# The Machine Learning as an Expert System

To cut a somewhat long story short, I think that I can “see” that Machine Learning (including Deep Learning) can actually be regarded as a rules-based expert system, albeit of a special kind.

I am sure that people must have written articles expressing this view. However, simple googling didn’t get me to any useful material.

I would deeply appreciate it if someone could please point out references in this direction. Thanks in advance.

BTW, here is a very neat infographic on AI: [^]; h/t [^]. … Once you finish reading it, re-read this post, please! Exactly once again, and only the first part—i.e., without recursion!. …

A song I like:

(Marathi) “visar preet, visar geet, visar bheT aapuli”
Music: Yashwant Dev
Lyrics: Shantaram Nandgaonkar

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# Why is the research on the foundations of QM necessary?

Why is the research on the foundations of QM necessary? … This post is meant to hold together some useful links touching on various aspects of this question.

Sabine Hossenfelder:

See her blog post: “Good Problems in the Foundations of Physics” [^]. Go through the entirety of the first half of the post, and then make sure to check out the paragraph of the title “The Measurement Problem” from her list.

Not to be missed: Do check out the comment on this post by Peter Shor, here [^], and Hossenfelder’s reply to it, here [^]. … If you are familiar with the outline of my approach [^], then it would be very easy to see why I must have instantaneously found her answer to be so absolutely wonderful! … Being a reply to a comment, she must have written her reply much on the fly. Even then, she not only correctly points out the fact that the measurement process must be nonlinear in nature, she also mentions that you have to give a “bottom-up” model of the Instrument. …Wow! Simply, wow!!

Lee Smolin:

Here is one of the most lucid and essence-capturing accounts concerning this topic that I have ever run into [^]. Smolin wrote it in response to the Edge Question, 2013 edition. It wonderfully captures the very essence of the confusions which were created and / or faced by all the mainstream physicists of the past—the confusions which none of them could get rid of, with the list including even such Nobel-laureates as Bohr, Einstein, Heisenberg, Pauli, de Broglie, Schrodinger, Dirac, and others. [Yes, in case you read the names too rapidly: this list does include Einstein too!]

Sean Carroll:

He explains at his blog how a lack of good answers on the foundational issues in QM leads to “the most embarrassing graph in modern physics” [^]. This post was further discussed in several other posts in the blogosphere. The survey paper which prompted Carroll’s post can be found at arXiv, here [^]. Check out the concept maps given in the paper, too. Phillip Ball’s coverage in the Nature News of this same paper can be found here [^].

…What Else?:

What else but the Wiki!… See here [^], and then, also here [^].

OK. This all should make for an adequate response, at least for the time being, to those physicists (or physics professors) who tend to think that the foundational issues does not make for “real” physics, that it is a non-issue. … However, for obvious reasons, this post will also remain permanently under updates…

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# Stay tuned to the NSF on the next evening…

Update on 2019.04.10 18:50 IST:

Dimitrios Psaltis, University of Arizona in Tucson, EHT project scientist [^]:

The size and shape of the shadow matches the precise predictions of Einstein’s general theory of relativity, increasing our confidence in this century-old theory. Imaging a black hole is just the beginning of our effort to develop new tools that will enable us to interpret the massively complex data that nature gives us.”

Update over.

Stay tuned to the NSF on the next evening (on 10th April 2019 at 06:30 PM IST) for an announcement of astronomical proportions. Or so it is, I gather. See: “For Media” from NSF [^]. Another media advisory made by NSF roughly 9 days ago, i.e. on the Fool’s Day, here [^]. Their news “report”s [^].

No, I don’t understand the relativity theory. Not even the “special” one (when it’s taken outside of its context of the so-called “classical” electrodynamics)—let alone the “general” one. It’s not one of my fields of knowledge.

But if I had to bet my money then, based purely on my grasp of the sociological factors these days operative in science as practised in the Western world, then I would bet a good amount (even Indian Rs. 1,000/-) that the announcement would be just a further confirmation of Einstein’s theory of general relativity.

That’s how such things go, in the Western world, today.

In other words, I would be very, very, very surprised—I mean to say, about my grasp of the sociology of science in the Western world—if they found something (anything) going even apparently contrary to any one of the implications of any one of Einstein’s theories. Here, emphatically, his theory of the General Relativity.

That’s all for now, folks! Bye for now. Will update this post in a minor way when the facts are on the table.

TBD: The songs section. Will do that too, within the next 24 hours. That’s a promise. For sure. (Or, may be, right tonight, if a song nice enough to listen to, strikes me within the next half an hour or so… Bye, really, for now.)

A song I like:

(Hindi) “ek haseen shaam ko, dil meraa kho_ gayaa…”
Lyrics: Raajaa Mehdi Ali Khaan
Singer: Mohammad Rafi [Some beautiful singing here…]

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# Further on QM, and on changing tracks over to Data Science

OK. As decided, I took a short trip to IIT Bombay, and saw a couple of professors of physics, for very brief face-to-face interactions on the 28th evening.

No chalk-work at the blackboard had to be done, because both of them were very busy—but also quick, really very quick, in getting to the meat of the matter.

As to the first professor I saw, I knew beforehand that he wouldn’t be very enthusiastic with any alternatives to anything in the mainstream QM.

He was already engrossed in a discussion with someone (who looked like a PhD student) when I knocked at the door of his cabin. The prof immediately mentioned that he has to finish (what looked like a few tons of) pending work items, before going away on a month-long trip just after a couple of days! But, hey, as I said (in my last post), directly barging into a professor’s cabin has always done wonders for me! So, despite his having some heavy^{heavy} schedule, he still motioned me to sit down for a quick and short interaction.

The three of us (the prof, his student, and me) then immediately had a very highly compressed discussion for some 15-odd minutes. As expected, the discussion turned out to be not only very rapid, and also quite uneven, because there were so many abrupt changes to the sub-topics and sub-issues, as they were being brought up and dispatched in quick succession. …

It was not an ideal time to introduce my new approach, and so, I didn’t. I did mention, however, that I was trying to develop some such a thing. The professor was of the opinion that if you come up with a way to do faster simulations, it would always be welcome, but if you are going to argue against the well-established laws, then… [he just shook head].

I told him that I was clear, very clear on one point. Suppose, I said, that I have a complex-valued field that is defined only over the physical 3D, and suppose further that my new approach (which involves such a 3D field) does work out. Then, suppose further that I get essentially the same results as the mainstream QM does.

In such a case, I said, I am going to say that here is a possibility of looking at it as a real physical mechanism underlying the QM theory.

And if people even then say that because it is in some way different from the established laws, therefore it is not to be taken seriously, then I am very clear that I am going to say: “You go your way and I will go mine.”

But of course, I further added, that I still don’t know yet how the calculations are done in the mainstream QM for the interacting electrons—that is, without invoking simplifying approximations (such as the fixed nucleus). I wanted to see how these calculations are done using the computational modeling approach (not the perturbation theory).

It was at this point that the professor really got the sense of what I was trying to get at. He then remarked that variational formulations are capable enough, and proceeded to outline some of their features. To my query as to what kind of an ansatz they use, and what kind of parameters are involved in inducing the variations, he mentioned Chebyshev polynomials and a few other things. The student mentioned the Slater determinants. Then the professor remarked that the particulars of the ansatz and the particulars of the variational techniques were not so crucial because all these techniques ultimately boil down to just diagonalizing a matrix. Somehow, I instinctively got the idea that he hasn’t been very much into numerical simulations himself, which turned out to be the case. In fact he immediately said so himself: “I don’t do wavefunctions. [Someone else from the same department] does it.” I decided to see this other professor the next day, because it was already evening (almost approaching 6 PM or so).

A few wonderful clarifications later, it was time for me to leave, and so I thanked the professor profusely for accommodating me. The poor fellow didn’t even have the time to notice my gratitude; he had already switched back to his interrupted discussion with the student.

But yes, the meeting was fruitful to me because the prof did get the “nerve” of the issue right, and in fact also gave me two very helpful papers to study, both of them being review articles. After coming home, I have now realized that while one of them is quite relevant to me, the other one is absolutely god-damn relevant!

Anyway, after coming out of the department on that evening, I was thinking of calling my friend to let him know that the purpose of the visit to the campus was over, and thus I was totally free. While thinking about calling him and walking through the parking lot, I just abruptly noticed a face that suddenly flashed something recognizable to me. It was this same second professor who “does wavefunctions!”

I had planned on seeing him the next day, but here he was, right in front me, walking towards his car in a leisurely mood. Translated, it meant: he was very much free of all his students, and so was available for a chat with me! Right now!! Of course, I had never had made any acquaintance with him in the past. I had only browsed through his home page once in the recent times, and so could immediately make out the face, that’s all. He was just about to open the door of his car when I approached him and introduced myself. There followed another intense bout of discussions, for another 10-odd minutes.

This second prof has done numerical simulations himself, and so, he was even faster in getting a sense of what kind of ideas I was toying with. Once again, I told him that I was trying for some new ideas but didn’t get any deeper into my approach, because I myself still don’t know whether my approach will produce the same results as the mainstream QM does or not. In any case, knowing the mainstream method of handling these things was crucial, I said.

I told him how, despite my extensive Internet searches, I had not found suitable material for doing calculations. He then said that he will give me the details about a book. I should study this book first, and if there are still some difficulties or some discussions to be had, then he would be available, but the discussion would then have to progress in reference to what is already given in that book. Neat idea, this one was, perfect by me. And turns out that the book he suggested was neat—absolutely perfectly relevant to my needs, background as well as preparation.

And with that ends this small story of this short visit to IIT Bombay. I went there with a purpose, and returned with one 50 page-long and very tightly written review paper, a second paper of some 20+ tightly written pages, and a reference to an entire PG-level book (about 500 pages). All of this material absolutely unknown to me despite my searches, and as it seems as of today, all of it being of utmost relevance to me, my new ideas.

But I have to get into Data Science first. Else I cannot survive. (I have been borrowing money to fend off the credit card minimum due amounts every month.)

So, I have decided to take a rest for today, and from tomorrow onwards, or may be a day later—i.e., starting from the “shubh muhurat” (auspicious time) of the April Fool’s day, I will begin my full-time pursuit of Data Science, with all that new material on QM only to be studied on a part-time basis. For today, however, I am just going to be doing a bit of a time-pass here and there. That’s how this post got written.

Take care, and wish you the same kind of luck as I had in spotting that second prof just like that in the parking lot. … If my approach works, then I know who to contact first with my results, for informal comments on them. … I wish you this same kind of a luck…

Work hard, and bye for now.

A song I like
(Marathi) “dhunda_ madhumati raat re, naath re…”
Music: Master Krishnarao
Singer: Lata Mangeshkar

[A Marathi classic. Credits are listed in a purely random order. A version that seems official (released by Rajshri Marathi) is here: [^] . However, somehow, the first stanza is not complete in it.

As to the set shown in this (and all such) movies, right up to, say the movie “Bajirao-Mastani,” I have—and always had—an issue. The open wide spaces for the palaces they show in the movies are completely unrealistic, given the technology of those days (and the actual remains of the palaces that are easy to be recalled by anyone). The ancients (whether here in India or at any other place) simply didn’t have the kind of technology which is needed in order to build such hugely wide internal (covered) spaces. Neitehr the so-called “Roman arch” (invented millenia earlier in India, I gather), nor the use of the monolithic stones for girders could possibly be enough to generate such huge spans. Idiots. If they can’t get even simple calculations right, that’s only to be expected—from them. But if they can’t even recall the visual details of the spans actually seen for the old palaces, that is simply inexcusable. Absolutely thorough morons, these movie-makers must be.]

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# Wrapping up my research on QM—without having to give up on it

Guess I am more or less ready to wrap up my research on QM. Here is the exact status as of today.

1. The status today:

I have convinced myself that my approach (viz. the idea of singular potentials anchored into electronic positions, and with a $3D$ wave-field) is entirely correct, as far as QM of non-interacting particles is concerned. That is to say, as far as the abstract case of two particles in a $0$-potential $1D$ box, or a less abstract but still hypothetical case of two non-interacting electrons in the helium atom, and similar cases are concerned. (A side note: I have worked exclusively with the spinless electrons. I don’t plan to include spin right away in my development—not even in my first paper on it. Other physicists are welcome to include it, if they wish to, any time they like.)

As to the actual case of two interacting particles (i.e., the interaction term in the Hamiltonian for the helium atom), I think that my approach should come to reproduce the same results as those obtained using the perturbation theory or the variational approach. However, I need to verify this part via discussions with physicists.

All in all, I do think that the task which I had intended to complete (and to cross-check) before this month-end, is already over—and I find that I don’t have to give up on QM (as suspected earlier [^]), because I don’t have to abandon my new approach in the first place.

2. A clarification on what had to be worked out and what had to be left alone:

To me, the crucial part at this stage (i.e., for the second-half of March) was verifying whether working with the two ideas of (i) a $3D$ wavefield, and (ii) electrons as “particles” having definite positions (or more correctly, as points of singularities in the potential field), still leads to the same mathematical description as in the mainstream (linear) quantum mechanics or not.

I now find that my new approach leads to the same maths—at least for the QM of the non-interacting particles. And further, I also have very definite grounds to believe that my new approach should also work out for two interacting particles (as in the He atom).

The crucial part at this stage (i.e., for the second half of March) didn’t have so much to do with the specific non-linearity which I have proposed earlier, or the details of the measurement process which it implies. Working out the details of these ideas would have been impossible—certainly beyond the capacities of any single physicist, and over such a short period. An entire team of PhD physicists would be needed to tackle the issues arising in pursuing this new approach, and to conduct the simulations to verify it.

BTW, in this context, I do have some definite ideas regarding how to hasten this process of unraveling the many particular aspects of the measurement process. I would share them once physicists show readiness to pursue this new approach. [Just in case I forget about it in future, let me note just a single cue-word for myself: “DFT”.]

3. Regarding revising the Outline document issued earlier:

Of course, the Outline document (which was earlier uploaded at iMechanica, on 11th February 2019) [^] needs to be revised extensively. A good deal of corrections and modifications are in order, and so are quite a few additions to be made too—especially in the sections on ontology and entanglement.

However, I will edit this document at my leisure later; I will not allocate a continuous stretch of time exclusively for this task any more.

In fact, a good idea here would be to abandon that Outline document as is, and to issue a fresh document that deals with only the linear aspects of the theory—with just a sketchy conceptual idea of how the measurement process is supposed to progress in a broad background context. Such a document then could be converted as a good contribution to a good journal like Nature, Science, or PRL.

4. The initial skepticism of the physicists:

Coming to the skepticism shown by the couple of physicists (with whom I had had some discussions by emails), I think that, regardless of their objections (hollers, really speaking!), my main thesis still does hold. It’s they who don’t understand the quantum theory—and let me hasten to add that by the words “quantum theory,” here I emphatically mean the mainstream quantum theory.

It is the mainstream QM which they themselves don’t understood as well as they should. What my new approach then does is to merely uncover some of these weaknesses, that’s all. … Their weakness pertains to a lack of understanding of the $3D \Leftrightarrow 3ND$ correspondence in general, for any kind of physics: classical or quantum. … Why, I even doubt whether they understand even just the classical vibrations themselves right or not—coupled vibrations under variable potentials, that is—to the extent and depth to which they should.

In short, it is now easy for me to leave their skepticism alone, because I can now clearly see where they failed to get the physics right.

5. Next action-item:

In the near future, I would like to make short trips to some Institutes nearby (viz., in no particular order, one or more of the following: IIT Bombay, IISER Pune, IUCAA Pune, and TIFR Mumbai). I would like to have some face-to-face discussions with physicists on this one single topic: the interaction term in the Hamiltonian for the helium atom. The discussions will be held strictly in the context that is common to us, i.e., in reference to the higher-dimensional Hilbert space of the mainstream QM.

In case no one from these Institutes responds to my requests, I plan to go and see the heads of these Institutes (i.e. Deans and Directors)—in person, if necessary. I might also undertake other action items. However, I also sincerely hope and think that such things would not at all be necessary. There is a reason why I think so. Professors may or may not respond to an outsider’s emails, but they do entertain you if you just show up in their cabin—and if you yourself are smart, courteous, direct, and well… also experienced enough. And if you are capable of holding discussions on the “common” grounds alone, viz. in terms of the linear, mainstream QM as formulated in the higher-dimensional spaces (I gather it’s John von Neumann’s formulation), that is to say, the “Copenhagen interpretation.” (After doing all my studies—and, crucially, after the development of what to me is a satisfactory new approach—I now find that I no longer am as against the Copenhagen interpretation as some of the physicists seem to be.) … All in all, I do hope and think that seeing Diro’s and all won’t be necessary.

I also equally sincerely hope that my approach comes out unscathed during / after these discussions. … Though the discussions externally would be held in terms of mainstream QM, I would also be simultaneously running a second movie of my approach, in my mind alone, cross-checking whether it holds or not. (No, they wouldn’t even suspect that I was doing precisely that.)

I will be able to undertake editing of the Outline document (or leaving it as is and issuing a fresh document) only after these discussions.

6. The bottom-line:

The bottom-line is that my main conceptual development regarding QM is more or less over now, though further developments, discussions, simulations, paper-writing and all can always go on forever—there is never an end to it.

7. Data Science!

So, I now declare that I am free to turn my main focus to the other thing that interests me, viz., Data Science.

I already have a few projects in mind, and would like to initiate work on them right away. One of the “projects” I would like to undertake in the near future is: writing very brief notes, written mainly for myself, regarding the mathematical techniques used in data science. Another one is regarding applying ML techniques to NDT (nondestructive testing). Stay tuned.

A song I like:

(Western, instrumental) “Lara’s theme” (Doctor Zhivago)
Composer: Maurice Jarre

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# Work Is Punishment

Work is not worship—they said.

It’s a punishment, full stop!—they said.

One that is to be smilingly borne.

And so lose everything else too. …

Hmmm… I said. … I was confused.

Work is enjoyment, actually. … I then discovered.

I told them.

They didn’t believe.

Not when I said it.

Not because they ceased believing in me.

It’s just that. They. Simply. Didn’t. Believe. In. It.

And they professed to believe in

a lot of things that never did make

any sense to themselves.

They said so.

And it was so.

A long many years have passed by, since then.

Now, whether they believe in it or not,

I have come to believe in this gem:

Work is punishment—full stop.

That’s the principle on the basis of which I am henceforth going to operate.

And yes! This still is a poem alright?

[What do you think most poems written these days are like?]

It remains a poem.

And I am going to make money. A handsome amount of money.

For once in my life-time.

After all, one can make money and still also write poems.

That’s what they say.

Or do science. Real science. Physics. Even physics for that matter.

Or, work. Real work, too.

It’s better than having no money and…

.

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# The self-field, and the objectivity of the classical electrostatic potentials: my analysis

This blog post continues from my last post, and has become overdue by now. I had promised to give my answers to the questions raised last time. Without attempting to explain too much, let me jot down the answers.

1. The rule of omitting the self-field:

This rule arises in electrostatic interactions basically because the Coulombic field has a spherical symmetry. The same rule would also work out in any field that has a spherical symmetry—not just the inverse-separation fields, and not necessarily only the singular potentials, though Coulombic potentials do show both these latter properties too.

It is helpful here to think in terms of not potentials but of forces.

Draw any arbitrary curve. Then, hold one end of the curve fixed at the origin, and sweep the curve through all possible angles around it, to get a 3D field. This 3D field has a spherical symmetry, too. Hence, gradients at the same radial distance on opposite sides of the origin are always equal and opposite.

Now you know that the negative gradient of potential gives you a force. Since for any spherical potential the gradients are equal and opposite, they cancel out. So, the forces cancel out to.

Realize here that in calculating the force exerted by a potential field on a point-particle (say an electron), the force cannot be calculated in reference to just one point. The very definition of the gradient refers to two different points in space, even if they be only infinitesimally separated apart. So, the proper procedure is to start with a small sphere centered around the given electron, calculate the gradients of the potential field at all points on the surface of this sphere, calculate the sum of the forces exerted on the domain contained inside the spherical surface by these forces, and then take the sphere to the limiting of vanishing size. The sum of the forces thus exerted is the net force acting on that point-particle.

In case of the Coulombic potentials, the forces thus calculated on the surface of any sphere (centered on that particle) turn out to be zero. This fact holds true for spheres of all radii. It is true that gradients (and forces) progressively increase as the size of the sphere decreases—in fact they increase without all bounds for singular potentials. However, the aforementioned cancellation holds true at any stage in the limiting process. Hence, it holds true for the entirety of the self-field.

In calculating motions of a given electron, what matters is not whether its self-field exists or not, but whether it exerts a net force on the same electron or not. The self-field does exist (at least in the sense explained later below) and in that sense, yes, it does keep exerting forces at all times, also on the same electron. However, due to the spherical symmetry, the net force that the field exerts on the same electron turns out to be zero.

In short:

Even if you were to include the self-field in the calculations, if the field is spherically symmetric, then the final net force experienced by the same electron would still have no part coming from its own self-field. Hence, to economize calculations without sacrificing exactitude in any way, we discard it out of considerations.The rule of omitting the self-field is just a matter of economizing calculations; it is not a fundamental law characterizing what field may be objectively said to exist. If the potential field due to other charges exists, then, in the same sense, the self-field too exists. It’s just that for the motions of the self field-generating electron, it is as good as non-existent.

However, the question of whether a potential field physically exists or not, turns out to be more subtle than what might be thought.

2. Conditions for the objective existence of electrostatic potentials:

It once again helps to think of forces first, and only then of potentials.

Consider two electrons in an otherwise empty spatial region of an isolated system. Suppose the first electron ($e_1$), is at a position $x_1$, and a second electron $e_2$ is at a position $x_2$. What Coulomb’s law now says is that the two electrons mutually exert equal and opposite forces on each other. The magnitudes of these forces are proportional to the inverse-square of the distance which separates the two. For the like charges, the forces is repulsive, and for unlike charges, it is attractive. The amount of the electrostatic forces thus exerted do not depend on mass; they depend only the amounts of the respective charges.

The potential energy of the system for this particular configuration is given by (i) arbitrarily assigning a zero potential to infinite separation between the two charges, and (ii) imagining as if both the charges have been brought from infinity to their respective current positions.

It is important to realize that the potential energy for a particular configuration of two electrons does not form a field. It is merely a single number.

However, it is possible to imagine that one of the charges (say $e_1$) is held fixed at a point, say at $\vec{r}_1$, and the other charge is successively taken, in any order, at every other point $\vec{r}_2$ in the infinite domain. A single number is thus generated for each pair of $(\vec{r}_1, \vec{r}_2)$. Thus, we can obtain a mapping from the set of positions for the two charges, to a set of the potential energy numbers. This second set can be regarded as forming a field—in the $3D$ space.

However, notice that thus defined, the potential energy field is only a device of calculations. It necessarily refers to a second charge—the one which is imagined to be at one point in the domain at a time, with the procedure covering the entire domain. The energy field cannot be regarded as a property of the first charge alone.

Now, if the potential energy field $U$ thus obtained is normalized by dividing it with the electric charge of the second charge, then we get the potential energy for a unit test-charge. Another name for the potential energy obtained when a unit test-charge is used for the second charge is: the electrostatic potential (denoted as $V$).

But still, in classical mechanics, the potential field also is only a device of calculations; it does not exist as a property of the first charge, because the potential energy itself does not exist as a property of that fixed charge alone. What does exist is the physical effect that there are those potential energy numbers for those specific configurations of the fixed charge and the test charge.

This is the reason why the potential energy field, and therefore the electrostatic potential of a single charge in an otherwise empty space does not exist. Mathematically, it is regarded as zero (though it could have been assigned any other arbitrary, constant value.)

Potentials arise only out of interaction of two charges. In classical mechanics, the charges are point-particles. Point-particles exist only at definite locations and nowhere else. Therefore, their interaction also must be seen as happening only at the locations where they do exist, and nowhere else.

If that is so, then in what sense can we at all say that potential energy (or electrostaic potential) field does physically exist?

Consider a single electron in an isolated system, again. Assume that its position remains fixed.

Suppose there were something else in the isolated system—-something—some object—every part of which undergoes an electrostatic interaction with the fixed (first) electron. If this second object were to be spread all over the domain, and if every part of it were able to interact with the fixed charge, then we could say that the potential energy field exists objectively—as an attribute of this second object. Ditto, for the electric potential field.

Note three crucially important points, now.

2.1. The second object is not the usual classical object.

You cannot regard the second (spread-out) object as a mere classical charge distribution. The reason is this.

If the second object were to be actually a classical object, then any given part of it would have to electrostatically interact with every other part of itself too. You couldn’t possibly say that a volume element in this second object interacts only with the “external” electron. But if the second object were also to be self-interacting, then what would come to exist would not be the simple inverse-distance potential field energy, in reference to that single “external” electron. The space would be filled with a very weird field. Admitting motion to the property of the local charge in the second object, every locally present charge would soon redistribute itself back “to” infinity (if it is negative), or it all would collapse into the origin (if the charge on the second object were to be positive, because the fixed electron’s field is singular). But if we allow no charge redistributions, and the second field were to be classical (i.e. capable of self-interacting), then the field of the second object would have to have singularities everywhere. Very weird. That’s why:

If you want to regard the potential field as objectively existing, you have to also posit (i.e. postulate) that the second object itself is not classical in nature.

Classical electrostatics, if it has to regard a potential field as objectively (i.e. physically) existing, must therefore come to postulate a non-classical background object!

2.2. Assuming you do posit such a (non-classical) second object (one which becomes “just” a background object), then what happens when you introduce a second electron into the system?

You would run into another seeming contradiction. You would find that this second electron has no job left to do, as far as interacting with the first (fixed) electron is concerned.

If the potential field exists objectively, then the second electron would have to just passively register the pre-existing potential in its vicinity (because it is the second object which is doing all the electrostatic interactions—all the mutual forcings—with the first electron). So, the second electron would do nothing of consequence with respect to the first electron. It would just become a receptacle for registering the force being exchanged by the background object in its local neighborhood.

But the seeming contradiction here is that as far as the first electron is concerned, it does feel the potential set up by the second electron! It may be seen to do so once again via the mediation of the background object.

Therefore, both electrons have to be simultaneously regarded as being active and passive with respect to each other. They are active as agents that establish their own potential fields, together with an interaction with the background object. But they also become passive in the sense that they are mere point-masses that only feel the potential field in the background object and experience forces (accelerations) accordingly.

The paradox is thus resolved by having each electron set up a field as a result of an interaction with the background object—but have no interaction with the other electron at all.

2.3. Note carefully what agency is assigned to what object.

The potential field has a singularity at the position of that charge which produces it. But the potential field itself is created either by the second charge (by imagining it to be present at various places), or by a non-classical background object (which, in a way, is nothing but an objectification of the potential field-calculation procedure).

Thus, there arises a duality of a kind—a double-agent nature, so to speak. The potential energy is calculated for the second charge (the one that is passive), in the sense that the potential energy is relevant for calculating the motion of the second charge. That’s because the self-field cancels out for all motions of the first charge. However,

The potential energy is calculated for the second charge. But the field so calculated has been set up by the first (fixed) charge. Charges do not interact with each other; they interact only with the background object.

2.4. If the charges do not interact with each other, and if they interact only with the background object, then it is worth considering this question:

Can’t the charges be seen as mere conditions—points of singularities—in the background object?

Indeed, this seems to be the most reasonable approach to take. In other words,

All effects due to point charges can be regarded as field conditions within the background object. Thus, paradoxically enough, a non-classical distributed field comes to represent the classical, massive and charged point-particles themselves. (The mass becomes just a parameter of the interactions of singularities within a $3D$ field.) The charges (like electrons) do not exist as classical massive particles, not even in the classical electrostatics.

3. A partly analogous situation: The stress-strain fields:

If the above situation seems too paradoxical, it might be helpful to think of the stress-strain fields in solids.

Consider a horizontally lying thin plate of steel with two rigid rods welded to it at two different points. Suppose horizontal forces of mutually opposite directions are applied through the rods (either compressive or tensile). As you know, as a consequence, stress-strain fields get set up in the plate.

From an external viewpoint, the two rods are regarded as interacting with each other (exchanging forces with each other) via the medium of the plate. However, in reality, they are interacting only with the object that is the plate. The direct interaction, thus, is only between a rod and the plate. A rod is forced, it interacts with the plate, the plate sets up stress-strain field everywhere, the local stress-field near the second rod interacts with it, and the second rod registers a force—which balances out the force applied at its end. Conversely, the force applied at the second rod also can be seen as getting transmitted to the first rod via the stress-strain field in the plate material.

There is no contradiction in this description, because we attribute the stress-strain field to the plate itself, and always treat this stress-strain field as if it came into existence due to both the rods acting simultaneously.

In particular, we do not try to isolate a single-rod attribute out of the stress-strain field, the way we try to ascribe a potential to the first charge alone.

Come to think of it, if we have only one rod and if we apply force to it, no stress-strain field would result (i.e. neglecting inertia effects of the steel plate). Instead, the plate would simply move in the rigid body mode. Now, in solid mechanics, we never try to visualize a stress-strain field associated with a single rod alone.

It is a fallacy of our thinking that when it comes to electrostatics, we try to ascribe the potential to the first charge, and altogether neglect the abstract procedure of placing the test charge at various locations, or the postulate of positing a non-classical background object which carries that potential.

In the interest of completeness, it must be noted that the stress-strain fields are tensor fields (they are based on the gradients of vector fields), whereas the electrostatic force-field is a vector field (it is based on the gradient of the scalar potential field). A more relevant analogy for the electrostatic field, therefore might the forces exchanged by two point-vortices existing in an ideal fluid.

4. But why bother with it all?

The reason I went into all this discussion is because all these issues become important in the context of quantum mechanics. Even in quantum mechanics, when you have two charges that are interacting with each other, you do run into these same issues, because the Schrodinger equation does have a potential energy term in it. Consider the following situation.

If an electrostatic potential is regarded as being set up by a single charge (as is done by the proton in the nucleus of the hydrogen atom), but if it is also to be regarded as an actually existing and spread out entity (as a $3D$ field, the way Schrodinger’s equation assumes it to be), then a question arises: What is the role of the second charge (e.g., that of the electron in an hydrogen atom)? What happens when the second charge (the electron) is represented quantum mechanically? In particular:

What happens to the potential field if it represents the potential energy of the second charge, but the second charge itself is now being represented only via the complex-valued wavefunction?

And worse: What happens when there are two electrons, and both interacting with each other via electrostatic repulsions, and both are required to be represented quantum mechanically—as in the case of the electrons in an helium atom?

Can a charge be regarded as having a potential field as well as a wavefunction field? If so, what happens to the point-specific repulsions as are mandated by the Coulomb law? How precisely is the $V(\vec{r}_1, \vec{r}_2)$ term to be interpreted?

I was thinking about these things when these issues occurred to me: the issue of the self-field, and the question of the physical vs. merely mathematical existence of the potential fields of two or more quantum-mechanically interacting charges.

Guess I am inching towards my full answers. Guess I have reached my answers, but I need to have them verified with some physicists.

5. The help I want:

As a part of my answer-finding exercises (to be finished by this month-end), I might be contacting a second set of physicists soon enough. The issue I want to learn from them is the following:

How exactly do they do computational modeling of the helium atom using the finite difference method (FDM), within the context of the standard (mainstream) quantum mechanics?

That is the question. Once I understand this part, I would be done with the development of my new approach to understanding QM.

I do have some ideas regarding the highlighted question. It’s just that I want to have these ideas confirmed from some physicists before (or along-side) implementing the FDM code. So, I might be approaching someone—possibly you!

Please note my question once again. I don’t want to do perturbation theory. I would also like to avoid the variational method.

Yes, I am very comfortable with the finite element method, which is basically based on the variational calculus. So, given a good (detailed enough) account of the variational method for the He atom, it should be possible to translate it into the FEM terms.

However, ideally, what I would like to do is to implement it as an FDM code.

So there.

Please suggest good references and / or people working on this topic, if you know any. Thanks in advance.

A song I like:

[… Here I thought that there was no song that Salil Chowdhury had composed and I had not listened to. (Well, at least when it comes to his Hindi songs). That’s what I had come to believe, and here trots along this one—and that too, as a part of a collection by someone! … The time-delay between my first listening to this song, and my liking it, was zero. (Or, it was a negative time-delay, if you refer to the instant that the first listening got over). … Also, one of those rare occasions when one is able to say that any linear ordering of the credits could only be random.]

Music: Salil Chowdhury
Lyrics: Gulzaar
Singer: Lata Mangeshkar

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# The rule of omitting the self-field in calculations—and whether potentials have an objective existence or not

There was an issue concerning the strictly classical, non-relativistic electricity which I was (once again) confronted with, during my continuing preoccupation with quantum mechanics.

Actually, a small part of this issue had occurred to me earlier too, and I had worked through it back then.

However, the overall issue had never occurred to me with as much of scope, generality and force as it did last evening. And I could not immediately resolve it. So, for a while, especially last night, I unexpectedly found myself to have become very confused, even discouraged.

Then, this morning, after a good night’s rest, everything became clear right while sipping my morning cup of tea. Things came together literally within a span of just a few minutes. I want to share the issue and its resolution with you.

The question in question (!) is the following.

Consider 2 (or $N$) number of point-charges, say electrons. Each electron sets up an electrostatic (Coulombic) potential everywhere in space, for the other electrons to “feel”.

As you know, the potential set up by the $i$-th electron is:
$V_i(\vec{r}_i, \vec{r}) = \dfrac{1}{4 \pi \epsilon_0} \dfrac{Q_i}{|\vec{r} - \vec{r}_i|}$
where $\vec{r}_i$ is the position vector of the $i$-th electron, $\vec{r}$ is any arbitrary point in space, and $Q_i$ is the charge of the $i$-th electron.

The potential energy associated with some other ($j$-th) electron being at the position $\vec{r}_j$ (i.e. the energy that the system acquires in bringing the two electrons from $\infty$ to their respective positions some finite distance apart), is then given as:
$U_{ij}(\vec{r}_i, \vec{r}_j) = \dfrac{1}{4 \pi \epsilon_0} \dfrac{Q_i\,Q_j}{|\vec{r}_j - \vec{r}_i|}$

The notation followed here is the following: In $U_{ij}$, the potential field is produced by the $i$-th electron, and the work is done by the $j$-th electron against the $i$-th electron.

Symmetrically, the potential energy for this configuration can also be expressed as:
$U_{ji}(\vec{r}_j, \vec{r}_i) = \dfrac{1}{4 \pi \epsilon_0} \dfrac{Q_j\,Q_i}{|\vec{r}_i - \vec{r}_j|}$

If a system has only two charges, then its total potential energy $U$ can be expressed either as $U_{ji}$ or as $U_{ij}$. Thus,
$U = U_{ji} = U_{ij}$

Similarly, for any pair of charges in an $N$-particle system, too. Therefore, the total energy of an $N$-particle system is given as:
$U = \sum\limits_{i}^{N} \sum\limits_{j = i+1}^{N} U_{ij}$

The issue now is this: Can we say that the total potential energy $U$ has an objective existence in the physical world? Or is it just a device of calculations that we have invented, just a concept from maths that has no meaningful physical counterpart?

(A side remark: Energy may perhaps exist as an attribute or property of something else, and not necessarily as a separate physical object by itself. However, existence as an attribute still is an objective existence.)

The reason to raise this doubt is the following.

When calculating the motion of the $i$-th charge, we consider only the potentials $V_j$ produced by the other charges, not the potential produced by the given charge $V_i$ itself.

Now, if the potential produced by the given charge ($V_i$) also exists at every point in space, then why does it not enter the calculations? How does its physical efficacy get evaporated away? And, symmetrically: The motion of the $j$-th charge occurs as if $V_j$ had physically evaporated away.

The issue generalizes in a straight-forward manner. If there are $N$ number of charges, then for calculating the motion of a given $i$-th charge, the potential fields of all other charges are considered operative. But not its own field.

How can motion become sensitive to only a part of the total potential energy existing at a point even if the other part also exists at the same point? That is the question.

This circumstance seems to indicate as if there is subjectivity built deep into the very fabric of classical mechanics. It is as if the universe just knows what a subject is going to calculate, and accordingly, it just makes the corresponding field mystically go away. The universe—the physical universe—acts as if it were changing in response to what we choose to do in our mind. Mind you, the universe seems to change in response to not just our observations (as in QM), but even as we merely proceed to do calculations. How does that come to happen?… May be the whole physical universe exists only in our imagination?

Got the point?

No, my confusion was not as pathetic as that in the previous paragraph. But I still found myself being confused about how to account for the fact that an electron’s own field does not enter the calculations.

But it was not all. A non-clarity on this issue also meant that there was another confusing issue which also raised its head. This secondary issue arises out of the fact that the Coulombic potential set up by any point-charge is singular in nature (or at least approximately so).

If the electron is a point-particle and if its own potential “is” $\infty$ at its position, then why does it at all get influenced by the finite potential of any other charge? That is the question.

Notice, the second issue is most acute when the potentials in question are singular in nature. But even if you arbitrarily remove the singularity by declaring (say by fiat) a finite size for the electron, thereby making its own field only finitely large (and not infinite), the above-mentioned issue still remains. So long as its own field is finite but much, much larger than the potential of any other charge, the effects due to the other charges should become comparatively less significant, perhaps even negligibly small. Why does this not happen? Why does the rule instead go exactly the other way around, and makes those much smaller effects due to other charges count, but not the self-field of the very electron in question?

While thinking about QM, there was a certain point where this entire gamut of issues became important—whether the potential has an objective existence or not, the rule of omitting the self-field while calculating motions of particles, the singular potential, etc.

The specific issue I was trying to think through was: two interacting particles (e.g. the two electrons in the helium atom). It was while thinking on this problem that this problem occurred to me. And then, it also led me to wonder: what if some intellectual goon in the guise of a physicist comes along, and says that my proposal isn’t valid because there is this element of subjectivity to it? This thought occurred to me with all its force only last night. (Or so I think.) And I could not recall seeing a ready-made answer in a text-book or so. Nor could I figure it out immediately, at night, after a whole day’s work. And as I failed to resolve the anticipated objection, I progressively got more and more confused last night, even discouraged.

However, this morning, it all got resolved in a jiffy.

Would you like to give it a try? Why is it that while calculating the motion of the $i$-th charge, you consider the potentials set up by all the rest of the charges, but not its own potential field? Why this rule? Get this part right, and all the philosophical humbug mentioned earlier just evaporates away too.

I would wait for a couple of days or so before coming back and providing you with the answer I found. May be I will write another post about it.

Update on 2019.03.16 20:14 IST: Corrected the statement concerning the total energy of a two-electron system. Also simplified the further discussion by couching it preferably in terms of potentials rather than energies (as in the first published version), because a Coulombic potential always remains anchored in the given charge—it doesn’t additionally depend on the other charges the way energy does. Modified the notation to reflect the emphasis on the potentials rather than energy.

A song I like:

[What else? [… see the songs section in the last post.]]
(Hindi) “woh dil kahaan se laaoon…”
Singer: Lata Mangeshkar
Music: Ravi
Lyrics: Rajinder Kishen

A bit of a conjecture as to why Ravi’s songs tend to be so hummable, of a certain simplicity, especially, almost always based on a very simple rhythm. My conjecture is that because Ravi grew up in an atmosphere of “bhajan”-singing.

Observe that it is in the very nature of music that it puts your mind into an abstract frame of mind. Observe any singer, especially the non-professional ones (or the ones who are not very highly experienced in controlling their body-language while singing, as happens to singers who participate in college events or talent shows).

When they sing, their eyes seem to roll in a very peculiar manner. It seems random but it isn’t. It’s as if the eyes involuntarily get set in the motions of searching for something definite to be found somewhere, as if the thing to be found would be in the concrete physical space outside, but within a split-second, the eyes again move as if the person has realized that nothing corresponding is to be found in the world out there. That’s why the eyes “roll away.” The same thing goes on repeating, as the singer passes over various words, points of pauses, nuances, or musical phrases.

The involuntary motions of the eyes of the singer provide a window into his experience of music. It’s as if his consciousness was again and again going on registering a sequence of two very fleeting experiences: (i) a search for something in the outside world corresponding to an inner experience felt in the present, and immediately later, (ii) a realization (and therefore the turning away of the eyes from an initially picked up tentative direction) that nothing in the outside world would match what was being searched for.

The experience of music necessarily makes you realize the abstractness of itself. It tends to make you realize that the root-referents of your musical experience lie not in a specific object or phenomenon in the physical world, but in the inner realm, that of your own emotions, judgments, self-reflections, etc.

This nature of music makes it ideally suited to let you turn your attention away from the outside world, and has the capacity or potential to induce a kind of a quiet self-reflection in you.

But the switch from the experience of frustrated searches into the outside world to a quiet self-reflection within oneself is not the only option available here. Music can also induce in you a transitioning from those unfulfilled searches to a frantic kind of an activity: screams, frantic shouting, random gyrations, and what not. In evidence, observe any piece of modern American / Western pop-music.

However, when done right, music can also induce a state of self-reflection, and by evoking certain kind of emotions, it can even lead to a sense of orderliness, peace, serenity. To make this part effective, such a music has to be simple enough, and orderly enough. That’s why devotional music in the refined cultural traditions is, as a rule, of a certain kind of simplicity.

The experience of music isn’t the highest possible spiritual experience. But if done right, it can make your transition from the ordinary experience to a deep, profound spiritual experience easy. And doing it right involves certain orderliness, simplicity in all respects: tune, tone, singing style, rhythm, instrumental sections, transitions between phrases, etc.

If you grow up listening to this kind of a music, your own music in your adult years tends to reflect the same qualities. The simplicity of rhythm. The alluringly simple tunes. The “hummability quotient.” (You don’t want to focus on intricate patterns of melody in devotional music; you want it to be so simple that minimal mental exertion is involved in rendering it, so that your mental energy can quietly transition towards your spiritual quest and experiences.) Etc.

I am not saying that the reason Ravi’s music is so great is because he listened his father sing “bhajan”s. If this were true, there would be tens of thousands of music composers having talents comparable to Ravi’s. But the fact is that Ravi was a genius—a self-taught genius, in fact. (He never received any formal training in music ever.) But what I am saying is that if you do have the musical ability, having this kind of a family environment would leave its mark. Definitely.

Of course, this all was just a conjecture. Check it out and see if it holds or not.

… May be I should convert this “note” in a separate post by itself. Would be easier to keep track of it. … Some other time. … I have to work on QM; after all, exactly only half the month remains now. … Bye for now. …

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# TL;DR: Why am I jobless?

TL;DR: Why am I jobless?

Because, they had no guts (or even sense) to give me a job in time, and thereby allow even me to become a rich man—even if they had always had the wealth to do so. Only if they were honest enough!

Simple enough a formulation, no?

But does it carry even a ring of a truth? The responsibility of finding an answer to this question rests with those who raise it.

A song I like:

(Hindi) “dil mein kisi ke pyaar kaa…”
Music: Ravi [Sharma]
Lyrics: Saahir Ludhiyaanvi
Singer: Lata Mangeshkar

[Lata is good here but I like her much better in the original song (i.e. another song of the same tune, by the same composer): “woh dil kahaan se laaoon…” If I were to rate that song, I would put her at the top, followed by Ravi and then by Rajinder Kishen (the lyricist for the original one). Rajinder Kishen’s lyrics for the original song were very good too, and he is a great lyricist—he has penned some really memorable songs in his career. But somehow, I like the theme and the tone of the present lyrics by Saahir better. “dil mein kisi ke pyaar kaa jalataa huaa diyaa, duniyaa ki aandhiyon se bhalaa yeh boojhegaa kyaa?” … Sublime!

Kishore Kumar, in comparison to all the four, comes across as a much lesser guy in his version of the present song. Having appreciated and admired him very deeply over so many years, it was not exactly a simple statement to make, but that’s the way things are here.]

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# Should I give up on QM?

After further and deeper studies of the Schrodinger formalism, I have now come to understand the exact position from which the physicists must be coming (I mean the couple of physicists with who I discussed the ideas of my new approach, as mentioned here [^])—why they must be raising their objections. I came to really understand their positions only now. Here is how it happened.

I was pursuing finding correspondence between the $3ND$ configuration space of the Schrodinger formalism on the one hand and the $3D$ physical space on the other, when I run into this subtle point which made everything look completely different. That point is the following:

Textbooks (or lecture notes, or lecturers) don’t ever highlight this point (in fact, indirectly, they actually obfuscate it), but I came to realize that even in the $1D$ cases like the QM harmonic oscillator (QHO), the Schrodinger formalism itself remains defined only on an abstract hyperspace—it’s just that in the case of the QHO, this hyperspace happens to be $1D$ in nature, that’s all.

I came to realize that, even in the simplest $1D$ case like the QHO the $x$ variable which appears in the Schrodinger equation does not directly refer to the physical space. In case of QHO, it refers to the change in the equilibrium separation between the centers of the two atoms.

Physicists and textbooks don’t mention this point, and in fact, the way they present QM, they make it look as if $x$ is the simple position variable. But in reality, no it is not. It can be made to look like a position variable (and not a change-in-the-interatomic-distance variable) by fixing the coordinate system to one of the two atoms (i.e. by making it a moving or Lagrangian coordinate system). But doing so leads to losing the symmetry in the motion of the two atoms, and more important, it further results in an obfuscation of the real nature of the issue. Mind you, textbook authors are trying to be helpful here. But unwittingly, they end up actually obfuscating the real story.

So, the $x$ variable whose Laplacian you take for the kinetic energy term also does not represent the physical space—not even in the simplest $1D$ cases like the QHO.

This insight, which I gained only now, has made me realize that I need to rethink through the whole thing once again.

In other words, my understanding of QM turned out to have been faulty—though the fault is much more on the part of the textbook authors (and lecturers) than on the part of someone like me—one who has learnt QM only through self-studies.

One implication of this better understanding now is that the new approach as stated in the Outline document isn’t going to work out. Even if there are a lot of good ideas in it (Only the Coulomb potentials, the specific nonlinearity proposed in the potential energy term, the ideas concerning measurements, etc.), there are several other ideas in that document which are just so weak that I will have to completely revise my entire approach once again.

Can I do that—take up a complete rethinking once again, and still hope to succeed?

Frankly, I don’t know. Not at this point of time anyway.

I still have not given up. But a sense of tiredness has crept in now. It now seems possible—very easily possible—that QM will end up defeating me, too.

But before outright leaving the fight, I would like to give it just one more try. One last try.

So, I have decided that I will “work” on this issue for just a little while more. May be a couple of weeks or so. Say until the month-end (March 2019-end). Unless I make some clearing, some breaththrough, I will not pursue QM beyond this time-frame.

What is going to be my strategy?

The only way an enterprise like mine can work out is if the connection between the $3D$ world of observations and the hyperspace formalism can be put in some kind of a valid conceptual correspondence. (That is to say, not just the measurement postulate but something deeper than that, something right at the level of the basic conceptual correspondence itself).

The only strategy that I will now pursue (before giving up on QM) is this: The Schrodinger formalism is based on the higher-dimensional configuration space not because a physicist like him would go specifically hunting for a higher-dimensional space, but primarily because the formulation of Schrodinger’s theory is based on the ideas from the energetics program, viz., the Leibniz-Lagrange-Euler-Hamilton program, their line(s) of thought.

The one possible opening I can think of as of today is this: The energetics program necessarily implies hyperspaces. However, at least in the classical mechanics, there always is a $1:1$ correspondence between such hyperspaces on the one hand and the $3D$ space on the other. Why should QM be any different? … As far as I am concerned, all the mystification they effected for QM over all these decades still does not supply any reason to believe that QM should necessarily be very different. After all, QM does make predictions about real world as described in $3D$! Why, even the position vectors that go into the potential energy operator $\hat{V}$ are defined only in the $3D$ space. …

… So, naturally, it seems that I just have to understand the nature of the correspondence between the Lagrangian mechanics and the $3D$ mechanics better. There must be some opening in there, based on this idea. In fact my suspicion is stronger: If at all there is a real opening to be found, if at all there is any real way to crack this nutty problem, then its key has to be lying somewhere in this correspondence.

So, I have decided to work on seeing if pursuing this line of thought yields something definitive or not. If it doesn’t, right within the next couple of weeks or so, I think I better throw in the towel and declare defeat.

Now, understanding the energetics program better meant opening up once again the books. But given my style, you know, it couldn’t possibly be the maths books—but only the conceptual ones.

So, this morning, I spent some time opening a couple of the movers-and-packers boxes (in which stuff was still lying as I mentioned before [^]), and also made some space in my room (somehow) by shoving the boxes a bit away to open the wall-cupboard, and brought out a few books I wanted to read  / browse through. Here they are.

The one shown opened is what I had mentioned as “the energetics book” in the background material document (see this link [^] in this post [^]). I am going to begin my last shot at QM—the understanding of the $3ND$$3D$ issue, starting with this book. The others may or may not be helpful, but I wanted to boast that they are just a part of personal library too!

Wish me luck!

(And suggest me a job in Data Science all the same! [Not having a job is the only thing that gets me (really) angry these days—and it does. So there.])

BTW, I really LOL on the Record of 17 off 71. (Just think what happened in 204!)

A song I like:

(Hindi) “O mere dil ke chain…”
Singer: Kishor Kumar
Music: R. D. Burman
Lyrics: Majrooh Sultanpuri

Minor editing to be done and a song to be added, tomorrow. But feel free to read the post right starting today.

Song added on 2019.03.10 12.09 AM IST. Subject to change if I have run it already.

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