Hi Bishal

Einsteins developed a very interesting "gedanken experiment" to conclude that the velocity of ligth is a constant, the so called Einsteins' mirror.

Hello Cesar,

that is the thought experiment not the one that was done practically by the use of rods and scales.

Hi

Yes. It was

Hello Cesar,

I didn't get you.

Hello Bishal

I just said you are right. This is a though experiment performed by Einstein.

Hi Bishal

Of course if you combine in an appropriate way the Gauss laws for the electric induction and for magnetic induction, Faraday-Maxwell law and Ampère law you will get Lorentz invariant second order diferential equations for the electric and magnetic fields and an expression that defines the velocity of light, c, in terms of the square root of the inverse of the product between the magnetic permeability and the electric permittivity on vacuum. And the value of c is a constant.

Yeah, that is a conventional way that gives a constant term of velocity in vacuum which doesn't mean the non-relative,in actual sense. Further, what I actually trying to mean is that, Faraday-Maxwell law equation will be resulted in a different form if we write the electric field in terms of my version (as derived in the attached file above) which results final Ampere-Maxwell equation as written in attached file below. This is only one version, the next is not written here.

Hi B.B. let me quote your question: 'Does the speed of light is constant from the theoretical point of view? ' I try to answer this question in the work posted in RG: 'Loose comments on the topic of speed of light ...' in particular in Sec.7:-)

Best regards, J.H.

Hi Bishal

I have to disagree. This is not just the conventional way to obtain the velocity of light starting from Maxwell equations. This is the only way. And if you write Maxwell equations in tensorial covariant form, this procedure can be repeated in the special relativity domain. And it is not only valid in vacuum. It is valid in any medium. The corresponding expression for the definition of the velocity of light is similar. Only has to use the corresponding magnetic permeability and the electric permittivity on medium.

It depends how speed and units of measure are defined.

at this point of time, c is constant by definition and length is defined by c*t where the second is a number of cycles of a particular atomic oscillator, which does not change under any circumstances.

When it comes to Maxwell equation, one can eliminate magnetic permeability and the electric permittivity of vacuum by suitable choice of units (eliminating kilogram from base units). In cuch case only c remains. That means it can only be determined from time and length measurements.

@all, the insertion of gamma (on the attachment in previous comment) in the fundamental step that finally altering the derived form of the Ampere-Maxwell equation, will let the light speed to be medium dependent.

“Does the speed of light is constant from the theoretical point of view?”

there cannot be any theoretical point of view relating to the speed of light, including mentioned in this case Maxwell equations. As well to anything else that relate to fundamental physical notions/phenomena, though: any indeed new and so indeed fundamental information about the External can be obtained by humans only experimentally.

If from such information some theory appears and from this theory some concrete consequences follow that are consistent with experiments, such cases are nothing more then some technical results. Including Maxwell equations are the result of fitting of human’s mathematical description of processes and relations in the external Matter basing on the Coulomb, Faraday, Ampere, etc. [and corresponding “purely experimental” corresponding laws] experiments.

The constancy of the speed of light is the experimental fact also, however further correct/incorrect using of the experimental data at developing some models, theories, etc. depends on humans, which interpret the data; what is the subjective process, where anything is possible.

Seems already the classical case, when the constancy of the light speed is postulated as something ultimately fundamental in the SR, for that even it was necessary to postulate also the absence of the absolute Matter’s spacetime, in spite of that from this postulate any number of evidently senseless consequences follow, including rather strange “relativistic transformations of the space and the time”.

Much more adequate interpretation is that Matter’s spacetime is the absolute [5]4D Euclidian manifold, which is filled by dense “aether”, where every material object can move only with 4D speeds in the 4D sub-spacetime, which have identical absolute values be equal to the speed of light [and with the speed of light in the 5-th, “true time”, dimensions ].

An example: let a boy in a wagon throw a ball orthogonally to , say, the wagon’s ceiling [let – along Z-axis] with a speed v and make a short light flash to a mirror on the sailing, the ball and light will move orthogonally up and down with speeds v and c;

If the wagon moves along the X-axis with a speed V, then:

- the ball’ moves in the plain (X,Z) with the speed v’=(v2+V2)1/2, the ball’s trajectory is along sides of an isosceles triangle; however the ball’s trajectory in the wagon remains be orthogonal when ball’s speed in the wagon remains be v;

- but photons move in the plain (X,Z) again with the speed of light, and photons’ trajectory is along sides of an other isosceles triangle, thus photons’ trajectories in the wagon remain be orthogonal; but, since photons move in the 3D space with the standard speed of light only, their speeds in the wagon become be, vl=(c2-V2)1/2=c(1-V2/c2)1/2, i.e., if that is applied as to the ball above, light speed in the wagon isn’t equal to c.

That is another thing, that clock moves with the wagon, but in the (X, cτ) [“cτ” is zero “coordinate time” dimension in the 4D sub-spacetime] plain with the speed of light also, and thus in this case the clock moves along this time axis with vc= c(1-V2/c2)1/2 as well, and, since the motion of some material object that has “rest mass” in the coordinate time is changing of the object’s internal states, the object “clock” ticks slower, and so measured inside the wagon the speed of light turns out to be equal to c again, when real speed [see above] is lesser in the Lorentz factor.

Etc.

More see, for example, https://www.researchgate.net/publication/273777630_The_Informational_Conception_and_Basic_Physics DOI 10.5281/zenodo.16494

Cheers

Hello Sergey,

you mentioned "The constancy of the speed of light is the experimental fact also " is simply correct, not overall correct. The what-soever experiment performed to light proves that light travels at some finite speed, not non-relative regardless whether it travels in empty or not. The famous MM experiment is simply capable to denote the same point of constancy of light speed, not non-relativeness. If we assume that there was ether and in-spite of that, there was no frequency-shift, then one could say that light is non-relative. But what we concluded, "there is no ether" overall.

Hello Bishal,

“…..The famous MM experiment is simply capable to denote the same point of constancy of light speed, not non-relativeness…”

I can here only repeat that assertions that using of terms/notions as “relative”, “non-relativeness”, etc. relating to the notion/phenomenon/physical variable “speed” [and “energy”, “momentum”, etc. as well] should be applied with some precaution, their meaning as a rule depends on the context, including on concrete physical situations, and can be rather different in opinions of different humans, including physicists.

Nonetheless all these physical parameters of physical systems always have real values, but only in the absolute, i.e. that are at rest in the absolute Matter’s [5]4D Euclidian spacetime, reference frames. In other frames, when any real human’s frame is the other in this sense, because of its speed in the absolute space isn’t known and so is uncertain, these parameters can be only measured, however, since practically with 100% probability the frames move in the space with some non-zero speeds, the measured results aren’t equal to the real ones and so are unreal.

However that in many cases is inessential, in rigid systems [when practically every of studied system of particles, bodies, etc. and every used at that reference frame are rigid because of the Earth gravity] the relativity principle works well, and obtained at “SR-theoretical” processing of these unreal experimental data results of processes and interactions in rigid systems are well adequate to the reality.

Including measured in such frames the speed of light value is always equal to c, when, in the reality [see the example with a wagon in the SS post above] that isn't really so. More about this point see, again, the paper “About some conventions in mechanics” linked in a SS post above also

“… If we assume that there was ether and in-spite of that, there was no frequency-shift, then one could say that light is non-relative. But what we concluded, "there is no ether" overall.”

That isn’t so and such conclusion [the absence of the aether] doesn’t follow from the MM experiment. In the reality the Matter’s spacetime is absolute, in this spacetime can be, and with rather large probability is, placed some 4D aether, which is a dense lattice of 4D primary fundamental logical elements (FLE) and which is at 3D [and even possibly at 4D spacetime rest] spatial rest; photons, which are some cyclic [as every other material particle and mostly every body] disturbances [close-loop algorithms that run on hardware of the FLEs] in the lattice; and in this aether MM experiment’s result is quite legitimate;.

In the lattice all/every material objects move with 4D speeds that have identical absolute values be equal to the speed of light, having at that energies E= ћω; and if some object, including photon, is impacted with transmission to it some energy/momentum, its frequency is [±] changed/ “shifted” without any physical problem.

Again see the paper https://www.researchgate.net/publication/273777630_The_Informational_Conception_and_Basic_Physics DOI 10.5281/zenodo.16494

Cheers

Hello Sergey Shevchenko ,

I see that you comment is not specified. I usually see this same comment to all posts repeated every time. I wish, if you make a short specific comment understanding the question and the comment you want defend, it will be more helpful to we like people.

Hello Bishal Banjara,

A short specified comment to your previous post would be as:

“….The famous MM experiment is simply capable to denote the same point of constancy of light speed, not non-relativeness…”

- that is senseless proposition till it isn’t pointed – “non-relativeness”, that is in a relation to what?

“…If we assume that there was ether and in-spite of that, there was no frequency-shift,…”

- that is physically incorrect, because of MM interferometer principally isn’t able to detect its photon’s frequency shifts, including when the interferometer moves in the absolute Matter’s space; so

“… then one could say that light is non-relative. But what we concluded, "there is no ether" overall…”

- [even if someone doesn’t take an attention to what is “that light is non-relative”?] for such conclusion there is no any rational base; moreover, since Matter’s spacetime is absolute, the conclusion is, with a large probability, incorrect and the ether exists

Cheers

Hello,Sergey Shevchenko,

First I would like to note some point on the difference between relative and constant. The concept for relative to relate light speed denote, in simple language, whether its value is variable to the different kind of observers who may be either moving or stationary. The usual concept of light is considered to be non-relative.taking respect along with either stationary or moving. This is foundation of relativity or say NON-Relativity inside Relativity. The meaning of constant is imposed to refer the condition of being in same velocity of its own (light) always but itself being variable to different observer or observer dependent. So, the Maxwell's equation to relate speed of light by Einstein was simply HEURISTIC act taking in correspondence with first case above. The actual sense of Maxwell's equation denote the second case. So, fundamentally there is hidden mistry that one ever noticed. The most impact of non-relative sense of light is, it would never allow to question on speed of light.

To your first query:-

I hope I might be able to clear on your first mark by above explainations.

To your second query:-

First, let me tell you that the concept of ether was introduced (officially) to denote the light's medium. Your objection is tilted towards on the base of second case (constant case). And you separate a single sentence without completing the main point or say diverted the meaning by isolating a single question. Yes, MM experiment didn't pointed the shift. What's the difference? I will question you, "when the interferometer moves in the absolute Matter’s space", will you please give me any link which proves this point? I read and saw only experiments which is based on path and phase differences linking to the measure of speed of light by the use of Interferometer, not by allowing to move the interferometer itself.

To your last query:-

I don't understood what you meant actually.

Hello Bishal Banjara,

“…I would like to note some point on the difference between relative and constant. The concept for relative to relate light speed denote, in simple language, whether its value is variable to the different kind of observers who may be either moving or stationary…”; etc.

if be short, all answers on your last posts exist already in the SS posts above; including the notion that the physical [vector] parameter “speed” is always “relative” since can be defined only relatively to a pair of points in the spacetime and relatively to some direction that is chosen in the spacetime.

Besides in any concrete physical situation there can be a lot of some, rather important nuances, when a next peculiar “relatively” can be defined. Including at that the conditions “moving/stationary” can be inessential, just such example when in the system “wagon” all is “stationary”, nonetheless the real speed of light isn’t equal to the standard value, was given in the SS posts above.

Correspondingly in some cases some people, including you, become be confused when determinate – what “relativity” is relevant in concrete physical task, that happens rather often, and therefore a number of “popular” situations are considered in the papers that are linked in the posts.

I would not like to repeat the explanations a next time and only note again, that the postulate about the constancy of the speed of light in the SR 1905 year version is nothing more then a reasonable suggestion, which allows to obtain the Lorentz transformation; when the transformations can be obtained in a number of other ways; the speed of light isn’t something “ultimately fundamental”; all/every material object moves constantly [because of the energy conservation law] in the [5]4D Euclidian Matter’s spacetime with 4D speeds of light only, photons move in the 3D space with this speed only because they are created by only spatial components of impacting momentums, in the rest they are rather banal particles that don’t differ in some unusual traits from any other Matter’s particle.

Relating to the MM experiment again see the posts and the papers above, besides it would be helpful to read the last SS post in .

https://www.researchgate.net/post/Does_Michelson_and_Morley_experiment_support_length_contraction?view=5a9eb2fbb0366d48b04d0296

Cheers

Hi Sergey Shevchenko ,

First of all, I am getting quite odd to understand your kind of explanation that is based on your new kind of hypothesis. If I am correct then, your point of matter space and movement concerns with Minkowsi space that appearing rest body in 3D will always in motion in 4D. But I was concerned to 3D last time relating its derivation in Maxwell's equation. Your suggestion doesn't cover my question relating the experimental base on movement of apparatus. And if you already knew the concept about the relative and constant, I think you would better not create the issue.

Hi Bishal Banjara,

“First of all, I am getting quite odd to understand your kind of explanation that is based on your new kind of hypothesis. If I am correct then, your point of matter space and movement concerns with Minkowsi space that appearing rest body in 3D will always in motion in 4D…” etc.

your problem in this case is in that you read SS posts too non-attentively. In all the posts and linked papers it is pointed that in the reality there is no some imaginary [mathematically] Matter’s “Minkowski space”, as that indeed is written in all mainstream physical textbooks.

However in the reality Matter’s spacetime is absolute and real [mathematically] [5]4D Euclidian empty container/[manifold in physical theories], where all/every material object move with 4D standard speed of light; and make that always and constantly because of the energy conservation law, the objects simply cannot stop.

Since the SR is nothing more then a re-formulation of the really adequate to the reality Lorentz transformations, in the SR all/every object also move in the 4D Minkowski space[time] with identical by absolute values [be equal to the speed of light] so called “4-speeds”, which are some analogues of the really existent 4D Euclidian speeds. But this analogy is rather subtle: e.g., all 4 components of the real speeds are mathematically real and are real really, when in Minkowski formalism ether temporal or spatial 4-speed components are mathematically imaginary and unreal really, for example for some fast body its spatial component of its 4-speed can be much more then the speed of light value because of the Lorentz factor; etc.

However, of course, if you don’t want to understand what the correct mechanics [including to understand “3D” Maxwell equations is necessary to understand the rest in physics, since to measure 3D speed of light is necessary to use having rest mass clocks, which move with 4D speeds ] is, I, of course, cannot force you to do that.

Cheers