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

No, you seem to misunderstand relativity theory. Relativity theory exactly predicts that we would not be able to see its weird consequences using only our senses. Thus, our senses alone are unable to confirm or disconfirm it. Special instrumentation is required. In physics, a good theory must be able to reproduce classical physics in the appropriate parameter regime. This is called the classical limit, or the correspondence principle: Correspondence principle - Wikipedia.

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It seems to me that relativity arose from Maxwell’s equations. And it seems a stretch to say that Maxwell’s equations are about how matter behaves.

First, I just want to make sure we’re both focused on the question of what fundamental reality is like, not on the question of how matter behaves. If so, the fact that we don’t observe any of the weirdness, regardless of the theory predicting that we can’t, I think still provides one piece of contrary evidence.

Edit: Particularly because we’re talking about unobserved reality. So the fact that relativity predicts that we can’t see it seems like a mute point to me.

Edit2: Also the fact that relativity is based on physical constraints, predicting what those constraints don’t allow us to see doesn’t seem to be relevant to the question being asked.

As far as I know physical theories are about predicting how matter behaves as it moves through space. I’m not sure what you’re getting at here?

It seems to me that you’re saying that:

  1. A set of “common sense” observations should dictate what “fundamental reality actually is” at all parameter regimes (from extremely small to extremely large, extremely slow to extremely fast), even if scientific experiments with special equipment reveal to us a very different world in certain parameter regimes that are not accessible via our direct senses.
  2. Weird scientific observations like those mentioned in point 1) should be interpreted in a non-realist way, meaning they are just pragmatic constructions to describe “how matter behaves” (or rather, how matter apparently behaves, from the point of view of scientific instruments), but they reveal nothing about what “fundamental reality actually is”.

Am I correct in phrasing this?

I’m not sure about that characterization. Many of the concepts of physics are abstract. Time and space are abstractions.

The physics of electricity and magnetism came up with electrical fields and magnetic fields. These are abstract mathematical constructs. And yes, they were used to predict motions of matter. Maxwell’s equations are mathematical relations of the electromagnetic fields themselves. With your concerns about realism and anti-realism, I would expect you to have an anti-realist view about electromagnetic fields. Yet Maxwell’s equations showed that electromagnetic fields support wave motion, and the speed of propagation of those waves is about the same as the speed of light. That’s part of what led Einstein toward his relativistic mechanics.

No, not really. I’m not sure but it seems like there’s a bit of a problem in keeping separate the two questions I mentioned previously. Focusing on the reality question means looking for the relevant evidence to see what the preponderance of the evidence points to.

So common sense observations don’t dictate, but play an evidential role in the process. The scientific experiments don’t produce observations of unobservable reality, but they can provide evidence when relevant that needs to be taken into account along with the rest of the relevant evidence to the question of fundamental reality in deciding how to best explain that evidence.

When I’m referring to the weirdness of a theory it’s not in connection with how matter behaves. This can be observed or detected and is generally not at issue here. What is at issue is the weirdness of a theory that concerns reality which is beyond physical constraints of observation or detection, like relativity theory claiming contrary to our perception that space, time, and simultaneity are fundamentally relative in nature, which leads to even more weirdness.

Does that help clear things up a bit?

Let me try and rephrase what you posted to see if that helps.

  1. A set of “common sense” observations should be taken into account as evidence for what “fundamental reality actually is” as well as what scientific experiments with special equipment reveal to us not accessible via our direct senses even if seemingly weird if relevant to the question being asked, as well as any other relevant evidence.
  2. Weird scientific observations like those mentioned in point 1) should be taken into account as evidence when relevant in deciding what best explains the evidence for what fundamental reality actually is. Weird scientific inferences about fundamental reality based solely on the success of a theory should be examined against all available relevant evidence to see how well they explain all the evidence, and judged accordingly.

With realism, I would say my position fits into metaphysical realism in general, and with regards to science it’s sort of in between realism and maybe instrumentalism–instrumentalism in regards to how matter behaves, and a very soft view of realism, where the success of a physical theory is evidence in support of the concept being representative of reality, but not necessarily so. It would have to be shown to be so based on all the available evidence.

I’m referring to physical theories, not physics in general. As far as I know physical theories are about predicting how matter behaves as it moves through space.

I’m not sure I’m following your point here?

Can you clarify what you mean by “observation”? Do you only mean phenomena that are directly accessible with our senses, such as “The sun turns red during a sunset”? If I experimentally verify a prediction of special using the help of scientific equipment, does that count as an “observation”? I am just confused what you mean by “reality beyond the physical constraints of observation”.

I agree that common sense observations, such as our subjective perception of time and space, should not be dismissed when trying to think about philosophical questions about space and time. They should be considered alongside with evidence from specialized experiments which reveal to us what happens in extreme situations. However, we also have to be cognizant of the limitations of our senses and intuition. Any philosophy of time and space must be consonant with both types of “evidence”.

However, my overall impression from this discussion and your prior posts is that:

  1. You are reluctant in wrestling with the weirdness of the consequences of SR, so you prefer to put the experimental evidence of SR under the heading of “how matter behaves” and differentiate between that and “what fundamental reality is”.
  2. You have in mind some arguments defending the absolute nature of time and space from subjective perceptions and common sense, which seem to conflict with standard interpretations of SR.
  3. You conceive the evidential situation as follows:
    a) Box A contains the scientific evidence supporting SR, which are “weird” and counterintuitive (from point 1).
    b) Box B contains the more familiar arguments from common sense supporting absolute time and space (from point 2).
  4. You view Box A and B as inherently in conflict, and one has to discard one versus the other.
  5. Using what you describe as “inference to the best explanation”, you regard the arguments in Box B as stronger than that in Box A, and thus you discard Box A entirely and view only Box B as telling us something actually true about reality.
  6. Because you discard Box A, you are accused of being anti-realist or instrumentalist with regards to scientific evidence.

My assessment: the problem here is viewing Box A and Box B as irreconcilable and in conflict. If you must hold to the idea of an absolute space and time, then for your view to be respectable you must wrestle with the things in Box A. You cannot simply sweep it under the rug as “how matter behaves”. Even if you are an instrumentalist, you still have to explain how the instruments result in Box A despite the true nature of space and time being absolute. Are the results simply wrong? Are we interpreting them incorrectly? How exactly are we doing that?

This is why philosophers who hold to an absolutist notion of space and time must be able to wrestle with the mathematics and experimental of SR in a rigorous way, such that they are able to philosophically re-interpret the results in a way that matches up with their absolutist philosophy. Some people have done that, but there are issues and problems. See this discussion for an example: Science and the Metaphysics of Time. This is the task in front of you if you want to go down that path. You can’t just whip out the “abductive reasoning” and “instrumentalist” cards and discard pieces of evidence that don’t line up with your preferred view. Your final view has to attempt to harmonize all the evidence from both Box A and B.

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I recall that both @dga471 and @PdotdQ have presented contrary comments, stating that you didn’t have enough knowledge of physics.

I think it depends on the subject matter. Here is how it’s defined by the SEP article on realism: the observable is that which can, under favorable conditions, be perceived using the unaided senses (for example, planets and platypuses); the unobservable is that which cannot be detected this way (for example, proteins and protons). This is to privilege vision merely for terminological convenience, and differs from scientific conceptions of observability, which generally extend to things that are detectable using instruments.

With regards to the physical constraints, I’m talking about how we as humans and our instrumentation can only operate within what the laws of physics constrain us to. We can’t empirically verify, for example, whether or not space exists. It may or may not. We just aren’t in a position because of physical constraints to verify it one way or another.

Do you have an example of one of these extreme situations? My concern is whether or not they are relevant to the question of the nature of fundamental reality.

Agreed. But I would also point out the need for being mindful of physical limitations of instrumentation as well.

I would add that we need to keep in mind the relevance of the evidence to the particular question of the specific aspect of fundamental reality being addressed.

Let me attempt to rephrase that the way I would represent it.

  1. I’m fine with the weirdness of SR when it comes to what can be empirically verified. I think that there are two distinct questions being conflated in physical theory, what are the regularities that matter obeys to allow it to be tracked as it moves through space, and what is fundamental reality like. The first question can generally be answered through empirical verification. The second has to be inferred. In following the relevant evidence where it leads in answering the second question, I don’t agree that it infers that the theoretical concept in SR of a relativistic spacetime continuum is representative of what actually underlies the reality that is observable. Empirically verified findings from SR aimed at answering the first question are not, for the most part, relevant evidence to the second question. There may be more, but the only relevant evidence to the second question from the theory that I’m aware of is that its success in describing how matter behaves lends support to the inference that the concept could be a possible candidate as an answer to that question.
  2. I have in mind some arguments defending the absolute nature of time, space, and simultaneity from evidence drawn from universally shared perceptions, and objective observations which would conflict with standard interpretations of SR, not in respect to the first question, but as it specifically relates to the second question.
  3. I conceive the evidential situation as follows:
    a) Box A contains the one and only piece of relevant evidence I’m aware of supporting the inference that the concept of SR of a relativistic simultaneity and spacetime continuum is representative of actual fundamental reality, a conclusion that results in “weird” counterintuitive and nonsensical conclusions (from point 1).
    b) Box B contains the relevant general evidence from perception and observation supporting the concept of absolute space, time, and simultaneity, which when inferred from that evidence results in intuitive common sense conclusions (from point 2).
  4. I view Box A and B inherently in conflict. However, there is no conflict between Box B and the empirically verified findings associated with the theory in Box A. As far as I can tell, the findings are simply irrelevant as evidence to the second question.
  5. Using what I describe as “inference to the best explanation”, I regard the inferences from Box B as stronger overall than that in Box A, and thus I choose Box B over Box A as telling us something actually true in regards to the second question.
  6. Because I choose Box B over Box A, I could be accused of being some type of a scientific anti-realist about physical theories. But more likely I would fit into some modified form of a scientific realist since I do acknowledge that there exists an underlying reality that cannot be observed. However, if any particular form of realism were to claim that a successful theory entails the concept it employs to be representative of fundamental reality, that would fall outside of my particular version of it. My position is that it’s only evidence that supports the concept as a possible candidate, not a foregone conclusion.

My assessment: In regards to the second question the evidence of Box A and Box B support conflicting inferences. However, holding to the idea of an absolute space and time for the second question and holding to SR as a successful theory in regards to the first question doesn’t present a conflict as far as I can tell.

Please explain in detail what you mean by “fundamental reality” (FR), including addressing these questions:

  1. Is the regular behavior of matter a subset of FR or something outside of it completely?
  2. How do you know that FR exists?
  3. Give general examples of entities that you think are part of FR but are not matter that can be scientifically observed.
  4. Give specific examples of entities that you think are part of FR and have something to do with time, space, and special relativity.
  5. What is the relation between FR and regular matter that science can observe? Is regular matter controlled or limited by the rules of FR (whatever they are)? Or is there no relation at all?

Maybe fundamental reality isn’t the best term to use. Let me see if I can simplify this as much as possible. The distinction I’m attempting to make is between questions in physics that can be decisively answered through empirical verification, and those that cannot. So maybe possible reality vs verifiable reality is a better way to convey what I’m getting at.

In other words, in a physical theory the equations can be verified to be correct by checking if they match up with what’s observed to answer the first question. But it’s not possible to verify by observation whether or not the concepts the formulas are based on match up with reality.

But even though not empirically verifiable, they can be inferred as possibilities of unobservable reality based on the initial evidence of the success of the theory that they are employed by. But that particular evidence is just one piece that needs to be weighed with all the other relevant evidence for and against to established what is the most likely explanation.

I can get into more specific examples if you like. Just want to see if that makes sense to you so far.

Here’s the thing: the issue is that you have said that verification only counts if it is detected using the senses directly. Thus, according to you there are 3 tiers of “reality”:

  1. Propositions about reality which can be verified with the senses directly (e.g. “grass is green.”)
  2. Propositions about reality which cannot be verified with the senses directly, but can be verified using scientific instrumentation (e.g. “Jupiter has at least four moons” - first discovered by Galileo using a telescope in the 17th century)
  3. Propositions about reality which cannot be verified with the senses directly nor scientific instrumentation, but perhaps can be deduced using higher-order philosophical argumentation, or is taken to be a basic belief.

You need to make a clear distinction between the three.

Yes, it would be helpful to get into a specific example - including both the equations that have been verified and which parts of the theory are not verifiable. I need examples! You have a weird tendency for never giving examples, mostly speaking in generalities. Concrete, detailed examples will help move this conversation forward more than anything else.

I think 1 is a pretty straightforward way of verification. 2 can be visual verification and nonvisual verification through detection. Detection can be used to verify basic existence but cannot verify visual aspects of reality. There may be specific instances of observation/verification through instrumentation that may be called into question, but otherwise I think 2 is generally a straightforward way of verification. Besides the caveats mentioned in 2, 3 is generally what I’m referring to as non-verifiable, although I would substitute the word deduced for abduced in that statement for this particular discussion.

Just to reiterate, in any physical theory, as I understand it, the equations would be the verifiable aspect that deal with the first question, and the concept would be the unverifiable aspect that would need to be inferred in dealing with the second question. So this would be the case in any physical theory as far as I can tell.

With that said, let’s use MSR as an example. E=mc2 is an equation used in SR to describe an aspect of reality that is empirically verifiable. However, the concept of a relative spacetime continuum is not and therefore has to be inferred from relevant evidence.

Edit: Sorry, I should have mentioned in regards to the first question for the equation, and in regards to the second question for the concept.

What is “detection” and how does it differ from “visual verification” and “verification through instrumentation”? I just am at a loss to interpret many of these sentences.

Sorry, this is not sufficient for me to understand.

  1. You did not describe any specific scientific experiments when talking about the empirical verification of the equation. The issue here is that to empirically verify “E = mc^2”, you have to interpret the equation and connect them to actual physical quantities, in order to be able to design an experiment with appropriate equipment.
  2. Once you have selected an example of a scientific experiment that verifies “E = mc^2”, then please tell me what that experiment verifies, what that experiment does not verify, and why you think so. Can you do that?

Hmm. My understanding is that there are many instances where the equations have been verified which it seems would be sufficient as far as our discussion is concerned. It’s really not clear to me why you’re asking the things you are asking. Maybe before we go any further you could at least give some reason as to why you think what you’re asking has any bearing on the discussion we’re having.

Because it is not clear to me to what extent you accept the results of experiments as telling us something true about reality. You seem to reject the relativity of time and space and think SR experiments have no bearing on that. OK, but then what do those experiments tell us? Do they tell us anything at all? You say they verify certain equations. But equations are in principle just concepts that are converted to more precise mathematical language. For example, in E = mc^2, E stands for energy, m is mass, c is the speed of light. “Speed” implies distance over time. Yet you don’t think experiments verifying that equation say anything about the “true nature” of space and time. So what do they say? These are just examples of the ambiguity of your position.

In other words, there are different degrees of realism vs. antirealism, and I’m not sure where your position is.

Depends on what aspect of reality we’re talking about. If it’s concerning empirically verified experiments dealing with equations for tracking how matter moves through space, then yes, that tells us something true about that particular aspect of reality, i.e., general patterns of motion.

But my objection is that it doesn’t entail that the concepts of successful physical theories from which the equations are formulated are true representations of reality in regards to questions about aspects of reality that cannot be empirically verified, like is space relative or absolute.

The success of the physical theory is evidence that indicates that the concepts they employ may represent actual reality. But that is just one piece of evidence and would need to be weighed with other evidence both for and against various positions.

Based on relevant evidence I reject the concept of relativity as it pertains to the empirically unverifiable question of whether space and time are absolute or relative. I don’t know of any results of SR experiments, which as far as I know are always directed at questions about empirically verifiable motion, that are relevant to that question. If you can suggest any I’d be interested to know what they are.

Again, they tell us something true about an aspect of reality that is verifiable, i.e., motion of matter in space. That’s the issue they are addressing. They are not directed at issues that are not empirically verifiable, like the question of whether space is relative or absolute.

I would rephrase that to say something like in physical theories equations are in principle used to convert concepts for practical purposes into more precise mathematical language.

I think the only real difference of my position and that of other realists’ is regarding whether concepts of successful physical theories would entail or simply be possible evidence for unverifiable aspects of reality.

In a nutshell, my position is pretty much in line with realism in general. The only real issue I might have with another realist is if they were to claim that successful physical theories entail that the concepts they employ are true representations of unverifiable aspects of reality, like the nature of space. My position is that it doesn’t follow that the concept is a true representation, but that the success of the theory only provides evidence to support the concept as a possible candidate for such a claim.

I think another point I’m getting at is, just because human conventions of measurement of motion are required to operate within human limitations, e.g., relativity of objects, doesn’t entail that those limitations carry over into what the nature of unverifiable reality is like, e.g., whether space is relative or absolute. It may be evidence, but it doesn’t a priori rule out other options.

Do you think physics experiments are all just about “tracking matter moving through space”?

For example, how can you explain the results of the muon lifetime experiment?

In short: when muons are not moving at a high velocity, their lifetime is only about 1.56 microseconds. Based on this result, we would expect very few muons raining from 10 km in the atmosphere to reach the Earth. However, when we measure muons at several different altitudes, we actually see way more muons arriving on Earth. The result is best explained by relativistic time dilation - at the muons experience time slower in their reference frame due to moving very fast relative to Earth (close to the speed of light).

Isn’t that more or less what’s being done? That seems to be what’s going on with the muon lifetime experiment as far as I can tell. Am I missing something?

I would say that it has to be assumed whether the measurement taken from the reference frame of the muons represents slower running time or just slower running clocks affected by velocity or gravity.

And to me what the experiment shows is that the measurements are more accurate using equations formulated from a relativistic conceptual framework than the measurements from a non-relativistic one which shows the successful theory as the one that employs a relativistic concept as opposed to the theory employing a non-relativistic concept.

But that brings us back to the question of whether a successful theory entails that the concept it employs is connected to unverifiable reality, or if it only provides evidence in support of that claim.

I’m not sure you appreciate the richness and depth of what it means to “track matter moving through space”. Physicists measure many quantities besides position and velocity. They measure charge, spin, temperature, fluorescence, mass, electric and magnetic fields, energy levels, phase transitions, and so on. I’m curious, what background do you have in physics?

Regarding your first alternative hypothesis, how would clocks run slower from being affected by velocity, which is no other than distance traveled over time? Please explain.

Regarding your second alternative hypothesis, how would clocks run slower from being affected by gravity?