Hi Valentin,

I didn’t predict you would be the first to answer, but I knew I could count on you to elucidate the question.  I thank you for your curiosity, because it’s well justified.

In my mind, when opinions among intelligent and educated people are as controversial about a subject, as they appear to be about SR, I am compelled to try to see if I can determine where the controversy stems from so that I may understand and rationally accept my personal conclusions on the subject.

I’m not trying to establish if SR is a valid theory or not, because if it is not, end of story, the controversy will end when it does and I am not evangelical enough, I’m sorry to say, to pursue its outcome one way or another.

On the other hand, if SR is valid as a model of Reality then I am very interested as to why the controversy appears to remain even amongst its believers when the discussions involve their interpretation as to the correspondence of the theory to physical Reality, especially when it comes to time dilation and simultaneity.  If I’m wrong about this last statement, I hope they will let me know.

To answer your question, when it comes to time dilation, I would like to know if the controversy lies in its physical interpretation or in the formulation.

For example, I have found that if I consider the wave properties of matter only (such as in de Broglie waves), ignoring its particle properties, I can very easily understand SR’s correspondence to physical Reality in terms of their spatial and temporal frequencies, thus their mass, kinetic energy and momentum.  I want to know if I’m wrong.

Best regards, Bernardo.

Valentin,

Thanks for respecting the nature of my question, but please don’t get a hernia exercising your will to not comment on what you call the “bigger controversy”, you comments are always welcome.  I just don’t want to throw the baby out with the bathwater at this time.  It occurs to me that if I can clean up in my mind, the interpretational scenarios of SR, I may find a healthy baby underneath, before I throw it away.

Let’ start with time dilation.  Do you think that SR supporters agree with me on what I interpret it to mean? That is, that time itself (the dimension) has some substance (fabric) that can dilate locally somehow under the influence of material motion?  Needless to say, this scenario is counter intuitive to me, but if that’s the case, I will try to understand it, if possible.

Or, do they mean that the frequency of moving clocks increases under the influence of their motion.  If this is the case, I can put my mind around it, and it’s just a matter of understanding what is meant by "frequency", because frequency is a very intimate property of the nature of a clock (and of matter), which could be, Compton, de Broglie, atomic, quantum mechanical, mechanical, etc.

These two scenarios are very important because we all have very definite ideas on what SR is and what it’s not and I don’t see why we cannot establish some consensus in our minds.

By the way, let’s try not to bring in accelerated frames into the discussion.  Correct me if I’m wrong, but my understanding is that SR formulation is meant to hold only in the absence of forces, right?

Regards to all, Bernardo.

Bernardo ~

I also have been following, on ResearchGate, the (seemingly interminable) controversy about the nature of time according to Special Relativity. (To be quite honest: I find it irritating…)

I feel that the the term “time dilation” is terribly misleading and is at the root of all the disagreements. It suggests different things to different people, that is the trouble. It should be thrown out!

                      __________________________________

"I hold these truths to be self-evident...":

(1) When a physicist refers to “time” he means “that which is measured by a clock”;

(2) Therefore, a "clock" can be used to measure the period of time elapsed between two observed events.

(2) According to SR, physical laws are the the same laws in all inertial frames;

(3) Clocks are governed by physical laws. Therefore, according to SR, identical clocks in different inertial frames “tick” at identical rates.

(4) According to SR, the time elapsed between two events is not an intrinsic property of the pair of events. It is a measured quantity that has a different value when measured by identical clocks if those clocks have a relative velocity with respect to each other. (I’m simply referring here to the Lorentz transformation, so I trust that no-one will contradict that?!)

Bernardo ~

You say"

“Correct me if I’m wrong, but my understanding is that SR formulation is meant to hold only in the absence of forces, right?”

 That is not correct. SR is called a “theory” but it is really a framework within which the whole of physics (excluding only gravitation…) can be formulated. SR is quite capable of handling dynamical problems involving forces and accelerations.

 Eric:

Am I right to say then, that time dilation is interpreted by some to mean that time (the dimension) expands, therefore clocks have more time to tick, which is a misinterpretation?  If that’s the case, am I right to say that SR formulation should be interpreted to mean that the frequency of a moving clock increases as a function of relative motion with respect to an identical slower moving clock?

I would be happy to defenestrate time dilation, if I can get some kind of a consensus in this post.  I have already expressed my dislike for it because of its counter intuitiveness.

Let me comment on your self-evident truths:

(1)    I agree. (2) I agree.

(2)    I agree.

(3)    I agree.

(4)    When you say “identical clocks”, do you mean structurally identical but ticking at different rates with respect to each other?

In your opinion, does SR include all types of clocks, such as those I have mentioned?

In regards to your subsequent post, I´m surprised because I didn’t know that SR formulation included forces and acceleration.  I now have researched that it is regarded as a common misconception.  But please let me assimilate things a piece at a time.

Regards, Bernardo.

Dear Valentin ~

 “…what Einstein said in the beginning: it's actually the time that stretches for each system in motion, including the rate of the clocks…”

 The interpretation of the theory that was in Einstein’s mind when the ideas were new even to him should not be taken too seriously. In 1905 he was still thinking things through; still finding his way. Since then much more thought has been applied, by many physicists including Einstein himself, to the meaning of Relativity (it’s implications about the nature of time, the relation between observation and reality, etc). It is my conviction that the simplest, most logical and rational interpretation follows from the four “self-evident truths”.

 You are probably right - the controversy will probably never be resolved because there will always be people who will insist that “the rate of a clock depends on its velocity”. Velocity relative to what? According to Einstein’s SR, there is no absolute reference frame and so no physical quantity can “depend on velocity”. A clock rate could be dependent on velocity only if the mechanism of the clock were interacting with “something” relative to which it is moving. That “something” would be the “ether”, the absolute reference frame. But that is the theory of Lorentz, not Einstein’s theory!! No experimental evidence can distinguish between the “ether” theory of Lorentz and the SR of Einstein. Einstein’s approach is much more elegant and far simpler, that all!

Dear Valentin ~

 “...Not even Einstein's reasoning, in which he considered a particle under constant acceleration to be at an instant equivalent to an inertial frame, that is not correct.”

 I don’t think that’s what Einstein thought. Relativity deals with observations. No-one claims that an accelerated particle is momentarily identical to an unaccelerated particle. It is being subjected to a force, so of course it is different!

In the "elevator" thought experiment we have an accelerated observer. He is acted on by a force (exerted by the floor of the elevator). He is not an “inertial” observer. The idea of his “instantaneous rest frame” is that we can imagine an inertial observer at any given instant (ie, for a “sufficiently small” time period) whose velocity relative to the accelerated observer is zero at that instant. Both observers observe the dynamical behaviour of physical objects in their vicinity. Those objects are not subject to the force producing the acceleration so it is reasonable to assume that the observations of the two observers will be the same.

Dear Bernardo ~

“When you say “identical clocks”, do you mean structurally identical but ticking at different rates with respect to each other?”

I mean structurally identical. Therefore they run at the same rate. That’s what “identical” means. But when a clock is observed by physicist who is moving relative to it, it appears to run slow (when he compares what he’s observing with his own clock which is at rest relative to him).  The “actual’ rate of a clock and the “observed” rate of a clock are not the same thing. The confusion seems to come from lack of appreciation of that.

UNIFICATION of GRAVITATION and ELECTROMAGNETISM 

I unified at Quantum level, Electromagnetism and Gravitation with Ferent equation for the energy of a photon:

E = h × f + a × f

Ferent equation for photon – graviton interaction:

E = h × f + a × f - a × ν

where - a × ν is the negative energy of the graviton

ν is the frequency of the graviton

“I am the first who understood and explained Gravitation with high speed gravitons   v = 1.001762 × 10^17 m/s, with Negative Momentum, Negative Mass and Negative Energy” Adrian Ferent

https://www.researchgate.net/publication/299135595_Ferent_Gravitation_theory

Article Ferent Gravitation theory

It is what it is, time dilation - moving clocks go slow and atoms will oscillate at a slower frequency as  a result of time dilation 

Valentin ~

"Unfortunately the equivalence of frames is not only about observations. It is also about experiments."

Sorry, I can't see the distinction. The result of an experiment is an observation.

When I said "both observers observe the physics of physical objects in their vicinity", those objects can include an experimental apparatus. Admittedly, It is not easy to imagine the two observers, in different states of acceleration, doing the same experiment with the same experimental apparatus in the limited time available while their velocities coincide! But we are not talking here about what can be done in practice. We are talking about "thought experiments" that elucidate matters of principle, not practical matters.

I think I can see what you are trying to say. A “clock” is an example of an “experimental apparatus”. Of course, if a clock is subjected to sufficiently severe acceleration, the forces involved will be expected to disrupt its internal workings so that it would not “tick at the same rate” as an unaccelerated clock. But then the clocks would not be “identical”, as required by the theory! Consider, for example, Cesium clocks, which in actual relativity experiments are assumed to be “identical”. The relevant question would then be “exactly what direct effect does acceleration have on the transition frequencies of an atom?” I can imagine an experiment in which Cesium atoms are put into a centrifuge to see if the observed frequency is different from the one predicted by Relativity. Under extremely great acceleration I would expect a tiny difference from the one predicted by the straightforward (naïve) application of Relativity theory. But that would not be because “Relativity is wrong”, it would be because the atoms have been deformed by inertial forces to such an extent that they are no longer “identical” to unaccelerated atoms. Any such anomalous effect would be the result of a potential energy difference across the diameter of an atom. Intuitively, I would expect such an effect to be utterly negligible, and undetectable,  in all realistic situations.

To all:

I see that we are once more involved in trying to convince each other to understand and accept each other’s interpretation or formulation of SR.  I believe that approach has already been overused at RG with no real consensus.  Consequently, since I am the one seeking understanding and consensus, I am requesting your patience and consideration of my goals to please place your discussion on a common ground that I believe all of us can understand independently of our skills.  This common ground scenario is a computer screen metaphor as follows:

• Reality is presented as images on a computer screen that is wrapped around upon the surface of a sphere of some radius R.
• All motion is constrained to images on the screen. In other words, the motional geometry of Reality is a 2-sphere.
• Observer S, the slow observer, belongs to the presentation and travels around the screen together with Atom S that oscillates with Compton (stationary) temporal frequency f0 and Compton spatial density (frequency) σ0. I use the term spatial density because it gives me a sense of substance that I can then equate to the concepts of mass, energy and momentum.
• Observer F, the faster observer, belongs to the presentation and travels around the screen together with Atom F that oscillates with Compton (stationary) temporal frequency f0 and Compton spatial density σ0.
• Both Atoms F and S are identical and oscillate at the same stationary frequency and are both travelling on the same geodesic of the screen.
• Observer A, the absolute observer, is external to the screen and is stationary in reference to the screen. He is measuring time with his own Atom A oscillating with Compton frequency f0 and spatial frequency σ0

The following are my present observation on the screen metaphor.

I would first like to agree on the metaphorical scenario so that you can then express your answers to my question under its terms.

Remember, we all have different ways of visualization, so please try to remain within the metaphor so that I can understand your answers better.

Have fun, Bernardo.

I'm having a problem understanding this string of posts. My understanding is that electromagnetic theory did not conform to the Galilean transformation which assumed absolute space and absolute time. Henrik Lorentz came up with a transformation that, for example, explained why a charge moving in the vicinity of an electric current felt an electric field. Electromagnetic theory has been incredibly successful. Einstein felt that all laws of physics should be the same for observers in different local inertial frames of reference. Why should Newton's laws of motion obey Galilean transformation while Maxwell's laws obeyed a different, Lorentzian, transformation?  The Lorentz transformation is the source of time dilation and length contraction. So, if you trash these concepts, what are you going to replace Maxwell's equations with?

Danci,

Maxwell's equations do obey the Lorentz transformation. An observer (say an electric charge) at rest next to an electric current does not detect an electric field. An observer moving parallel to the current does. This is described by the Lorentz transformation. If no transformation is needed then a charge moving parallel to a current would not experience a force. But it does. I have yet to see a situation where the Lorentz transformation fails. I don't know what "LET" is, but i suspect it is a theory based on the idea of an "ether". In modern physics there is no need for an ether. Particle accelerators can be designed perfectly well with special relativity. Unless i see some experimental evidence contradicting special relativity, i'm happy with it.

Experiments to test Ferent Gravitation theory!

In the double slit experiment the interacting observer is an instrument, detector…

My experiment is: if you replace the detector with a piece of metal the wave will collapse into a particle because of my theory photon – graviton interaction:

Ferent equation for photon – graviton interaction:

E = h × f + a × f - a × ν

where - a × ν is the negative energy of the graviton

ν is the frequency of the graviton

Here we know the frequency of the photon f and the frequency of the graviton f. With different metals we have different frequencies of the graviton ν.

A lot of experiments can be done, and will result a lot of data!

Ferent gravitation theory explains the double slit experiment!

https://www.researchgate.net/publication/299135595_Ferent_Gravitation_theory

You can read on my theory:

Decoherence explained by my theory

The electromagnetic wave is the superposition of 3 sinusoids; this means the electromagnetic wave will be collapsed by the presence of an electric field, of a magnetic field, of a gravitational field, by another electromagnetic wave… 

In my electromagnetic theory, gravity does collapse quantum superpositions, gravity bends light because light has 3 sinusoids, has a gravitational sinusoid!

In Maxwell electromagnetic theory, gravity does not collapse quantum superpositions, gravity does not bend light, because light has only 2 sinusoids!

So decoherence is due to the gravitational field, for example to the gravitational waves generated by the observer in the double-slit experiment.

Article Ferent Gravitation theory

``Time dilation. By this I mean the local or nonlocal dilation of time (of the dimension) itself, where the concept of time is not invariant to motion

Clock frequency increase. In the case of natural clocks such as atomic clocks, in contrast to mechanical clocks, the frequency of clocks (number of clicks/time-cycle) varies with local motion. In this case, the concept of time is absolute (nonlocal) and invariant to local speed.''

Let me try to comment on that question, and not on STR.

First I find a difficulty in the second part of the question: why is a distinction made between atomic clocks and mechanical clocks? In fact, although quartz clocks, for example, are not presently accurate enough to detect relativistic effects, there is little doubt that their frequency is affected by motion in exactly the same way as atomic clocks. The reason for this belief is the principle of relativity: were it otherwise, then it would be possible to detect uniform rectilinear motion by seeing whether a given quartz clock goes at the same rate as an atomic clock that is at rest with respect to it.

So, if the principle of relativity is to be satisfied, different clocks moving at a given speed v cannot go at different rates. This goes against what Thierry says. Since electromagnetism is in fact fully covariant (something Thierry seems to deny, but I cannot fathom his reasons for doing so) this will in fact be true of arbitrary electromagnetic clocks. And again, it will extend to any clocks that can be described via a Lorentz invariant theory.

So what happens is that, if we believe we have merely clock frequency increase, then all clocks at the same speed are slowed down by *exactly* the same factor.

But then, how do we define time? Time is a numerical quantity. As a physicist, I am happiest with a definition that leads to a way of determining this quantity numerically. But I know no other way to determine time than to consult a clock. This being so, the universal change of rate of clocks leads me to think that it is impossible to distinguish this from a change in the rate at which time itself proceeds.

This is getting ridiculous. I'm outta here.

Not talking about you, Leyvraz, just some of the other nut cases involved in this stoopid thread. I have better things to do.

F. Leyvraz,

Thanks for taking the time to answer my question.

First of all, I would like to make clear that like apparently a lot of other members of RG, I have preconceived ideas on the interpretation of SRT that differ in very radical ways. Needless to say, I was very surprised to find that out, thus the reason for my question and for my effort to find some common ground and consensus on the subject.

I made the distinction between atomic and mechanical clocks because I wanted to simplify the scenario thinking that mechanical clocks, with levers, gears, friction, rotating parts, pendulums, etc. would tend to blur the question, but the distinction, as you have pointed out, is probably not really relevant to the question.

By the way, defining time as the number of ticks of clock is fine with me.

In terms of my computer screen metaphor that simulates Reality exactly:

Bernardo.

Bernardo ~

Q1: Does Atom F (the Faster moving clock) according to Observer A, as referenced by Atom A (the absolutely motionless clock) tick faster or slower than Atom S (the slower moving clock)?

A: Slower

Q2: Does Atom S according to Observer F as referenced by Atom F, tick slower or faster than atom F?

A: Slower

Q3: Does Atom F according to observer S as referenced by Atom S, tick slower or faster that Atom S?

A: Slower

Faster moving clocks always appear to be “ticking” slower than slowly moving clocks (a straightforward consequence of the Lorentz transformations). All the phrases in bold face here emphasize that this is an artifact of the process of observation. It’s how things seem to an observer - an illusion. Nothing bizarre is really happening to any of the clocks. That’s what a lot of people don’t seem to get… :-)

 A simple analogy: If we look at each other through a magnifying glass, I appear bigger to you and you appear bigger to me. It is an illusion created by the properties of light. “Time dilation" is, similarly, an illusion created by the properties of light…

Eric:

You just blew my mind!

According to your interpretation of Time dilation, all “Faster moving clocks always appear to be “ticking” slower than slowly moving clocks…” and “Time dilation is an illusion”.  Even to our hypothetical absolutely stationary observer?

Explain to me then how clocks and observers moving with the clocks, gain mass, and energy with increasing velocities?

I would think that an increase in total energy can only be due to an increase in total mass and total frequency, be it Compton or de Broglie.  Unless you are saying that an atom's Compton or de Broglie frequencies are not related to its energy or that mass and energy gains are also an illusion?

Please explain,

Bernardo.

Eric,

It is not that they gain mass it is that the perception is that they gain mass.  The idea goes back a long way but it has been made something it is not suppose to be. 

If I move mass faster and faster the kinetic energy of the mass increases and there for by E=MC2 the mass increases.  Depending on the frame of reference as to how much.  You see it is a mess.

"Explain to me then how clocks and observers moving with the clocks, gain mass, and energy with increasing velocities?"

They don't!

Observed energy and mass of a moving object, like observed clock rate, appear different to different observers. The "actual" mass (energy) of a body is its "rest mass" − the mass that would be measured by a hypothetical observer at rest relative to it. That doesn't change − it's an invariant.

The observer-dependence of frequency shouldn't be surprising. We have a version of that even in classical (pre-Einsteinian Relativity) physics − it's called the "Doppler effect" (-;

Professor Wolfgang Rindler in his textbook on relativity has a great example explaining how observers with different motions can claim other clocks are ticking more slowly. He imagines two spaceships passing each other in opposite directions with each ship having an observer in the nose and tail. The observers note the times of their clocks and the clocks of the other observers as they pass.  When they examine and compare the times, each pair of observers concludes the other spaceship has been length contracted and time dilated.

This brings up an important point: the relativistic Doppler shift.  When you are moving away from a clock, the Doppler shift makes it appear to be running slower, but if you approach a clock it appears to be running faster, even though, in your rest frame, the other clock is moving and you aren't. So where's the time dilation?

Time dilation and length contraction are local observations. They are manifest when a "stationary" observer records times of clocks in a moving frame of reference as they pass her by.  (And close enough that the transverse Doppler effect is negligible.)

Ignoring the local nature of the Lorentz transformation has led to some errors. For example, the conventional wisdom is that an observer traveling parallel to an electric current sees an electric field because of length contraction of the ions versus the charge carriers, since they are moving at different speeds, supposedly creating a net linear charge distribution on the wire carrying the current. This misconception ignores Coulomb forces and is due to considering a global Lorentz transformation to an extended frame of reference where the electric field lines are radial with respect to the wire.

However, the field lines depend on the local motion of the observer. If an observer moving parallel to a current changes direction ever so slightly, the field lines he sees will no longer be exactly radial. The real reason an observer traveling at a velocity with a component parallel to a current detects an electric field is because of the relativity of simultaneity, not length contraction. This has important consequences for paradoxes like the one Masud Mansuripur has posed. I have written this up in a paper that is now under review.

George ~

"You see it is a mess."

No, I don't see see it is a mess. I see it is simple and elegant. I see people making a mess out of it!  (-;

Eric,

You are correct they do make a mess out of it.

Charles,

I understand proper time, proper distance and invariant mass m0, but tell me then what is relativistic mass mr and why do we still talk about the mass-momentum relation E2=(pc)2+(m0c2)2?  Isn’t there a relativistic mass mr involved in the (pc)2 and the E2 terms?

So is it just that, what I call mass is the relativistic mass and what you call mass is the invariant mass?

Eric:

Ditto to what I said to Charles.

OK, the Doppler Effect is similar in that there is a shift in frequency, but the relation of the shift to velocity is not even close, as you well know.

By the way, I´m not contradicting, I'm trying to understand in my own terms.

Charles,

I don’t have a problem accepting that relativistic mass is a misleading name for energy.  I very much dislike the concept of mass in general, but why do you think that invariant (rest) mass is not a misleading name for rest energy? Which leads to the question, can we talk about rest energy and relativistic energy?

Charles, OK i won't cross over his bridge. There was an interesting discussion a few years back, i believe in the Letters section of Physics Today, about whether or not there was such a thing as relativistic mass. What is involved is the spatial relativistic momentum given by gamma X mv, where gamma is the Lorentz factor, m is the rest mass, and v is the speed.  So, should one consider gamma to be the coefficient of mv, the nonrelativistic spatial momentum, or just of m? This was sort of like the mathematical version of a semantic argument to me, but tempers did get heated.

I don't know if this has been mentioned or not, but you can write E = mc2 = hf, where f is the frequency of a photon. Then the photon's "rest mass" is hf/c2.  This comes to play in pair production. It also shows that the photon's momentum is hf/c. I'm sure most of the contributors here are well aware of this.

Gosh, Bernardo, what would you replace mass with in physics? Talking about Newtonian physics for a moment, mass and energy are just something physicists have defined.  Gravitational mass is defined by Newton's law of gravity. Inertial mass by F = dp/dt where p= mv.  (Galileo showed them to be proportional. Einstein showed them to be the same.) If these definitions are consistent with what you see in nature, then what's the problem?

You can define kinetic energy from Newton's laws of motion and the definitions of speed and acceleration. But first you have to define work as force F times distance d. With that definition you can show mathematically that the work done on a mass by a single force is Fd = 1/2mv2, where v is the speed of m after the force quits working. However, the work has been done, the force is no longer in play, yet the mass still has the 1/2 mv2. What is this quantity? Physicists say. "Let's call it kinetic energy, the energy of motion." Work is then viewed as a process that converts one form of energy (whatever supplied the force, e.g., chemical energy) to another.

Gravitational potential energy can be defined also by doing work in lifting a mass. Here we save the conservation of energy by saying the force stored energy in the gravitational field, capable of being released as kinetic energy when you drop the mass. Another definition. Physicists love definitions, but they are only so good insofar as they produce useful results.

Professor Wolfgang Rindler in his textbook on relativity has a great example explaining how observers with different motions can claim other clocks are ticking more slowly. He imagines two spaceships passing each other in opposite directions with each ship having an observer in the nose and tail. The observers note the times of their clocks and the clocks of the other observers as they pass.  When they examine and compare the times, each pair of observers concludes the other spaceship has been length contracted and time dilated.

Unfortunately this is heavily disputable. The affirmation according to which equally accelerated twin oscillators, if they started in sync, after a while, when the acceleration ceases, they may present a shift in their gauges which is proportional to the acceleration and the duration of the acceleration phase, is something which does not make sense at all.

It is like having the same clock which started from two different points in flat space time and followed always the same law of motion. At the end presents different value if started at the first point than if started from the second point. 

It is not an acceptable result from SR and this can only determine a limit in the application of special relativity not a verified prediction.

Bernardo,

the time dilation or time retardation of two atomic clock is something which occurs everyday in GPS systems and can be verified easily in static gravitation with accurate devices.

The only reason why two atomic clocks delay is because there have been a difference between them in their energy per unit mass integrated in a certain interval of time. This difference of energy can be kinetic or/and potential.

Stefano,

You seem to think that I am disputing time dilation, I’m not.  I’m trying to understand how it can be apparent as Eric stated.

I know that GPS clocks are experimental proof for time dilation, that’s why I don’t understand why Eric says it is apparent.

I you let a GPS clock take a few laps around the earth, not correct it and then bring it back, will it still be synchronized?

If it’s still synchronized, I can begin to suspect that time dilation is apparent, but I would have to investigate if the process was not somehow reversed on the way back, before I conclude it apparent.

Another point is that I thought time dilation was interpreted to mean that the time dimension itself expanded and therefore the clock had more time to tick thus increasing its frequency, which according to Eric is not the case, the clock actually shows a lower frequency because it somehow stretched with the dimension and then he goes on to say that it’s all apparent.

Do you see now why I feel side whacked?

F. Redfern,

I feel that mass is a mathematical device that has been anthropomorphized to the extent that it has become counterproductive to the point that motion seems unexplainable without it.

I have found that motion can be explained by expressing motional relations in terms of only the wave properties of matter (wavicles) and have written various monographs that, at least to me, explain motion in a more intuitive fashion, including SRT.  It is for this same reason that I seek the accepted, hopefully consensual, interpretation of SRT, to make sure that my wavicle derivation of it is in concordance.

@ Bernardo

Just few weeks ago I had raised the same question with different examples. But none conclusive result could be obtained. People give justification that it is experimentally verified and well tested. But the underlying question is that it does not fits our intuition. See, https://www.researchgate.net/post/Twin_paradox_Measurement_of_time_in_special_relativity

Here is how I interpret SRT from a wavicle point of view:

With the above in mind:

• Length contraction means wavelength contraction.
• Time dilation. If the wavelength of a wavicle contracts because of the Lorentz Transformation (LT), the ST relation (λf=c0) must hold, therefore its frequency must increase correspondingly. In this sense time dilation can be interpreted to mean that time increases, therefore more ticks can occur.
• If a wavicle’s frequency increases because of the LT; its mass, energy and momentum must also increase.

Comments:

• All wavicle property transitions are real from an absolute point of view and apparent from a relative point of view.
• Structural problems originating from the rigidity of particle properties are obviated.
• SRT paradoxes can be resolved.
• All LTs remain intact.

Regards, Bernardo.

Bernardo,

As your RG question is a kind of Quiz on the subject, please find hereunder my answers to your 3 reformulated questions :

Q1: Does Atom F (the Faster moving clock) according to Observer A, as referenced by Atom A (the absolutely motionless clock) tick faster or slower than Atom S (the slower moving clock)?

A: Slower

Q2: Does Atom S according to Observer F as referenced by Atom F, tick slower or faster than atom F?

A: Slower

Q3: Does Atom F according to observer S as referenced by Atom S, tick slower or faster that Atom S?

A: Slower

They are the same as those given by Eric Lord one day ago. According to my understanding of the subject, they are in perfect line with the principle of relativity as updated by Special Relativity.   

Guibert,

Do you agree with Eric that “It’s how things seem to an observer - an illusion. Nothing bizarre is really happening to any of the clocks.”?

Even for Observer A, the hypothetical absolute observer?

This leads me to two more questions.  In your opinion, for which of the physical properties are the LTs real?  And can you explain to us in non mathematical terms why you think the transformations are real/apparent?

Thanks, Bernardo.

Bernardo,

Yes , I fully agree with Eric that “It’s how things seem to an observer - an illusion. Nothing bizarre is really happening to any of the clocks.” (even for Observer A).

Concerning the two other questions, my meaning is very practical (I'm an engineer). One should not speak of LTs real of apparent. Physical measurements are real. The only problem is to secure coherence of physical laws in different reference frames (= for different observers).

Since Galileo, we have the relativity principle : you cannot make difference between inertial frames  (systems of coordinates) at rest or in constant rectilinear motion with respect to one another. Everyday life measurements (e.g. of time) in one inertial frame can then be converted into measurements in another by a Galilean transformation.

The 1905 Einstein updating of Galilean relativity principle ("On the electrodynamics of moving bodies"-"Zur Elektrodynamik bewegter Körper" - Annalen der Physik, Sep.1905) is just saying that this is no longer sufficient when one of the inertial frames is approaching the speed of light «c » . Then you have to take account of the constancy of « c » in all inertial frames (an Einstein postulate based on the results of Michelson-Morley experiment) and make the conversion using Lorentzian transformation.

So « nothing bizarre is really happening ». It is just a question of correctly converting descriptions of physical observations from one inertial frame to another one in all encountered cases (even when approaching « c »).

Dear Bernardo

"Stefano,

You seem to think that I am disputing time dilation, I’m not.  I’m trying to understand how it can be apparent as Eric stated. I know that GPS clocks are experimental proof for time dilation, that’s why I don’t understand why Eric says it is apparent.

I you let a GPS clock take a few laps around the earth, not correct it and then bring it back, will it still be synchronized? If it’s still synchronized, I can begin to suspect that time dilation is apparent, but I would have to investigate if the process was not somehow reversed on the way back, before I conclude it apparent."

If I let a GPS SAT take a few laps around the earth without any correction on the clock rate of its atomic clock aboard, the GPS clock will increase the time dilation with the clock on the ground progressively.

Time dilation intended as clock retardation is not apparent at all. It is testified even for atomic clocks which are one upon the other separated by 1 meter (this is possible after 2005, you have to have a accuracy lower than 10-13), there you can directly see the gauges of the clocks which at a certain point present differences in their digits, different digits at the same time.

What GR and SR cannot include is the absolute simultaneity, because in principle such property cannot be measured (the quantum entanglement can though) because everything is mediated by the speed of light . it would be impossible, relying on the speed of light to measure two events spatially distant at the same time. On the contrary we have to accept the presence of simultaneous events, like the accelerated points of the wheel from the central shaft.

Stefano wrote, "Unfortunately this is heavily disputable. The affirmation according to which equally accelerated twin oscillators, if they started in sync, after a while, when the acceleration ceases, they may present a shift in their gauges which is proportional to the acceleration and the duration of the acceleration phase, is something which does not make sense at all."

First, yes SR does predict some things that are hard to believe, but i have a 30 year career in physics, and i haven't heard of any heavy dispute about this. Secondly, I guess this means you reject the twin paradox. (In my opinion the acceleration part  in the explanation of this paradox is a bit overdone,but still important.) Here's my explanation of the twin paradox.

Let's say you are an alien traveling close to the speed of light, passing Earth on the way to the center of the galaxy. Do to length contraction in your frame of reference the whole galaxy would be shorter in your direction of motion, although, of course, all you can see are the photons you detect at any given time. If you are traveling at 99.999999% of the speed of light, this contraction means the center of the galaxy is only 42 light years away for you, whereas, for the Earth you are passing, it is 30,000 light years distant.

Since you are traveling at almost the speed of light it takes you just a smidgen over 42 years to travel the 42 light years and get to the center of the galaxy. However, according to Earth's population (who have followed you on the Trump Beyond Huge Telescope), it has taken you 30,042 years.

Now say just as you get to the center of the galaxy, another spaceship passes you by in the opposite direction, also traveling at 99.999999% of the speed of light. In the reference frame of this alien, the Earth is 42 light years away. It takes her 42 years to reach Earth, whereas the Earth, again using the TBHT, sees it takes her 30,042 years.  So no acceleration has occurred, yet the sum of the two alien clocks is 84 years. Earth clocks record 60,084 years for this scenario to work out.

However, if you thought the other alien was really hot, you might beam over to her spaceship. This would be your acceleration as you just changed direction. Say you beamed over when the ships were just abreast. Your clock will read 84 years when you pass Earth.

How would you view the Earth clock if you came to a stop at the galactic center? It has been incredibly red shifted from your perspective, and when you look at it (having a powerful alien telescope) it reads 42 years, the same as your clock! However, you know you are 30,000 light years from Earth, so, extrapolating back, you infer that on the Earth the clock must read 30,042 years

Returning toward Earth, the Earth's clock is incredibly blue shifted such that another 30,042 years passes by on that clock by the time you reach Earth. You are traveling back into a signal already emitted. It is different for those on Earth, since they aren't looking at signals already emitted. In fact, since you are traveling close to the speed of light and almost keeping pace with your light signals (in the Earth's reference frame), your light signals arrive shortly (42 years) before you do, and they see 42 years has gone by on your clock since you left the center of the galaxy, making 84 years for your round trip by their reckoning of your clock. This is the twin paradox effect of your acceleration upon changing directions at the galactic center.

Both time dilation and length contraction follow directly from the Lorentz transformation. So, if you believe in the Lorentz transformation, you have to believe in these two effects. If you don't believe in the Lorentz transformation, you are going to have to come up with a new set of equations to replace those of Maxwell and explain why Maxwell's equations aren't valid but we still have electrical and electronic technology based on them. Maxwell's equations transform in time and space according to the Lorentz transformation. Now we know the other laws of physics do also.

Francis,

"First, yes SR does predict some things that are hard to believe, but i have a 30 year career in physics, and i haven't heard of any heavy dispute about this. Secondly, I guess this means you reject the twin paradox. (In my opinion the acceleration part  in the explanation of this paradox is a bit overdone,but still important.) Here's my explanation of the twin paradox."

The space ship paradox or bell paradox is strictly connected to such problem relevant to equally accelerated frames and such paradox has been discussed many times till recently.

The twin paradox does not have anything to do with the equally accelerated frames I'm afraid it has to do with a inertial reference frame and one accelerated frame. If somebody still sustains that it is the acceleration which is responsible of the time dilation DIRECTLY, then it is difficult to explain why in 99,9 percent of the cases it is the difference in kinetic and potential energy, like for GPS to dictate the time dilation. And so far there are not experimental demostration that acceleration by itself is a direct reason for time dilation.

In that case (equally accelerated frames) the time dilation is only apparent.

Sorry, Stefano and Valentin, but you guys are out of your freakin' minds. Take a physics course and don't call me in the morning. Physics thankfully progresses without you. I hate to be sarcastic, but this thread is toast as far as i'm concerned.

Dear Valentin ~

To express observed physical laws mathematically one can choose:

either

(1) one can insist on an “absolute” reference frame but retain Newtonian dynamics in all reference frames. Reference frames are then related to each other through the Galilean transformations. Maxwell’s electromagnetic theory then has its familiar form only in the “absolute” frame but looks very different (and very complicated) in a “non-absolute” frame

or

(2) one can deny the existence of any “absolute” frame and retain the form of Maxwell’s electrodynamics in all frames. The transformation law between equivalent frames is then a Lorentz transformation and Newtonian dynamics has to be modified accordingly.

 If I’ve understood you correctly, your point of view corresponds to choice (1). Einstein’s Special Relativity corresponds to choice (2).

 I am willing to concede that the two choices may be, in some sense, equivalent: not distinguishable by experiment and observation. It's not a question of "right or wrong", "true or false".

 Choice (2), if properly interpreted, is mathematically simple and elegant, and conceptually satisfying. Choice (1) would lead to a mathematical and conceptual nightmare if followed through in detail. It’s not worth the effort involved.

OK, one more comment before disappearing. In Texas we have this saying, "All hat and no cattle." I think this applies to a lot of the opinion expressed in this thread. Eric Lord definitely has an extensive ranch. Most of you other guys need to round up some mavericks.

Francis,

Lorentz transformations are right but alone do not account for any time dilation. I'm afraid that years of physics did not help you much to clarify crucial points. It is enough to read Feynman to show that your view point is Not correct.

OK Valentin ~ I stand corrected:

The choices (1) and (2) are not the only possibilities. Lorentz developed a third approach. He accepted the existence of an “absolute frame” − the frame in which the “ether” is at rest. He postulated interactions between the ether and material objects that would render the “absolute frame” (the “ether”) experimentally undetectable. (That was after all what he set out to do − to explain the result of the Michelson-Morley experiment.) This led him to the discovery of the transformation laws now known as “Lorentz transformations".

 I’m not very familiar with the details of Lorentz’s theory, but what bothers me about it is this: if something is in principle undetectable by experiments and observations, how can one claim that it physically exists?

 I really am sincerely convinced that what you are attempting is “not worth the effort”. You will not convince me otherwise and, reciprocally, I cannot expect to convince you. So I won’t get into an argument; that would be a pointless waste of your time as well as mine.

 There is however just one question I want to ask, to satisfy my curiosity:

 in what way is your theoretical approach different from that of Lorentz?

                       _______________________________

(Incidentally: I see that somebody down-voted your previous comment. It wasn’t me!)

Forgive me for violating my pledge, but for Valentin's edification, i have traveled all over the world and lived in Pakistan and Arabia and even learned the languages (to some extent, at least). (This is a physics thread?)

il mumlika il-'arabia iS-Sa'udia

Francis,

let alone any personal comment about people this attitude is something I usually avoid unless somebody else begins to do make unnecessary appreciations . How could you possibly state a time dilation using LT alone? Who is the one who is moving respect to whom? Clock retardation is not something like speed which is relative due to how it has been defined.Clock retardation is something which if occurs it involves the gauges of atomic clocks and here there is no room for saying that one sees the other delayed and viceversa. With the LT you can only derive the Relativistic Doppler Effect, you cannot state which is delayed respect to which. You have to have an inertial observer and a non inertial one, or two RFs with a different hystory of motion (FEYNMAN, FOCK, PENROSE).

``Clock retardation is something which if occurs it involves the gauges of atomic clocks and here there is no room for saying that one sees the other delayed and viceversa.''

This seems to be the problem for several people. We really must distinguish two cases:

1) The two clocks are in uniform motion one with respect to the other (at least over the time of observation, in which case it really does not matter whether it was accelerated earlier). Then there is no symmetric way to compare the rates of two clocks, and it is really possible to say that the slowing down happens symmetrically. The point is that, two measure the relative rate of moving clocks A1, A2 ... with respect to clocks at rest B1, B2 ... can be done in several ways. For example, let one single clock, A1, fly past several B clocks (B1, B2, ...). The measurements of the B clocks allow to determine the rate at which the A clocks operate, and will show that the A clocks are slower than the B clocks. But if you now look at the same data, but view the A clocks as being at rest and the B clocks to be moving, the set up is different, since we are having several clocks flying past one single resting clock. In that case, one finds that the moving clocks move faster than the resting ones, due to desynchronisation.

2) The clocks are not in uniform motion. Then it is possible to compare one and the same pair of clocks twice. We then see that if one of the clocks is inertial and the other one not, then the noninertial clock will show the smaller time. There is then no problem of the two clocks being symmetric: as Valentin correctly emphasises, accelerated frames are not equivalent, so there is no reason to expect any kind of symmetry in that case.

Yes Charles this way you are falling right into Dingle's exceptions, you affirm that you Just make it impossible to let one clock delay. It is Not relative motion which determines the clock retardation. It is the difference of energy per unit mass and this is defined with An initial Common reference frame where systems start. In any other cases the problem cannot be determined it is Ill posed.