Theoretical Concepts and Empirical Equivalence: Will the Real Concept Please Stand Up

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That’s right, but time dilation is just one of the corrections. As I showed in my post, physicists study all kinds of physical effects that can affect atomic clocks, not just time dilation from special and general relativity.

The point is that we find we can’t keep them in sync without applying the relativistic corrections. And we’ve studied all sorts of physical mechanisms (unrelated to SR and GR) that can result in the clocks rate changing, but none of them were significant enough to explain the change in clock rate when we change the altitude of the clocks. The best explanation that fits the evidence is that the relativistic correction is physically real; i.e. it’s not a fudge factor that physicists put in to reflect their ignorance about physical effects on clocks, but the result of actual time dilation at different attitudes as predicted by GR.

I’m not a logical positivist, and neither is @structureoftruth (who knows about A-theory and the neo-Lorentzian interpretation of SR) nor hundreds of professional philosophers of time out there who know the physics well. The issue is not with logical positivism. It’s rather just about being informed about what you want to talk about!

I don’t think you understand “effects of altitudes”. If a physicist sees that the ticking rate (frequency) of her clock changes as its altitude is changed, they are usually not satisfied with that fact. Why does altitude cause a change in its rate? What mechanism does that correspond to?

It could be that when I lifted the clock from the floor to a table a meter above the ground, I accidentally expose it to heater that just happens to be lying on the same table. Exposure to heat is well-known to cause changes in atomic energy levels that the clock uses. There is a whole theory explaining why (see the paper I cited above). So it is unsurprising that the clock rate changes. In response, I remove the heater from the table and shield the clock using a shroud to keep it isolated from any temperature changes as I change its altitude.

I repeat the experiment again, lowering the clock back to the floor and back up to the table, taking note of its frequency. I notice that there is still a small but noticeable frequency shift as I do this. Where is this coming from? I look around for other physical effects that might possibly cause changes in frequency, such as whether my laser intensity changes, the electric fields I apply to the atom, etc. I measure and study these shifts independently of the altitude problem. Even after going through all of these known effects, I still can’t find a way to explain that frequency shift.

Then I open my general relativity book, which argues that time dilates as a clock is shifted in altitude, which would cause it to shift frequency. I calculate the amount of shift predicted by the equations of GR (which assume that time dilation exists) for my clock. I find that it matches the measured frequency shift as I change the altitude of the clock very well. Thus, I conclude that time dilation must have been responsible for the frequency shift, because it’s well calculated by GR which assumes that the mechanism by which this happens is time-dilation.

Now, there are some alternate possibilities:

  1. The frequency shift is only coincidentally the same as that predicted by GR. Its real mechanism is something completely different that I failed to take into account. The problem with this hypothesis is that people have studied atomic clocks very well and have a good handle on various kinds of regular physical mechanisms that can disturb them. The burden of proof is on the proposer to empirically demonstrate a physical mechanism that has not been considered before.

  2. GR does predict the frequency shift well, but GR has been interpreted wrongly. There is a different and possibly deeper theory which produces the same equations as GR for atomic clocks changing altitude, but with different philosophical presuppositions (which for example do not involve time dilation). Once again, the burden of proof is on the proposer of this explanation to elucidate what that theory is and why it is more preferable to the conventional interpretation of GR. This seems closest to your stance, but I just haven’t seen any sort of elaboration from you on what that theory is.

Some more comments on cause and effect and equations. Your statement that

seems confused. It’s true that there could be a deeper explanation of what causes the equations to be true to reality (that’s why there’s all these arguments about God causing them to be true, for example). However, that does not preclude the possibility of lower-order causes and effects being encoded and reflected in the equations of physical theories. For example, with Newtonian mechanics I can physically describe how one billiard ball hits another one and causes it to start moving. Similarly, I can physically describe the curvature of spacetime causing time dilation at different altitudes.

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I’m even more confused. I offer an example of subjective evidence that time can seem to slow down, and you dismiss that as a mere psychological phenomenon. We’ve been talking about evidence from the physical sciences that time can slow down, and you dismiss that as being “unverifiable”. If physical sciences and private perception are both unreliable to determine the nature of time, then what is your basis for whether we can know anything about time?

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OK. I see what you’re saying now. So we’re talking about accounting for an effect that can’t be accounted for by physical effects that we can detect, right? If so, the assumption is, since we can’t detect it, it must be time slowing down since that’s the concept of SR on which time dilation is based. Correct?

But if that’s the case, why can’t we also instead assume that it could be some physical effect from something like gravitational fields that we’re just not capable of detecting causing the clock rates to change? Both are equally valid assumptions as far as I can tell.

So for you, the fact that we can’t detect a physical cause for the clocks slowing down, and that the concept of time slowing down is the framework for formulating the successful time dilation equations of SR that accurately account for the “missing” time is evidence that supports the claim that time itself can “slow down,” and by doing so can actually have physical effects on reality and cause clock rates to change at varying altitudes. And the way you see it, that evidence sufficiently outweighs the contrary evidence of our everyday experiences and observations.

And for me, I see the weight of the evidence coming down on the side of some physical effect that we are unable to detect possibly having something to do with gravitational fields that are effecting the clock rates themselves, and that time is just a human convention that if it exists at all is simply a causally effete abstract object similar to mathematical numbers. Would you agree with that assessment of our two opposing positions?

Personally how I see it is that it doesn’t make sense to say that, even though unverifiable, the physical cause of time dilation is time itself as some kind of physical entity actually physically slowing down and having a physical effect on clock rates.

To me it makes more sense to say that even though unverifiable there is some physical effect to the clocks most likely caused by changes in their location within the gravitational field that cannot be detected. The evidence that I’ve laid out in the argument I made, in my opinion, comes down on the side of the latter.

I wasn’t implying anything about anyone’s personal position on logical positivism. What I was implying is that there are remaining vestiges of it and other related views no longer recognized as valid positions, that in my opinion, haven’t been fully recognized as such but nonetheless are still lurking underneath claims made today in science and philosophy.

If you’r asking about the mathematical mechanism, I would say that time dilation would apply just as much to the one explanation as to the other. What the relevant question should be that the mathematical mechanism doesn’t answer is, “What is the physical cause?” And that is a question that cannot be resolved by verification. It has to be abduced.

And as far as I can tell, there are two possible options.

  1. Some undetectable physical effect possibly from gravitational fields is causing clock rates to change at varying altitudes.
  2. Time itself is some kind of undetectable physical entity which inexplicably changes speed when clocks are placed at different altitudes, which in turn somehow, without being detectable, physically affects the clock rates and causes them to change.

Though I did the best I could, I may not have understood how to correctly represent the second option. But if that is a correct representation, I would say that the first option is by far the most reasonable of the two options.

I would argue that this is confused. The discussion isn’t about the equations. It’s about whether or not a concept in a mechanical theory is true to unverifiable reality. The equations simply give an accurate description of verifiable reality.

Umm, I’m not sure you’ve understood my positions. First I would ask if you recognize that all experiences are not created equal. For example, I would argue that experiences centered around emotions are probably the least reliable of our experiences in determining what’s real.

And I never said that the physical sciences are not reliable. For the most part, they are extremely reliable when it comes to verifiable reality. That the assumptions made in general, and particularly about whether or not the concepts employed in mechanical theories are reliable accounts of unverifiable reality, are really all that I’m questioning.

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As I predicted, your position matches option No. 3 in my previous post (did you miss it?):

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No. I don’t agree with this. The way I see it the question of the truth of unverifiable reality is not what mechanical theory is about. It’s directed at verifiable reality. As far as I’m concerned equating mechanical theory with such is to claim that the truth of unverifiable reality is entailed by the theory.

Relativity does what it is designed to do, successfully describe verifiable reality. That’s all that’s required of it. It’s not an either, or situation when it comes to unverifiable reality. It’s just not what mechanical theory is about. It can indicate what unverifiable reality might be, but it doesn’t entail what it is. And I would argue that anyone who claims otherwise needs to demonstrate why that’s the case.

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It’s called relativity. More specifically, time contraction between inertial frames.

As I mentioned earlier, the observation that light travels at the same velocity in all inertial frames demands that time itself ticks at different rates in different inertial frames. We can predict how much time will contract between observers from first principles, and all we need is the observation that light travels at a constant speed.

I would strongly recommend taking a look at the webpage below. It demonstrates how to derive Einstein’s equations from first principles.

http://dallaswinwin.com/Special_Relativity/timedelation.htm

What I am saying is that they are in sync sitting next to each other. If you take one of those clocks up into an airplane, fly around for a while, and then bring the clocks back together what you will observe is that they don’t show the same time anymore. The rate at which time itself passed for each clock was different which is why they no longer show the same time.

You want to claim that there is some other force or mechanism that is throwing the clocks off. What is it?

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OK. I think the term mechanism needs to be clarified. I believe what the term means in this context is the mathematical formulas that describe aspects of verifiable reality. They don’t have causal powers, but are only descriptions. But the question being addressed is, “What is the physical cause of what’s happening?”

Is it time slowing down, or somethings else? If it’s time slowing down, can it be verified in terms of what it is that physically causes time to slow down when clocks are moved around? Not what the mechanism is. That’s just mathematical formulas that describe the effect. But what physically causes time to slow down, and how does that in turn cause clock rates to be effected? I don’t think there’s any way to verify that.

And it can said that evidence suggests that the concept of time slowing down employed for formulating time dilation is physically real, but it can’t verified. It can only be abduced. Just as it can be said that evidence suggests that an undetectable force, something like gravitational waves, is causing clock rates to be affected. It also can’t be verified but has to be abduced. So the question is, “Which explanation makes the most sense of the relevant available evidence?”

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Mechanism means the physical cause. In my field, a drug’s mechanism of action is the description of the specific chemical and physical interactions that the drug has with the body. Mechanisms are causal powers.

Why not?

Again, a constant speed of light demands that time contracts.

http://dallaswinwin.com/Special_Relativity/timedelation.htm

Time contraction makes the most sense of the constancy of the speed of light and the results from all of these experiments.

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That may be the case in your field, but how I understand it, not when it comes to mechanical theories. They are simply mathematical equations that describe aspects of verifiable reality. They are abstractions that are causally effete.

OK. Explain to me how concepts which are mental constructs that may or may not be true representations of physical realty which cannot be physically observed nor detected can be verified. And don’t confuse the issue with mathematical equations of time contraction.

They simply describe the effect. Verification would be actual observations of time itself slowing down, which to my knowledge no one has been, or most likely ever will be able to do, especially if time itself is in actuality just an abstract object at best.

Time contraction is simply a concept that provides the framework for formulating equations. It’s an unverifiable idea in the mind and therefore if claimed as actual reality has to be inferred from relevant evidence.

Seems we’re still going round and round in circles about what’s verifiable and what’s not. If you can explain to me how the concept of time contraction is verifiable as per my above comment, then please do so.

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Then you understand it wrong.

They can be physically observed, detected, and verified. I have given you examples of the experiments where this was done.

It was done in the Hafele-Keating experiment.

Time contraction was verified in the Hafele-Keating experiment.

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OK. This seems to be where the major hang up is. No point answering the rest of your comments as they all hinge on this issue. So explain to me, how can a mathematical formula possess causal powers?

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I never said it does. What I am saying is the definition of the word “mechanism” means “the physical cause of an event”.

You are claiming that elevation somehow causes clocks to incorrectly measure time. I am asking for the physical cause that results in clocks incorrectly measuring time.

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So what then are you referring to as a mechanism in a mechanical theory in physics? Are you saying the concepts are the mechanisms?

You are claiming that time can slow down and result in clocks incorrectly measuring time. What is the physical cause for time itself slowing down which in turn somehow causes clocks to incorrectly measure time? And how do we even know if time exists other than as a human construct or at best as an abstract object?

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The theories are describing the proposed mechanisms. The mechanisms are the actual physical processes.

No, I am not saying that. What I am saying is that the clocks accurately measure time in their frame of reference and it is time itself that ticks at different rates.

You are saying that changing elevation somehow makes clocks measure time incorrectly since time itself is ticking at the same rate at different elevations. This is your explanation for why clocks tick at different rates in different inertial frames. I am asking for the physical cause that results in clocks incorrectly measuring time.

I already explained this.

It’s called relativity. More specifically, time contraction between inertial frames.

As I mentioned earlier, the observation that light travels at the same velocity in all inertial frames demands that time itself ticks at different rates in different inertial frames. We can predict how much time will contract between observers from first principles, and all we need is the observation that light travels at a constant speed.

I would strongly recommend taking a look at the webpage below. It demonstrates how to derive Einstein’s equations from first principles.

http://dallaswinwin.com/Special_Relativity/timedelation.htm

If there was no time then entropy could not exist. If entropy does not exist then we can’t exist. Since we do exist, time has to exist.

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I tried to throw a bone to @Jim earlier in the thread regarding the muon lifetime experiment (see the thread that split off from this one here, and my discussion with @T_aquaticus therein). For my part I think @dga471 is exactly right when he says that the following is what Jim is (or should be) aiming for:

I haven’t attempted to fully read every post here and I don’t understand why Jim isn’t on board with that option. But I’ll try to throw him another bone regarding the question of gravitational time dilation:

It will help to reiterate how we can see things for special relativistic time dilation, before moving on to gravitational time dilation. Let’s set up the special relativistic situation: two observers, Alice and Bob, are equipped with measuring rods and clocks and are moving relative to each other. Alice sees that Bob’s measuring rods are contracted in the direction of their relative motion, and that his clocks tick more slowly. (Not only that, but Bob himself is flattened in the direction of motion, and his heart is beating more slowly, along with every other bodily motion and biological process!) And likewise, Bob sees length contraction and time dilation of Alice’s instruments, and Alice herself.

Length contraction and time dilation are often presented as being, somehow, merely the result of perspective. But it is important to realize that this is not the case. These are real physical effects. Bell’s spaceship paradox demonstrates this: if you accelerate the two ends of a taut string so that they keep the same distance apart, the string will experience elastic stresses and eventually break, because it is trying to undergo length contraction as its velocity increases.

More directly, the effects of length contraction and time dilation can be derived directly from the laws of physics in any single reference frame: there is no need to invoke the notion of a change of reference frame. A stationary charged ion has a spherically symmetric electric field distribution. A test particle would orbit the ion in a circle with a certain frequency (suppose it has much smaller charge and mass than the central particle, like an electron orbiting a nucleus with high atomic number - this lets us ignore back-reaction effects from the test particle). But a moving charged particle has an electric field with ellipsoidal symmetry (along with a magnetic field), and a test particle would orbit it in an ellipse (length contracted from a circle in the direction of motion) with a lower frequency (time dilation). These are consequences of Maxwell’s equations, the Lorentz force, and the relativistic relationship between momentum and velocity. To the extent that all the laws of physics share Lorentz symmetry with Maxwell’s equations, these effects will occur for all moving systems.

So Alice can say that Bob does indeed observe her instruments to be length contracted and time dilated from his perspective. But that is in fact the combined effect of his own instruments being length contracted and time dilated, and his clock synchronization procedure being out (relative to Alice’s) due to his motion. (And it can be shown mathematically that all these effects do combine to produce the correct result.)

Now, the usual interpretation of special relativity says that the universe is a 4D spacetime, and Alice and Bob’s reference frames are equally valid (as is any other inertial frame). By contrast, the neo-Lorentzian interpretation says that the universe is a 3D space changing over time, that there is some reference frame (most likely not either Alice’s or Bob’s) which accurately describes the 3D space changing over time (where the apparent simultaneity generated by Einstein synchronization of clocks matches absolute simultaneity), and the physical effects of length contraction and time dilation in this frame accounts for the observations of relativistic effects in all reference frames.

Now, the point I wanted to make here is that something similar can be said about gravitational time dilation. The usual interpretation of general relativity says the universe is a 4D spacetime, with spacetime curvature. A neo-Lorentzian interpretation says that the universe is a 3D space changing in time, with spatial curvature and gravitational effects. Just as length contraction and time dilation are physical effects arising from the special relativistic laws of physics considered in one reference frame, gravitational time dilation is a physical effect arising from the general relativistic laws of physics considered in one coordinate system - all physical processes (and therefore all clocks as well) run slower if they happen closer to a gravitating body compared to farther away. The mechanism for this is just the general relativistic laws of physics operating at the fundamental level of the matter that makes up the clocks, and the processes that make the clock tick.

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What exactly do you mean by that? That isn’t very clear at all. The question I’m asking is, what is the mechanism in a mechanical theory of physics? Is the physical cause, i.e., the proposed mechanism of the theory, the concepts employed by the theory, or the mathematical descriptions of the theory? Unless I’m missing something, for what you’re saying to make sense it would have to be one or the other.

So which is it? I think it’s important to get this clear as I think this may be what the main cause of the general disconnect is in this discussion overall. And I think until this issue is sufficiently settled, responding to any of the other comments that followed by you or @structureoftruth will be fruitless.

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I wouldn’t call that a “neo-Lorentzian” interpretation of general relativity. That’s just the standard (3+1) split in the conventional interpretation of general relativity. To be “neo-Lorentzian” I think would require an appeal towards the existence of some sort of aether, or at the very least, a privileged reference frame.

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Right, I meant to imply that the neo-Lorentzian interpretation considers one of the ways of foliating the 4D space-time into successive 3D slices to be the one that objectively and correctly describes the 3D universe changing over time. (And I’m glossing over the difficulties for postulating such a foliation, which we’ve discussed before.)

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Already answered.

The mechanisms are the actual physical processes.

Once again . . .

You are saying that changing elevation somehow makes clocks measure time incorrectly since time itself is ticking at the same rate at different elevations. This is your explanation for why clocks tick at different rates in different inertial frames. I am asking for the physical cause that results in clocks incorrectly measuring time.

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Right. I think we’ve already established that. But my question is, what is the proposed mechanism in a mechanical theory? Is it the equations, or the concepts?

Since I didn’t receive an answer to that question I’m just going to assume that the concepts in the theory are what are being understood as the mechanisms of the theory since by your response to my question about their causal powers the equations seem to have already been ruled out. So let me see if I can figure out what’s going on based on that assumption.

The question of the mechanisms we’re concerned with is about unverifiable reality. The observations/experiments we’re concerned with verify the effect the equations describe. But the only evidence I see from these observations/experiments for the truth of the concepts, which I’m left to assume are what you hold as the mechanisms of the theory, is the fact that they verify the theory as successful. However it’s not that these observations/experiments in themselves are evidence, but that they simply back up the success of the theory, which in turn is evidence that would support the concepts as possibly true to reality.

But that’s just one piece of evidence to support the truth of the concepts. Another possible evidence I’m wondering about in support of the truth of the concepts in a theory as the actual mechanisms is explanatory scope. But that is something I’m doubtful about until someone can come up with a reasonable argument to show that the different concepts in the theory flow out of one core concept. Otherwise it seems like each concept would have to stand on its own two feet, and therefore it seems wouldn’t count as explanatory scope for the theory as a whole.

Once again, possibly some aspect of gravity that is undetectable. And just to be clear, I’m assuming your proposed physical cause/mechanism is possibly time itself slowing down?

And just to clarify, I’m not saying that my proposed explanation is the only valid explanation. I’m simply arguing for it as the best explanation.

And one more thing. It’s not agreed upon whether or not time exists as an actual physical entity, which as a mechanism would have to be assumed. It’s arguable that it’s just an abstract or humanly constructed measure of change.