Some comments on QM and CM—Part 2: Without ontologies, “classical” mechanics can get very unintuitive too. (Also, a short update.)

We continue from the last post. If you haven’t read and understood it, it can be guaranteed that you won’t understand anything from this one! [And yes, this post is not only long but also a bit philosophical.]


The last time, I gave you a minimal list of different ontologies for physics theories. I also shared a snap of my hurriedly jotted (hand-written) note. In this post, I will come to explain what I meant by that note.


1. In the real world, you never get to see the objects of “classical” mechanics:

OK, let’s first take a couple of ideas from Newtonian mechanics.

1.1. Point-particles:

The Newtonian theory uses a point particle. But your perceptual field never holds the evidence for any such an object. The point particle is an abstraction. It’s an idealized (conceptual-level) description of a physical object, a description that uses the preceding mathematical ideas of limits (in particular, the idea of the vanishingly small size).

The important point to understand here isn’t that the point-particle is not visible. The crucial point here is: it cannot be visible (or even made visible, using any instrument) because it does not exist as a metaphysically separate object in the first place!

1.2. Rigid bodies:

It might come as a surprise to many, esp. to mechanical engineers, but something similar can also be said for the rigid body. A rigid body is a finite-sized object that doesn’t deform (and unless otherwise specified, doesn’t change any of its internal fields like density or chemical composition). Further, it never breaks, and all its parts react instantaneously to any forces exerted on any part of it. Etc.

When you calculate the parabolic trajectory of a cricket ball (neglecting the air resistance), you are not working with any entity that can ever be seen/ touched etc.—in principle. In your calculations, in your theory, you are only working with an idea, an abstraction—that of a rigid body having a center of mass.

Now, it just so happens that the concepts from the Newtonian ontologies are so close to what is evident to you in your perceptual field, that you don’t even notice that you are dealing with any abstractions of perceptions. But this fact does not mean that they cease to be abstract ideas.


2. Metaphysical locus of physics abstractions, and epistemology of how you use them:

2.1. Abstractions do exist—but only in the mind:

In general, what’s the metaphysics of abstractions? What is the metaphysical locus of its existence?

An abstraction exists as a unit of mental integration—as a concept. It exists in your mind. A concept doesn’t have an existence apart from, or independent of, the men who know and hold that concept. A mental abstraction doesn’t exist in physical reality. It has no color, length, weight, temperature, location, speed, momentum, energy, etc. It is a non-material entity. But it still exists. It’s just that it exists in your mind.

In contrast, the physical objects to which the abstractions of objects make a reference, do exist in the physical reality out there.

2.2. Two complementary procedures (or conceptual processings):

Since the metaphysical locus of the physical objects and the concepts referring to them are different, there have to be two complementary and separate procedures, before a concept of physics (like the ideal rigid body) can be made operational, say in a physics calculation:

2.2.1. Forming the abstraction:

First, you have to come to know that concept—you either learn it, or if you are an original scientist, you discover/invent it. Next, you have to hold this knowledge, and also be able recall and use it as a part of any mental processing related to that concept. Now, since the concept of the rigid body belongs to the science of physics, its referents must be part of the physical aspects of existents.

2.2.2. Applying the abstraction in a real-world situation:

In using a concept, then, you have to be able to consider a perceptual concrete (like a real cricket ball) as an appropriate instance of the already formed concept. Taking this step means: even if a real ball is deformable or breakable, you silently announce to yourself that in situations where such things can occur, you are not going to apply the idea of the rigid body.

The key phrases here are: “inasmuch as,” “to that extent,” and “is a.” The mental operation of regarding a concrete object as an instance of a concept necessarily involves you silently assuming this position: “inasmuch as this actual object (from the perceptual field) shows the same characteristics, in the same range of “sizes”, as for what I already understand by the concept XYZ, therefore, to that extent, this actual object “is a” XYZ.

2.2.3. Manipulation of concepts at a purely abstract level is possible (and efficient!):

As the next step, you have to be able to directly manipulate the concept as a mere unit from some higher-level conceptual perspective. For example, as in applying the techniques of integration using Newton’s second law, etc.

At this stage, your mind isn’t explicitly going over the defining characteristics of the concept, its relation to perceptual concretes, its relation to other concepts, etc.

Without all such knowledge at the center of your direct awareness, you still are able to retain a background sense of all the essential properties of the objects subsumed by the concept you are using. Such a background sense also includes the ideas, conditions, qualifications, etc., governing its proper usage. That’s the mental faculty automatically working for you when you are born a human.

You only have to will, and the automatic aspects of your mind get running. (More accurately: Something or the other is always automatically present at the background of your mind; you are born with such a faculty. But it begins serving your purpose when you begin addressing some specific problem.)

All in all: You do have to direct the faculty which supplies you the background context, but you can do it very easily, just by willing that way. You actually begin thinking on something, and the related conceptual “material” is there in the background. So, free will is all that it takes to get the automatic sense working for you!

2.2.4. Translating the result of a calculation into physical reality:

Next, once you are done with working ideas at the higher-level conceptual level, you have to be able to “translate the result back to reality”. You have to be able to see what perceptual-level concretes are denoted by the concepts related to the result of calculation, its size, its units, etc. The key phrase here again are: “inasmuch as” and “to that extent”.

For example: “Inasmuch as the actual cricket ball is a rigid body, after being subjected to so much force, by the laws governing rigid bodies (because the laws concern themselves only with the rigid bodies, not with cricket balls), a rigid body should be precisely at 100.0 meter after so much time. Inasmuch as the cricket ball can also be said to have an exact initial position (as for a rigid body used in the calculations), its final position should be exactly 100 meter away. Inasmuch as a point on the ground can be regarded as being exactly 100 meter away (in the right direction), the actual ball can also be expected, to that extent, to be at [directly pointing out] that particular spot after that much time. Etc.

2.3: A key take-away:

So, an intermediate but big point I’ve made is:

Any theory of classical mechanics too makes use of abstractions. You have to undertake procedures involving the mappings between concretes and abstractions, in classical mechanics too.

2.4. Polemics:

You don’t see a rigid body. You see only a ball. You imagine a rigid body in the place of the given ball, and then decide to do the intermediate steps only with this instance of the imagination. Only then can you invoke the physics theory of Newtonian mechanics. Thus, the theory works purely at the mental abstractions level.

A theory of physics is not an album of photographs; an observation being integrated in a theory is not just a photograph. On the other hand, a sight of a ball is not an abstraction; it is just a concretely real object in your perceptual field. It’s your mind that makes the connection between the two. Only can then any conceptual knowledge be acquired or put to use. Acquisition of knowledge and application of knowledge are two sides of the same coin. Both involve seeing a concrete entity as an instance subsumed under a concept or a mental perspective.

2.5. These ideas have more general applicability:

What we discussed thus far is true for any physics theory: whether “classical” mechanics (CM) or quantum mechanics (QM).

It’s just that the first three ontologies from the last post (i.e. the three ontologies with “Newtonian” in their name) have such abstractions that it’s very easy to establish the concretes-to-abstractions correspondence for them.

These theories have become, from a hindsight of two/three centuries and absorption of its crucial integrative elements into the very culture of ours, so easy for us to handle, they seem to be so close to “the ground” that we have to think almost nothing to regard a cricket ball as a rigid body. Doesn’t matter. The requirement of you willingly having to establish the correspondenc between the concretes and abstractions (and vice versa) still exists.

Another thing: The typical application of all the five pre-quantum ontologies also typically fall in the limited perceptual range of man, though this cannot be regarded as the distinguishing point of “classical” mechanics. This is an important point so let me spend a little time on it.

Trouble begins right from Fourier’s theory.


3. “Classical” mechanics is not without tricky issues:

3.1. Phenomenological context for the Fourier theory is all “classical”:

In its original form, Fourier’s theory dealt with very macroscopic or “every day” kind of objects. The phenomenological context which gave rise to Fourier’s theory was: the transmission of heat from the Sun by diffusion into the subterranean layers of the earth, making it warm. That was the theoretical problem which Fourier was trying to solve, when he invented the theory that goes by his name.

Actually, that was a bit more complicated problem. A simpler formulation of the same problem would be: quantitatively relating the thermal resistance offered by wood vs. metal, etc. The big point I want to note here is: All these (the earth, a piece of wood or metal) are very, very “everyday” objects. You wouldn’t hesitate saying that they are objects of “classical” physics.

3.2. But the Fourier theory makes weird predictions in all classical physics too:

But no matter how classical these objects look, an implication is this:

The Fourier theory ends up predicting infinite velocity for signal propagation for “classical” objects too.

This is a momentous implication. Make sure you understand it right. Pop-sci writers never highlight this point. But it’s crucial. The better you understand it, the less mysterious QM gets!

In concrete terms, what the Fourier theory says is this:

If you pour a cup of warm water on ground at the North pole, no doubt the place will get warmer for some time. But this is not the only effect your action would have. Precisely and exactly at the same instant, the South pole must also get warmer, albeit to a very small extent. Not only the South Pole, every object at every place on the earth, including the cell phone of your friend sitting in some remote city also must get warmer. [Stretching the logic, and according a conduction mode also to the intergalactic dust: Not just that, every part of the most distant galaxies too must get warmer—in the same instant.] Yes, the warming at remote places might be negligibly small. But in principle, it is not zero.

And that’s classical physics of ordinary heat conduction for you.

3.3. Quantum entanglement and Heisenberg’s uncertainty principle are direct consequences of the same theory:

Now, tell me, how intuitive was Fourier’s predictions?

My answer: Exactly as unintuitive as is the phenomenon of quantum entanglement—and, essentially, for exactly the same ontological-physical-mathematical reasons!

Quantum entanglement is nothing but just another application of the Fourier theory. And so is Heisenberg’s uncertainty principle. It too is a direct consequence of the Fourier theory.

3.4. Another key take-away:

So, the lesson is:

Not all of “classical” mechanics is as “intuitive” as you were led to believe.

3.5. Why doesn’t any one complain?

If classical physics too is that unintuitive, then how come that no one goes around complaining about it?

The reason is this:

Classical mechanics involves and integrates a conceptually smaller range of phenomena. Most of its application scenarios too are well understood—even if not by you, and then at least by some learned people, and they have taken care to explain all these scenarios to you.

For instance, if I ask you to work out how the Coriolis force works for two guys sitting diametrically opposite on a rotating disco floor and throwing balls at each other, I am willing to take a good bet that you won’t be able to work out everything on your own using vector analysis and Newton’s laws. So, this situation should actually be non-intuitive to you. It in fact is: Without searching on the ‘net, be quick and tell me whether the ball veers in the direction of rotation or opposite it? See? It’s just that no pop-sci authors highlight issues like this, and so, no philosophers take notice. (And, as usual, engineers don’t go about mystifying anything.)

So, what happens in CM is that some expert works out the actual solution, explains to you. You then snatch some bits and pieces, may be just a few clues from his explanation, and memorize them. Slowly, as the number of such use-cases increases, you get comfortable enough with CM. Then you begin to think that CM is intuitive. And then, the next time when your grandma asks you how come that motorcyclist spinning inside the vertical well doesn’t fall off, you say that he sticks to the wall due to the centrifugal force. Very intuitive! [Hint, hint: Is it actually centrifugal or centripetal?]

OK, now let’s go over to QM.


4. The abstract-to-concretes mappings are much more trickier when it comes to QM:

4.1. The two-fold trouble:

The trouble with QM is two-fold.

First of all, the range of observations (or of phenomenology) underlying it is not just a superset of CM, it’s a much bigger superset.

Second: Physicists have not been able to work out a consistent ontology for QM. (Most often, they have not even bothered to do that. But I was talking about reaching an implicit understanding to that effect.)

So, they are reduced to learning (and then teaching) QM in reference to mathematical quantities and equations as the primary touch-stones.

4.2. Mathematical objects refer to abstract mental processes alone, not to physical objects:

Now, mathematical concepts have this difference. They are not only higher-level abstractions (on top of physical concepts), but their referents too in themselves are invented and not discovered. So, it’s all in the mind!

It’s true that physics abstractions, qua mental entities, don’t exist in physical reality. However, it also is true that the objects (including their properties/characteristics/attributes/acctions) subsumed under physics concepts do have a physical existence in the physical world out there.

For instance, a rigid body does not exist physically. But highly rigid things like stones and highly pliable or easily deformable things like a piece of jelly or an easily fluttering piece of cloth, do exist physically. So, observing them all, we can draw the conclusion that stones have much higher rigidity than the fluttering flag. Then, according an imaginary zero deformability to an imaginary object, we reach the abstraction of the perfectly rigid body. So, while the rigid body itself does not exist, rigidity as such definitely is part of the natural world (I mean, of its physical aspects).

But not so with the mathematical abstractions. You can say that two (or three or n number of) stones exist in a heap. But what actually exists are only stones, not the number 2, 3, or n. You can say that a wire-frame has edges. But you don’t thereby mean that its edges are geometrical lines, i.e., objects with only length and no thickness.

4.3. Consequence: How physicists hold, and work with, their knowledge of the QM phenomena:

Since physicists could not work out a satisfactory ontology for QM, and since concepts of maths do not have direct referents in the physical reality as apart from the human consciousness processing it size-wise, their understanding of QM does tend to be a lot more shaky (the comparison being with their understanding of the pre-quantum physics, esp. the first three ontologies).

As a result, physicists have to develop their understanding of QM via a rather indirect route: by applying the maths to even more number of concrete cases of application, verifying that the solutions are borne out by the experiments (and noting in what sense they are borne out), and then trying to develop some indirect kind of a intuitive feel, somehow—even if the objects that do the quantum mechanical actions aren’t clear to them.

So, in a certain sense, the most talented quantum physicists (including Noble laureates) use exactly the same method as you and me use when we are confronted with the Coriolios forces. That, more or less, is the situation they find themselves in.

The absence of a satisfactory ontology has been the first and foremost reason why QM is so extraordinarily unintuitive.

It also is the reason why it’s difficult to see CM as an abstraction from QM. Ask any BS in physics. Chances are 9 out of 10 that he will quote something like Planck’s constant going to zero or so. Not quite.

4.4. But why didn’t any one work out an ontology for QM?

But what were the reasons that physicists could not develop a consistent ontology when it came to QM?

Ah. That’s too complicated. At least 10 times more complicated than all the epistemology and physics I’ve dumped on you so far. That’s because, now we get into pure philosophy. And you know where the philosophers sit? They all sit on the Humanities side of the campus!

But to cut a long story short, very short, so short that it’s just a collage-like thingie: There are two reasons for that. One simple and one complicated.

4.4.1. The simple reason is this: If you don’t bother with ontologies, and then, if you dismiss ideas like the aether, and go free-floating towards ever higher and still higher abstractions (especially with maths), then you won’t be able to get even EM right. The issue of extracting the “classical” mechanical attributes, variables, quantities, etc. from the QM theory simply cannot arise in such a case.

Indeed, physicists don’t recognize the very fact that ontologies are more basic to physics theories. Instead, they whole-heartedly accept and vigorously teach and profess the exact opposite: They say that maths is most fundamental, even more fundamental than physics.

Now, since QM maths is already available, they argue, it’s only a question of going about looking for a correct “interpretation” for this maths. But since things cannot be very clear with such an approach, they have ended up proposing some 14+ (more than fourteen) different interpretations. None works fully satisfactorily. But some then say that the whole discussion about interpretation is bogus. In effect, as Prof. David Mermin characterized it: “Shut up and calculate!”

That was the simple reason.

4.4.2. The complicated reason is this:

The nature of the measurement problem itself is like that.

Now, here, I find myself in a tricky position. I think I’ve cracked this problem. So, even if I think it was a very difficult problem to crack, please allow me to not talk a lot more about it here; else, doing so runs the risk of looking like blowing your own tiny piece of work out of all proportion.

So, to appreciate why the measurement problem is complex, refer to what others have said about this problem. Coleman’s paper gives some of the most important references too (e.g., von Neumann’s process 1 vs. process 2 description) though he doesn’t cover the older references like the 1927 Bohr-Einstein debates etc.

Then there are others who say that the measurement problem does not exist; that we have to just accept a probabilistic OS at the firmware level by postulation. How to answer them? That’s a homework left for you.


5. A word about Prof. Coleman’s lecture:

If Prof. Coleman’s lecture led you to conclude that everything was fine with QM, you got it wrong. In case this was his own position, then, IMO, he too got it wrong. But no, his lecture was not worthless. It had a very valuable point.

If Coleman were conversant with the ontological and epistemological points we touched on (or hinted at), then he would have said something to the following effect:

All physics theories presuppose a certain kind of ontology. An ontology formulates and explains the broad nature of objects that must be assumed to exist. It also puts forth the broad nature of causality (objects-identities-actions relations) that must be assumed to be operative in nature. The physics theory then makes detailed, quantitative, statements about how such objects act and interact.

In nature, physical phenomena differ very radically. Accordingly, the phenomenological contexts assumed in different physical theories also are radically different. Their radical distinctiveness also get reflected in the respective ontologies. For instance, you can’t explain the electromagnetic phenomena using the pre-EM ontologies; you have to formulate an entirely new ontology for the EM phenomena. Then, you may also show how the Newtonian descriptions may be regarded as abstractions from the EM descriptions.

Similarly, we must assume an entirely new kind of ontological nature for the objects if the maths of QM is to make sense. Trying to explain QM phenomena in terms of pre-quantum ontological ideas is futile. On the other hand, if you have a right ontological description for QM, then with its help, pre-QM physics may be shown as being a higher-level, more abstract, description of reality, with the most basic level description being in terms of QM ontology and physics.

Of course, Coleman wasn’t conversant with philosophical and ontological issues. So, he made pretty vague statements.


6. Update on the progress in my new approach. But RSI keeps getting back again and again!

I am by now more confident than ever that my new approach is going to work out.

Of course, I still haven’t conducted simulations, and this caveat is going to be there until I conduct them. A simulation is a great way to expose the holes in your understanding.

So take my claim with a pinch of salt, though I must also hasten to note that with each passing fortnight (if not week), the quantity of the salt which you will have to take has been, pleasantly enough (at least for me), decreasing monotonically (even if not necessarily always exponentially).

I had written a preliminary draft for this post about 10 days ago, right when I wrote my last post. RSI had seemed to have gone away at that time. I had also typed a list of topics (sections) to write to cover my new approach. It carried some 35+ sections.

However, soon after posting the last blog entry here, RSI began growing back again. So, I have not been able to make any substantial progress since the last post. About the only things I could add were: some 10–15 more section or topic names.

The list of sections/topics includes programs too. However, let me hasten to add: Programs can’t be written in ink—not as of today, anyway. They have to be typed in. So, the progress is going to be slow. (RSI.)

All in all, I expect to have some programs and documentation ready by the time Q1 of 2021 gets over. If the RSI keeps hitting back (as it did the last week), then make it end-Q2 2021.

OK. Enough for this time round.


A song I like:

[When it comes to certain music directors, esp. from Hindi film music, I don’t like the music they composed when they were in their elements. For example, Naushad. For example, consider the song: मोहे पनघट पे (“mohe panghat pe”). I can sometimes appreciate the typical music such composers have produced, but only at a somewhat abstract level—it never quite feels like “my kind of music” to me. Something similar, for the songs that Madan Mohan is most famous for. Mohan was a perfectionist, and unlike Naushad, IMO, he does show originality too. But, somehow, his sense of life feels like too sad/ wistful/ even fatalistic to me. Sadness is OK, but a sense of inevitability (or at least irromovability) of suffering is what gets in the way. There are exceptions of course. Like, the present song by Naushad. And in fact, all songs from this move, viz. साथी (“saathi”). These are so unlike Naushad!

I have run another song from this movie a while ago (viz. मेरे जीवन साथी, कली थी मै तो प्यासी (“mere jeevan saathee, kalee thee main to pyaasee”).

That song had actually struck me after a gap of years (may be even a decade or two), when I was driving my old car on the Mumbai-Pune expressway. The air-conditioner of my car is almost never functional (because I almost never have the money to get it repaired). In any case, the a/c was neither working nor even necessary, on that particular day late in the year. So, the car windows were down. It was pretty early in the morning; there wasn’t much traffic on the expressway; not much wind either. The sound of the new tires made a nice background rhythm of sorts. The sound was very periodic, because of the regularity of the waviness that comes to occur on cement-concrete roads after a while.

That waviness? It’s an interesting problem from mechanics. Take a photo of a long section of the railway tracks while standing in the middle, especially when the sun is rising or setting, and you see the waviness that has developed on the rail-tracks too—they go up and down. The same phenomenon is at work in both cases. Broadly, it’s due to vibrations—a nonlinear interaction between the vehicle, the road and the foundation layers underneath. (If I recall it right, in India, IIT Kanpur had done some sponsored research on this problem (and on the related NDT issues) for Indian Railways.)

So, anyway, to return to the song, it was that rhythmical sound of the new tires on the Mumbai-Pune Expressway which prompted something in my mind, and I suddenly recalled the above mentioned song (viz. मेरे जीवन साथी, कली थी मै तो प्यासी (“mere jeevan saathee, kalee thee main to pyaasee”). Some time later, I ran it here on this blog. (PS: My God! The whole thing was in 2012! See the songs section, and my the then comments on Naushad, here [^])

OK, cutting back to the present: Recently, I recalled the songs from this movie, and began wondering about the twin questions: (1) How come I did end up liking anything by Naushad, and (2) How could Naushad compose anything that was so much out of his box (actually, the box of all his traditional classical music teachers). Then, a quick glance at the comments section of some song from the same film enlightened me. (I mean at YouTube.) I came to know a new name: “Kersi Lord,” and made a quick search on it.

Turns out, Naushad was not alone in composing the music for this film: साथी (“saathee”). He had taken assistance from Kersi Lord, a musician who was quite well-versed with the Western classical and Western pop music. (Usual, for a Bawa from Bombay, those days!) The official credits don’t mention Kersi Lord’s name, but just a listen is enough to tell you how much he must have contributed to the songs of this collaboration (this movie). Yes, Naushad’s touch is definitely there. (Mentally isolate Lata’s voice and compare to मोहे पनघट पे (“mohe panghat pe”).) But the famous Naushad touch is so subdued here that I actually end up liking this song too!

So, here we go, without further ado (but with a heartfelt appreciation to Kersi Lord):

(Hindi) ये काैन आया, रोशन हो गयी (“yeh kaun aayaa, roshan ho gayee)
Singer: Lata Mangeshkar
Music: [Kersi Lord +] Naushad
Lyrics: Majrooh Sultanpuri

A good quality audio is here [^].

]


PS: May be one little editing pass tomorrow?

History:
— 2020.12.19 23:57 IST: First published
— 2020.12.20 19:50 IST and 2020.12.23 22:15 IST: Some very minor (almost insignificant) editing / changes to formatting. Done with this post now.