0 Members and 1 Guest are viewing this topic.

By corresponding, I mean empirical correspondence, as SR is an empirical theory. If you argue it doesn't do this, then you claim a falsification test. But I think you simply claim it doesn't correspond to metaphysical reality, which is fine since SR is a scientific theory and makes no metaphysical claims about the underlying reality. Reality indeed has no correspondence to a theory that is mute on the subject.

The abstract claim is based on the one-way speed of light.

If the contention is that the co-ordinate reference system in no way represents the physical world, then there is no issue.

The sourse of the misunderstanding is that you cannot recognise that the abstract mathematical claim is a claim about a physical system.

If it remains in the abstract mathematical domain and isn't put forward as a model of the pyhsical system, that is, if it is stated categorically that it does not represent an accurate model of the physical world, then yes it is a purely abstract claim.

You're assuming the validity of the convention, which is not a given.

Then the interpretation you're comparing is a different one than I am using. Conclude what you wish about it. My Alice is utilizing the theory which makes no such assumption.

No assertion about the coordinate system representing the real world is made. Any such assertion would be an additional premise, and I've made none.

QuoteThe sourse of the misunderstanding is that you cannot recognise that the abstract mathematical claim is a claim about a physical system.I don't recognize it because I am making no such claim. You insisting that I am making this claim commits the strawman fallacy. I'm not defending an interpretation that makes such a claim.

I didn't say it does not represent an accurate model of the physical world. Such a statement would be a physical claim, and I'm not making one. I simply said I've made no claim that it represents an accurate model of the physical world. It may or may not be accurate. Nobody can know.

I is a pure mathematical convention. If you can find an error in the mathematics, be my guest and point it out. Else you've no grounds for a claim of it being invalid.

Quote from: HalcA statement is not a prediction. A prediction is an anticipated result of a measurement. The word implies the measurement has not yet been performed.If the one-way speed of light can be measured - a proposition you and others seem to be optimisic about - then it represents a prediction.

A statement is not a prediction. A prediction is an anticipated result of a measurement. The word implies the measurement has not yet been performed.

If the one-way speed of light cannot be measured, then the simultaneity of clock syncing events is an untestable prediction.

QuoteWhen the causal effect of interest is ill defined, the counterfactual theory of causal inference from observational data and the elegant statistical methods derived from it lead to predictions that are untestable.//academic.oup.com/aje/article-abstract/162/7/618/204321

When the causal effect of interest is ill defined, the counterfactual theory of causal inference from observational data and the elegant statistical methods derived from it lead to predictions that are untestable.

Quote from: Halc on 10/07/2019 04:49:26A local comparison is not frame dependent. That comparison can be (and was) done in any frame. It isn't possible to not be in the other frames. H-K beginning and end events were not done by equipment that was stationary in the same frame as each other. It was an unnecessary requirement and no care was taken to do so. Likewise with the twins at both ends of the journey. The requirement is that they be together. That's all. Comparisons are objective if they're local. I suppose mass comparisons are not.I didn't say it was frame dependent, I said that it privileges the reference frame in which the local comparison is made.

A local comparison is not frame dependent. That comparison can be (and was) done in any frame. It isn't possible to not be in the other frames. H-K beginning and end events were not done by equipment that was stationary in the same frame as each other. It was an unnecessary requirement and no care was taken to do so. Likewise with the twins at both ends of the journey. The requirement is that they be together. That's all. Comparisons are objective if they're local. I suppose mass comparisons are not.

The H-K comparison was done in the "at rest relative to the Earth frame", where the Airplanes had to accelerate and decelerate to come to be at rest reltive to the earth. It wouldn't have been practical to accelerate and decelerate the Earth while the airplane was in the air - as I'm sure you understand.

This is from the Pablo Acuna paper I have referenced several times:QuoteIf we apply Occam‘s razor and excise the ether from Lorentz‘s theory, what we obtain is not special relativity. It is still possible to retain the Newtonian space-time plus conspiring dynamical effects by defining by fiat a privileged reference frame. For example, the Lorentzian could baldly say that the privileged frame is the one in which the real time is measured, period.On the Empirical Equivalence between Special Relativity and Lorentz’s Ether Theory by Pablo Acuna. I can send a copy of the paper if you like.

If we apply Occam‘s razor and excise the ether from Lorentz‘s theory, what we obtain is not special relativity. It is still possible to retain the Newtonian space-time plus conspiring dynamical effects by defining by fiat a privileged reference frame. For example, the Lorentzian could baldly say that the privileged frame is the one in which the real time is measured, period.

So, as you can see the privileged reference frame can be any reference frame where "real time" is defined, it isn't a requirement that it be the absolute rest frame.

Quote from: HalcAn inertial frame cannot be accelerated. An accelerated frame can, but it has different properties.A spaceship represents an inertial frame - perhaps you mean inertial co-orddinate frame - a spaceship can be accelerated.

An inertial frame cannot be accelerated. An accelerated frame can, but it has different properties.

So, if you say you are comparing the "raw theory" to the mathematics of the absolute interpretation, then you are in actual fact not comparing one thing to another, because there is only one thing and no other. It's the same mathematics for both.

If you are comparing the "raw theory" to the absolute interpretation (not just the mathematics) then you are comparing apples to oranges. You need to be comparing one interpretation to the other.

Quote from: HalcNeither a theory. If either is a theory, what prediction does it make? It's an interpretation until it has a falsification test.I quoted the prediction it makes, it predicts that the one-way speed of light is not isotropic relative to all reference frames. Esseentially, it predicts that, if the one-way speed of light can be measured then absolute motion could be determined. If the one-way speed of light is found to be isotropic relative to all inertial frames, the theory is falsified.

Neither a theory. If either is a theory, what prediction does it make? It's an interpretation until it has a falsification test.

Quote from: Halc I persisted with it because you suggested that he cannot have done what he did (which was measuring light speed utilizing a one-way method, not measuring the one-way speed of light).And I repeat, measuring the one-way speed of light requires the syncing of two spatially separated clocks, which requires an accurate measurement of the one-way speed of light which requires the syncing of two spatially separated clocks, which requires a an accurate measurement of the one-way speed of light which requires.....see where I'm going with this?

I persisted with it because you suggested that he cannot have done what he did (which was measuring light speed utilizing a one-way method, not measuring the one-way speed of light).

Quote from: HalcYou still deny it! This is the 2nd reason why I didn't let it drop. SR says the method is valid and should yield exactly c. The theory says that, not any interpretation. It follows trivially from the empirical premises of SR. If your interpretation denies this, it is wrong.SR says Romers method is valid and should yield exactly c? How did that work out can you tell me?

You still deny it! This is the 2nd reason why I didn't let it drop. SR says the method is valid and should yield exactly c. The theory says that, not any interpretation. It follows trivially from the empirical premises of SR. If your interpretation denies this, it is wrong.

Quote from: Halc What do you think a convention is? Is that another word that is going to get redefined?In the context of Einstein's sync convention it means something which is established without being empirical verified/verifiable.

What do you think a convention is? Is that another word that is going to get redefined?

If I'm measuring Usain Bolt's speed as he runs the 100m and I use imprecise methods of time keeping and get a value 25% less than the official Olympic measurement, have I really measured Usain Bolt's speed? Or have I just arrived at some value that doesn't actually represent his speed?

Would I have a better chance of measuring his speed if I could use and sync two spatially separated clocks - one at the starting line and one at the finish line?

Quote from: HalcIf you could meausre 1WSoL, yes, but that doesn't mean that SoL cannot be measured using a one way method. If it yields c every time (as PoR say it must), then no absolute motion can be detected. Tooley is quite right about this.If you can propose a method of measuring the 1WSoL that doesn't require the syncing of spatially separated clocks (by convention) or that doesn't make assumptions pertaining to the rigidy of the bodies used in the measurement, then fame and notoriety await you.

If you could meausre 1WSoL, yes, but that doesn't mean that SoL cannot be measured using a one way method. If it yields c every time (as PoR say it must), then no absolute motion can be detected. Tooley is quite right about this.

Tooley's point is that any philosophical reason for favoring Einstein's interpretation over an interpretation based on an absolute reference frame is rendered null and void, because the testing of the 1WSoL represents the falsification test for both.

We might be talking about slightly different things here. I'm talking about the idea that an interpretation of relativity that incorporates an absolute reference frame - with two frames moving relatively to that, where the Lorentz Transformation is used between the absolutely moving frames - does not predict reciprocal time dilation the way Einstein's interpretation does. In the absolute interpretations both Alice and Bob's clocks are slowed.

If it were a simple case of comparing the two clocks without needing to reuinite them, Alice would see the photon in her light clock travel the perpendicular distance between the mirrors of her light clock, while she would see the photon in Bob's clock travel the longer perpendicular distance.The critical difference is that the duration of both would be the same. That is, the photon in Alice's clock would reach the opposite mirror at the same instant as it does in Bob's clock.

From this Alice would either conclude that the photon travels faster in Bob's clock or that the photon in her clock actually travels the longer distance too.

It is the need to reuinte the measurement instruments which circumvents this fact and which reduces it to the kind of privileged reference frame theory I have been "redefininig". The same is true for Einstein's interpretation.

Quote from: Halc on 10/07/2019 13:11:23A comparison of respective elapsed time has nothing to do with the tick rates of either clock. You read what each clock says and subtract. The rates of the clocks play no rote in that calculation.Alice and Bob moving relative to each other. Alice sees Bob's clock running slow. Bob sees Alice's clock running slow.How do you compare clocks on the fly to show that Alice's clock runs slower than Bob's and that Bob's clock runs slower than Alice's?

A comparison of respective elapsed time has nothing to do with the tick rates of either clock. You read what each clock says and subtract. The rates of the clocks play no rote in that calculation.

So, in the H-K experiment the clocks aren't brought back together to a position at rest relative to the Earth?

I presume you mean that she cannot determine that she, along with the spaceship and everything on board, remains at the same location, yes?

It would appear that the issue lies in your mispprehension of the idea that RoS is part of the "raw" mathematics of the theory.The problem is that it isn't. The reason we can deduce that it isn't derived from the "raw" mathematics is bcos it forms part of one interpretation but doesn't form part of the other. If it was part of the "raw theory" i.e. the mathematics it would, by necessity, form part of both interpretations.

Quote from: Halc on 10/07/2019 14:56:19Poincare derived RoS before anybody else, but their interpretation uses a different convention to define simultaneity. Einstein used an empirical convention. Lorentz-Poincare does not.Quote from: UAIn a contribution for a volume celebrating the 25th anniversary of Lorentz‘s doctorate, Poincaré explained his point by means of an illustration that strikingly resembles Einstein‘s method for the synchronization of clocks. He showed that if two observers at rest with respect to each other, but in motion with respect to the ether, try to synchronize their clocks by means of light pulses, the result is that their synchronized clocks are late with respect to the real time.His convention to define simultaneity is, in effect, the same as Einstein's. Indeed, it is indiscgernible from Einstein's treatment of cco-ordinate systems.

Poincare derived RoS before anybody else, but their interpretation uses a different convention to define simultaneity. Einstein used an empirical convention. Lorentz-Poincare does not.

In a contribution for a volume celebrating the 25th anniversary of Lorentz‘s doctorate, Poincaré explained his point by means of an illustration that strikingly resembles Einstein‘s method for the synchronization of clocks. He showed that if two observers at rest with respect to each other, but in motion with respect to the ether, try to synchronize their clocks by means of light pulses, the result is that their synchronized clocks are late with respect to the real time.

Imagine Poincare starting with the absolute reference frame, then adding one relatively moving inertial frame. Now stop. You've got something that is indiscernible from Einstein's treatment of co-ordinate systems.

QuoteImagine two observers who wish to adjust their watches by optics signals; they exchange signals, but as they know that the transmission of light is not instantaneous, they take care to cross them. When the station B perceives the signal from the station A, its clock should not mark the same hour as that of station A at the moment of sending the signal, but this hour augmented by a constant representing the duration of the transmission. Suppose, for example, that the station A sends its signal when its clock marks the hour 0, and that the station B perceives it when its clock marks the hour t. The clocks are adjusted if the slowness equal to t represents the duration of the transmission, and to verify it the station B sends in turn a signal when its clock marks 0; then the station A should perceive it when its clock marks t. The time pieces are then adjusted. And in fact, they mark the same hour at the same physical instant, but on one condition, namely, that the two stations are fixedChange station A and Station B for Clock at A and Clock at B and you've effectively got Einsein's sync convention. This is in Alice's "stationary system".

Imagine two observers who wish to adjust their watches by optics signals; they exchange signals, but as they know that the transmission of light is not instantaneous, they take care to cross them. When the station B perceives the signal from the station A, its clock should not mark the same hour as that of station A at the moment of sending the signal, but this hour augmented by a constant representing the duration of the transmission. Suppose, for example, that the station A sends its signal when its clock marks the hour 0, and that the station B perceives it when its clock marks the hour t. The clocks are adjusted if the slowness equal to t represents the duration of the transmission, and to verify it the station B sends in turn a signal when its clock marks 0; then the station A should perceive it when its clock marks t. The time pieces are then adjusted. And in fact, they mark the same hour at the same physical instant, but on one condition, namely, that the two stations are fixed

QuoteIn the contrary case the duration of the transmission will not be the same in the two senses, since the station A, for example, moves forward to meet the optical perturbation emanating from B, while the station B flies away before the perturbation emanating from A. The watches adjusted in that manner do not mark, therefore, the true time; they mark what one may call the local time, so that one of them goes slow on the other. It matters little, since we have no means of perceiving it.This is what Alice see's from the stationary system.

In the contrary case the duration of the transmission will not be the same in the two senses, since the station A, for example, moves forward to meet the optical perturbation emanating from B, while the station B flies away before the perturbation emanating from A. The watches adjusted in that manner do not mark, therefore, the true time; they mark what one may call the local time, so that one of them goes slow on the other. It matters little, since we have no means of perceiving it.

Now, imagine that neither Alice nor Bob is in the absolute rest frame, both are moving relative to it. What do you think will be the case there?

You use the term "non-empirical" as though it means something other than "assumption".

Are you now saying that the one-way speed of light cannot be measured?

You sounded pretty optimistic earlier that it could

Quote from: HalcIt deduces RoS using the empirical convention to define simultaneity.Is it an empirical convention or a non-empirical convention?

It deduces RoS using the empirical convention to define simultaneity.

Is RoS derived from the "raw" mathematics or is it derived using the convention of one of the interpretations and therefore not part of the "raw" theory?

Also, with regard to the convention being an assumption (of any kind).

standard formulations of the Special Theory of Relativity involve an assumption that is not even in principle testable if the rest of the theory is true: the status of the One-Way Light Principle will be that of a gratuitous metaphysical assumption.

Also, you use a term there, that I'm not familiar with, "non-empirical assumption". Perhaps if you tell me what the opposite of that would be, then I might better understand it.

Also, are you suggesting that the Einstein convention is not based on an assumed premise?

Bcos, in case you hadn't noticed, they do make some pretty different predictions, it just appears as though they are not testable.

Quote from: HalcA mark on the floor does not designate a location since no definition of the floor being stationary has been established. A coordinate system is required to do that, and 'Clock A' makes no reference at all to that essential coordinate system.There's that word "stationary" again. Relative to what, would you like to say the physical floor of the spaceship is "stationary"?

A mark on the floor does not designate a location since no definition of the floor being stationary has been established. A coordinate system is required to do that, and 'Clock A' makes no reference at all to that essential coordinate system.

Step back into the "physical-world" for a second. You're onboard Alice's ship and she calls out, "Where are you Halc?" and you answer "I'm at the point marked A on the floor". Alice now knows your location.

1) Any experiment (twins, H-K) anything at all, can be done and analyzed in any frame. It doesn't change the result. 2) Mohammad need not stop at the mountain any more than the mountain need stop at Mohammed.

Specifying which reference frame doesn't need to undergo acceleration/deceleration privileges it.

You're here, the clocks are over there.

You send a light signal from here to there.

How can you determine empirically, when the light signals arrive "over there"?How can you determine that the arrival of the light signals to the clocks "over there" coincide with the reading [d/c] on your clock C0?

Are you saying that the clocks and light signals "over there" are not over there bcos you can't see them? Bcos that is what your analogy implies.

If the moon is stil there when you look away

I'm gonna be offline again, for at least 2 weeks (more meditation).

I'll leave you with this one. I felt it deserved a separate post of its own.Quote from: HalcBy corresponding, I mean empirical correspondence, as SR is an empirical theory. If you argue it doesn't do this, then you claim a falsification test. But I think you simply claim it doesn't correspond to metaphysical reality, which is fine since SR is a scientific theory and makes no metaphysical claims about the underlying reality. Reality indeed has no correspondence to a theory that is mute on the subject.You've just been arguing how SR is an abstract mathematical theory to which the rules of empiricism do not apply. Now you are stating that it is an empirical theory, which claims emprical correspondence.

Therefore, we are back in the domain of empiricism where the rules of empiricism apply.

By the rules of "empirical correspondence", any conclusion formed which incorporates a statement that doesn't correspond empirically [to the physical world], by way of logical necessity, assumes that conclusion and therefore employs circular reasoning.

Any conclusion formed which incorporates a statement that doesn't correspond empirically [to the physical world], by way of logical necessity, is not empirically correspondent.

We have our statement about the configuration of the physical system - pertaining to the clock syncing events and the reading on clock [d/c]

Does this statement have "empirical correspondence"?

We simply do not (and probably cannot) know [from within our frame].

Therefore, according to the rules of empiricism which applies to empirical theories which claim "empirical correspondence", it is a non-non-empirical assumption (or "empirical assumption").

Since such a statement forms part of the conclusion of relativity of simultaneity

[in Einstein's theory/interpretation], it is either an assumed conclusion or Einstein's relativity doesn't correspond empirically and therefore isn't a valid scientific theory.

You're discussing RoS. RoS is derived from the mathematis + the metaphysical assumption about the isotropic one-way speed of light relative to all reference frames. The alternative interpretation uses the same mathematics but doesn't include RoS, therefore RoS is not a consequence of the "raw" mathematical theory.

Quote from: HalcNo assertion about the coordinate system representing the real world is made. Any such assertion would be an additional premise, and I've made none.See the post addressing "empirical correspondence"

Quote from: HalcQuoteThe sourse of the misunderstanding is that you cannot recognise that the abstract mathematical claim is a claim about a physical system.I don't recognize it because I am making no such claim. You insisting that I am making this claim commits the strawman fallacy. I'm not defending an interpretation that makes such a claim.Does the "raw" mathematical theory correspond empirically to the physical world?

Does Einstein's interpretation correspond empirically to the real world?

Quote from: Halc I simply said I've made no claim that it represents an accurate model of the physical world.So, no one can know if a model of the world which incorporates RoS is an accurate model of the world?

I simply said I've made no claim that it represents an accurate model of the physical world.

Can the sync convention be used in the physical world, or is it "purely mathematical"?