SR with Apparent Simultaneity

[xyzt]

In this paper I'm talking about simultaneity, not synchronization

I know, this is why I pointed out that you are mixing up the two concepts.

 

 

"In the definitive work [1] on special relativity (SR), Albert Einstein acknowledges

that an assumption is required in order to define a common time between

two events at separate respective locations A and B. To answer this, Einstein

defines what is now called standard simultaneity, establishing that the time

required for a light signal to travel from A to B is the same as the time required

for a signal to travel from B to A. While it is generally acknowledged that

this remains an assumption, it is consistent with observation and is used in the

physical representation of time throughout modern physics. Einstein justifies

the definition by its practical benefit of independence of observer standpoint

with the clock, but it is tempting to presume that the definition has a

fundamental physical basis, since it is consistent with observations of an

invariant speed of light and with a classical interpretation thereof."

 

Yet, your confusion persists. You are just repeating the same error I already pointed out: you are mixing up "Einstein synchronization method" (what you are trying to describe, incompletely) with what you call Einstein "standard" simultaneity (a non-existent term; based on the description and your intentions, the correct term would be "relativity of simultaneity"). If this is what you want, your description is wrong.

Edited December 17, 2013 by xyzt

[Cap'n Refsmmat]

Yet, your confusion persists.

I'm not sure this is an effective way of correcting it.

[xyzt]

I'm not sure this is an effective way of correcting it.

I already corrected the same exact errors earlier (twice), I corrected it again following your suggestion. So, this is the third time I correct his same exact errors.

Edited December 17, 2013 by xyzt

[md65536]

Yet, your confusion persists. You are just repeating the same error I already pointed out: you are mixing up "Einstein synchronization method" (what you are trying to describe, incompletely) with what you call Einstein "standard" simultaneity (a non-existent term; based on the description and your intentions, the correct term would be "relativity of simultaneity"). If this is what you want, your description is wrong.

Relativity of simultaneity is the concept that observers in different reference frames generally measure a different simultaneity of events. That is not at all what I'm speaking of here.

 

In SR, for a given inertial observer, there is a definite simultaneity of events. For observer O in an inertial reference frame, two events are either simultaneous or not. Einstein provided a definition that determines whether two separate events are simultaneous. This definition can be used to define Einstein synchronization of clocks. However, the definition of simultaneity applies whether it's used to set clocks or not. You can say for certain in SR whether two events are simultaneous for a given inertial observer using Einstein's definition, without needing to synchronize any clocks.

 

Other people have argued that Einstein's definition of simultaneity is not unique. This is usually debated as "conventionality of simultaneity". Some people (Reichenbach and Grünbaum notably) have argued that simultaneity is conventional, and often involving a different speed of light on each leg of a return trip of light. Other people argue that simultaneity is unique, and usually base this argument on a set of "reasonable" assumptions, which usually involve Einstein's assumption of equal timing of both legs of a return trip. It doesn't really matter I think, because the whole conventionality argument turns out to be pointless with respect to the contents of my paper. Einstein's definition is the simplest and most useful that I've found.

 

 

What I'm describing in the intro is "standard simultaneity". The term is used in the following places:

 

Uniqueness of Simultaneity, Domenico Giulini. http://arxiv.org/abs/gr-qc/0011050

Conventionality of Simultaneity, http://plato.stanford.edu/entries/spacetime-convensimul/

Apparent Simultaneity, Ben-Yami, Hanoch, http://philsci-archive.pitt.edu/3260/

 

 

Even if "standard simultaneity" is not a common enough phrase, I explained what it means.

 

The concept of simultaneity is clear in SR. I don't think I have to explain it all. Einstein states that an assumption is required. He establishes by definition that the time required by light to travel from A to B is equal to the time required for it to travel from B to A. These statements are true! Given the other postulates and assumptions of SR, standard simultaneity as I've described it is a sufficient and a necessary assumption to uniquely define simultaneity per inertial frame.

 

 

I've left out the rest of the details of SR from the first paragraph of the intro. If you read past it, you'll see that all of the relevant details and assumptions that I need are stated.

Edited December 17, 2013 by md65536

[xyzt]

Relativity of simultaneity is the concept that observers in different reference frames generally measure a different simultaneity of events. That is not at all what I'm speaking of here. In SR, for a given inertial observer, there is a definite simultaneity of events. For observer O in an inertial reference frame, two events are either simultaneous or not. Einstein provided a definition that determines whether two separate events are simultaneous. This definition can be used to define Einstein synchronization of clocks.

Einstein clock synchronization method has nothing to do with simultaneity of events. As the name says it, it is a method of synchronizing clocks (there are others). None of them has anything to do with the definition of simultaneity. Simultaneity has nothing to do with light propagation, this is why I recommended that you buy the Zhang book. It is really simple, if the transform for time is :

 

[math]t'=\alpha t+\epsilon x[/math]

 

then, a time interval [math]dt[/math] between two events transforms as:

 

[math]dt'=\alpha dt+\epsilon dx[/math]

 

If the events separated by a distance [math]dx \ne 0[/math] are simultaneous in one frame , F, ([math]dt=0[/math]) then, in any other frame F':

 

[math]dt'=\epsilon dx[/math]

 

[math]\epsilon dx[/math] encodes the amount of lack of simultaneity between the two events in frame F', nothing to do with "the time required by light to travel from A to B is equal to the time required for it to travel from B to A.". You keep persisting in your confusions in an attempt at justifying your paper.

Some people (Reichenbach and Grünbaum notably) have argued that simultaneity is conventional, and often involving a different speed of light on each leg of a return trip of light.

Experiment rules out this hypothesis, we already talked about this in the first posts. The only part that is true is that indeed, the concept of simultaneity is conventional (and, as such, not testable, there are no tests for relativity of simultaneity).

Edited December 17, 2013 by xyzt

[md65536]

[math]\epsilon dx[/math] encodes the amount of lack of simultaneity between the two events in frame F', nothing to do with "the time required by light to travel from A to B is equal to the time required for it to travel from B to A.". You keep persisting in your confusions in an attempt at justifying your paper.

I am quoting from the paper that I cited. It is written by Einstein. I quote the defining assumption upon which his definitions of time, simultaneous, and synchronous are built.

 

You can use SR consistently without understanding the assumptions used to define it. I am examining one of those assumptions.

 

Experiment rules out this hypothesis, we already talked about this in the first posts. The only part that is true is that indeed, the concept of simultaneity is conventional (and, as such, not testable, there are no tests for relativity of simultaneity).

You're mixing your terms. Relativity of simultaneity is confirmed by experiment.

Edit: No particular definition of simultaneity is confirmed, but it is confirmed that absolute simultaneity of events is not physically possible.

 

Anyway I don't argue in favour of conventionality of simultaneity. It is irrelevant for my paper; standard simultaneity is uniquely defined whether or not it is conventional, and apparent simultaneity is unique whether or not it is conventional. I see no point in considering both relativity of simultaneity and conventionality of simultaneity separately. This point is addressed in the paper. Relativity is essential. Conventionality is not.

Edited December 17, 2013 by md65536

[xyzt]

I am quoting from the paper that I cited. It is written by Einstein. I quote the defining assumption upon which his definitions of time, simultaneous, and synchronous are built.

 

You can use SR consistently without understanding the assumptions used to define it. I am examining one of those assumptions

You are a prime example of that.

 

 

You're mixing your terms. Relativity of simultaneity is confirmed by experiment.

 

False. Since you think otherwise, I challenge you to cite the experiment that "confirms" relativity of simultaneity. Please.

 

 

Anyway I don't argue in favour of conventionality of simultaneity.

I didn't say you did, what I said is that you are mixing simultaneity with clock synchronization methods. You still persist in this error, even after all the information I provided you with.

 

 

 

It is irrelevant for my paper; standard simultaneity is uniquely defined whether or not it is conventional, and apparent simultaneity is unique whether or not it is conventional. I see no point in considering both relativity of simultaneity and conventionality of simultaneity separately. This point is addressed in the paper.

 

I am pointing the errors in your paper. You cannot answer by saying "look at my paper, I am right". This is a standard crackpot type of response. Tell you something, why don't you submit your paper to a peer reviewed journal, let us know when you get an acceptance. I am done trying to correct your misconceptions, I see no point in trying to educate you. I would still like an answer to my challenge above.

Edited December 17, 2013 by xyzt

[md65536]

I am pointing the errors in your paper. You cannot answer by saying "look at my paper, I am right". This is a standard crackpot type of response. Tell you something, why don't you submit your paper to a peer reviewed journal, let us know when you get an acceptance. I am done trying to correct your misconceptions, I see no point in trying to educate you. I would still like an answer to my challenge above.

Your challenge is off topic! Fine, I retract my statement that relativity of simultaneity is experimentally confirmed. Is it enough to state that relativity of simultaneity is a theoretical consequence of SR? Would you accept that?

 

Do you have a suggestion for a peer review journal that would be appropriate to submit this to?

[xyzt]

Your challenge is off topic! Fine, I retract my statement that relativity of simultaneity is experimentally confirmed.

How can my challenge be "off topic" since you made a false claim? A claim that you are now retracting as false.

 

 

 

Is it enough to state that relativity of simultaneity is a theoretical consequence of SR? Would you accept that?

 

Yes, I just explained that to you in an earlier post. Why are you trying to make it look as if I am disagreeing with this?

 

 

Do you have a suggestion for a peer review journal that would be appropriate to submit this to?

 

Try Philosophy of Science and/or Foundations of Physics. Let us know what they answer.

Edited December 17, 2013 by xyzt

[phyti]

md65536

 

I could not follow your reasoning on the subject. It seemed too complicated for such a simple idea. I lose interest in any logical arguments with a high content of 'lemons', and cannot offer an opinion.

[md65536]

I could not follow your reasoning on the subject. It seemed too complicated for such a simple idea. I lose interest in any logical arguments with a high content of 'lemons', and cannot offer an opinion.

Thanks for trying. The idea is simple but proving correspondence with SR is complicated. It could probably be done much simpler.

[md65536]

Has anyone else (historically) proposed a unification of relative simultaneity and measurable delay of light? Wouldn't such a model be a valuable simplification, if it was consistent with SR?

 

 

 

 

What I mean by this is: Depending on observer viewpoint, a delay of light between a transmission event and a reception event appears to be somewhere between 0 seconds to 2d/c inclusive. A receiver of light sees transmission and reception appearing simultaneous, a transmitter sees it take 2d/c, and an observer equidistant to transmitter and receiver sees it appear to take a time of d/c.

 

It is possible with an alternative simultaneity (based on appearance of simultaneity) to treat these observed apparent delays of light as relativity of simultaneity.

 

Is there anything valuable in that? Would it be more important to prove that this model is consistent with the observables of SR, or would it also have to be shown that there is a practical benefit to such a model?

[xyzt]

Has anyone else (historically) proposed a unification of relative simultaneity and measurable delay of light? Wouldn't such a model be a valuable simplification, if it was consistent with SR?

 

 

 

 

What I mean by this is: Depending on observer viewpoint, a delay of light between a transmission event and a reception event appears to be somewhere between 0 seconds to 2d/c inclusive. A receiver of light sees transmission and reception appearing simultaneous, a transmitter sees it take 2d/c, and an observer equidistant to transmitter and receiver sees it appear to take a time of d/c.

 

It is possible with an alternative simultaneity (based on appearance of simultaneity) to treat these observed apparent delays of light as relativity of simultaneity.

 

Is there anything valuable in that? Would it be more important to prove that this model is consistent with the observables of SR, or would it also have to be shown that there is a practical benefit to such a model?

How do you know when the pulse of light was sent from the perspective of the moving observer? You don't and you can't, nature "conspires" against all your attempts at finding out. .

Edited January 6, 2014 by xyzt

[md65536]

How do you know when the pulse of light was sent from the perspective of the moving observer? You don't and you can't, nature "conspires" against all your attempts at finding out. .

That's why you define "simultaneity". (Once you have that you can set the time of clocks at each of the locations. They can be synchronized if they're at relative rest.)

 

Whether you use the standard definition of simultaneity in SR, or some alternative, you can still measure the apparent delay for any given observer, between when it observes an event occurring coincident with the signal being sent, and an event coincident with the signal being received.

 

SR lets you predict these things for a given inertial observer by considering both relativity of simultaneity and delay of light. However, I'm trying to argue that by using the alternative "apparent simultaneity", delay of light can be treated as relativity of simultaneity (meaning that the receiver of a signal can treat the transmission and reception as apparently simultaneous, but the two events are not apparently simultaneous for other observers in general).

[xyzt]

SR lets you predict these things for a given inertial observer by considering both relativity of simultaneity and delay of light.

SR lets you do that by using the Lorentz transforms that encapsulate all the effects. So far, the Lorentz transforms have proven totally adequate for the task.

 

 

 

However, I'm trying to argue that by using the alternative "apparent simultaneity", delay of light can be treated as relativity of simultaneity

 

This is quite obvious given the known fact that the delay between two remote events can be measured through "probing" the events via light signals. This is not novel. Nor is it very useful since relativity of simultaneity has little to no application in practice (actually, it is the only prediction of relativity that isn't even testable).

Edited January 7, 2014 by xyzt

[md65536]

SR lets you do that by using the Lorentz transforms that encapsulate all the effects. So far, the Lorentz transforms have proven totally adequate for the task.

The Lorentz transformations don't consider delay of light. They give you what is "measured" in SR, and what is "seen" can then be calculated by considering delay of light. For example, if you take Lorentz time dilation and include delay of light you get the relativistic Doppler effect.

 

I agree that the Lorentz transformations have proven totally adequate, but surely it is not a fact that there is no room for possible improvement, or for other consistent models with their own benefits?

 

This is quite obvious given the known fact that the delay between two remote events can be measured through "probing" the events via light signals. This is not novel. Nor is it very useful since relativity of simultaneity has little to no application in practice (actually, it is the only prediction of relativity that isn't even testable).

I don't quite get exactly what you're speaking of when referring to "relativity of simultaneity" because it doesn't match what I'm speaking of. If events can't be absolutely simultaneous (with simultaneity agreed upon by all observers), then there must be relativity of simultaneity, correct? And absolute simultaneity is logically impossible in SR, correct? Then isn't relativity of simultaneity a requirement of SR at relativistic speeds? How can you have SR without relativity of simultaneity?

 

When you say "relativity of simultaneity" do you mean only the specific convention that is used to specify simultaneity in SR? When you say it isn't testable do you mean that there is no test to rule out other conventions?

 

 

Or do you mean that whether two observers agree or not on the simultaneity of two events makes no practical difference (has no effect on the outcome of any experiment), and thus basically there's no reason to care?

 

 

Doesn't it matter to someone, if for example we say "This supernova we're just seeing now occurred a million years ago" vs "It occurred just now." Doesn't a simultaneity convention greatly affect the interpretation of quantum mechanics?

[xyzt]

The Lorentz transformations don't consider delay of light.

 

 

 

 

 

 

 

 

Sure they do, this is how they were derived.

 

 

They give you what is "measured" in SR, and what is "seen" can then be calculated by considering delay of light.

What is "measured" and what is "seen" are one and the same thing.

 

 

For example, if you take Lorentz time dilation and include delay of light you get the relativistic Doppler effect.

This is not how the relativistic Doppler effect is derived.

 

 

I agree that the Lorentz transformations have proven totally adequate, but surely it is not a fact that there is no room for possible improvement, or for other consistent models with their own benefits?

Based on what I seen in your paper, the answer is no.

 

 

I don't quite get exactly what you're speaking of when referring to "relativity of simultaneity" because it doesn't match what I'm speaking of. If events can't be absolutely simultaneous (with simultaneity agreed upon by all observers), then there must be relativity of simultaneity, correct? Then isn't relativity of simultaneity a requirement of SR at relativistic speeds? How can you have SR without relativity of simultaneity?

Then, what you are speaking of is not mainstream. There is a very simple, mainstream definition of RoS. It has a very clean cut mathematical definition. This is what I am talking about.

 

 

 

And absolute simultaneity is logically impossible in SR, correct?

This is false , as well. SR permits (under certain circumstances) that two events simultaneous in one frame are simultaneous in all frames.

 

 

 

When you say it isn't testable do you mean that there is no test to rule out other conventions?

Yep, there isn't such test. Which makes your paper DoA.

 

 

 

Or do you mean that whether two observers agree or not on the simultaneity of two events makes no practical difference (has no effect on the outcome of any experiment), and thus basically there's no reason to care?

Not measurable means no way of telling the difference in practice.

 

 

Doesn't it matter to someone, if for example we say "This supernova we're just seeing now occurred a million years ago" vs "It occurred just now."

This is not what RoS means, so you are mixing concepts.

 

 

Doesn't a simultaneity convention greatly affect the interpretation of quantum mechanics?

Not. The PoI tells you something completely different about simultaneity but it has nothing to do with RoS.

Edited January 7, 2014 by xyzt

[md65536]

Then, what you are speaking of is not mainstream. There is a very simple, mainstream definition of RoS. It has a very clean cut mathematical definition. This is what I am talking about.

Well there are two things. One is "In physics, the relativity of simultaneity is the concept that distant simultaneity – whether two spatially separated events occur at the same time – is not absolute, but depends on the observer's reference frame." (http://en.wikipedia.org/wiki/Relativity_of_simultaneity)

 

Two is, the mathematical formulation of that concept according to SR.

 

What term should be used to describe an alternative simultaneity convention in which simultaneity is also relative? ... if not "relativity of simultaneity"?

 

Yes, this alternative is not mainstream, but the paper is consistent with SR. What I'm doing is showing that the alternative simultaneity is consistent with the predictions of SR, AND that the postulates of relativity can be interpreted to allow it, which I think is novel.

 

 

This is not what RoS means, so you are mixing concepts.

Right, well when I spoke of "standard simultaneity vs apparent simultaneity" you said I was speaking of RoS. The former statement ("an example supernova millions of light years away that is seen now occurred millions of years ago") corresponds with standard simultaneity, while the latter ("a supernova seen now is occurring now") corresponds with apparent simultaneity.

 

The paper is about the choice of definition of simultaneity. The relativity of either choice of simultaneity is not questioned here (it can be assumed along with the rest of SR).

 

Not. The PoI tells you something completely different about simultaneity but it has nothing to do with RoS.

What is PoI?

[xyzt]

Well there are two things. One is "In physics, the relativity of simultaneity is the concept that distant simultaneity – whether two spatially separated events occur at the same time – is not absolute, but depends on the observer's reference frame." (http://en.wikipedia.org/wiki/Relativity_of_simultaneity)

 

Two is, the mathematical formulation of that concept according to SR.

 

What term should be used to describe an alternative simultaneity convention in which simultaneity is also relative? ... if not "relativity of simultaneity"?

The "two" are one and the same. What is the (simple) mathematical formalism that describes it?

 

 

Yes, this alternative is not mainstream, but the paper is consistent with SR. What I'm doing is showing that the alternative simultaneity is consistent with the predictions of SR, AND that the postulates of relativity can be interpreted to allow it, which I think is novel.

 

We have already been over your claim, the "paper" is not consistent with SR. Have you submitted it to either journal I suggested? If yes, have they answered? If yes, what was the answer?

 

 

 

Right, well when I spoke of "standard simultaneity vs apparent simultaneity" you said I was speaking of RoS. The former statement ("an example supernova millions of light years away that is seen now occurred millions of years ago") corresponds with standard simultaneity.

 

Nope, you are clearly confused on the basic concept of what RoS means. Write down the mathematical formulation and we can talk.

 

 

 

What is PoI?

 

Principle of Incertitude.

Edited January 7, 2014 by xyzt

[md65536]

Nope, you are clearly confused on the basic concept of what RoS means. Write down the mathematical formulation and we can talk.

Oh brother. It's the Lorentz transformation of time.

[math]t' = \gamma (t - xv/c^2)[/math] for relative movement along the x-axis.

 

Principle of Incertitude.

I don't see how that is at all relevant. I was speaking of interpretations of QM involving "spooky action at a distance", which depends on simultaneity convention.

[xyzt]

Oh brother. It's the Lorentz transformation of time.

[math]t' = \gamma (t - xv/c^2)[/math] for relative movement along the x-axis.

 

Nope. If it were, there wouldn't be a separate term for it. You have been talking all along about it without knowing what it is.

 

 

 

I don't see how that is at all relevant. I was speaking of interpretations of QM involving "spooky action at a distance", which depends on simultaneity convention.

 

Also no. Try to learn the basics first, before you go into more complex issues.

[md65536]

Nope. If it were, there wouldn't be a separate term for it. You have been talking all along about it without knowing what it is.

What is the answer then?

[xyzt]

What is the answer then?

Have you considered taking a class?

[md65536]

Have you considered taking a class?

Yes. Do you know the answer?

[xyzt]

Yes. Do you know the answer?

Yes, I know the answer, I never make statements I don't already know the answer. The reason I asked is that taking a class would be a much better way of spending your time than making fringe posts and writing fringe "papers". So why didn't you take the class? You might learn physics (relativity) the proper way...