I don’t agree with this, though. It might well be the case that motion is perspectival, i.e. you need to define a reference frame in order to speak meaningfully of motion, and yet also say that change is real.
I believe it is useful to note that while a theory can be ‘verified empirically’, it doesn’t imply that it is an accurate ‘picture’ of ‘physical reality’. Newtonian mechanics is clearly verified empirically in most of experiments. Yet, the fact that ‘works’ doesn’t imply that it accurately ‘describes’ physical reality.
Of course, in the case of Newtonian mechanics, we have also empirical evidence that it is wrong to interpret it in a descriptive way. But why can’t we take other scientific theories in a similar way? Why we must think that the ability of making very, very good predictions must mean that the theory is also a ‘good description’ of physical reality?
With standard QM a ‘literal’ interpretation would imply that the ‘wavefunction’ is a physical object that instaneously ‘collapses’ even in Interaction-free measurements. If instead the ‘collapse’ is interpreted as an update of the agent’s knowledge/belief, then yes it does make sense. But once you do this, you have to say that standard QM doesn’t give us a description of reality.
How could you consistently doubt that, and yet seek my answer?
There’s something very mistaken with the idea that we don’t know the “mental state” of other folk.
The Wittgensteinian point is that it’s not a “state”.
“I have a phone in my hand” and “I have a pain in my hand” have the same grammatical structure, but while you can pass me your phone, you cannot pass me your pain. Pain is not a thing in your hand. The similarity in the grammatical structure is misleading.
This assumes that knowledge must be, at least in principle, somehow an entirely public feature.
Let’s say that instead of pain, Bob says to Alice that he is tasting the most delicious cake he ever eat. Let’s say that Bob informs Alice about all the ingredients of the cake, the procedure of cooking it and so on. I would still say that Alice acquires new knowledge about the taste of the cake the moment in which she also eats it. Once she experience the taste, she had a knowledge that she couldn’t have without personally eating the cake.
I’m not saying that relativity means change is not real. What I’m saying is that it removes the importance of truth in the description of the motions. If we can get the predictions which we want, equally from a geocentric model or a heliocentric model, then there is no need to determine a true model. We could use whichever one was easiest for the application.
I think that a key problem with empirical verification is inconsistency between one experience and another. We see this at a basic, particular level, when two people disagree about what happened at a particular time and place. In a more general way, we see inconsistencies between universal principles which are each “verified empirically”, such as Newtonian and Einsteinian.
Often the inconsistencies are due to the limitations of applicability. Within a specific field of observation theory X is empirically verified, and within another field of observation theory Y is empirically verified. X and Y may be somewhat inconsistent. If the fields overlap there is a problem. If they do not overlap then there is a no mans land in between, which is also a problem. This exposes Hume’s problem of induction. Generalizations are never absolute, and need to have clear boundaries as to applicability.
I don’t think that it is wrong to interpret Newtonian mechanics in a descriptive way. Newton described the motions of material bodies with mass, and produced some fundamental inductive laws, concerning these motions which allowed mathematics to be applied. The key point in our attempts to understand “reality” is to recognize the limits of such descriptive laws. “Bodies in motion” is a very limited part of reality when we consider electromagnetism, and start breaking down bodies into fundamental parts.
Newton studied optics extensively, and produced many fundamental observations. He knew that his laws of motion were not applicable, but he developed a “corpuscular theory of light”, which involved a sort of inversion of mass. His corpuscular theory was replaced by the wave theory, but QM brings back the particle theory.
There is no reason to believe that the ability to predict implies a good description. The two are based in completely different principles. Prediction is based in mathematics, quantitative analysis. Description is based in qualitative analysis. There is a gap between the two which manifests when we apply numbers to the quality, and we say things like “red is 700nm”. The entire range of applicability of the qualitative description is not captured by quantitative representation. If we were to take the quantitative representation, and see that it has very good predictive capacity, “all instances of pure 700nm” will be observed as red, it doesn’t cover all instances of red, and therefore is a bad description overall.
To bring back the heliocentric/geocentric analogy, the geocentric model was very good for a lot of predictions. However, occurrences outside the boundaries of its applicability, such as planetary retrogrades, indicated that despite having very good predictive capacity, the somewhat narrow range of applicability meant that the qualitative description at the base was not very good.
I don’t agree with this. I believe as @Wayfarer does, a “literal” interpretation of “wavefunction” would very clearly show it to be a mathematical representation, not a description of a physical object. The fact that it works with probabilities rather than an actual description of a physical object reveals this decisively. Those who assume the wavefunction to be a description of a physical object are taking unjustified liberties in their interpretation.
I believe you are misrepresenting Wittgenstein’s point. The point, as made at 253 Philosophical Investigations, is that because we have no formal “criterion of identity” there is ambiguity with respect to this issue.
Therefore he is not saying “pain is not a thing in your hand”. He is saying pain may be a thing in your hand, or it may not be a thing in your hand, depending on the criterion of identity which you choose to employ.
So he proceeds to demonstrate the ambiguity with respect to that criterion, with an example where someone marks “S” in a journal every time they have “the same” sensation. Obviously, pain is an identifiable thing which we can talk about, as the person who marks “S” does. The question is what is the criterion of identity which is being employed.
And the problem of identity is given more light with the beetle in the box analogy.
I wouldn’t say ‘eliminated’, but rather, as I’ve said, experience is ‘transcended’ by theory. Because experience is particular, it cannot be transmitted; what is transmitted is its meaning. It’s like when they spoke of pain: pain itself cannot be transmitted, but its meaning can. We must bear in mind that experience is not a tabula rasa; it is shaped by meaning. A scientist conducting an experiment has, so to speak, the theory in their mind that gives meaning to the experiment. Furthermore, the scientist is trained and educated (the storage of meaning and various interpretations in memory) to make sense of the experiment.
The ‘no-where’ perspective is merely an effect of meaning that is capable of transcending experience and particular subjectivity. A statement such as ‘the triangle is X’ takes the form of the third person, and takes the form of nowhere. But this is the very nature of language and meaning, since it is inherent to meaning to transcend experience. Science is impossible without the possibility of meaning-theory transcending experience, and circumstantial expressions such as ‘I see this and that’ are always particular.
Experiments, insofar as they are repeatable under various subjective circumstances and capable of reproducing the same conditions in ‘the laboratory’, constitute the basic requirement for the particular experience to be neutralised and for meaning to emerge and enter into correlation with the experiment. There is a correlation between the repeatability of the experiment and the ideality of the theory: ideality is founded on repetition within a universal horizon. The meaning of the theory has, as its most intrinsic possibility, the potential to be the same for you as for me, and it is under this condition that science is said to be universal (I would say quasi-universal, bearing in mind that universality is an indefinite telos).
Not ‘seeing’ but understanding. We understand the world as if we weren’t there to see it. And this is true even for quantum physics.
When you learn to ride a bike, do you gain access to a previously hidden private knowledge? Or do you become able to perform actions that you previously could not?
When Alice tastes the cake, does she gain access to a previously hidden, private item? Or does she become able to recognise the taste, to compare it to other cakes, to participate in a practice in a different way?
Is it that she knows something previously unknown, but private? Or that she can participate in public activities in a novel way?
Nagel was careful in ways that others were not. He was looking for a reconciliation between a first person perspective and objectivity, and objected to being understood as suggesting private access to hidden inner objects.
The “Ah!” isn’t about access to private mental furniture, but access to public discrimination and discussion.
So again, how could you consistently doubt that we do have some knowledge of the other’s mental states and yet seek my answer?
And again, the problem is in thinking of a “metal state”, of mind as something we own, rather than something we do.
What this amounts to, for the purposes of this thread, is that while we might agree with Nagel that there is an ineliminable aspect to first person perspective, that is not sufficient to undermine an “objectivity” that is found in public agreement. Nor does it place mind in a position that is ineliminable. We need a mind for things to be known, not for them to be the case. Hence, again,
I don’t think that is the intention. What is being called into question whether objectivity is the sole criterion for veracity.
For example - is mathematics objectively true? Most would say yes, but I say that the type of veracity which mathematics possesses is something more than objective. We rely on mathematics to discern what is objective, in disciplines such as statistics and other sciences.
Yet I think the English lexicon is lacking in adjectives for veracity other than ‘objective’. The Greeks had a richer vocabulary — episteme, nous, doxa , dianoia, noesis — each designating different modes of knowing and corresponding modes of being.
None of which undermines the role or importance of objectivity, but it does call into question the universality of its scope.
But this sanguine assumption that ‘the world is just so, regardless of what we think’ is precisely what quantum physics has called into question! This has already been illustrated in this thread with frequent references, so I don’t know if there’s any point in repeating them.
If you think about it, quantum theory works. It is studied and passed on throughout the scientific community, and its experiments are reproducible. If you say that an experiment shows X or Y (or both X and Y at the same time), it is because you have already accepted the reproducibility of the experiment as well as the ideal nature of the theory. It is still science. Why do we continue to call that science? I have already given some clues: the ideal nature of the theory (that the theory is capable of being the same for both you and me), the repeatability of the experiments, the transmission of meaning, etc. Multiple factors that transcend the particular nature of the experience.
We shouldn’t cut the branch we’re sitting on just because there are strange leaves at the end of it.
Two of the books that have provided me the best oversight:
Manjit Kumar, Einstein, Bohr, and the Great Debate About the Nature of Reality; and David Lindley, Uncertainty: Einstein, Heisenberg, Bohr, and the Struggle for the Soul of Science
Notice the implications - ‘debates about the nature of reality’, ‘struggle for the soul of science’. Why these titles? Are they hyperbole? Exaggerations to sell more books?
I don’t think so. From the jacket description of the first:
In this tour de force of science history, Manjit Kumar shows how the golden age of physics ignited the greatest intellectual debate of the twentieth century. Quantum theory is weird. …Werner Heisenberg’s uncertainty principle and Erwin Schrodinger’s famous dead-and-alive cat are similarly strange. As Niels Bohr said, if you weren’t shocked by quantum theory, you didn’t really understand it.
And the second:
Werner Heisenberg’s ‘uncertainty principle’ challenged centuries of scientific understanding, placed him in direct opposition to Albert Einstein, and put Niels Bohr in the middle of one of the most heated debates in scientific history. Heisenberg’s theorem stated that there were physical limits to what we could know about sub-atomic particles; this ‘uncertainty’ would have shocking implications.
Einstein, for his part, continued to say that quantum theory must be incomplete, because the indeterminacy of the picture it provided couldn’t be the whole story. He insisted that there must be a deeper theory which explains why all science could do was to generate accurate statistical probabilities rather than fully objective descriptions of what is the case. Einstein really did feel that quantum physics ‘cut off the branch he was sitting on’, that branch being the conviction that science should deliver us a precise description of the nature of its objects of analysis, independently of any act observation. Scientific realism, in short.
It has never been at issue that quantum physics makes accurate predictions - more so than any previous scientific theory. That was never in doubt. It’s what is implied about the nature of reality. Hence those dramatic titles.
You’re missing the point. Quantum physics cannot call into question what we call science. Because its entire practice is already scientific. By ‘scientific’, I mean the characteristics I have outlined regarding its practice: the transmission of theoretical knowledge, the repeatability of experiments, and so on. Quantum physics presupposes the nature of scientific practice. It follows certain rules, etc. But what if we ask ourselves about the nature of this scientific practice? We can’t ask it from the field of quantum physics because it presuposses it. If we do that, We come up against the nature of scientific practice itself. A nature that is presupposed by and conditions quantum physics, which is why we call quantum physics science.
Hence, you fall into a sort of liar’s paradox: you accept the results of quantum physics as objective, only to later criticise or question their objectivity. This is because you fail to take into account the order of the conditions and the conditioned. Scientific practice in general and a particular scientific practice (quantum physics).
Perhaps if you might address the points raised in the above post, I might be able to see why.
I will re-iterate - it’s not scientific practice that has been called into question by physics. It is the suggestion of the indeterminate nature of the sub-atomic domain, which calls classical scientific realism into question.
You cannot question scientific realism without contradicting yourself, whilst at the same time taking it for granted when referring to the evidence for that very questioning.
I don’t believe that the wavefunction is physical. It is a distribution of possibilities. One interpretation that makes sense of that is aspects of Kastner and Cramer’s ‘transactional interpretation’, particularly it’s incorporation of Heisenberg’s ‘potentia’. By expanding the definition of reality, the quantum’s mysteries disappear. In particular, “real” should not be restricted to “actual” objects or events in spacetime. Reality ought also be assigned to certain possibilities, or “potential” realities, that have not yet become “actual.”
Yes, but, probabilities of what? For me it is simple: the probability that the system is currently in a particular configuration in the real world. My concern with saying the probability is of “potential” realities is that this means other people do not have definite reality, but only “potential” reality.
Maybe you can blame my own biases, but I find it too outlandish to suggest that other observers do not have a definite reality just as much as I do myself. The state of other observer’s minds should be value definite and invariant.
I mean, I do agree with the other points that the wavefunction is not physical and the wave-like entity only arises in ensembles of systems, and thus is a property of the ensemble and not of individual systems. This was Einstein’s and Blokhintsev’s view.
My concern is moreso what the probability distribution actually refers to. Other people are made up of particles. Your brain is made up of particles. If I cannot admit that particles have definite values and invariant states, even if they evolve statistically such that I cannot meaningfully track them at all times, then I cannot admit that your brain has a definite value and an invariant state, i.e. that a distinct and definite “you” really exists from my perspective, only the “potentia” of “you.”
It feels strange to suggest that the definite, non-potential way in which I experience the world is something I cannot admit is also true for other observers, as they only exist as an indefinite “potentia” with a potential for reality but are not immediately real, at least that is what that seems to suggest.
Maybe I am just not phrasing my concern well enough for it to be understood.