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the Atemporal Universe - Resolving the Problem of Time
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The prediction is derived, not the observation. The accuracy of the prediction has to be assumed. The prediction is central to the conclusion of RoS. Assuming that the prediction is correct, RoS follows as a matter of necessity. Dropping the prediction and the assumption means RoS disappears.It's derived from the assumption of the isotropic constancy of the speed of light.
Relate this to Alice's observation of Bob. While the comoving observer will not be able to determine this, the observations off all other, relatively moving observers, will support this contention.As I said above all theories have brute assumptions. Similarly Poincaré-Lorentz theory assumes that the two halves of the light beams paths occur at different speeds. This also cannot be directly confirmed. It's an ontological assumption about what is occurring behind the scenes.
As I've mentioned before, the literature points to the fact that the Lorentz-Poincare interpretation can be formulated without reference to an Ether. I argue that it can be formulated witout reference to an absolute reference frame also.These two different assumptions lead to the same mathematics. In the standard case it's because the structure described by those mathematics, Minkowski space, is assumed to be real, in the Lorentz-Poincaré case it's all a complex illusion due to the odd dynamical properties of the aether.
Since the former is simpler we usually go with it. Also there doesn't seem to be a clear way to explain General Relativity from the latter. Also when you move to Quantum Field Theory particles that actually live in a Galilean background operate completely differently from those in a Lorentz background. Massless Spin-1 particles for example have different polarization states. To allow the Lorentz-Poincaré picture to be extended to particle physics you'd have to assume there is some complex mechanism in detectors that always "masks" one of the three polarization states of light to make it seem like there are two.
The whole construct just becomes increasingly ad-hoc and complex.
As mentioned, it should - I'm inferring - be possible to forumulate a kinemtical interpretation by following Einstein's formalism and dropping the assumption of the one-way speed of light. This would make no reference to an Ether, conspiratorial dynamics, or an absolute reference frame; the mathematics and predictions would remain unchhanged, apart from the untestable notion of RoS.0 -
That part of the argument is somewhat separate to the primary conclusion that is drawn. It is more along the lines of the Einsteinian interpretation conflicting with itself, but it isn't necessary.
The primary conclusion is that the simultaeity of [clock synchronisation] evens in the stationary system is not supported by observational evidence. The theory makes a critical prediction about the time value on two physical clocks which is entirely untestable by the foundational assumptions of the theory. This accuracy of this prediction - upon which the Relativity of Simultaneity rests - must thereore be assumed. Rendering that aspect of the theory unfalsifiable - but still, clearly requiring the conclusion to be assumed.
You're still using terms in your reasoning that aren't theory-neutral. E.g. You say simultaneity is not supported by observational evidence. But according to the theory of relativity, Alice will indeed observe simultaneous events under the standard of measurement specified by her frame of reference. This is what simultaneity means in the context of relativity. If, instead, you mean simultaneity in some non-relativistic sense (like absolute simultaneity), then sure there won't be observational evidence, but that's one of the lessons of relativity.As a consequence/conclusion of the the theory, predicated on the basis of a prediction about the reading on two physical clocks, a prediction which is untestable under the foundational assumptions of the the theory itself, a prediction whose accuracy must be assumed to be true, it is a consequene/conclusion which is assumed and indeed unfalsifiable under the foundational assumptions of the theory itself.
The most charitable way I can read this paragraph is: RoS follows from relativity, and the postulates of relativity are assumed over the postulates of some other alternative theory that makes the same predictions as relativity.
Am I reading it correctly?0 -
That would mean that the real symmetry group is the Galilean group. Particles under the Galilean group have completely different properties, really truly totally different. So you have to explain why they appear to have the properties they have under the assumption of the reality of Minkowski space, e.g. why light has two polarizations as opposed to three.As I've mentioned before, the literature points to the fact that the Lorentz-Poincare interpretation can be formulated without reference to an Ether. I argue that it can be formulated witout reference to an absolute reference frame also.
As mentioned, it should - I'm inferring - be possible to forumulate a kinemtical interpretation by following Einstein's formalism and dropping the assumption of the one-way speed of light. This would make no reference to an Ether, conspiratorial dynamics, or an absolute reference frame; the mathematics and predictions would remain unchhanged, apart from the untestable notion of RoS.0 -
She won't observe the reading on her co-located, physical clock which coincides with the pertinent events i.e. the photons making physical contact with the clocks she is trying to synchronise.You're still using terms in your reasoning that aren't theory-neutral. E.g. You say simultaneity is not supported by observational evidence. But according to the theory of relativity, Alice will indeed observe simultaneous events under the standard of measurement specified by her frame of reference. This is what simultaneity means in the context of relativity. If, instead, you mean simultaneity in some non-relativistic sense (like absolute simultaneity), then sure there won't be observational evidence, but that's one of the lessons of relativity.
She is forced to assume that the prediction made - in accordance with her specified frame of reference - that the same reading on her co-located, physical clock coincides with both of the pertinent events - this is partly what simultaneity means in the physical world. The foundational assumptions of the theory render this prediction untestable. Meaning this prediction, about the relevant reading on a physical clock face, must be assumed to be true - hence the conclusion is assumed.
The claim as to what Relativity says that Simultaneity is, how it derives predictions, etc. etc. can be reframed in any infinite number of ways, it won't change the fact that in the real-world experimental set-up, the necessary observation simply cannot be made - the foundational assumptions of the theory preclude this possibility! It has to be assumed to be true!
It's the same point that has been repeated throughout and again above.The most charitable way I can read this paragraph is: RoS follows from relativity, and the postulates of relativity are assumed over the postulates of some other alternative theory that makes the same predictions as relativity.
Am I reading it correctly?
Relativity makes a prediction about the reading on a physical clock coinciding with 2 events. This observation cannot - not even in principle (given the foundational assumptions of the theory - see the light clock convention) - be verified. It is instead assumed to be true i.e. the prediction made about a physical clock is not, nor can it be, observed; it is assumed. The conclusion of RoS rests entirely on this assumption.
The coordinate system is the map; the experimental set-up is the territory; the map is not the territory. The map has a picture of the Loch Ness Monster drawn in, over Loch Ness. None of the observational evidence contradicts the map but there is no observational evidence that Nessy be in them there waters. The key of the map says that Nessy has to be assumed to be in the lake. The conclusion that Nessy is in the lake is therefore circular.0 -
Why would it be Galilean?That would mean that the real symmetry group is the Galilean group. Particles under the Galilean group have completely different properties, really truly totally different. So you have to explain why they appear to have the properties they have under the assumption of the reality of Minkowski space, e.g. why light has two polarizations as opposed to three.0 -
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Apologies, this is one of the limitations of my understanding.What is the symmetry of the underlying space then if it is not Galilean and not Minkowskian?
What determines the symmetry of the underlying space, is it the coordinate transformations?
I'm basing that on
If so, coordinate transformations would still be done in the same way. The mathematics would be identical and there would be no absolute reference frame.wiki: symmetry: physics wrote:In physics, a symmetry of a physical system is a physical or mathematical feature of the system (observed or intrinsic) that is preserved or remains unchanged under some transformation0 -
Its the geometrical structure of the space. Different geometrical structures give rise to different particles.Apologies, this is one of the limitations of my understanding.
What determines the symmetry of the underlying space, is it the coordinate transformations?
I'm basing that on
If so, coordinate transformations would still be done in the same way. The mathematics would be identical and there would be no absolute reference frame.
This is part of why people don't accept other views of Special Relativity. If let's say General Relativity and Quantum Field Theory hadn't turned out to be relevant to the world we'd probably still have some conflicting views on Einsteins approach vs. Poincaré-Lorentz. They both have subtle unobserved predictions related to their central assumptions and both contradict intuition in some manner.
However General Relativity and Quantum Field Theory are very hard to explain if you stick to the Poincaré-Lorentz view.
This has happened before in physics. In Electromagnetism you can replace the Electric and Magnetic force fields with potentials and there was a discussion as to whether the potentials or the fields were the "real" physical structures. In electromagnetism this is essentially unresolvable. However in quantum mechanics there are effects that immediately result from the potential view and are much more difficult to explain via the force fields.
So two equivalent interpretations are not equivalent upon further development. So it is with Lorentz-Poincaré.0 -
How would the geometrical structure be determined? I'm presuming it has something to do with the mathematical formulation but bcos I don't see the mathematics changing I'm struggling to see the issue.Its the geometrical structure of the space. Different geometrical structures give rise to different particles.
The Lorentz-Poincare interpretation was predicated on an absolute reference frame preserving Galilean geometry/symmetry, wasn't it? (Apologies if I've butchered that). But the LP interpretation was predicated on this absolute space and time, isn't that (roughly speaking) the issue you're referring to?This is part of why people don't accept other views of Special Relativity. If let's say General Relativity and Quantum Field Theory hadn't turned out to be relevant to the world we'd probably still have some conflicting views on Einsteins approach vs. Poincaré-Lorentz. They both have subtle unobserved predictions related to their central assumptions and both contradict intuition in some manner.
However General Relativity and Quantum Field Theory are very hard to explain if you stick to the Poincaré-Lorentz view.
This has happened before in physics. In Electromagnetism you can replace the Electric and Magnetic force fields with potentials and there was a discussion as to whether the potentials or the fields were the "real" physical structures. In electromagnetism this is essentially unresolvable. However in quantum mechanics there are effects that immediately result from the potential view and are much more difficult to explain via the force fields.
So two equivalent interpretations are not equivalent upon further development. So it is with Lorentz-Poincaré.
If so, then the contention is that an LP-style* interpretation can be formulated without reliance upon an absolute reference frame
The preconceptions of the LP interpretation might confuse the issue, which is why another way of thinking about it would be Einstein's kinematical interpretation, without an assumption of simultaneity of events in the stationary system. Such an interpretation would make no reference to an absolute reference frame. It effectively just extends the Galilean principle of Relativity to the notions of Simultaneity/Synchronization; that is to say, there is no experiment which can determine these.
Am I right in thinking that no absolute reference frame addresses - at least in part - the issue you raise?0 -
The mathematics of the effective coordinate transformations is unchanged, but the metrical structure of the underlying space is different.How would the geometrical structure be determined? I'm presuming it has something to do with the mathematical formulation but bcos I don't see the mathematics changing I'm struggling to see the issue.
No, I'm referring to it retaining a different underlying geometric structure. One which doesn't respond to curvature the same way and doesn't give the same symmetry for particles.The Lorentz-Poincare interpretation was predicated on an absolute reference frame preserving Galilean geometry/symmetry, wasn't it? (Apologies if I've butchered that). But the LP interpretation was predicated on this absolute space and time, isn't that (roughly speaking) the issue you're referring to?0 -
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She won't observe the reading on her co-located, physical clock which coincides with the pertinent events i.e. the photons making physical contact with the clocks she is trying to synchronise.
She is forced to assume that the prediction made - in accordance with her specified frame of reference - that the same reading on her co-located, physical clock coincides with both of the pertinent events - this is partly what simultaneity means in the physical world. The foundational assumptions of the theory render this prediction untestable. Meaning this prediction, about the relevant reading on a physical clock face, must be assumed to be true - hence the conclusion is assumed.
The claim as to what Relativity says that Simultaneity is, how it derives predictions, etc. etc. can be reframed in any infinite number of ways, it won't change the fact that in the real-world experimental set-up, the necessary observation simply cannot be made - the foundational assumptions of the theory preclude this possibility! It has to be assumed to be true!
Relativity makes a prediction about the reading on a physical clock coinciding with 2 events. This observation cannot - not even in principle (given the foundational assumptions of the theory - see the light clock convention) - be verified. It is instead assumed to be true i.e. the prediction made about a physical clock is not, nor can it be, observed; it is assumed. The conclusion of RoS rests entirely on this assumption.
The coordinate system is the map; the experimental set-up is the territory; the map is not the territory. The map has a picture of the Loch Ness Monster drawn in, over Loch Ness. None of the observational evidence contradicts the map but there is no observational evidence that Nessy be in them there waters. The key of the map says that Nessy has to be assumed to be in the lake. The conclusion that Nessy is in the lake is therefore circular.
Relativity makes predictions about what will happen if Alice places a detector equidistant between two locations (defined by the standards of measurement outlined by her frame of reference), and registers signals from simultaneous events at those locations (defined by the standards of measurement outlined by her frame of reference).
More importantly, the above also affirms my suspicion that what you mean to do is argue that no observation can distinguish between special relativity and some other alternative theory that makes all the same predictions about what we will observe, and that special relativity also contains superfluous assumptions that are dropped in simpler alternatives. But you have misidentified the offending assumption as relativity of simultaneity, as opposed to, say, the universal speed of light.
There are projects out there attempt to formulate a theory of relativity with weaker assumptions (like Hsu's "extended relativity", which drops the speed of light postulate and uses Edwards transformations instead of Lorentz transformations). It's great that these projects exist, but it's not automatically the case that these alternatives make equivalent predictions, or are as easily generaliseable as special relativity. Special relativity has been, hands down, the most successful project to date in these matters.
So while any single prediction-observation pair will not uniquely specify a correct theory over all alternatives, you won't be able to use Occam's razor against relativity unless you demonstrate an alternative is just as successful over a wide range of observations.0 -
The mathematics of the effective coordinate transformations is unchanged, but the metrical structure of the underlying space is different.
No, I'm referring to it retaining a different underlying geometric structure. One which doesn't respond to curvature the same way and doesn't give the same symmetry for particles.
How is the underlying metrical structure determined?0 -
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Note the assumption in the emboldened part, that the events are simultaneous in the given frame. That they are "defined by the standards of measurement outlined by her frame of reference" is simply a restatement of the idea that the synchronisation of clocks must be established by definition i.e. that it must be assumed. It is simply restating what we already have stated about what the Einsteinian interpretation assumess.Relativity makes predictions about what will happen if Alice places a detector equidistant between two locations (defined by the standards of measurement outlined by her frame of reference), and registers signals from simultaneous events at those locations (defined by the standards of measurement outlined by her frame of reference).
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More importantly, the above also affirms my suspicion that what you mean to do is argue that no observation can distinguish between special relativity and some other alternative theory that makes all the same predictions about what we will observe, and that special relativity also contains superfluous assumptions that are dropped in simpler alternatives. But you have misidentified the offending assumption as relativity of simultaneity, as opposed to, say, the universal speed of light.
It is from the standards of measurement defined by her frame of reference that we can derive the prediction about the configuration of the pysical system, which predicts that the reading on a clock [colocated with the observer], corresponding to a value of d/c, will coincide with two events at spatially separted clocks.
That prediction is, under the foundational assumptions of the theory itself, untestable/unverifiiable. Therefore, the prediction must be/can only be assumed to be correct. The conclusion of RoS hangs on the thread of this prediction/assumption.
It might also be worth pointing out that the interpretation of "Length Contraction" under the Einsteinian interrpretation also rests entirely on the assumption that clocks in the stationary system are synchronised.
As I said, frame it anyway that you like. The basic fact remains, there is no empirical observation that can be made to verify (or falsify) the claim that the clocks in the given frame are synchronised. The conclusion of RoS rests entirely on this claim.
It would be like Alice’s belief that the Flying Spaghetti Monster created the initial conditions of the universe. Then, all empirical evidence demonstrates where the initial conditions of the universe came from and there is no sign of the FSM. If Alice’s thesis says that we must establish by definition that the FSM created the initial conditions i.e. we must assume that the FSM created the initial conditions, then of course she will conclude that the FSM is responsible for the universe in its current configuration (derived from the initial conditions). The empirical observation of a Universe in its current configuration will not contradict her story about the FSM being responsible for the current configuration of the Universe. However, the totality of empirical evidence demonstrating where the initial conditions came from (with no sign of the noodly appendage of the FSM) certainly contradicts her assumption. Richard Dawkin’s might use the term “delusional” to describe Alice’s beliefs.
As it cannot be verified/falsified, it can only be assumed. Given that the totality of empirical evidence demonstrates that the clocks onboard the spaceship are not synchronised, the conclusion of frame dependent simultaneity i.e. the conclusion of RoS hangs entirely the assumption that the clocks onboard the spaceship are synchronised (from the perspective of the comoving observer). Without this assumption, on the part of the comoving observer, the conclusion of RoS simply isn't reached. Thus, the conclusion of RoS that simultaneity is frame depedent, that simultaneity is relative is entirelly assumed i.e. it rests entirely on circular reasoning.
Again, if a map of the territory says we must assume that the Loch Ness Monster is in Loch Ness, but all empirical observation (including underwater footage of Loch Ness)
Cheers, I will check those out.There are projects out there attempt to formulate a theory of relativity with weaker assumptions (like Hsu's "extended relativity", which drops the speed of light postulate and uses Edwards transformations instead of Lorentz transformations). It's great that these projects exist, but it's not automatically the case that these alternatives make equivalent predictions, or are as easily generaliseable as special relativity. Special relativity has been, hands down, the most successful project to date in these matters.
So while any single prediction-observation pair will not uniquely specify a correct theory over all alternatives, you won't be able to use Occam's razor against relativity unless you demonstrate an alternative is just as successful over a wide range of observations.
Without wanting to get sidetracked, before resolving the main issue of contention thus far:
We can substittue the Einteinian interpretation of "the constancy of the speed of light" for an interpretation that says the measurement of the speed of light will always return the same value.
If we examine Einstein's interpretation of the constancy of light speed, his interpretation doesn't say that the measure the speed of light, conducted by each observer [relative to themselves] will always return a value of c. His thought experiment can be used to demonstrate how each oberver's attempt to measure the speed of light will yield the same value - without resorting to time dilation or length contraction (in the Einsteinian sense).
What the Einsteinian interpretation does is interpret the constancy of the speed of light to mean that all observers will fit their observations to the idea that the speed of light to is constant relative to themselves and relative to all other observers.
If Alice measures the speed of light relative to herself she will get a value of c. If she measures it relative to Bob she will get a value of c - v. If she observes Bob attempting to measure the speed of light, she will see that his slowly ticking clock biases his result "conspiring" to give him the same value for the speed of light.
That is one way in which it could be interpreted. Simply that Bob's clocks conspire to give him the same mesurement for the speed of light. We don't need to rely on any dynamics to explain this or to rely on any asbolute reference frame.
The Einsteinian interpretation goes further. With "time" dilation implying that Alice can somehow square her measurement of the speed of with an idea that the speed of light is constant relative to all observers. While this is not expressly stated, we can derive it.0 -
I have an of what it is, I'm wondering how this description is determined/derived. What is it that gives us the information about the true space/spacetime in the model.It's just a description of the true space/spacetime in the model, not the effective one generated by the "quirk" of dynamics that makes things look as if Minkowski space were true.
If it isn't the mathematics, or the coordinate transformations, or it isn't the postulation of an absolute reference frame, from where do we derive statements about the nature of the geometrical structure [required by an interpretation]?0 -
I wil be offline for the next 3-4 weeks as I am doing a meditation retreat in Thailand and Malaysia, so you guys don't have to reply immediately - assuming that you choose to reply at all.
Before I sign off for a few weeks, I want to again express my gratitude for the time you guys have taken to engage in discussing the ideas. Either one of us (me) or all of us will be the richer because of it (figuratively speaking, in terms of acquiring knowledge).0 -
Note the assumption in the emboldened part, that the events are simultaneous in the given frame. That they are "defined by the standards of measurement outlined by her frame of reference" is simply a restatement of the idea that the synchronisation of clocks must be established by definition i.e. that it must be assumed. It is simply restating what we already have stated about what the Einsteinian interpretation assumess.
It is from the standards of measurement defined by her frame of reference that we can derive the prediction about the configuration of the pysical system, which predicts that the reading on a clock [colocated with the observer], corresponding to a value of d/c, will coincide with two events at spatially separted clocks.
That prediction is, under the foundational assumptions of the theory itself, untestable/unverifiiable. Therefore, the prediction must be/can only be assumed to be correct. The conclusion of RoS hangs on the thread of this prediction/assumption.
As I said, frame it anyway that you like. The basic fact remains, there is no empirical observation that can be made to verify (or falsify) the claim that the clocks in the given frame are synchronised. The conclusion of RoS rests entirely on this claim.
The frame-dependent description of two clocks as synchronised follows deductively from the postulates of special relativity and the application of the Einstein synchronisation procedure. Even if we cannot carry out an experiment involving the clocks that distinguishes special relativity from some alternative, simultaneity is not assumed. Alice's confidence in special relativty would have come from its broad predictive power, its practical successes, and the simplicity of its postulates.
This would only amount to Flying Spaghetti Monster circular reasoning if Alice assumed special relativity, concluded simultaneity, and concluded special relativity based on simultaneity. She does not do this.We can substittue the Einteinian interpretation of "the constancy of the speed of light" for an interpretation that says the measurement of the speed of light will always return the same value.
Broadly speaking, there seems to be two ways you could do this: i) Adopt some instrumentalist interpretation that treats special relativity like a recipe for making predictions about what we will observe. ii) Construct a formalism not based on a universal speed of light postulate that reproduces all the success of special relativity with simpler commitments.
Your thesis attempts ii), but it doesn't give special relativity a fair shake, as it misrepresents Alice's conclusions as explained in a previous post.0 -
The fact that no experiment can be carried out to verify the synchrony of the clocks means precisely that the simultaneity of the [clock synchronisation] events must be assumed. It may follow deductively from the postulates but so too does the prediction about the clock reading that is supposed to co-incide with both events. Einstein even talks about something similar in the 1905 paper when he talks about the train arriving at 7 O'Clock, with the arrival of the train being simultaneous with the time on the watch. Given that this prediction cannot be validated experimentally, empirically speaking, its accuracy can only be assumed.The frame-dependent description of two clocks as synchronised follows deductively from the postulates of special relativity and the application of the Einstein synchronisation procedure. Even if we cannot carry out an experiment involving the clocks that distinguishes special relativity from some alternative, simultaneity is not assumed. Alice's confidence in special relativty would have come from its broad predictive power, its practical successes, and the simplicity of its postulates.
This would only amount to Flying Spaghetti Monster circular reasoning if Alice assumed special relativity, concluded simultaneity, and concluded special relativity based on simultaneity. She does not do this.
The presence of an alternative explanation for the actual observations Alice makes, only serves to demonstrate that the contention - the clocks in her system are synchronised - is an assumption.
In the paper - I still use the word "paper" for want of a more accurate term - I definitely don't flesh out the issues pertaining to the Einsteinian interpretation fully, or the alternative interpretation I have in mind. That is largely down to my lack of experience in constructing arguments in a rigorous manner from the outset. It is through disscussions like this that I flesh out the ideas - another reason I am grateful for yer engagement. I have had a bit of time to try and clarify my thoughts on the alternative interpretation, which might [hopefully] help to illuminate my thinking.Broadly speaking, there seems to be two ways you could do this: i) Adopt some instrumentalist interpretation that treats special relativity like a recipe for making predictions about what we will observe. ii) Construct a formalism not based on a universal speed of light postulate that reproduces all the success of special relativity with simpler commitments.
Your thesis attempts ii), but it doesn't give special relativity a fair shake, as it misrepresents Alice's conclusions as explained in a previous post.Lorentz-Poincare style InterpretationI say its an LP style interpretation to differentiate it from the Einsteinian interpretation, but the interpretation I have in mind doesn't presuppose an Ether or absolute reference frame. There are 2 ways I have been thinking about this, one is the LP route, the other is the SR route. I'm not sure which works best for explanatory purposes, but I will try the LP route first.
Removing the Ether
Lorentz and Poincare were trying to develop a constructivist theory which is why they were so intent that there must be an Ether. The Ether however was undetectable in the theory and as such could simply be removed to leave an absolute reference frame. This effectively leaves us with a kinematical intepretation, albeit with an undetectable absolute reference frame.
Removing the absolute referene frame
We can think of the absolute reference frame as a sort of scaffolding that we can later remove. We need it, in this case, only for the psychological purposes of helping us to imagine a scenario in which Alice's clocks are not synchronised in her own frame.
Poincare used the absoute reference frame to define the motion of two subsequent reference frames. With the motion of each, defined relative to the absolute reference frame, he then derived the Lorentz transformation for the transfer of co-ordinates between those two frames.
With this done, and with the absolute reference frame being undetectable, we can simply remove the "scaffolding" and we are left with the two relatively moving frames, with their local, unsynchronised clocks, where length contraction is an issue of measurement arising from the non-synchronised clocks.
If we go the Einsteinian route, we simply drop the assumption that clocks in the "stationary system" are synchronised. This is obviously the simpler route, theoretically, but when Special Relativity has become inuitive, it might run into cognitive resistance.The Conclusions
Relativity of Simultaneity
As has been mentioned, there are two parts to the conclusion that simultaneity is reltaive/frame dependent; the first part - "events which are simultaneous in one frame i.e. the "stationary" frame" - cannot be verified experimentally and so it must be assumed. This is borne out by the possible alternative intepretations. The second part - "are not simultaneous in relatively moving frames" - is based on empirical observation - insofar as the thought experiment represents and idealised experiment.
The alternative interpretation simply drops the untestable assumption/prediction.
Length Contraction
If we think about "the Ladder Paradox" and think about how it is resolved. Obviously, it cannot be resolved on the basis of empirical observation, because there could be no possible way that an observation of the ladder both fitting inside the garage and not fitting inside the garage could be made. In the physical world, it would be a paradox. Instead, it is resolved on the basis of the disagreement over clock synchronisation.
This is precisely how the [actual] LP interpretation would see the issue resolved, as an issue pertaining to clock synchronisation. What then is the difference? It's that the Einsteinian interpretation adds the extra assumption pertaining to the synchony of the clocks and gives rise to the idea of real, reciprocal length contraction. Again, it just involves the same additional, untestable assumption about clock synchronisation.
Time Dilation
I was having trouble with this for a while, until I realised that it actually provides the justification for a preferred/privileged reference frame.
If we think back to how Poincare derived the formula for the Lorentz contraction, he started with the absolute reference frame and then had two reference frames moving relative to that. For the sake of this discussion, lets imagine that each reference frame was moving relative to the absolute frame with the same relative velocity. Essentially, both clocks tick slowly by the same amount.
If we imagine Alice and Bob in those frames each with their light clock. Each would see the photon in their clock travel the perpendicular distance between the mirrors. Alice would see the photon in Bob's clock travel the longer, diagonal distance. However, unbeknownst to her, the photon in her clock is also traveling the same distance. This means that the duration of her "tick-to-tock" (perpendicular distance) is the same as Bob's "tick-to-tock" diagonal distance. This would mean that she doesn't actually see Bob's clock tick slower; she would either conclude that light travels faster for Bob or that the photon in her clock is also traveling the longer distance.
This would make it seem that the LP interpretation doesn't actually predict "time dilation" at all. Indeed, it would be an issue if such an obseration were possible. It would however, be an even bigger issue for the Einsteinian interpretation if such an observation were possible, because the paradox of reciprocal contractions would be laid bare.
Instead, we need only think about how the Twin Paradox is resolved and the Hafele-Keating experiment is conducted. In both cases, the clocks must be reuinited in a single reference frame and the differences in elapsed times compared. This has the effect of privileging the reference frame in which the clocks are reunited. It isn't that nature privileges a reference frame, we, as experimenters must privilege a reference frame as a matter of operational necessity. Indeed, any reference frame could, in theory, be chosen as the "privileged" reference frame meaning that it isn't really all that privileged. Of course, there exists a class of reference frames which we can subject to accelearation more readily than others.
As a further matter of operational necessity, a reference frame is privileged when it is chosen as the reference frame in which to define the units of measurement that we use in experiments. For us, that is obviously the reference frame of the Eearth - be that the atomic clocks in Colorado or Greenwich.0 -
I'm just reading Time, Tense, and Causation by Michael Tooley and I read something in there that might help to clarify one of the points I was making:
Round-Trip Light Principle—where this is the principle,not that the round-trip speed of light is a constant relative to all inertial frames,but rather that the round-trip speed of light is a constant as measured within all inertial frames.
I'm not sure if that exactly fits with what I am saying, but it sounds similar.0 -
The fact that no experiment can be carried out to verify the synchrony of the clocks means precisely that the simultaneity of the [clock synchronisation] events must be assumed.
What Alice assumes (for the purposes of your thought experiment) is the postulates of relativity. Alice gives a justification for her belief in the synchronised clocks, based on relativity and proper adherence to the synchronisation procedure. The synchronised clocks are inferred, not assumed.
This is not some small quibble about language since, in your paper, you use "assume" to mean neither Alice nor Bob can justifiably assert their clocks are synchronised. But both can justifiably assert their clocks are synchronised if relativity is assumed.The presence of an alternative explanation for the actual observations Alice makes, only serves to demonstrate that the contention - the clocks in her system are synchronised - is an assumption.
There are always alternative explanations to any observation.
I don't think we continue with the rest of the conversation until this point is resolved.0 -
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I've been addressing this very issue in a similar discussion on another platform. I think it might be an intuitive response to say that Alice assumes the postulates of relativity, bcos there is an assumption that the self-consistency of relativity is being challenged. I'm inferring this from the other discussion, so apologies if it isn't the case here. It might be worth stating however, that the internal consistency isn't being challenged here, indeed the self-consistency of SR is assumed in the context of this discussion.What Alice assumes (for the purposes of your thought experiment) is the postulates of relativity. Alice gives a justification for her belief in the synchronised clocks, based on relativity and proper adherence to the synchronisation procedure. The synchronised clocks are inferred, not assumed.
This is not some small quibble about language since, in your paper, you use "assume" to mean neither Alice nor Bob can justifiably assert their clocks are synchronised. But both can justifiably assert their clocks are synchronised if relativity is assumed.
There are always alternative explanations to any observation.
I don't think we continue with the rest of the conversation until this point is resolved
So, Alice doesn't assume the postulates of SR. Alice is aware that there are different, contradictory interpretations of the evidence. She carries out the clock "synchronisation" procedure and then does a cross-comparison of the competing interpretations, to see if she can gleam any further insight by playing the different interpretations off against each other.
Alice can see that, according to one interpretation (SR) the clocks in her frame of reference are synchronised, however, acccording to other [absolutist] interpretations (Etherless-Lorentz-Poincare/Michael Tooley/Michael Tooley sans absolute reference frame) the clocks in her frame are not synchronised. All of the interpretations are empirically equivalent.
Given that the same evidence leads to contradictory interpretations:
1) clocks are synced in her frame
2) clocks are not synced in her frame
The evidence does not distinguish between the two and so neither proposition can be inferred from the evidence. If Alice concludes that the clocks in her frame are in sync - as the first part of the conclusion of RoS does - she does so by assuming that he clocks are synced, in her frame. In doing so, the conclusion of RoS is assumed.
Implicit assumption of simultaneity
Given that Einstein's clock synchronisation convention establishes by deffinition that the time for the signal from emitter to clock A is equal to the time from emitter to clock B (with the reverse for the return journey), by extension the synchronisation of the clocks is estabished by definition. Said another way, the simultaneity of clock synchronisation events is implicitly assumed, by the synchronisation convention.
It's like saying, assume that Alice is moving relative to Bob. Implicit in this, is that Bob is moving relative to Alice. Establishing one fact implicity/simultaneously establishes the other.
Derived from the Isotropic, one-way speed of light
If we take the contention that the simultaneity of clock synchronisation events is derived and not assumed; obviously, from the above, I disagree, but for arguments sake, we can examine that propostition:
If we establish by definition that the time from emitter (with its own clock) to A equals the time from emitter to B (and likewise for the return jounrey) then there are 2 things that we can "derive" from that:
1) the clock synchronisation events are simultaneous, in the given frame i.e. they co-incide
with the reading d/2 on the clock at the emitter (mid-point)
2) the light pulses will return to the mid-point simultaneously.
Here, we have derived two statements about the configuration of the physical system. While the two statements have been derived from the same information, there is a key difference between them. That difference pertains to their empirical verifiability. As we know, statement #2 above can easily be tested and indeed it is. It represents a testable prediction of all of the various interpretations.
As we both know, #1 above simply cannot be tested. While the fact that it can't be tested puts it into a different class than statement #2, this different classification doesn't explain away the fact that it represents an untestable prediction.
It might not be such an issue if one of the most counter-intuitive conclusions, in the SR interpretation, didn't depend entirelly upon it. The fact that the conclusion, that simultaneity is relative, rests entirely on this untestable prediction makes it a bug, not a feature, of the interpretation.
It cannot be tested, therefore it is assumed. In assuming this, so is the conclusion of RoS assumed - because without that assumption, RoS simply disappears.0 -
Alice can see that, according to one interpretation (SR) the clocks in her frame of reference are synchronised, however, acccording to other [absolutist] interpretations (Etherless-Lorentz-Poincare/Michael Tooley/Michael Tooley sans absolute reference frame) the clocks in her frame are not synchronised. All of the interpretations are empirically equivalent.
Implicit assumption of simultaneity
Given that Einstein's clock synchronisation convention establishes by deffinition that the time for the signal from emitter to clock A is equal to the time from emitter to clock B (with the reverse for the return journey), by extension the synchronisation of the clocks is estabished by definition. Said another way, the simultaneity of clock synchronisation events is implicitly assumed, by the synchronisation convention.
In this case, Alice is doing a very peculiar thing. She appears to be initially agnostic about special relativity vs other accounts, but then assumes her clocks are synchronised, assumes relativity of simultaneity, and concludes special relativity as the superior account. Few people would find her reasoning compelling.
Special relativity, of course, wasn't established on an experiment involving moving trains. It was established on its Lakatosian success as a research program.As we both know, #1 above simply cannot be tested. While the fact that it can't be tested puts it into a different class than statement #2, this different classification doesn't explain away the fact that it represents an untestable prediction.
Similarly to the above, if Alice arbitrarily adheres to the one-way speed of light postulate, this experiment will do little cement her views.
If your claim is merely that this thought experiment, evaluated in isolation, does not constitute evidence for special relativity over other interpretations, you won't get many arguments. But your paper seems to be doing something else. It seems to be arguing that the experiment reveals some sort of deficiency in SR.0 -
Alice represents anyone who concludes that simultaneity is relative. They do so by assuming the conclusion.In this case, Alice is doing a very peculiar thing. She appears to be initially agnostic about special relativity vs other accounts, but then assumes her clocks are synchronised, assumes relativity of simultaneity, and concludes special relativity as the superior account. Few people would find her reasoning compelling.
Its success as a Lakatosian research program appears to have inspired a number of people to develop thought experiments that allow us to examine the empirical consequences of the theory in a manner that would otherwise not be practical. As idealised representations of plausible [but not practical] real-world experiments, the thought experiments allow us to derive statements about what the theory logically necessitates. One such statement pertains to the simultaneity of clock synchronisation events in a given frame. Whether it represents the kind of "hard core" assumption that would be under consideration in a Lakatosian research program, it nonetheless represents a conclusional assumption, an assumption that forms an integral part of the conclusion of RoS.Special relativity, of course, wasn't established on an experiment involving moving trains. It was established on its Lakatosian success as a research program.
It reveals that the simultaneity of clock synchronisation events in a given frame is derived from [but not necessarily implied by] the mathematics of the theory. This derivation is in the domain of abstract mathematics. Mathematically derived predictions require empirical verification, by way of experiment - a domain in which the rules of empiricism apply.If your claim is merely that this thought experiment, evaluated in isolation, does not constitute evidence for special relativity over other interpretations, you won't get many arguments. But your paper seems to be doing something else. It seems to be arguing that the experiment reveals some sort of deficiency in SR.
Given that the simultaneity of clock synchronisation events cannot be determined by way of experiment, they cannot be empirically verfified or falsified, therefore, in terms of empiricism, they represent assumptions.
As the conclusion of RoS includes a statement about the simutaneity of [clock synchronisation*] events which cannot be empirically tested and must therefore be assumed - empirically speaking - the conclusion of RoS is therefore an assumed conclusion i.e. it is circular reasoning.
If this is some sort of deficiency in SR - and I argue that it most certainly is - then it is bcos circular reasoning and unfalsifiable predictions are deficiencies; particularly when it is possible to derive an interpretation which explains the body of existing empirical tests without any of the additional untestabe claims.
*not specifically clock synchronisation events, but inclusive of them, and in such a way that we can extrapolate to all "simultaneous events", in the given frame.0 -
It needn't be that difficult to see. Just put yourself in Alice's shoes. You are located at the mid-point between two clocks; you have your own clock; you send out a light pulse from the mid-point to each clock. Can you be sure that the light pulses reached each clock simultaneously? Can you be sure that as your clock read the time d/c, the light pulses were making physical contact with the other two clocks?
You know that you can't be sure. You know that you cannot verify this empirically. You know, therefore, if you make any statement whatsoever, to the effect that the clocks are synced - in a frame dependent manner or otherwise - you are making an assumption.
Simply by virtue of the fact that you haven't observed it.0 -
Alice represents anyone who concludes that simultaneity is relative. They do so by assuming the conclusion.
I don't know what you mean by this.
Presumably, either Alice is agnostic about special relativity and adopts seemingly arbitrary assumptions about auxiliary hypotheses re/ clock synchronisation to arrive at it as the correct theory.
Or Alice, being well versed in physics as a discipline, accepts the postulates of special relativity with a high degree of confidence and interprets the theory in a sound and consistent manner.Its success as a Lakatosian research program appears to have inspired a number of people to develop thought experiments that allow us to examine the empirical consequences of the theory in a manner that would otherwise not be practical. As idealised representations of plausible [but not practical] real-world experiments, the thought experiments allow us to derive statements about what the theory logically necessitates. One such statement pertains to the simultaneity of clock synchronisation events in a given frame. Whether it represents the kind of "hard core" assumption that would be under consideration in a Lakatosian research program, it nonetheless represents a conclusional assumption, an assumption that forms an integral part of the conclusion of RoS.
I don't know what you mean by "conclusional assumption". It is an uncontroversial inference from the postulates of relativity, as is relativity of simultaneity.Mathematically derived predictions require empirical verification, by way of experiment - a domain in which the rules of empiricism apply.
Why? Lots of theories make all sorts of predictions about observations we cannot make.0 -
Or Alice, being well versed in physics as a discipline recognises that there are contradictory theories/interpretations.I don't know what you mean by this.
Presumably, either Alice is agnostic about special relativity and adopts seemingly arbitrary assumptions about auxiliary hypotheses re/ clock synchronisation to arrive at it as the correct theory.
Or Alice, being well versed in physics as a discipline, accepts the postulates of special relativity with a high degree of confidence and interprets the theory in a sound and consistent manner.
She does the sync procedure and the light signals return simultaneously. She looks at the two interpretations and thinks:
"My clocks might be synced, or equally, they might not be. The evidence is inconclusive. I cannot be sure that they are synced. If I conclude that they are synced, without having observed it, then that is a conclusion which I am assuming to be true - precisely bcos I haven't obseerved it, I haven't verified it empirically"
However, it is a controversial (and unjustified) inference from the available empirical evidence.I don't know what you mean by "conclusional assumption". It is an uncontroversial inference from the postulates of relativity, as is relativity of simultaneity.
Conclusional assumption as opposed to foundational assumption.
If the assumptions of those theories form a critical part of their conclusions then they too assume their conclusions.Why? Lots of theories make all sorts of predictions about observations we cannot make.
It is possible to interpret relativity in such a way as not to assume conclusions.0 -
Or Alice, being well versed in physics as a discipline recognises that there are contradictory theories/interpretations.
She does the sync procedure and the light signals return simultaneously. She looks at the two interpretations and thinks:
"My clocks might be synced, or equally, they might not be. The evidence is inconclusive. I cannot be sure that they are synced. If I conclude that they are synced, without having observed it, then that is a conclusion which I am assuming to be true - precisely bcos I haven't obseerved it, I haven't verified it empirically"
We are beginning to go in circles.
If Alice accepts special relativity, she does not say "my clocks might be synced, or equally, they might not be". She instead infers clock synchronisation as a frame-dependent description. She infers it with good reason (the unparalleled success of relativity as a scientific theory). Describing it as an assumptions implies she cannot justifiably assert it. But she can justifiably assert it, based on the remarkable success of special relativity.However, it is a controversial (and unjustified) inference from the available empirical evidence.
If by "all available evidence" you mean the observations made during this experiment and this experiment alone, sure. But nobody would claim that special relativity, clock synchronisation, or relativity of simultaneity is established by this experiment and this experiment alone.
If, instead, special relativity is a well-established theory, then the inference is uncontroversial and justified.0 -
Except that the remarkable success of Special Relativity is equally the remarkable success of those mathematically and empirically equivalent theories. Check out a paper titled:We are beginning to go in circles.
If Alice accepts special relativity, she does not say "my clocks might be synced, or equally, they might not be". She instead infers clock synchronisation as a frame-dependent description. She infers it with good reason (the unparalleled success of relativity as a scientific theory). Describing it as an assumptions implies she cannot justifiably assert it. But she can justifiably assert it, based on the remarkable success of special relativity.
On the Empirical Equivalence between Special Relativity and Lorentz’s Ether Theory by Pablo Acuna. I have attached a copy here. Acuna argues in favor of SR saying the two can be distinguished on the basis of empirical evidence, but he outlines how the two theories are equally "remarkably successful".
Given this empirical equivalence, Alice doesn't simply accept Special Relativity, she is skeptical of it. She sees two empirically equivalent interpretations, one which says that the clock syncing events were simultaneous in her frame, the other which says they weren't. Therefore, she concludes, "my clocks might be synced, or equally, they might not be, I simply cannot make that determination on the basis of the empirical evidence".
Given that a critical part of the conclusion of RoS includes a statement about the simultaneity of [clock syncing] events, in her frame, coupled with the fact that she cannot determine the truth of that statement empirically, she therefore, can only assume the truth of it. Assuming the truth of that statement assumes a critical part of the conclusion of RoS.
The finite speed of light is sufficient to demonstrate that she cannot make an empirical observation of the clock syncing events, and so, can only assume its validity.
Except for the fact that the mathematically and empirically equialent competing theories, which make the opposite claim, are equally well-established (by the empirical evidence).If by "all available evidence" you mean the observations made during this experiment and this experiment alone, sure. But nobody would claim that special relativity, clock synchronisation, or relativity of simultaneity is established by this experiment and this experiment alone.
If, instead, special relativity is a well-established theory, then the inference is uncontroversial and justified.
This thought experiment allows us to make further deductions about the different interpretations.0 -
To me this discussion has become pointless and will only form an empirical test of Morbert's patience.
The isotropic constancy of the speed of light is the assumption Einstein makes, he does not assume synchonisation. This has been explained to you multiple times and is blatantly obvious if one knows the theory mathematically. There is no point continuously asserting that they are assuming synchronisation.
Here we have two options. That the world is described by Minkowski spacetime because that is the actual structure of the world (Einstein's view ultimately) or that the Minkowski structure is an illusion of the underlying dynamics. There's no real reason to go with the latter. One can make the same statement about any physical theory, is there really an electric field or is it just an illusion due to how some objects move for other reasons.
Add to that that if the world wasn't really Minkowskian particles would operate differently. The "illusion" argument only works with Special Relativity in isolation. If the world isn't really Minkowskian it is very difficult to explain why particles work as they do.
It's the actual mathematical geometric structure of the true space/spacetime. How particles behave is then a result of the symmetry group of the true space/spacetime. They won't operate based on an illusory one, only the geometry of the true one. This is why I find this "illusion of the dynamics" argument hard to believe.I have an of what it is, I'm wondering how this description is determined/derived. What is it that gives us the information about the true space/spacetime in the model.
I've looked over your posts and I see you have been arguing about Relativity for ten years without ever reading a textbook on Relativity. Instead reading multiple discursive monographs with little mathematics by people with alternate views. Wouldn't it be better to just read a standard college textbook on the subject so that you actually understand the mathematics of what you are arguing against.
Arguing against a theory that you have to be half-educated in as you debate it is pointless.
This is my final post on the topic.0 -
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Except that the remarkable success of Special Relativity is equally the remarkable success of those mathematically and empirically equivalent theories.
Except for the fact that the mathematically and empirically equialent competing theories, which make the opposite claim, are equally well-established (by the empirical evidence)
From the paper you included
"Lorentz‘s theory—in spite of its predictive equivalence with respect to special relativity—does not fit within general relativity. As mentioned above, it claims that the physical world, in its spatiotemporal features, has the structure of Newtonian space-time. Therefore, even if we take Lorentz‘s theory as holding for a local region of a global space-time, it is in conflict with the meaning of general relativity. Einstein‘s gravitational theory states that the geometry of an infinitesimal region of a global space-time does not approximate to the geometry of a Newtonian space-time, but to the geometry of a Minkowski space-time. Despite the mathematical and empirical equivalence between Lorentz ̳s theory and special relativity, the former cannot be understood as a special case of general relativity; the theories are incompatible."
Special relativity's fundamentally geometric account of the laws of physics and spacetime lets us relax assumptions about the global structure of events via the principle of equivalence. The laws of physics become the same (on a fundamental level) in curved as well as flat spacetimes. Geometries as prior inputs to a theory can be eschewed in favour of geometries that emerge as solutions to equations involving matter and energy. These geometries also naturally account for gravity, thereby coupling matter and energy to gravity, giving us a powerful theory of gravity.
Even in the frontiers of physics, where a quantum theory of gravity is not complete, the flexibility of fundamentally geometric accounts lets us apply the equivalence principle and study quantum mechanics on curved spacetimes and all its concomitant implications.
These are impressive notches, clearly evidencing special relativity's success over competing projects.0
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