vikram sees "the observer” in the theory as a “metaphysical entity”. I disagree. In the real world we all know what an “observer” is − a real human being perceiving things. When I encounter “the observer” while reading about relativity, I take that to mean a physicist equipped with any instruments he may require to receive and send signals, to measure and record distances and times − not at all a metaphysical entity!

If the employment of “thought experiments” in formulating and understanding a physical theory renders that theory “metaphysical”, then all theoretical physics is metaphysical. Because no theory can exist in the absence of thought.

You don't even need an observer. Physical instruments could continue measuring & recording long after humans have gone extinct, and continue interfering with the phenomena that they are measuring & recording. The observer effect is a misnomer; it should be called the "measuring instruments effect" or somesuch. If you want to find significant metaphysics in physics, string theory rather than SR is the place to look, since so much of it is ostensibly unverifiable or unfalsifiable experimentally.

Dear Eric

Many thanks for your comments.

“He arrived at it and presented it, through “thought experiments”. Since then, the theory has been amply verified by real experiments.”

In the abstract I wrote “the main undesirable effects of SR, when it was presented in 1905, were: … ” Thus I agree with your first comment.

However, after examining M&M and some other later experiments I am really worried about two issues.

• An experiment can be wrongly analysed resulting in misleading conclusion. More than one century after two physicists came to the wrong conclusion from M&M experiment nobody has ever tried to re-examine the experiment to disclose the erroneous deduction, length contraction. This is the same for the light clock. It reminds us of the Bertrand Russel's criticism of Aristotle, “Aristotle maintained that women have fewer teeth than men; although he was twice married, it never occurred to him to verify this statement by examining his wives’ mouths.”
• All the later experiments are done with Lorentz’s length contraction as an accepted premise. They tried hard to show their results agree with that false conclusion. Don’t you agree with me that this is a troubling phenomenon. We are now left with a huge body of theoretical and experimental structure built upon a false premise.

Dear Ziaedin ~

"In my own development Michelson’s result has not had a considerable influence. I even do not remember if I knew of it at all when I wrote my first paper on the subject (1905). The explanation is that I was, for general reasons, firmly convinced that there does not exist absolute motion and my problem was only how this could be reconciled with our knowledge of electro-dynamics. One can therefore understand why in my personal struggle Michelson’s experiment played no role or at least no decisive role." − Einstein 1942

I agree with you that “an experiment can be wrongly analysed resulting in misleading conclusion”. But your further statements that “nobody has ever tried to re-examine the experiment to disclose the erroneous deduction, length contraction” and “all the later experiments are done with Lorentz’s length contraction as an accepted premise” are not true!

As I understand it, Michelson and Morley had in mind the “ether” theories current at the time. They were not thinking of “length contraction” because that was Lorentz’s much later proposal to attempt to explain the result. (In any case, Lorentz’s proposal of “length contraction” was the idea that objects are really contracted due to their velocity relative to the “ether”. In the theory proposed by Einstein, known as “Special Relativity”, there is no “ether” and “length contraction” is only an artifact of the process of observation, not a real deformation.) The experiment has been repeated more than a dozen times times throughout the 20th century with ever greater accuracy https://en.wikipedia.org/wiki/Michelson%E2%80%93Morley_experiment#Subsequent_experiments. Only Miller’s experiments of 1926-1927 gave puzzling and controversial non-null results.

“Length contraction” is not a “premise” of Special Relativity. It is a deduction form the premises, and is a property of observation (like a mirage or an optical illusion). The premises of Einstein’s 1905 are very simple:

(1) In every “inertial frame” (ie, unaccelerated reference system) the 3-dimensional space of physics is Euclidean.

(2) In every inertial frame the speed of light is always the same constant c.

I can’t see much to worry about in (1). It has been accepted from common experience for more than two thousand years and is employed daily by all who are concerned with measuring distances (builders, land surveyers, engineers, physicists, etc). Premise (2) is a deduction from Maxwell’s electromagnetic theory, which in turn is based securely on the earlier experimental results of Faraday, Ampère and others. It isn’t just a “metaphysical” notion that Einstein thought up!

Of course, complications come in when the logical implications of those premises and their physical interpretation are unravelled. People can (and do) get confused and arrive at wrong conclusions. I’ve seen that many times in Researchgate discussions and I have seen how people blame the theory for their own wrong conclusions! But that's another story...

https://www.researchgate.net/publication/305260245_Notes_on_the_Meaning_of_Einstein's_Special_Theory_of_Relativity

Dear Eric

Many thanks for your detailed comments.

May I respond to one important point first. I am sorry to say, but I do not think physicists are happy with your comment that length contraction, and I guess time dilation, are “mirage or an optical illusion”. Nobody sets up a fly fishing school when he sees a mirage and then issues licenses for the successful students. In fact, physicists try hard to show length contraction, time dilation and relativistic mass and energy are in fact for real, please see also Christian Baumgarten’s affirmation of this point. This said, my article tries to show something similar to your statement. What I try to say is based on re-examining M&M experiment. I say there is no point of debating whether length contraction is real or illusion as it is based on a wrong analysis of a famous experiment. What we need to do is to accept the mistake, forget about the theories which are based on this mistake, do not try to prove them right with experiment anymore and find a better theory. The three article I have written so far is nothing but to show where the mistakes are.

At the end of the first paragraph in page 3 of the article I have quoted the highlight of the same Einstein’s admission. In fact, I tried to show this statement as an evidence that Einstein tried to distance himself from real experiment and rely on thought experiment.

I have not rejected the accuracy of M&M experiment at all, what I have found out is the wrong analysis of the experiment by Lorentz and FitzGerald which has resulted in length contraction. I also wrote that later experiments such as Kennedy–Thorndike experiments or the Robertson-Mansouri-Sexl test theory rely on length contraction as a proven premise. Please note these later tests were done long after ether theory was rightly dismissed by Einstein.

In the article it has shown why length contraction, which eventually resulted in Lorentz transformation equations, is one of the proven premises/foundations for constructing SR, though as you have rightly pointed out the two declared premises of SR are the ones you have higlighted.

Dear Ziaedin ~

Yes, I know that many other physicists can’t see it and insist that “length contraction”, “clock retardation” and “increase of mass with velocity” are real properties of physical objects. That is a misunderstanding that has plagued the literature of Special Relativity since its inception.

(I’ve already had this argument many times in Researchgate discussions!)

The idea that any actual physical property of an object can depend on “velocity” goes against the very spirit of Relativity as Einstein presented in 1905, according to which there is no such thing as “absolute velocity” (or velocity relative to an “aether”). According to that theory the “length of a rod” is its length measured when it is at rest. That cannot change just because the observer estimating its length is moving relative to it. It only seems to change because the moving observer estimates the length by locating the positions of the two ends of the rod at the same instant (simultaneously) according to his time measurements; it is simultaneity, not rod lengths, that are different in different inertial reference systems.

Real length contractions were postulated in the earlier Lorentz-Fitzgerald theory (now long ago discarded by the vast majority of theoretical physicists), not in Einstein’s Relativity. As I said in my earlier comment “...people blame the theory for their own wrong conclusions.” This is a prime example!

It is a familiar fact that direct observation can produce effects that are not objectively real. For example, distant objects look smaller than they really are, a microscope makes things appear bigger, a reed sticking out of water can look as if it is bent, the phenomenon of stellar abberation is an apparent shift in the position of a "fixed star". All these illusions are effects created by the properties of light. According to Einstein’s 1905 Relativity theory, properly interpreted, “length contraction” is, similarly, an illusion created by the properties of light.

If we talk about Metaphysics, we must ask Philosophy. Kant answers your question clearly: Metaphysics is a natural disposition of human beings but can never be a science. The language of Phisics is mathematical so it can confirm a priori the validity of "thoughts experiments". The progress of Physics is accompanied by the progress of mathematical instruments, therefore "thoughts experiments" can not be Metaphysics.

I consider time, space, causality and numbers metaphysical concepts par excellence. Nobody has ever seen or measured time and space or seen causality and numbers.

To "measure time" means to compare two processes in certain conditions. The fact that we call the outcome of this comparison "time" does not mean that any "time" physically exists beyond the human language.

I doubt any mathematician has ever seen number 7, let alone number 17,34578909876. Time, space, causality and numbers are parts (concepts) of the human language, by which people try to describe (to themselves) their perception and understanding of the outer reality.

Dear Christian ~

“For the physicist in the lab, the lifetime of accelerated muons REALLY increases, for a comoving observer (the muon "itself") it does not.”

Yes, but I would be wary of the word “REALLY” in that conext, which could be misinterpreted. The observation is a REAL observation, but the phenomenon is due to the fact that “time” in the physicist’s lab is not the “proper time” of the muon’s trajectory.

“Physics can only to be understood and developed on the basis of those quantities that are invariant. Space- and time- intervals are not of this kind.”

Precisely! Reference systems contain no physics; predictions deduced from a theory must be expressed in terms of invariants if they are to be physically meaningful.

SR has nothing to do with metaphysics. Like any theory or design it is initiated in the mind based on gathered knowledge and objectives. It has an intention to prove a part of reality and prepares for real experiments through thought experiments. Yes, thought experiment may contain errors.

Einstein's postulates were anthropocentric. The theory should be simple and produce the same equations for equivalent physical processes. It was a gamble. If the nature did not do the time dilation it would be an epic failure. If the round trip average speed of light was a function of inertial system velocity, it would be an epic failure but experiments seem to confirm this.

The fact people have trouble understanding the nature of theory based on specific non simultaneous synchronization of clocks rather than them being absolutely synchronized is understandable and scientific establishment is to blame to give up on absolute rest and simultaneity.

The reality is surprising. More than I thought. I am in a position to say that absolute clock synchronisation and absolute rest are well defined concepts and also available for experimental determination. The twist is there is no contradiction with SR and in fact it is pivotal to the derivation of this concept. I can talk about details when I make my arguments public. This time is not if but when.

The author of the linked paper says that "The theory rightly rejected the idea of aether " which it did not because there was no proof to this effect although narratives were leaning into this direction. But not always.

In EInstein's words:

More careful reflection teaches us, however, that the special theory of relativity does not compel us to deny ether. We may assume the existence of an ether only we must give up ascribing a definite state of motion to it, i.e. we must by abstraction take from it the last mechanical characteristic which Lorentz had still left it.

Time, space, causality are metaphysical concepts because they are the pure concepts of our intellect, that is the rational structures of human mind with wich we build our knowledge. This concept of Metaphysics is not trascendental or dogmatic. We have no other possibilities.

A small addition. Metaphysics used to deal with gods, souls, meaning of life and similar things. However, there is something called "descriptive metaphysics", which aims to develop a basic (and universal) conceptual system, by means of which we can describe phenomena of the physical world. This kind of metaphysics is a scientific activity rather than religious (speculative) one.

“…Can special relativity be categorized as metaphysics?…”

to answer on this question is necessary firstly to define – what is “metaphysics”?, how it relates to physics?, and, further, how it relate to the, both, though, relativity theories, the SR and the GR?.

Seems for corresponding consideration it is possible to use some Maria Letizia Parisi’s posts; so:

“…If we talk about Metaphysics, we must ask Philosophy…”

yeah, that is so but that

“…Kant answers your question clearly: Metaphysics is a natural disposition of human beings but can never be a science…”

isn’t. Metaphysics appeared near 2000 years before Kant, and, for example ancient Greeks defined the “philosophy” as the science, which consists of three main branches: “Physics”, “Logic”, and “Ethics”.

Physics, in turn, in fact was divided on two branches, “simply physics” that, in fact, was engineering and studied [mostly mechanical] relations between concrete material objects, without answering on the fundamental question “from what matter are these objects built?”, and “Metaphysics”, which attempted answer on the question above, i.e. on “what is this Matter”.

Ethics studied the relation between humans, or, more correctly, between humans’ consciousnesses, and attempted to answer on fundamental questions “what are the human’s, and some transcendent mighty [“Idea”, “Spirit”, etc. consciousnesses?” and “what are ”perfect” relations between humans”; inventing at that, for example, models of perfect states and perfect laws systems in the states.

Logic studied the cause-effect relations for Physics and Ethics.

From these times in philosophy nothing essentially new appeared, and Philosophy now exists, as that was thousands years before, as the two main doctrines, “Materialism” and “Idealism”, which are based on fundamentally non-provable and non-disprovable believes in omnipotent Essences “Matter” and “Consciousness/Idea/Spirit”,

i.e. the existent mainstream philosophy is simply some secular religion, where the number of sub-doctrines is not lesser, seems, that number of sects in all “usual” religions on Earth. By other words the mainstream philosophy has very small relation to the notion/phenomenon “Science”. Including Kant and his answers that relate to the Metaphysics isn’t correct , that below

“…Time, space, causality are metaphysical concepts because they are the pure concepts of our intellect, that is the rational structures of human mind with which we build our knowledge…”

is some version of Kant’s assertions, which aren’t correct. Time, space, and causality are quite objectively existent, independently on – some human think something about them or not.

As well as that

“… This concept [about time…in the last quote above] of Metaphysics is not trascendental or dogmatic. We have no other possibilities….”

isn’t correct, if applied to the mainstream philosophy [as that is in this case], in the mainstream, because of the main fundamental notions/phenomena “Matter” and “Consciousness” are fundamentally transcendent and so non-cognizable, nothing can be “not transcendental”.

Besides, the notion “dogmatic” in the quote above is scientifically very questionable – indeed Science is based on the maxima that there cannot be different explanations of the same object/process, if there are a number N of explanations, that means only that (N-1) explanation are wrong, or, what is more often, all N are wrong.

Indeed Science is principally “dogmatic”, and existence “non-dogmatically” huge number of the mainstream philosophical sects simply follows, again, from that the mainstream philosophy isn’t a science when attempts to solve indeed fundamental problems, what are the main subjects for study in an indeed philosophy.

The main philosophical problems can be solved only in framework of the Shevchenko and Tokarevsky “The Information as Absolute” conception https://www.researchgate.net/publication/260930711_the_Information_as_Absolute DOI 10.5281/zenodo.268904

where rigorous enough definitions of the main philosophical notion “Matter” and “Consciousness” are given, and, besides, the fundamental also notions/phenomena “Space” and “Time” are rigorously defined also.

Thus, returning to this thread’s question more concretely, we can note that the SR relates, though rather specifically, to physics, since is based on the indeed fundamental relativity principle, and in this case it is, in kinematics and essentially in dynamics, only some inessential re-formulation of the Voigt-FitzGerald-Larmor…-Lorentz-Poincaré theory. Though, of course, the contribution of Einstein in the dynamics is very essential.

However when Minkowski and Einstein attempted to solve indeed Metaphysical problems, in this case – what are Space and Time, the result had no relations to the objective reality [and to the indeed Metaphysics]; all “fundamental properties of the space/time/spacetime” that were “discovered” in [both] relativity theories are nothing more then some fantasies. .

More, besides the linked paper above, relating to the SR/GR one can find in the SS post in https://www.researchgate.net/post/Does_spacetime_possess_the_properties_of_a_relativistic_aether

and in threads and papers that are linked in this post.

Cheers

“…If we talk about Metaphysics, we must ask Philosophy…” ...

“…Kant answers your question ...”

Forget history. It make no sense to quote people who lived hundred or more years ago, except for poetic reasons. I tried to tell above what metaphysics is about today. Let me repeat it.

"... there is something called 'descriptive metaphysics', which aims to develop a basic (and universal) conceptual system, by means of which we can describe phenomena of the physical world. This kind of metaphysics is a scientific activity rather than religious (speculative) one."

Dear Eric

It has never occurred to me and I definitely will not believe that Einstein developed special relativity knowing it was just “mirage and optical illusion”. My point in the article is that one mistake (the ORIGINAL mistake) by Lorentz and FitzGerald has derailed the whole physics establishment. It was just an honest mistake and unfortunately no one realized it. Consequently, as the base of SR was baseless it churned out so many contradictions, confusions and misunderstandings.

Thinking and theorizing are important bases for science. What it is not scientific, as we have learned it from the history of science, is relying solely on them, insisting on them and not validating them with real experiments. Einstein, when he proposed SR in 1905, claimed that everything was done by thought experiment. Worse than that, he produced thought instrument to side-step real experiment. I call SR metaphysics only because Einstein abandoned the valuable “lesson learned” and insisted that experiment had not much influence in his theory.

Dear Mario

We do not see number 7 or 8 but none of us agree that 7+8=14. Try to go home late, say at 2AM and you will experience the reality of time, thanks to our non-metaphysician partners. Yes, a lot of concepts are metaphysical but various experiments have made them tie up tightly with the reality of the universe.

@Christian

Please see the third footnote in page 1 of the article. I deliberately quoted L. Barnett’s assertion about relativistic mass and how experiments have proven it right. But physicists are now abandoning it despite those experiments. It is sad to say that some of the experiments related to SR need to be re-examined or reinterpreted. I do not want to say anymore.

Dear Ziaedin ~

“I deliberately quoted L. Barnett’s assertion about relativistic mass and how experiments have proven it right.”

in Newtonisn dynamics momentum of an object with velocity u is mu. The mass m is an invariant constant (the “amount of stuff” the object contains). For consistency with Special Relativity momentum has to be redefined to be γmu (where γ = 1/√(1 − u2/c2)). That can be written either as (γm)u or as m(γu); Algebraically there is no difference, but conceptually there is a very great difference! No actual physical characteristic of a material object can “depend on velocity” because that would violate the Principle of Relativity, so calling γm “relativistic mass” and saying that experiments confirm that objects get more massive when they move fast is an (unfortunately very common) error of interpretation. In Special Relativity as in Newtonian dynamics, it is energy, not mass, that is observer-dependent (ie, velocity-dependent). That is what experiments have confirmed.

Stanley Wilkin

Eric Lord

Christian Baumgarten

Thanks for your comments

“…Forget about Einstein, what he claimed, thought or considered. This is interesting for the history of science but irrelevant when discussing STR… The undeniable experimental basis of STR is not to be seen in some tiny Doppler effects or clock frequency shifts, but in the huge and undeniable effects of working accelerators and the corresponding physics experiments…It is an unlucky historical coincidence that STR was and still is discussed as a theory of "coordinate systems" or "reference frames".”

it seems some former true believers in the SR/GR after a few years SS posts on the RG understood eventually

that indeed, the “discovered” in the SR/GR “fundamental properties of the space/time/spacetime” and corresponding “relativistic effects”, when some “reference frames” by some magic forces “contract space”, “dilate time”, “curve the spacetime” etc. and further these “contracted”/ “dilated”/ “curved”, etc. space/time/spacetime, again by some magic forces, contract lengths of material objects, slow down thick rates of material clocks, force, say, Earth to rotate around Sun, etc.,

are nothing more, then some having no relation to the objective reality bare declarations.

Though these true believers quite frankly believed yet a few years ago, that all relativistic “properties” and “effects” above indeed really exist, and, say, unstable particles at experiments on accelerators indeed reach targets/detectors because of they contract the distances between points, where they were born and the targets/detectors. As, for example, the believers near 80 years frankly believed that famous mu-mesons/mouns, which are born in Earth atmosphere, reach Earth surface because of they contract corresponding distances/ “atmosphere” also.

And, as any other member of some “scientific community”, after understanding, they immediately claim that they always thought so – and, correspondingly, never refer on the authors of scientific works and comments, which explained to these members corresponding physics, in this case – what are the SR/GR really. At that, in parallel, other members start massively and disciplinedly refer on those “who understood” and thoroughly and disciplinedly prevent in any possible case sharing of any information about real works and real authors.

If the works are fundamental, even attempting to kill the real authors, as that is in this case.

However, in the quoted case above there are a couple wrong assertions again. First of all the quote doesn’t relate clearly to the thread’s question, which is about “metaphysics” of the SR, GR, which can appear only if the “fundamental discoveries” above are considered, not about some concrete experiments on accelerators; and, besides,

the “The undeniable experimental basis of STR” doesn’t, and cannot follow only from “undeniable effects of working accelerators and the corresponding physics experiments” and without “a theory of "coordinate systems" or "reference frames"”; or from “As Eric said: coordinate systems contain no physics.”.

Any experiments’ data, including of working accelerators, can be analyzed only by using the "coordinate systems" and "reference frames", and all physicists practically in every case use transitions from, for example, a “laboratory system/frame” to corresponding “center of mass system/frame”; and use, at that inevitably the Lorentz transformations. The main point, however, here is: it is necessary at that to understand – what are the letters “x” and “t” in the transformations.

Including, besides, in the coordinate systems there is the fundamental physical fact, that, because of the transformations are developed at the suggestion that Matter’s spacetime is uniform, and, at that, they are quite adequate to the objective reality, from that follows, that the very possibly existent ether, i.e. the dense lattice of the fundamental logical elements (FLE), where everything in Matter, as disturbances of the lattice, constantly moves, is uniform also.

Again, the indeed understanding in this case is possible in the Shevchenko and Tokarevsky informational model only, here more see at least

https://www.researchgate.net/publication/317620440_About_some_conventions_in_mechanics DOI 10.5281/zenodo.1142628

and, of course, the links in the SS post above

Cheers

Dear Christian

There is no argument whatsoever against any accurate experiment. What is criticized here is the interpretation of it. Take M&M experiment as a well known example. I want to ask you all a simple question; do you think length contraction can be derived from this experiment or not?

I have shown that it cannot. To make it easy for all please see figures 12 and 13 of the attached file which is now uploaded to the question (Michelson and Morley Experiment Does not Validate Length Contraction-ZS-1p2) that illustrate my argument. I also repeated the derivation of the equations, which I am sure everyone is familiar with, in Appendix A.

If you can prove that I am wrong, then I deeply apologize to you all. If not, then you should accept that for more than a century this interpretation has wrongly been accepted as scientific fact, etc, etc.

Dear Ziaedin ~

“Take M&M experiment as a well known example. I want to ask you all a simple question; do you think length contraction can be derived from this experiment or not?”

No, it cannot. Lorentz suggested length contraction as a possible explanation of the M-M result. That isn’t the same thing as “deriving” length contraction from the M-M result.

Thank you Eric

But the possibility of length contraction has turned to certainty for so many physicists. If Lorentz had checked the movement of the half-silver mirror in the experiment he would have abandoned the possibility and looked for some other causes for the null result. Moreover, if all physicists after him did this simple check the theory could not have lasted that long as an accepted fact within SR.

The main difference between Lorentz and Galileo transformations is that Lorentz has a limited velocity for every body in motion. The limit velocity is finite and very high with respect to our usual velocities, this makes that we are not accostumed to use SRT. Thus we can imagine a particle moving at a velocity close to c but never at c if it is not massless. The form that the particle cannot go through the volocity of light is just increasing its mass. This is REAL and not a coordinate transformation. In the same form we can see that the particles decrese their size when they have relativistic velocities and also their times go slower.

Another thing which can create confussion is that one can think that one observer moving at a great velocity could see any object as moving also with respect to him at such a velocity that it has enormous mass, slow time rate of its velocity and ...Obviously this would be wrong. This is the same that one car driver could see that buildings of a city moving, but that is not real, who is moving is him.

Everyday there are measurements of incresing of masses of particles moving at high velocities in agreement with SRT, time delays, shorting distances and so. You only need to read reports of CERN experiments for high energy scattering particles, etc...

We must realize that all of physics is of our creation. Physics is human cognition interpreting what we as humans experience and observe in the Universe. We describe the Universe and its properties and dynamics that would otherwise continue were we not here to observe, record and interpret them. In that sense all is metaphysical in that it is what is happening in the Universe processed through the mental faculties of the human brain that fill the pages of physics textbooks and research papers. Of course, the human brain is itself a product of the dynamic evolution of the Universe and we would hope that the brain operates on principles inherent in and consistent with those that guide the Universe so that what we are viewing is not a grand illusion and deception. So human physics, we hope, is the "meta" that applies to the "real" physics of the Universe. But there are tantalizing deceptions of a possibly cagey magician. Why is ice less dense than liquid water at 4º celsius? So that the oceans freeze from the top down instead of from the bottom up thereby permitting a habitable planet Earth. Physics is a game played against an unknown opponent but oh what a wonderful and joyous game it is as we advance towards our adversary's king.

Hello,

Einstein said, "A single experiment can prove me wrong." This is the view I suggest we take in this question.

Please see also https://www.researchgate.net/post/What_are_the_worse_yet_enduring_misconceptions_about_mass_and_energy_in_special_relativity , which should answer the question too.

Cheers, Ed Gerck

Dear Daniel ~

My way of thinking is this:

In Newtonian dynamics, mass is a constant and energy ½mv2 increases with velocity.

Similarly, in SR, mass is a constant and energy E = γmc2 = mc2 + (½mv2 + 3mu4/8c2 +...) inceases with velocity.

The famous formula E = mc2 applies only to an object at rest (v = 0). That’s why m is called “rest-mass”. To try to force E = mc2 to apply to moving objects is an unfortunate mistake; it implies that there is some other kind of “mass” called “relativistic mass”, given by γm. That idea is completely unnecessary, inappropriete, and confusing.

Dear Eric,

I absolutely agree with you in the point. The mass in such a formula is only applied to a rest system:

To try to force E = mc2 to apply to moving objects is an unfortunate mistake; it implies that there is some other kind of “mass” called “relativistic mass”.

What I don't agree is with the phrase that you have written in a previous post:

No actual physical characteristic of a material object can “depend on velocity” because that would violate the Principle of Relativity, so calling γm “relativistic mass” and saying that experiments confirm that objects get more massive when they move fast is an (unfortunately very common) error of interpretation. In Special Relativity as in Newtonian dynamics, it is energy, not mass, that is observer-dependent (ie, velocity-dependent).

1. The characteristics of the material must depend of the velocity, over all the mass because it is necessary to be always below c, although you supply all the energy that you want. The only physical magnitude that can do it is the mass. This is accepted nowadays in any textbook that you want to read. It is true that in most of these books never is discussed the difficulties associated with the mass which is not "really" a physical magnitude easy imagine changing the physical properties of material. For instance, nobody knows why the fundamental particles have the mass that they have.

2. It is true that the formula m=gamma.m_0 is really very confussing and even difficult to accept, but the other

m= c-2(E2-(pc)2)-1/2

is exact and contains all the information that I have told you on the limit of c.

3. The suggestion of v=gamma v_0 is for me also very bad and dangerous because could oblige to distinguish many different states of motion for one unique observer.

O dear! The right last formula is

m= c-2(E2-(pc)2)1/2

with plus in the last square root.

“….Of course, a survey of the accelerator layout is usually done using a coordinate system. But that's trivial…”

that is indeed trivial, however that is also fundamentally inevitable and any experiments and further any processing/ analysis of the experimental data are done only with using a coordinate systems. In other case a lot of useful experimental data can be lost, and so in every experimental installation all possible distances and angles are measured with accessible precision; and, especially in high energy, where interactions often aren’t, in certain sense, “pointlike”, some rather sophisticated systems are used, which measure coordinates of the interactions. That is also a trivial and well known fact.

So the quoted assertion above seems as rather strange, however. As well as the claim that

“[the “trivial fact” above] …has nothing to do with STR…”

seems as rather strange also, everybody who indeed knows what the STR is, knows also, that the Lorentz transformations are the fundamental base of this theory.

And though the claim

“… You can measure E(p)=sqrt(m^2c^4+p^2c^2) without any use of any transformation whatsoever….”

is indeed true in some relations, it by any means doesn’t decrease the strangeness above, that is rather specific case only, when some dynamical parameters of physical systems don’t depend on the [“kinematical”] Lorentz transformations directly; they depend, nonetheless, implicitly. Mechanics indeed consists of two main branches, of the kinematics and dynamics, but every physicist knows that these branches by no means are mutually independent.

For example, indeed, the first physical phenomena outside the “classical mechanics” were discovered before the discovering of the Lorentz transformation, that was the electrodynamics, where the Maxwell equations aren’t invariant at Galileo transformations, of course in the spacetime, and, of course, between inertial reference frames. And to fit physics to the objective reality it was necessary for Voigt to invent corresponding transformations, which, though erroneous, were similar to the Lorentz transformations, including Voigt, at that, obtained the true quantitative estimation of the notorious “relativity of the simultaneity”, Vx/c2.

However in the absence of the correct transformations only limited cases in the dynamic could be elaborated, the example with the formula E(p)=sqrt(m^2c^4+p^2c^2) above isn’t unique, thus, for example, in electrodynamics only simplest cases were analyzed, with the transverse and the longitudinal masses. And therefore the development of full dynamics of fast bodies, where Einstein’s contribution is evidently important [and where the “simplest” masses above appear quite naturally], was, and that happened so in the reality, possible only after the discovery of the Lorentz transformations.

All the above in this post seems as well known for those, who understands what is the SR, and thus the quoted claims above are so evidently strange, that even a question appears – what bad things the poor Lorentz transformations and the coordinate systems made for some people, so that they want to delete them from physics?

Cheers

Dear Daniel ~

“The characteristics of the material must depend on the velocity...”

According to the Principle of Relativity (Galileo 1632) physical laws do not depend on the velocity of the observer. Since the characteristics of a material object (such as its mass or its length) are the result of physical laws, they cannot depend on the velocity of the object relative to the observer.

Energy, on the other hand, is not a “characteristic of the object”, it is a characteristic of an observation of the object. That can, and does, depend on the relative velocity between object and observer. (Remember ½mv2?...).

“This [“relativistic mass” γm0] is accepted nowadays in any textbook that you want to read...”

No it’s not. One encounters it in many textbooks, not in any textbook! (Even in my own textbook published 40 years ago I introduced “relativistic mass”; at that time I didn’t know any better!)

You say “It is true that the formula m = γm0 is really very confusing and even difficult to accept, but the other [m02c4 = E2 − (pc)2] is exact and contains all the information...”

Yes! That is my point. So where is our disagreement??

Dear Eric,

It is very simple and I'm going to write just the equations for you.

PμPμ=(m0c)2=Lorentz invariant= independent of the observer

Pμ=mvμ

PμPμ=m2 c2(1-β2)= m2 c2 γ-2

Thus it is

m2= (m0 γ)2

Dear Daniel ~

I have no quarrel with the fact that the algebra works out OK if you define m = γm0. What I'm saying that it shouldn't be done because it doesn't make sense physically. It creates misunderstanding of Relativity Theory.

I see you began with Pμ=mvμ. Right there, you already assumed what you are setting out to prove! The Lorentz-covariant four-vector expression is Pμ= m0Uμ where Uμ is the four-velocity (γv, γc). The γ belongs with the velocity, not with the mass.

Dear Christian

“But we should not focus on one single experiment …”. The focus on M&M experiment is only because it is the origin of all theories that we are told explain the world, and all phenomena in it, in better light and most accurately. So much so that the later experiments, which I mentioned in the article, took the conclusions from Lorentz as a proven premise and started their experiments with length contraction already as one of their initial assumptions. As you know, even test theories are created based on these assumptions. I have thus tried to question the foundation of our relativistic theory. If we cannot explain the null result it is just not fair to dismiss it and at the same time stick to our wrong conclusion from it.

“Study accelerator physics in more detail instead of sticking with M&M experiment and other ~100 years old stuff” Please excuse me if I am not able to find a politer way to explain this but I think science is not fashion industry. We cannot put an arbitrary time margin for relevant scientific experiments. We cannot remove all equations and theories from our test books only because they are old and out of fashion. As mentioned before, nobody should have any objection at all that data from accelerator physics showing some agreement to the theory of relativity. But then how do you want to explain M&M experiment, as you rightly pointed out, we should not focus on single experiment. Thus, the agreement might be due to some other reasons/theories we have not considered before, because we are assured a theory is already in place. Please do not forget that particle physicists said the same for proving relativistic mass based on date from various accelerators. It is important that whatever theory explains accelerator physics it should agree with M&M experiment too.

Dear Eric,

Notice that I was not speaking on algebra but Lorentz scalars and constants as c. Thus I'm writing the things thinking also in Physics.

And this also works in the laboratories. What are the difficulties with Relativity?

ZS>Can special relativity be categorized as metaphysics?

Dear Ziaedin,

Yes, I completely agree with your views but would go a step further – both the theories of relativity are not even metaphysics, but mysticism and definitely not physics! Please see the parallel forum that I initiated about a month ago; where I question the validity of both SR and GR as “scientific” theories in the usual meaning of the term: https://www.researchgate.net/post/Is_Any_Effective_Refutation_of_Einsteins_Theories_of_Relativity_Possible

I have been doing it for more than a decade through published books, journal articles and through comments in social media particularly in the Guardian science section under the pseudo-name “futurehuman”.

The two main components of metaphysics as it came down from the early Greeks; - idealism (including mathematical idealism) that asserts that “thought” is primary and “matter” is but a secondary derivative, while materialism take the opposite view. Mysticism on the other hand is nebulous without any defined boundary and in reality it thrives through ambiguity. Mysticism is subjective in nature and a mystic always have to be mysterious keeping the focus on him or her; but at the same time always promote a preferred world outlook in disguise.

In formal philosophy, mysticism first appeared with Immanuel Kant after David Hume raised questions on the criteria of knowledge and attempted to show that some of the conceptions specially causality - the epistemology of formal logic is defective for acquiring knowledge and is illusory as it leads to the mystery of a “First Cause” or God. Kant taking up Hume’s view showed that beyond ordinary everyday life experience, causality leads to contradictions and to antinomies. To save causality and the cherished notions of rationalism and the established order; Kant declared the objective reality as an unknowable thing-in-itself. But he took an ambiguous position. Like the materialist he accepted the notion of the existence of object reality, but then declared it to be unknowable, thus making room for idealism, solipsism etc. and the notion of an observer dependent reality. This mysticism in Kant gave shelter to all kinds of conflicting philosophical interpretations and scholasticism that continues till today!

But of course; Hegel cleared all this mess in philosophy created by the subjective idealism of Kant; by making the much hated “contractions” of causality (or what Hegel called “the view of understanding”) the very soul of his philosophy that he called dialectics or “the view of reason”. Hegel thus formed the basis for materialist dialectics of Marx and Engels.

After the breakdown of causality with the recognition of quantum uncertainty, Einstein like Kant took resort to similar mysticism to save the world view of causality of Newtonian physics. In place of Kant’s (self-fabricated) logical categories, Einstein imposed his (own fabricated) categories of mathematical idealism (the epitome of causality) on the unknowable objective reality. Einstein always tried to foster mysteries and ambiguities about himself and about his theories by promoting conflicting notions of both the “real” and the “ideal”, but always preferring the “ideal” at any decisive moment. This is very clear in his formulation of GR as demonstrated by historian Jürgen Renn, in his 2015 lecture at the Perimeter Institute: https://www.theguardian.com/science/life-and-physics/2015/jun/23/the-genesis-and-renaissance-of-general-relativity

Einstein himself claimed his physics as metaphysics when he said: “Our experience hitherto justifies us in believing that nature is the realization of the simplest conceivable mathematical ideas. I am convinced that we can discover by means of purely mathematical constructions the concepts and the laws connecting them with each other, which furnish the key to the understanding of natural phenomena. … In a certain sense, therefore, I hold it true that pure thought can grasp reality, as the ancients dreamed” A. Einstein, “Essays in Science”, Translated by Alan Harris from “Mein Weltbild, Quedro Verlag, Amsterdam, 1933), The Wisdom Library, N.Y., p48 – 49, (1934).

The confusing notion of time dilation, relativistic mass, Twin Paradox, singularities and other Zeno type paradoxes coming from these theories that are still being debated among the physicists themselves and gave rise to hundreds of scientific publications claiming “proofs” of these theories, attracting Nobel awards, created mystery writings, science fictions and movies etc., made Einstein a household name in the first place. Trying to put some polish now to show the "scientific" credibility on the theories of relativity cannot erase the big picture and the myths of the theories of relativity created around the world at the behest of monopoly capitalism and theology.

As with Kant’s mysticism, we need the Hegelian approach of putting “contradictions” at the very heart of physics and its theories to rid it of all mysticism and mathematical idealism imported into physics by Einstein. Subjective, contrived, deceptive and ambiguous “proofs” of axiom-based esoteric theories of relativity is no substitute for genuine criteria of knowledge that must be relative to man and his subjective practice through his material existence.

Dear Daniel ~

This isn't just about the algebra. Its about its physical interprestation; it's about what the symbols mean.

What is meant by the "mass" of an object? How would you define it?

Dear Ed

“Einstein said, "A single experiment can prove me wrong." This is the view I suggest we take in this question.”

Thanks for your comment.

Unfortunately, the number of mistakes in SR is not limited to one. Take for example the light clock. The clock that is supposed to prove the idea of time dilation. But when it is examined closely more oversights emerge. The clock is studied only when the movement of light (if the clock is stationary to the observer) is perpendicular to the relative speed between the observer and the clock frame. Please see my article attached to another question, Is Einstein light clock a trusted timekeeper?

It is like proposing a law of gravity that only applies when two bodies are 1000m apart from each other, not any distance shorter or longer. If the clock is tilted or is dropped to its side, then not only its ticks become irregular but also the supposed time dilation increases.

Does time go faster in one tick and slower in the next one? One also wonders what happen to our heart rates in these cases. Does the heart beat become faster in one tick and slower in the following one? Can we control our pace of aging by changing the orientation of the clock? This is not even imagined in a science fiction.

Dear Eric,

I know that this is a problem of physics, of mathematics, but based in deep mathematics which are impossible to be explained here. Most of the discussions in RG are semantic due to be obliged to write in words ideas which can even be interpreted in different forms. For instance saying that Relativity belongs to Metaphysics. I am sure that in some aspects that can be justified because we are speaking about a very general theory which has changed not only the Physics, but also our form to think (our culture). Einstein didn't received the Nobel Prize for these fundamental works but for the photoelectric effect, which nobody associates to him (in the street) when no physicits speak about this effect related to him, and even the physicits in a very high percentage only think of him as the creator of the Relativity. Therefore I tried to be short and the most clear, not for discussing on formalisms but given you the PHYSICAL reason that it seems that you don't follow or simply don't want to follow. Both options are for me good and we don't need to fight in this point. Certainly I don't want to convince you in these short posts, but I will just try to tell you my physical and mathematical (both are necessary) reasons:

1-Between 1892-1895 Lorentz was fighting for interpreting what could mean a length contraction and over all an electromagnetic mass which was function of the velocity of the system of coordinates. And till 1904 worry by the negative experimental results of M&M and the theoretical criticisms of Poincaré, he tried to generalize his Electrodymics theory introducing his famous transformations, which Minkowski would interpret geometrically and Einstein used for his SR. But here the mathematicians were playing a parallel important role as Hilbert, Noether and the mentioned Poincaré.

2- But at those times one experimental fact was that the electromagnetic mass incresed with the velocity. This was a fact and it was Poincaré who tried more seriously such effect introducing his fractional electromagnetic mass studied by Abraham-Lorentz-Poincaré (and even much later Dirac-Wheeler-Feynman without being successful). Hence this interpretation of the mass depending of the velocity is not at all new and whose difficulty knew very well Einstein.

3- The problem of the mass in Relativity and, in fact, the whole Physics is not completely resolved. For instance, the Higgs mass field contained the Standard Model only allows to know the Goldstone-Higgs mechanism associated to the spontaneous breaking of symmetry, but there are much more mechanisms as the topological ones (Chern-Simons terms) waiting for a clear explanation. And what is worse, nobody knows the actual values of the mass for any particle or their herarchy. Therefore, it would be a waste of time to enter in this thread on the meaning of the mass concept in Physics nowadays. Sorry for that Eric.

4- Finally, I understand that you triy to simplify the physical interpretation simply by avoiding the mass transformation, but this is an experimental fact and, by the way , as I said, this is the only variable capable of stopping a particle in the vacuum to continuing to reach a greater speed ​​than c, which would be out of the experimental facts I think that the formulae that I have attached previously show clearly that the invariance on the SO(3,1) Lorentz group implies that mass must transform as a Lorentz quantity, as most of textbooks present to the students of SR.

Have a good Sunday!

Dear Christian

Your argument is relevant but not helpful at solving the problem we are facing and there are plenty of counter examples. We do not trust geocentric model because we found out it is wrong though it was happily used for centuries. Please note that our various calendars are originated from geocentric era.

My question is simple; do you still accept geocentric theory if you found a few mistakes here and there? If you discovered that the theory started with a wrong assumption and arrived at conclusion not noticing some planetary movements or the proponents created a faulty or imaginary instrument for their measurements?

Dear Daniel ~

You said to me “...it seems that you don't follow or simply don't want to follow”.

I could say the same thing to you!

I know that many relativists have adopted the idea of “relativistic mass”. I know that the idea is presented in many textbooks. The algebra is OK (“it works”) but the physical interpretation is not OK. Many physicists (including you), both theoretical and experimental, are comfortable with the concept. I am not, for reasons that to me are quite sound and rational, as I’ve attempted to clarify in our discussion. If you are happy with the concept, I have no wish to belabour the point any more to try to convince you to change your mind − why should I? I expected only that you might appreciate the logic of my point of view, that’s all.

As you say, “...the problem of the mass in Relativity and, in fact, the whole Physics is not completely resolved”. Yes, that is true. But at the most basic level in Newtonian dynamics and in SR, I see no need for controversy. To me, quite simply, the “mass” of a body is “the amount of stuff” it contains. It is an intrinsic property of that body “as it is in itself”, not a “relative” property that depends on its relationship to something else. In particular, intrinsic properties of bodies such as their masses, charges, or lengths (or, as in the well known example of the muon, their “proper times”) cannot depend on relative velocity.

“Finally, I understand that you try to simplify the physical interpretation simply by avoiding the mass transformation, but this is an experimental fact and, by the way , as I said, this is the only variable capable of stopping a particle in the vacuum to continuing to reach a greater speed ​​than c.”

Not true! The variable that’s capable of preventing a massive body from reaching the speed c is its kinetic energy, which is velocity-dependent and increases without limit as the speed approaches c. That is the experimental fact.

As I read these various responses I can't help but see a group of blindfolded physicists groping to understand what is the elephant standing before them. Theories abound of what be the elephant depending on who is examining what part of the elephant. I believe it was Karl Popper who pointed out that you can never prove a theory to be correct, you can only prove a theory to be wrong - and when you do prove it wrong you first see if it can be fixed within the theory's domain of applicability or, if not, you seek a new theory. Newtonian physics worked to describe one part of the elephant but had to be extended by SRT and GRT to apply to other parts of the elephant if not the whole elephant.

A theory in physics is only a representation of an underlying reality and the value of a theory depends on how well the theory is found to accord with experiment and observation. Theories are depictions of what might be; they in themselves are not the real thing. Given a theory you seek its failings and in so doing you advance your understanding and the theory's realm of applicability hoping one day to grasp the whole of the elephant.

Dear Eric,

The kinetic energy in SRT assumes what I have been saying, it is that the mass changes multiplying the rest mass by gamma. Notice that the only velocity is c in such a formula and never a velocity v alone. This was the previous formulae that I have shown.

Ec =(γ-1) m0c2

There are only two possibilities:

You don't understand so simple formua or you just want to enter in semantic discussion. In any case I give you my sincere respect and considerations but I think that I deserve a rest on this discussion.

Dear Eric and Daniel,

better to talk about rest energy E0 than mass.

In principle you find the mass associated with the gamma factor only in the relativistic momentum and releativistic energy.

Lev Okun clarifies quite well what you are talking about

https://arxiv.org/pdf/hep-ph/0602037.pdf

it is always a point of view... but the Physical point of Daniel has a weight in the discussion.

Hello Christian and all,

You wrote, "What I am saying is that the category of "truth" should be addressed with care. Physics is more subtle and the laws of physics are often neither right nor wrong. They are just an immensely useful approximation and I am not sure if anything else can ever be achieved. Ignoring this may lead to fanatic rigor and raise false expectations of what physics is about."

In physics, some scientists believe we should be able to approach observer-independence, d'Espaganat is just one of them. Others, equally competent, believe that reality is "weird", so we should just abandon anything more specific than intersubjective. A medical diagnosis is intersubjective, believing otherwise is contradicting experience. Would physics have to follow the same rule?

Either answer, YES "or" NO, to this intersubjectivity question above, contradicts (for different reasons) experimental evidence in physics. Some believe the answer is using "and" instead of "or", above, and reality would be dubious, sway according to majority group opinion, as climate science, in this case also for physics. Some people prefer this way. Others believe that we need more logic levels between YES, NO. The YES, for example, remains Yes but some cases could be X, don't care. Other physicists see even more than 3 levels.

In any case, this is not metaphysics if we are willing to discuss reality modes (as above), or could indeed be metaphysics if we put a limit to what is known. In other words, not discussing what we observe might fall into metaphysics, where we leave to others the role of doing it.

Cheers, Ed Gerck

“The question whether objective truth can be attributed to human thinking is not a question of theory but a practical question. In practice man must prove the truth, i.e., the reality and power, the “this-sidedness” of his thinking. The dispute over the reality or non-reality of thinking which is isolated from practice is a purely scholastic question.” , Karl Marx, "Theses on Feuerbach".

"The proof of the pudding is only in its eating!" : Popular saying.

Hello Ziahedin and all,

Your questions on time dilation reflect a general sentiment, because it seems to contradict intuition. However, in experimental terms, Lorentz time dilation is permanent, isotropic and observable by "friends and foes" alike. It has the characteristics of objectivity, of observer-indepedent reality. We could call it truth... but there is always the possibility of a meta-system, ignored today, that can explain it like the sunset, an illusion caused by motion, whereas the Sun itself does not set. In that, physics can never prove truth, although it aims to reach it. Please see my presentation for more details, Presentation Science and the Search for Truth: Scientific Method

Cheers, Ed Gerck

Hello Christian,

Yes this does not straighten the path of physics education, but we can find and note shortcuts, alert for misconceptions. This is not a problem, it is fun, and we shall not run out of work in that :-)

But, does it follow that we should NOT be concerned about the world according to X laws, which laws do not describe the world we live in? When that world is wrong in X's own laws, own restricted domain, we should or .. someone else will do it ... or we have to accept a metaphysical excuse. We do not accept the "ultraviolet catastrophe" formula, for example, in electromagnetic radiation. Philosophers, by scope of profession, can easily entertain something they know to be false or unprovable experimenrally. Physics is bound by experiment, by nature.

Einstein wrote that length contraction is not physically real for comoving observers, but can be physically real for non-comoving observers. Of course, sonething is real iff it is real for all observers, Einstein was simply wrong in that; you can't have a special class of observers and assume neutrality.

But, if something is real when it is real for non-comoving friends only, Einstein could be right. Now, one can take another stance, neutral and not personal, that Einstein was intersubjectively right, although not objectively right. This stance was taken, and seems not to have been understood at its time, 1911, even by its proponent, Vladimir Varićak. This could solve the isuue we face here, today, on length contraction.

So, we are learning, reality may not be mapped onto a Boolean logic level, YES/NO, but of a matrix, multi-valued logic, with different logic levels representing facets of a more complex object. In that case, Intersubjective and Objective logic levels can be real, and others such as Abstract (no observers!), just in different order of significance. A medical diagnosis can be quite real to an insurance agent, but is not Objective nor Abstract, it is Intersubjective. Asking for another opinion will not change the logic level, although it should be done. More opinions are possible, but the level will not change. More logic levels are, however, possible. A student is preparing a paper on this approach.

Cheers, Ed Gerck

Dear Christian,

The Lorentz transformations (as well as Newtonian mechanics) are free of "errors". They are mathematically consistent, sound and free from contradictions.

yes, but Physically they are sound in the way they are written if the speed of light is c constant in every IRF, which has never been demonstrated so far by any experiment.

On the contrary what can be considered quite hard to falsify is their outcome knowing experimentally that the speed of light is always average c in vauco in a two way communication.

Dear Christian,

On Stefano's note on your comment, Newtonian mechanics is not free of errors. Take a look at no reaction force to Corilolis, or centrifugal acceleration that actually (edited posting to make the violation clearer in its own terms) has zero work (work as usual, as F.dr) .

Cheers, Ed Gerck

It is very amusing to see that the differences of opinion and conflicts among the admirers of Einstein’s theories of relativity (and formally trained physicists) arise only when fundamental philosophical questions and the questions of historical/social “practice” are asked in relation to these theories! The fact is that there are fundamental contradictions in the theories of relativity because the polar opposits of the “real” and the “ideal’ are dituted and intermixed with cloudy idealized mathematics!

Without these questions, everything among the physicists is nice and dandy; there is agreement and conformity without any contradiction and has been so for more than hundred years! The contradictions and the confusions are hidden under mountains of mathematical/geometrical constructs; as idealized mathematics is very flexible to manupulation and is contradiction free!

Hello Abdul and all,

These are neither fundamental differences nor so important; they are not publishable. No competent physicist would think they are new, either. We just like "what if" scenarios, much like philosophy, to entertain notions and see where they go. However, when it comes to papers, it is a different standard. No one would seriously publish today using "relativistic mass" -- the concept has no legs to walk on. But, people can mention it, and see by themselves why it fails, education is a good point in RG.

Cheers, Ed Gerck

The math is not clear if its objects are not clear. That particular confusion started with Einstein himself, so we should expect others may do the same, although competent. It is not publishable, so it will literally die off as Max Planck said. Time is a factor in change, but eventually even mountains flow.

Cheers, Ed Gerck

Dear ED,

I post below a comment that I made in another related forum:

[CB> "It's strange that you pray materialist dialectics and argue against relativity, while ignoring the practice of its use in accelerator physics."

Christian Baumgarten,

I don’t think even many of your fellow physicist colleagues will agree with this statement. There is NO “practice” based on the theories of relativity. If “time dilation”, “relativistic mass” etc. are NOT REAL but only APPARENT to a distant observer in RF (like the Doppler effect) as the following quotes from Prof. Eric Lord and L.B. Okun would show; then there cannot be any application ("practice") of the theories of relativity in accelerator physics as also in GPS – the only two cases in which this claim is made. ALL claims to this effect (I can provide a list of about 10 publications only on muon’s half-life) are patently false, as are many “proofs” of the theories of relativity.

“I’m firmly convinced that “relativistic mass” (that appears in far too many textbooks) is a false notion that has confused and misled generations of students learning about Relativity. The mass of a body is a constant m. It doesn’t increase with velocity. According to Newton: a body has momentum p = mv and (kinetic) energy E = mv2/2. According to Einstein: momentum and energy satisfy (E/c)2 − p2 = (mc)2 (where the energy E now includes rest energy mc2 as well as kinetic energy). In either prescription, it is the energy, not the mass, that increases with increasing momentum (ie, with increasing speed).”. Eric Lord, comment addressed to me in: Article Free Fall in Gravitational Theory

"It is not good to introduce the concept of the mass M = m/(1 ‒ v2/c2)1/2 of a moving body for which no clear definition can be given. It is better to introduce no other mass concept than the 'rest mass' m. instead of introducing M it is better to mention the expression for the momentum and energy of a body in motion.»… as I show, this terminology had some historical justification at the beginning of our century, but it has no rational justification today. When doing relativistic physics (and often when teaching relativistic physics), particle physicists use only the term "mass". According to this rational terminology the terms "rest mass" and "relativistic mass" are redundant and misleading. There is only one mass in physics, m, which does not depend on the reference frame. As soon as you reject the "relativistic mass" there is no need to call the other mass the "rest mass" and to mark it with the index 0.» . Ref.[L. B. Okun, Phys. Today 42(6), 31- 36 (1989)]

Dear Ed Gerck ~

Just a note on your remark to Christian, to the effect that “Newtonian mechanics is not free of errors.”

Newton’s laws are applicable only for inertial observers and their inertial (ie, unaccelerated) reference systems. An unfortunately very prevalent error of interpretation (responsible for confusion in the minds of generations of students) is to refer to the centrifugal and Coriolis effects as “inertial” or “fictitious” (!) forces. As your remark implies, there are no such forces. A noninertial observer (whose appropriate reference system is accelerating or, in particular, rotating) observes apparent accelerations, which are merely consequences of his own state of motion. The error is to inappropriately apply Newton’s second law to to those apparent accelerations and attribute them to forces. It is an error of interpretation, not an error in Newtonian Mechanics.

Errors of interpretation are abundant in Relativistic theories. They arise from muddled thinking, not from anything “wrong” with the theories.

Dear Christian

" The Lorentz transformations … are free of "errors". They are mathematically consistent, sound and free from contradictions. "

" The math is clear, simple and rock solid, at least to those who are willing and able to understand it. "

In reference to the above two quotes, I have no answer but referring you to contradiction in the theory shown in Figures 12 and 13 of the M&M article attached to the question. Please let me know if you do not consider it a contradiction.

I salute your enthusiasm for the subject and data from particle accelerators but what I want to see first is a rock-solid foundation of SR. I do not think any theory based on neglecting the movement of the half-silvered mirror can be considered as “mathematically consistent, sound and free from contradictions”.

Hello Eric,

Newton has somethings wrong, but they were right at his time, on each of the three laws. A man of his time, thanks for his contributions. Of course, no one can describe what a straight line is, so not even inertial reference frames were well-defined at his time. The idea that one needs an external reference was first shown not to be the case by Gauss, later used by Einstein.

About anything "wrong" with special relativity, we still have the concept of length contraction as objective, used by the great Feymann to "justify" the existence of magnetism, and many others, including Morin when at Harvard. Those were not interpretations, but a lack of.

We need a theory, in physics, of what is real and what are the options? D'Espaganat is proposing some points, and the discussion show that, after 150 years, determinism is at the end in physics, but realism seems to be the next frontier

Cheers, Ed Gerck

Dear Ed ~

You say “Newton was a man of his time.” One could say, on the other hand, that he was “a man for all time”. His ideas laid the foundations for physics as we know it today, and they are still valid (and always will be) except in extreme “peculiar circumstances”. It was his dynamics and his gravitational theory that enabled men to set foot on the moon and for space probes to successfully navigate to (and around) the planets!

What troubles me is that physics as we know it today works so well in accounting for experimental results, in spite of the fact that its fundamental concepts (space, time, mass, energy, force, etc) seem to have no clear definitions. Are they any more than abstractions drawn from subjective perceptions? Is the physicist’s understanding of “mass” and “force” any more than “knowing what it is like” to push, pull, or lift (or to be pushed pulled or lifted)? (“It is important to realize that in physics today, we have no knowledge what energy is.” − Richard Feynman.)

“Pure” mathematics starts out from undefined “things”, related by “axioms”. ("Mathematics may be defined as the subject in which we never know what we are talking about, nor whether what we are saying is true." − Bertrand Russell). It seems to me that “applied” mathematics (theorising about physical “laws”) proceeds in much the same way. Is Newton’s second law anything more than a definition of “force” once we accept “mass” as undefined, and vice versa?

Wigner spoke of “The unreasonable effectiveness of mathematics in the Natural Sciences”. Einstein expressed the same sense of astonishement: “The most incomprehensible thing about the world is that it is comprehensible.” Bertrand Russel: “Physics is mathematical not because we know so much about the physical world, but because we know so little; it is only its mathematical properties that we can discover.”

[Incidentally, when you say "about anything "wrong" with special relativity, we still have the concept of length contraction as objective", I most strongly disagree! I’ve had many wearisome arguments in Researchgate discussions trying (usually in vain) to convince people that “length contraction” is an artifact of the process of observation (a straightforward consequence of the relativity of simultaneity), not an “objectively real” distortion of physical objects. But that’s another topic...]

Hello Eric,

I just want to add to your last comment above that when you say that you "most strongly disagree!" you are validating my point, that we still have to disagree on what was abandoned even by Einstein in 1911, who was among those who originally said it. I don't think it is publishable today. We may have, soon, not to disagree any more, it is intersubjectively valid. It is real if you see it, not that every observer agrees or that is permanent, like time dilation. It's like the sunset, observers agree but the Sun never sets.

Cheers, Ed Gerck

“…This is a wrong interpretation of what is "real" and what is "apparent". In terms of accelerators, the length contraction causes the particles bunches to be shortened and this *has* effects in the "lab frame".”

Indeed, in “lab frame” on Earth the fast particles that move in accelerators become be really contracted, but, of course, not because of that some omnipotent unbelievable Essence “length contraction” causes that using some magic forces; as that the “true” SR, in certain sense, postulates.

Here “in certain sense” is since in the quoted assertion above is principally erroneous in framework of the SR, in the SR there is no “length contraction”, there is the “space contraction”; Minkowski didn’t say that “…Henceforth lengths of bodies by itself, and clocks by itself, are doomed to fade away into mere shadows,…”, he said “…Henceforth space by itself, and time by itself, are doomed to fade away into mere shadows,…” .

In the reality

[see the Shevchenko and Tokarevsky’s informational physical model, since the last SS post is rather far above in this thread, I repeat a link: at least first 6 pages in https://www.researchgate.net/publication/259463954_Measurement_of_the_absolute_speed_is_possible DOI 10.5281/zenodo.48709 ]

moving in the 3D space particles become be indeed really contracted, but because of they are accelerated up to a large speeds by quite material and quite non-magic EM forces.

Further, since every particle is some close-loop algorithm that works as constant sequential switching of fundamental logical elements, so it is a 4D gyroscope, and, at that, this gyroscope constantly moves with 4D speed of light in the 4D Euclidian sub-spacetime of the absolute Matter’s [5]4D Euclidian spacetime,

the gyroscope’s “FLE flipping point” has a 4D helix trajectory. If a particle moves in the 3D space, the gyroscope’s rotation rate vector becomes be turned on an angle and this helix’s 3D spatial projection becomes be really spatially “compressed”. When particles constitute a rigid body, and the body moves in the 3D space, the particles rotate the body as a whole in the (X,cτ) plain

[“cτ” is the zero coordinate of the 4D Euclidian sub-spacetime of the absolute Matter’s [5]4D Euclidian spacetime, and if a body is at absolute 3D spatial rest, it moves with the speed of light only in the cτ-dimension, thus its spatial projection is maximal]

so that the body’s spatial projection becomes be lesser as of articles above, i.e. in the Lorentz factor.

That’s all relating to “apparent/ non-apparent” .

“…To say that this is "just apparent" (and here I decidedly disagree with Eric Lord) is misleading and just based on the theoretical insight that if you would move along with the bunches, the length contraction would not be visible...”

yeah, that is indeed in accordance with the SR, from the SR indeed follows that (i) - if somebody would move along with the bunches, the length contraction would not be visible; however in this case the SR states nothing new comparing with the developed before the SR Voigt-…..Poincaré-Lorentz theory. But the SR asserts in this case also (ii) - that in this case all Matter outside a moving “bunch”, including everybody on Earth, including all true believers in the SR, are quite “non-apparently” really contracted also. Moreover, when a cyclic accelerator, say, LHC, works, all humans become be really contracted in 105 times and all these блинчики/ pancakes move around the LHC practically with the speed of light.

But thank heavens nobody feels any troubles when be rotating and contracted. At that those, who understand that the SR postulates about total equivalence of the reference frames and real spacetime transformations are nothing more then some fantasies, simply don’t take any attention to such “relativistic effects”. What at that think the SR/GR true believers is unknown…

Cheers

Christian Baumgarten,

Prof. Eric Lord is one physicist in RG for whom I have the highest regard. But of course, I do not agree with everything he says and neither does he of me. I agree with him on “time dilation”, “gravitational mass” etc., not only because he has taken a materialist position (in opposition your and others' idealist position on these issues) but also because I consider space and time as abstract entities beyond any physical manipulation.

Just for curiosity, I would like to know your stand on “gravitational mass” (increase of mass at very high speed). For a proton (or any other object) for example, at very high speed, what is the nature of the new (increased) mass? Is it the same kind as the mass of the original particle or is it different? What happens to the new (increased) mass when the particle slows down to ordinary speed? Please do not try to explain it in terms of “apparent or effective mass-energy”; in that case you take the same position as that of Prof. Lord. You have to explain it in terms of the “physical picture” (deformation), like the way you did for “length contraction”, for example

For your information; I also reject the concept of “spacetime field” (of Minkowski and Einstein) as a geometric manifold with supposedly (tangible) physical, mechanical, metric etc. attributes. It makes no sense to me from a materialist dialectical perspective. My booklet, “The Philosophy of Space-Time : Whence Cometh Matter and Motion?” deals with this issue :

https://www.amazon.com/Philosophy-Space-Time-Whence-Cometh-Matter/dp/984041884X

Dear Abdul,

When you say:

It makes no sense to me from a materialist dialectical perspective. My booklet,.....

You immediately are out of Science. Nature doesn't understand about materialistic dialectical or idealistic perspectives. That is one non scientific point of view. Science is only made experimental results and their interpretations (theories if you want), even Mathematics doesn't depends directly of experiment, needs from a pure logic behind any kind of ideology.

Frankly I don't understand why Relativity has attracted so great number of non-scientists to try to "opine" on it without a basic knowledge or even contradicting its experimental supporting background. There are other parts of Physics as Quantum Fields or Cosmology which are much more full of pure theoretical results, but the non-scientific people is not enough interested.

Dear Christian ~

In your reply to Abdul above, you say “If “time dilation”, “relativistic mass” etc. are NOT REAL but only APPARENT to a distant observer in RF (like the Doppler effect) as the following quotes from Prof. Eric Lord and L.B. Okun would show; then there cannot be any application ("practice") of the theories of relativity in accelerator physics as also in GPS.”

It seems to me that the diffence in your way of thinking about Relativistic physics and mine are only “apparent”, not “real” (-;. Our disagreement is a matter of semantics, not physics.

What is Relativity about anyway? It’s about reference systems and the mathematical transformations between reference systems. A reference systems contain no physics, yet statements about physics cannot be formulated without one. According to Relativity a physical quantity has “objective reality” only if it is an invariant, only if it is independent of any particular choice of reference system.

As you say, “not only many but all my fellow physicists should agree that, within the lab in which we use the accelerators, these effects are measurable and are as real as can be.”

Yes: when an experimental physicist reports the results of observations and measurements those results are “real” for him; he really has made those observations and measurements and reported those results. As you point out, they relate to and are expressed in only one reference system. So why can he not dispense with Relativity altogether? Because, without Relativity theory − without an understanding of the conceptual possibility of other reference systems − those results would not be intelligible; any explanation of his observed “length contractions”, “time dilations”, “relativistic masses”, etc would be absent; they would remain utterly mysterious and unintelligible! Relativity theory allows us to understand that they are properties of the process of observation, not “objective realities”. I use the word "illusion" in this context to add emphasis to that point.

Dear Eric,

I see most of your explanations to the relativistic effect are far a way from the real physical reality. I consider them only bedtime stories since they are far away from the experimental results. For example the Mössbauer Experiment, where the experimental results of the Mössbauer Experiment proving the wave-particle duality and the uncertainty principle which is in violation with the Minkowski space-time continuum that is keeping on the independent reality. Furthermore the Sagnac effect and GPS positioning system and the explanation of Ashby by considering the Galilean time t'=t instead Lorentz time t’ = γ (t - x v/c2 ), and there are more and more. But your problem you refuse to discuss any of these experimental results, because you understand well how that in violation with what you propose about SRT and GR. So all of your explanations are only bedtime stories, and this is the truth. Please do not be angry from my criticism to your comments. This is the truth! I am against courtesy, sympathy and hypocrisy in science! You are mistaken and you are telling bedtime stories in physics dear Eric!!

Regards,

Azzam

Dear Christian Baumgarten

Tesla said the following on the theory of relativity in a 1935 New York Times interview:

"The theory, wraps all these errors and fallacies and clothes them in magnificent mathematical garb which fascinates, dazzles and makes people blind to the underlying errors. The theory is like a beggar clothed in purple whom ignorant people take for a king. Its exponents are very brilliant men, but they are metaphysicists rather than scientists. Not a single one of the relativity propositions has been proved."

I want to correct something in Tesla statement,

The theory is like a devil clothed in purple whom ignorant people take for a king. Its exponents are very brilliant men, but they are Alchemists rather than scientists.

Dear Eric,

I think that you need to reflect why the non-scientists take you as their reference for relativity. You have a tendency to say that an observer, as an element of the group of Lorentz, cannot have a unique physical observable quantity (which immediatally some people thinks that this might mean "at livitum" interpretation). This is true, but only a part of the truth. The groups have invariants which are independent of the transformations, for instance the stable set of electromagnetic fields for the Lorentz transformations is only two. One scalar and pseudoscalar which allows to define the the electromagnetic action or the energy-momentum tensor. Both are the main ingredients of Electrodynamics given its motion equations and conservation quantities.

But the Relativity has gone further because it has postulated that any physical interaction cannot reach an state of motion having a velocity higher than c, i.e. the velocity of the electromagnetic field. That is to say all the Physics follows the rules of transformation of Electrodynamics instead of the Mechanics. In electrodynamics this was not at all new and only new interpretations or even formulations where introduced, but the important achievement of Relativity was in mechanics because new phenomenology arises with this new background out of its Galilean group. For example, in a nucleus there is much more mass than the one of its elements by separated and the difference is transformed in energy coming from a pure mass element. This is reproduced with clear accuracy everyday in centres as the CERN. That result is independent of the observer and it is related directly with the invariant rest mass. From the physical point of view the most import part is to show how the different parts of a physical magnitude respond under a change of its relativistic components. This is not coordinate dependent and a given observer can unirversally measure it in all (its,his or her) class of inertial frames.

The problem of the non educated scientifics is that they can think that the trajectories of a falling parachutist of an aeroplain, seen by the pilot as a straight line or the terrestrial one as a parabole, are different physical events. You are right, they exactly the same event although we see so different results in Galilean relativity (and also Lorentzian, of course). But the Physics is exactly the same thanks that we have the group of transformations, they are mathematics, but necessary to relate both configurations as the same . The only difference between the Lorentz and Galileo transformations is the limit of the velocities that a movil can reach and no the time which is just a consequence. The simultaneity of the time or not, doesn't give directly a physical outcome, or better, there could be many different theories having this same outcome while the fine value of the velocity must be a unique observable fact.

I'm sure that you and Christian don't need these kind of explanations but I tell them because I see that there are many people opining or even writing very bad things on Relativity without understanding that it is not so simple and obvious to be a professional of this field of knowledge who needs apply the subtly tools for obtaining real results.

Sorry for so long post!

DB> You immediately are out of Science..

Dear Daniel,

I am sorry to say that you do not know what you are talking about. It is you who is “out of science” when you talk about the theories of relativity. As I said above, the theories of relativity are not even metaphysics, but for me these are mysticism (a contradictory mix of the real and the imaginary); please see my first comment in this forum.

These theories are based on axioms, postulates etc. like geometry, that are then imposed on Nature and reality (and also on natural science) like Kant’s logical categories. I agree with Prof. Eric Lord that these theories are abstract thought objects, are mathematically and logically consistent in and within themselves, but whether or not these correspond to the real world has to be established. And please do not tout “experimental results” to make these theories “scientific”!

The experiments carried out so far are all theory driven, with the primary aim to subjectively “prove” these theories. The experiments are commissioned by vested interest groups; are contrived, manipulated, deceptive and corrupted by the lure of fame, fortune and funds and still continues! I have discussed in the Guardian also in RG about how for example the “discovery” of the much publicized “God Particle” (Higgs boson) is contrived! I have discussed these in my published works (books and articles) and the various forums of RG.

A “real” scientific theory on the contrary is based and driven by experiments. It does not need century long multitudes of fake “proofs” to establish its validity. Like the theories of Newtonian physics (real science); scientific theories are proved daily through their social/technological practice – the only criteria of knowledge that separates a scientific theory from fantasy and imagination. Unfortunately for advocates like you lot, the glory of the theories of relativity has worn out because these are not scientific theories like the theories of Newtonian physics and “matter particle” based QED. You just have to come to terms with the reality!

CB> And, since such an increase implies that "the observer" is in a different "frame", kinetic energy is as much of an illusion as any other motion dependent quantity.

Christian Baumgarten,

You made good efforts in response to my comment, but unfortunately you say less than nothing, both on “relativistic mass” and Minkowski "spacetime"; because what you say are full of confusions and inconsistencies – the hallmarks of Einsteinian physics. If “relativistic mass” is an illusion, why “time dilation” for muon half-life for example or “length contraction” are also not illusions for you, as consistent Prof. Lord says?

Minkowski claimed his “spacetime “ is a revolutionary idea about objective reality and forms the bed-rock of the theories of relativity! We are discussing the theories of relativity here!

“The views of space and time which I wish to lay before you have sprung from the soil of experimental physics, and therein lies their strength. They are radical. Henceforth space by itself, and time by itself, are doomed to fade away into mere shadows, and only a kind of union of the two will preserve an independent reality”. Minkowsky, H. “Raum und Zeit”, 1909, Jahresberichte der Deutschen Mathematiker-Vereinigung, 75-88, English tr. M. Saha. “Space and Time” 1920.

In any case, it does not make much sense for me to repeat the same things that I said in the long forum of Dr. Engelhardt (and in the one of mine), particularly in my discussion with Prof. Eric Lord. So, I will not enter into any more long discussion in this forum.

Dear Christian Baumgarten,

At first you have not answered the question of Abdul Malek relative to the relativistic mass, and you understand well how the relativistic mass in SRT is in violation with the principle of relativity in SRT. We don't need to repeat the same discussion. Everything is well known now for physicists!! Do not forget basis on the math of SRT and the physical reality that adopted by SRT, SRT is classical theory. At least try to understand how SRT is classical theory!! Are relativists cheating us when they say that SRT is classical theory or what!? So try to answer the question which is related to the relativistic mass in SRT within the framework of the classical theory that adopted according to the math and the physical reality in SRT!! If you can't, then the physical reality adopted by the wrong math in SRT is not real, and it is only fake! Even the math adopted in relativity in order to keep on its fake physical reality is wrong!!

Hello all,

Some questions, even wrong, are worth debating. Some, are not. I want to add some words in nuance, to Christian's posting above, of one hour ago.

Mass, in physics, is what you define it to be ... not what it is, which is, essentially unknowable. Therefore, every opinion in this forum is right, according to one's own definition. Everyone wins!

We cannot get on top of a soapbox and say "In physics, mass is" . We can, however say the definition we use or agree with in physics. Others, in physics, taken as equally competent, hard-working, and honest, maybe even as an ideal "computer" as originally meant, may have a different and, for them, valid defintion.

Mass, in Special Relativity, is _defined_ (no discussion here) to be the magnitude of the 4-vector of energy-momentum. There is no wiggle room, right or wrong , in nature or in someone's mind ... It is a definition in SR, live with free speech.

Christian is right, to that definition. Consequently, in that definition, mass is an invariant and has the same value in all reference frames of SR, so there is no different mass in that theory. However, it is not conserved in SR, even though it is invariant. For why, and more, in SR, see my "20 theses" in RG, the misconceptions.

In Newton's theory, mass is also absolute and invariant, ... but conserved. That creates a BIG difference between living in Newton's world and living in this world, even at zero speeds (in one's own eigen frame), which difference is smaller in SR. Christian would not have a job in Newton's world, l and many others neither. Contradictions, abound, even theoretically, in form and substance.

Cheers, Ed Gerck

Dear Christian Baumgarten,

I'm discussing with you about the relativistic mass as SRT is classical theory as a result of the independent reality in SRT by the Minkowski geometry. "Henceforth space by itself, and time by itself, are doomed to fade away into mere shadows, and only a kind of union of the two will preserve an independent reality”."

The invariance of the energy momentum four vector is associated with the fact that the rest mass is invariant. What about the relativistic mass in this case resulted from the independent reality in SRT!? You can't say according to the Geometry of SRT that is keeping on the independent reality there is no relativistic mass in this case! You can't also considering that is related to the relativistic kinetic energy since the rest mass of the photon (energy) is zero. Also in this case the relativistic mass is in violation with the principle of relativity in SRT. Also if you want, let's generalise the concept of the relativistic mass in GR according to the equivalence principle in this case!! You can review in this case the paper of W.W. Engelhardt or you want to refuse to discuss that!?

Article Free Fall in Gravitational Theory

Hello all,

Mutatis mutandis, we can say the same about length.

Length, in physics, is what you define it to be ... not what it is, which is, essentially unknowable.

Therefore, every opinion is right, according to one's own definition. Everyone is right -- that is what I call the Subjective mode.

One cannot get on top of a soapbox and say "Length is..." . One can, however say the definition one uses, or agrees with. Others, taken as equally competent, hard-working, and honest, maybe even as an ideal "computer" as originally meant, may have a different and, for them, as a group, valid definition. Everyone wins, each in their own group, that is what I call the Intersubjective mode, similar to a medical diagnosis.

Length, however, in Special Relativity, is in what I call the Objective mode, valid for all observers, possibly correcting for mathematical transformations, as rotation, reflection, dilation, and translation.

Length, in SR, is _defined_ (no discussion here) to be three spatial coordinates of a space-time 4-vector. This is Objective, for everyone the same, even for those who don't agree. There is no wiggle room, right or wrong , in nature or in someone's mind ... It is a definition in SR, live with free speech.

Consequently, in that definition, length is not invariant, it may not have the same value in all reference frames of SR, so there may be different values of length in each frame, in that theory, except in the special eigenframe, where the relative velocity is zero for all points.

Furthermore, in SR, length can partly appear or disappear: for a non-comoving observer, length contraction is measurable for speeds larger than zero, but must be the same for co-moving observers, with speed equal to zero (as stated by the principle of equivalence in SR).

This statement has caused much confusion in SR, that two types of observer would disagree, when measuring the same rod. Some think this is caused by a “mystery” in SR, or “paradox,” or simply does not make sense to ask

One can resolve the issue by regarding the statements as Intersubjective, for both types of observers are right in their own group. Objectively though, in a narrower case, it's easy to see that length contraction does not cause a permanent change, and returns to zero immediately whenever the speed returns to zero (immediate action signals by itself a violation of SR); so, this is NOT the sign of an Objective change. Length contraction is, thus, Subjective, Intersubjective, but not Objective.

With time, the same happens, mutatis mutandis. Time dilation is, though, permanent, as revealed by the Twin Paradox, day-to-day operation of particle accelerators, GPS, and others, with no exceptions. Time, in Special Relativity, is thus Subjective, Intersubjective, and Objective, contrary to length contraction. This explains all measurements, including length contraction, and opinions.

In Newton's theory, length is absolute... and conserved. That creates a BIG difference between living in Newton's world and living in this world, even at zero speeds (in one's own eigenframe). No current physicist would have a job in Newton's world.

Cheers, Ed Gerck

Dear Ed ~

These issues can be easily resolved by issuing a Proclamation:

“The comoving observer is always right!” (-;

Dear Christian Baumgarten,

I'm discussing the experimental results and observations according to the Minkowski geometry that is keeping the independent reality in SRT and GR. And I want to understand why QM and GR do not merge also. I know you can't discuss according that, because you understand well how the observations and experiments are against SRT and GR in this case.