“Spring break!” (Also other updates)

1. Spring break!

I have completed going through the first 12 lectures of the QM-I course at MIT OCW (the 08.04 course, Spring 2013 version). A “spring break” occurs in the video series at this time, and I took one.

I hadn’t exactly planned on taking the break, but it happened that way. I had completed the first 12 lectures by 11th May 2021 evening. Then I got diverted to some other sources on QM and all. So, it’s exactly a week since I’ve gone away from the course-work.

A break this long wouldn’t have happened, but frankly, I find scattering boring (the topic currently going on), and the next two lectures are on this topic. (Scattering is an essential topic in learning QM, but isn’t terribly important if your interest is rather limited to the foundational issues.)

Yes, the pace of going through the course has been somewhat slow, because I can’t stop taking fairly good notes for myself (handwritten). Still, I think I can comfortably manage two lectures per day. (The most I did was four lectures on one day. But it’s not efficient; the next day I found myself to be too tired, rather, lacking of patience to go through all the subtleties of the next lecture.)

I am not even cursorily looking into the problem sets. Yet, I’m not skipping the multiple-choice questions directly discussed in the lecture, either. … Yes, sometimes I make mistakes, but surprisingly (or perhaps not so surprisingly), I found that I was actually doing better on many of the questions where the class didn’t seem to do so well. I made mistakes on some other questions where they were doing great!… It’s all a consequence of uneven backgrounds and personal perspectives / objectives. … And yes, making mistakes is good, because you learn in the process. That’s what I believe in.

Anyway, I intend to resume the remaining lectures of this course (QM-I) soon, may be starting later today or tomorrow afternoon. Once these get over, then I intend to go over to QM-II (08.05, Fall 2013 version).

Implications for the planned document on my new approach:

I will come to writing the document (the one on my new approach) a little after I finish QM-II.

But when will it be? … I don’t know. Perhaps you can tell!… But in any case, just because I took a break in this specific MIT course, it doesn’t mean I also took a break from QM. No, I didn’t…

But yes, tentatively speaking, I could finish QM-II and start writing my document some time in June, I think. … It all depends on many things… Let’s see how it all goes.


2. The STOC Test of Time Awards:

I came to know of these awards via Prof. Scott Aaronson’s blog. I liked the idea and left a comment, here [^]. Let me copy-paste it here, for convenience (with minor editing):

Re.: The STOC Test of Time Award

Someone should study the correlations between the usual measures of (an author’s) “impact factor” on the one hand and the papers chosen for this award on the other—how well go the correlations.

I guess this is the first time I am seeing an award of this nature, and I like the idea. Reason: Mainly because it involves natural intelligence, and not some mechanically computed indices / AI… Awards like these should provide better insight into the real impact, IMO.

On another, related, point: I don’t know of any other field in engineering / physics which does something similar… May be they do, perhaps in some slightly different form(s), but I don’t know it. In case not, guess they could implement the same / similar ideas.

Best,
–Ajit

If someone is going to study correlations and all, there can be some indirect sources too, with certain parameters / weights attached to them. I mean, things like the following…

  • Papers chosen for other awards (like the best thesis award, best conference presentation award, etc.)
  • Papers highlighted in reputed review papers (e.g. “Annual Review” series, e.g., Annual review of Fluid Mechanics)
  • Papers highlighted in reputed key-note addresses
  • Salient papers from senior researchers who are specially honored / recognized (say upon super-annuation, via special conference sessions or special journal issues)
  • Etc.

All in all, it should be interesting to apply statistical / ML / AI techniques in a better manner, not relying purely on the mechanically computed indices (like the h-index).


3. My comments about QM:

Dr. Roger Schlafly has been posting many interesting entries on QM at his blog, and I’ve been posting my replies fairly regularly. … Recently, he highlighted some of the comments I made for more detailed discussions, by mentioning them in the main text of his blog posts proper.

My comments are pretty context specific and long. So, it’s not practical to copy-paste them here. Instead, it’s best if you go visit his blog, read the main posts first, and then see my comments. The recent posts on which I posted comments are (in the chronological order):

  • “Philosophers try to discredit Realism” [^]
  • “Does Quantum AI have Free Will?” [^]
  • “Quantum wavefunction is not everything” [^] (where I’ve made as many as five comments!)
  • “Rethinking entanglement of a single particle” [^]

Just thought of letting you know…


That’s about it, for now.

…I guess I’ll return here after I’ve completed the MIT 08.04 (QM-I) course, or some time after that (even if I am still going through their QM-II).

…In the meanwhile, take care and bye for now…


A song I like:

(Hindi, Instrumentals version) इशारों इशारों में दिल लेने वाले (“ishaaron ishaaron mein dil lene waale…”)
Musician: Brian Silas

I good quality audio is here [^]. … Though based on a Hindi film song, this instrumentals version feels like a separate song in its own right! Silas’ treatment of this song is refined and sensitive… (In certain other songs, occasionally, he might sound just a shade mechanical, but not here…)

The credits for the original song go as:
Singers: Asha Bhosale, Mohammad Rafi
Music: O. P. Nayyar
Lyrics: S. H. Bihari

A good quality audio for what looks like the original song can be found here [^]. An apparently “Revival” series version is here [^].

BTW, Google search throws up yet another series version over others. This version can be found here [^]. Personally, I find the sound processing in this version to be: bad!. There are unnecessary echo-like effects, and the depth is gone from the singers’ voices …

The original song has been a top favorite for many people, even for decades.

However, personally, I like the above mentioned instrumentals version (by Brian Silas) much, much more! Indeed, it’s this version that automatically surfaces up in my mind (whenever it does, that is); in comparison, the original song  is much less likely to similarly “come up”.

Anyway, see if you enjoy any of these versions and if yes, which one. … Anyway, bye for now…

 

Some great videos on QM…

Since my last post here, I did quite a few searches on the QM spin, and in the process, I found quite a few neat resources on QM. Let me give you the links to the neat ones among them…


The best video on the philosophical interpretations of QM:

Eugene Khutoryansky has an awesome talent for simplifying presentations and offering videos full neat of computer animations / visualization. (And they come with some neat background music too!) He has uploaded a great many videos on a lot of topics at his channel, here [^]. … Over time, I’ve watched some 8–10 of his videos.

It was only this week that I found that he has made an outstanding video on the philosophical interpretations of QM; see here [^]. The video covers all of the interpretations that are worth noting—-and then, also one or two that are not! He covers them all in a brief but illuminating manner.

The visualizations here are fairly good, though they aren’t as good as Khutoryansky’s visualizations usually are. The visualizations in this video weren’t always consistently illuminating. … Indeed, I think that for some of the interpretations, the visualizations here can be somewhat misleading! For instance, in the portion on the MWI, Khutoryansky shows all the four cats turning their heads in the same direction, all in synchronization with each other. But according to MWI, each cat (in each of the four example worlds) would be doing something little different, and so, that synch should not be there.

Yet, this video still is quite outstanding. The reason is: the script.

As I indicated above, the author is being comprehensive here. But I found really impressive was even while being brief, he so perfectly captures the peculiarity of each interpretation. He shows a marvelous talent to encapsulate the essence of these diverse set of ideas.

Another thing: The visualization here turns the meme of Schrodinger’s cat on its head—which was a neat idea, IMO.

Bottomline: Strongly recommended to all: the layman, the philosopher, and the QM specialist too!


ViaScience’s playlist on QM:

I was doing a search on the QM angular momentum when this video [^] came up. I browsed the video rapidly, liked it a lot, and so, had a rapid look at the channel [^] too.

You may perhaps want to check out the “featured video” for this channel, which is here [^]. In this video, the author says:

“Physics is not mathematics but mathematics is the language of physics. Elsewhere there are many math-free graphics-rich videos covering these topics, and there also are formal university courses and textbooks. This channel aims to following the sparsely populated region in between. We try to emphasize physical concepts but also include enough math so that the presentations are more than mere hand-waving.”

Neat! ….To be honest though, I didn’t in fact bother to see this featured video until today.

What I had done, immediately after the aforementioned video on the angular momentum, was to quickly go over to the playlist on QM [^]. Here, I noticed, as the first thing, that the ordering of the topics was more or less completely to my liking. So, I quickly browsed through a few of these videos, by way of sampling.

Highly satisfied with the treatment in those sample, I then started going through the entire playlist on QM in a systematic manner: one by one, in the order presented. … Since then, I’ve watched through all the videos up to the part “9c”. I expect to finish the remaining videos too, soon enough.

Each video of this playlist is short (something that I appreciate a lot!), fully accurate (which is a big deal with me!), and carries enough visualization to keep your attention riveted at all times. None of the videos has any clutter in any of the frames. Each video proceeds at just the right pace—a pace that is rapid enough that I never felt bored even for a second, and yet, none of the videos, I found, ever misses out on any of the truly important points. Indeed, some of the videos actually mentioned some points / perspectives that were kindaa new to me!

… All in all, these videos are a master-piece in condensation and essentialization.

Indeed, this playlist on QM was actually responsible for accelerating my research on my new approach too. (I will note a status update at the end of this post…)

…Coming back to the playlist itself, let me mention that, in the feedback of some video from this series, some viewer has left a comment which says something like: “best things are hidden in plain sight”. Spot on! These videos were posted years ago (starting the year 2013!), and despite my routine and extensive searches, I’ve managed to find them only last week or so. (On 13th April, to be exact; I began systematically watching them from 15th April.)

Now, a bit on what I found somewhat odd:

The author at times places too much emphasis on the uncertainty principle (UP for short), IMO. … I mean to say, he tries to explain the essential “quantum mechanical-ness” of some QM phenomenon / situation in reference to the UP—and not in reference to the specific details of the underlying physics for that specific situation. This was a shade disappointing to me—and unexpected, given how well these videos otherwise are!

Of course, this tendency to deploy the UP to explain the QM-ness is not peculiar to this author alone. It’s been part and parcel of the entire pedagogy of QM for decades and decades by now. Professors have been routinely presenting QM as if the UP were at the base of the theory—even if it demonstrably is not!

For one thing, historically, Heisenberg formulated the UP only in 1927, i.e., after all of non-relativistic QM had already been formulated. Even his own approach to the QM—let alone Schrodinger’s—had already been developed by that time. So, the UP was an after-thought; it was not, originally, a principle essential or vital to the very development of the mechanics.

Also, careful studies concerning the hierarchy of the concepts and principles involved in the QM have shown that the proper hierarchical place of the UP is only as a higher-level implication of certain other fundamental principles, and not as a fundamental truth/postulate itself. For evidence, refer to the postulates document [ (PDF) ^] which I’ve compiled recently (in particular, to the last section therein).

But coming back to the ViaScience’s playlist itself, speaking overall, this emphasis on the UP is only a minor short-coming it has. Indeed, this aspect becomes worth noting down precisely because the video series otherwise is so excellent!

Bottomline: To my mind, this is the best series of videos on QM that I’ve ever come across.

It’s ideally suited to the UG students. However, perhaps even the layman might want to check it out. The videos are short enough for the layman to try, and I guess he too should get a good flavour of what the actual mechanics of the actual QM is like.

[I am going to check out the other playlists on this channel too, including the one on relativity and QFT, but some time later (after I’ve put out a document on my new approach)…]


QuantumVisions Physikdidaktik WWU Münster’s video on the Stern-Gerlach experiment:

The visualization here more or less proceeds precisely like how I used to think it should be presented, but had not found thus far. The video in question is here [^]. … Of course, the visualization which I had worked out in the mind was much more detailed; in fact, it would take a computational simulation to bring out every detail I had in mind… But still, it was so wonderful to find some aspects of the broad idea so well executed.

[Viewers don’t always appreciate it, but creating a scientifically accurate visualization is a pain! It takes a lot of planning and hard-work to put out even 30 seconds of a good video. Making it involves all the troubles of the routine animation, and then, a whole bunch more complexity if you want the representation to be also accurate enough!]


2veritasium’s video: “What is quantum mechanical spin?”:

A good coverage is offered by Prof. Dr. Andrea Morello [^]. One of the notable moments occurs at around the 01:03 mark: “The neutron also has the spin, but it has no charge”. Point driven home!


The Science Asylum’s video on the QM spin:

The video [^] begins with the narrator saying:

“Hey crazies, let’s talk a little more about the quantum spins…”.

He also actually delivers on the promise… I mean, who else talks about the spin 3\,1/2 particles—and also tries to show something about them?


Eugene Khutoryansky’s video on Pauli’s exclusion principle:

The video in question is here [^]. It is a technical video. It’s highly relevant to the UG student taking the very first course on QM/QChem. However, the technical subtleties covered are such that it’s not suitable for a lay audience.

The title of this video is: “What causes the Pauli Exclusion Principle?”. … As a title, it is somewhat misleading. The video deals only with the non-relativistic QM, and it aims to generate only an intuitive feel for the inevitability of the principle; but it does not show (and could not have actually shown) why the principle is necessary.

But it’s a very good video.

I did find the pace to be a bit too slow for my liking. The script also seems a bit too repetitive. I mean to say: Unless you are paying careful attention to the small but significant changes in the conditions of simulation that the author goes on presenting, the similar-looking phrases (and even visuals!) could easily induce erroneous impressions! You have to be careful…

However, one great point overriding all short-comings is that Khutoryansky covers not just the “spatial” part (i.e. the Schrodinger wavefunction) taken in isolation, and then just the spin part taken in isolation, but both these parts taken together too! Among the videos I’ve seen thus far, this is the only video / visualization which does that.


NoahExplainsPhysics’s playlist on the QM spin:

Here is another helpful playlist on the topic of QM spin [^].

The strong point of this series is that that author works out each and every step about the mathematical equations (or “derivation”s, as these usually get called). …Judging from the viewer-comments, a lot of people seem to have appreciated this part.

However, I found that the overall ordering of the topics wasn’t much to my liking. The author follows too deductive an approach (IMO). After going through the first two videos, I’ve kept this series on the back-burner for a while.

… Oh yes, it’s a very handy resource to have, very useful. It’s just that I am going to look into it later, as the need arises… (That’s what I do with any deduction-heavy treatment, be it the second volume of Feynman’s lectures (on EM), or the text-book on QM by another Nobel laureate: Cohen-Tannoudji. … Excellent, if you’ve already learnt all the topics being deductively tied together. Pathetic, if even a single of those topics has not been learnt—from other, better, sources!)


Apart from it all, I also watched a couple of lectures from the MIT course 08.05 (2013 version), available at OCW. … Wish I had the time to systematically pursue this entire three-course sequence!

…It’s not an empty wish. I actually haven’t learnt many of the topics that this series covers, and when physicists begin responding to my new approach (once I publish it), they all are going come from a background that includes an expertize of all of that stuff—and much more, in fact!! … Which brings me to the status update on my research.


Status update: “Yeah, kindaa…”

Guess it will be convenient to refer to the videos while giving the current status on my research.

As indicated above, it was while going through ViaScience’s series on QM that I realized that my new approach should work OK—also for the spin.

However, going through the other videos has also further highlighted the need for me to delimit my claims. …It’s going to take months before I am able to deal with every minute detail involved in the maths (like that in NoahExplainsPhysics, and more!), using my new approach.

However, I need to wrap up this full-time occupation with QM as soon as possible, so that I can turn to Data Science and start hunting for suitable jobs.

So, my tentative plan as of today is this:

I am going to resume writing my document on the new approach, now also including some basic indication regarding the spin. By “basic indication”, I mean, the case of the outer-most single electron in the Ag or H atom, in the context of the SG experiment.

A rigorous theory for photons cannot anyway be developed within the non-relativistic QM, and so, a treatment of the photons was always out of the scope of my upcoming document. Now, the spin for all the other particles (neutron, photon, higher-spin particles) also will be kept out of the scope. …Also out of the scope will be more detailed look at the case of the spin in multi-electron atoms like He, Li, etc. (I will cover the He atom, and will conceptually indicate the Schrodinger wavefunctions for an arbitrary number of particles. But I will not cover the spin for such systems.)

Now, two possibilities open up.

If I am able to finish such a document by this month-end, then I will upload it soon later, say by the first week of May.

OTOH, if I find, over the next few days, that I will not be able to finish the document (to the detail indicated above), then I will still write down my theory for the spinless particles (i.e. up to the Schrodinger wavefunctions, including the GS energy of the He atom). Then, I will also throw in a purely conceptual level description for the QM spin, and be done with this project, in the same time-frame. … As to working out the exact details of QM spin and writing them down, I will take up that part of the project only after I am already in a good Data Science job, and am already settled enough in it to be able to find time to work on QM on the weekends and all.

So, either way, I am wrapping up this project by this month-end. At the most, by the first week of May 2021. … I’ve had enough of this research project by now, and the series by ViaScience has told me that I need not bother a lot about every query on every aspect of QM that every random physicist may throw up at me (especially those concerning the QM spin). They are important, but not so important!

So, there.

Take care and bye for now…


A song I like:

(Western, instrumental) “Wonderful land”
Band: The Shadows

[I mean the version here [^] and here [^]. It’s the only version I’ve heard. Also, I do not know any other details about this song—nor do I care to learn about them, as of now… I just like the music, that’s all…]

Still loitering around…

As noted in the last post, I’ve been browsing a lot. However, I find that the signal-to-noise ratio is, in a way, too low. There are too few things worth writing home about. Of course, OTOH, some of these things are so deep that they can keep one occupied for a long time.

Anyway, let me give many (almost all?) of the interesting links I found since my last post. These are being noted in no particular order. In most cases, the sub-title says it all, and so, I need not add comments. However, for a couple of videos related to QM, I do add significant amount of comments. … BTW, too many hats to do the tipping to. So let me skip that part and directly give you the URLs…


“A `digital alchemist’ unravels the mysteries of complexity”:

“Computational physicist Sharon Glotzer is uncovering the rules by which complex collective phenomena emerge from simple building blocks.” [^]


“Up and down the ladder of abstraction. A systematic approach to interactive visualization.” [^]

The tweet that pointed to this URL had this preface: “One particular talent stands out among the world-class programmers I’ve known—namely, an ability to move effortlessly between different levels of abstraction.”—Donald Knuth.

My own thinking processes are such that I use visualization a lot. Nay, I must. That’s the reason I appreciated this link. Incidentally, it also is the reason why I did not play a lot with the interactions here! (I put it in the TBD / Some other day / Etc. category.)


“The 2021 AI index: major growth despite the pandemic.”

“This year’s report shows a maturing industry, significant private investment, and rising competition between China and the U.S.” [^]


“Science relies on constructive criticism. Here’s how to keep it useful and respectful.” [^]

The working researcher, esp. the one who blogs / interacts a lot, probably already knows most all this stuff. But for students, it might be useful to have such tips collected in one place.


“How to criticize with kindness: Philosopher Daniel Dennett on the four steps to arguing intelligently.” [^].

Ummm… Why four, Dan? Why not, say, twelve? … Also, what if one honestly thinks that retards aren’t ever going to get any part of it?… Oh well, let me turn to the next link though…


“Susan Sontag on censorship and the three steps to refuting any argument” [^]

I just asked about four steps, and now comes Sontag. She comes down to just three steps, and also generalizes the applicability of the advice to any argument… But yes, she mentions a good point about censorship. Nice.


“The needless complexity of modern calculus: How 18th century mathematicians complicated calculus to avoid the criticisms of a bishop.” [^]

Well, the article does have a point, but if you ask me, there’s no alternative to plain hard work. No alternative to taking a good text-book or two (like Thomas and Finney, as also Resnick and Halliday (yes, for maths)), paper and pen / pencil, and working your way through. No alternative to that… But if you do that once for some idea, then every idea which depends on it, does become so simple—for your entire life. A hint or a quick reference is all you need, then. [Hints for the specific topic of this piece: the Taylor series, and truncation thereof.] But yes, the article is worth a fast read (if you haven’t read / used calculus in a while). … Also, Twitterati who mentioned this article also recommended the wonderful book from the next link (which I had forgotten)…


“Calculus made easy” [^].

The above link is to the Wiki article, which in turn gives the link to the PDF of the book. Check out the preface of the book, first thing.


“The first paper published in the first overlay journal (JTCAM) in Solid Mechanics” [^]

It’s too late for me (I have left mechanics as a full-time field quite a while ago) but I do welcome this development. … A few years ago, Prof. Timothy Gowers had begun an overlay journal in maths, and then, there also was an overlay journal for QM, and I had welcomed both these developments back then; see my blog post here [^].


“The only two equations that you should know: Part 1” [^].

Dr. Joglekar makes many good points, but I am not sure if my choice for the two equations is going to be the same.

[In fact, I don’t even like the restriction that there should be just two equations. …And, what’s happenning? Four steps. Then, three steps. Now, two equations… How long before we summarily turn negative, any idea?]

But yes, a counter-balance like the one in this article is absolutely necessary. The author touches on E = mc^2 and Newton’s laws, but I will go ahead and add topics like the following too: Big Bang, Standard Model, (and, Quantum Computers, String Theory, Multiverses, …).


“Turing award goes to creators of computer programming building blocks” [^] “Jeffrey Ullman and Alfred Aho developed many of the fundamental concepts that researchers use when they build new software.”

Somehow, there wasn’t as much of excitement this year as the Turing award usually generates.

Personally, though, I could see why the committee might have decided to recognize Aho and Ullman’s work. I had once built a “yacc”-like tool that would generate the tables for a table-driver parser, given the abstract grammar specification in the extended Backus-Noor form (EBNF). I did it as a matter of hobby, working in the evenings. The only resource I used was the “dragon book”, which was written by Profs. Aho, Sethi, and Ullman. It was a challenging but neat book. (I am not sure why they left Sethi out. However, my knowledge of the history of development of this area is minimal. So, take it as an idle wondering…)

Congratulations to Profs. Aho and Ullman.


“Stop calling everything AI, machine-learning pioneer says” [^] “Michael I. Jordan explains why today’s artificial-intelligence systems aren’t actually intelligent”

Well, “every one” knows that, but the fact is, it still needs to be said (and even explained!)


“How a gene for fair skin spread across India” [^] “A study of skin color in the Indian subcontinent shows the complex movements of populations there.”

No, the interesting thing about this article, IMO, was not that it highlighted Indians’ fascination / obsession for fairness—the article actually doesn’t even passingly mention this part. The real interesting thing, to me, was: the direct visual depiction, as it were, of Indian Indologists’ obsession with just one geographical region of India, viz., the Saraswati / Ghaggar / Mohan Ja Daro / Dwaarkaa / Pakistan / Etc. And, also the European obsession with the same region! … I mean check out how big India actually is, you know…

H/W for those interested: Consult good Sanskrit dictionaries and figure out the difference between निल (“nila”) and नील (“neela”). Hint: One of the translations for one of these two words is “black” in the sense “dark”, but not “blue”, and vice-versa for the other. You only have to determine which one stands for what meaning.

Want some more H/W? OK… Find out the most ancient painting of कृष्ण (“kRSNa”) or even राम (“raama”) that is still extant. What is the colour of the skin as shown in the painting? Why? Has the painting been dated to the times before the Europeans (Portugese, Dutch, French, Brits, …) arrived in India (say in the second millennium AD)?


“Six lessons from the biotech startup world” [^]

Dr. Joglekar again… Here, I think every one (whether connected with a start-up or not) should go through the first point: “It’s about the problem, not about the technology”.

Too many engineers commit this mistake, and I guess this point can be amplified further—the tools vs. the problem. …It’s but one variant of the “looking under the lamp” fallacy, but it’s an important one. (Let me confess: I tend to repeat the same error too, though with experience, one does also learn to catch the drift in time.)


“The principle of least action—why it works.” [^].

Neat article.

I haven’t read the related book [“The lazy universe: an introduction to the principle of least action”] , but looking at the portions available at Google [^], even though I might have objections to raise (or at least comments to make) on the positions taken by the author in the book, I am definitely going to add it to the list of books I recommend [^].

Let me mention the position from which I will be raising my objections (if any), in the briefest (and completely on-the-fly) words:

The principle of the least action (PLA) is a principle that brings out what is common to calculations in a mind-bogglingly large variety of theoretical contexts in physics. These are the contexts which involve either the concept of energy, or some suitable mathematical “generalizations” of the same concept.

As such, PLA can be regarded as a principle for a possible organization of our knowledge from a certain theoretical viewpoint.

However, PLA itself has no definite ontological content; whatever ontological content you might associate with PLA would go on changing as per the theoretical context in which it is used. Consequently, PLA cannot be seen as capturing an actual physical characteristic existing in the world out there; it is not a “thing” or “property” that is shared in common by the objects, facts or phenomena in the physical world.

Let me give you an example. The differential equation for heat conduction has exactly the same form as that for diffusion of chemical species. Both are solved using exactly the same technique, viz., the Fourier theory. Both involve a physical flux which is related to the gradient vector of some physically existing scalar quantity. However, this does not mean that both phenomena are produced by the same physical characteristic or property of the physical objects. The fact that both are parabolic PDEs can be used to organize our knowledge of the physical world, but such organization proceeds by making appeal to what is common to methods of calculations, and not in reference to some ontological or physical facts that are in common to both.

Further, it must also be noted, PLA does not apply to all of physics, but only to the more fundamental theories in it. In particular, try applying it to situations where the governing differential equation is not of the second-order, but is of the first- or the third-order [^]. Also, think about the applicability of PLA for dissipative / path-dependent processes.

… I don’t know whether the author (Dr. Jennifer Coopersmith) covers points like these in the book or not… But even if she doesn’t (and despite any differences I anticipate as of now, and indeed might come to keep also after reading the book), I am sure, the book is going to be extraordinarily enlightening in respect of an array of topics. … Strongly recommended.


Muon g-2.

I will give some the links I found useful. (Not listed in any particular order)

  • Dennis Overbye covers it for the NYT [^],
  • Natalie Wolchoever for the Quanta Mag [^],
  • Dr. Luboš Motl for his blog [^],
  • Dr. Peter Woit for his blog [^],
  • Dr. Adam Falkowski (“Jester”) for his blog [^],
  • Dr. Ethan Siegel for the Forbes [^], and,
  • Dr. Sabine Hossenfelder for Sci-Am [^].

If you don’t want to go through all these blog-posts, and only are looking for the right outlook to adopt, then check out the concluding parts of Hossenfelder’s and Siegel’s pieces (which conveniently happen to be the last two in the above list).

As to the discussions: The Best Comment Prize is hereby being awarded, after splitting it equally into two halves, to “Manuel Gnida” for this comment [^], and to “Unknown” for this comment [^].


The five-man quantum mechanics (aka “super-determinism”):

By which, I refer to this video on YouTube: “Warsaw Spacetime Colloquium #11 – Sabine Hossenfelder (2021/03/26)” [^].

In this video, Dr. Hossenfelder talks about… “super-determinism.”

Incidentally, this idea (of super-determinism) had generated a lot of comments at Prof. Dr. Scott Aaronson’s blog. See the reader comments following this post: [^]. In fact, Aaronson had to say in the end: “I’m closing this thread tonight, honestly because I’m tired of superdeterminism discussion.” [^].

Hossenfelder hasn’t yet posted this video at her own blog.

There are five people in the entire world who do research in super-determinism, Hossenfelder seems to indicate. [I know, I know, not all of them are men. But I still chose to say the five-man QM. It has a nice ring to it—if you know a certain bit from the history of QM.]

Given the topic, I expected to browse through the video really rapidly, like a stone that goes on skipping on the surface of water [^], and thus, being done with it right within 5–10 minutes or so.

Instead, I found myself listening to it attentively, not skipping even a single frame, and finishing the video in the sequence presented. Also, going back over some portions for the second time…. And that’s because Hossenfelder’s presentation is so well thought out. [But where is the PDF of the slides?]

It’s only after going through this video that I got to understand what the idea of “super-determinism” is supposed to be like, and how it differs from the ordinary “determinism”. Spoiler: Think “hidden variables”.

My take on the video:

No, the idea (of super-determinism) isn’t at all necessary to explain QM.

However, it still was neat to get to know what (those five) people mean by it, and also, more important: why these people take it seriously.

In fact, given Hossenfelder’s sober (and intelligent!) presentation of it, I am willing to give them a bit of a rope too. …No, not so long that they can hang themselves with it, but long enough that they can perform some more detailed simulations. … I anticipate that when they conduct their simulations, they themselves are going to understand the query regarding the backward causation (raised by a philosopher during the interactive part of the video) in a much better manner. That’s what I anticipate.

Another point. Actually, “super-determinism” is supposed to be “just” a theory of physics, and hence, it should not have any thing to say about topics like consciousness, free-will, etc. But I gather that at least some of them (out of the five) do seem to think that the free-will would have to be denied, may be as a consequence of super-determinism. Taken in this sense, my mind has classified “super-determinism” as being the perfect foil to (or the other side of) panpsychism. … As to panpsychism, if interested, check out my take on it, here [^].

All along, I had always thought that super-determinism is going to turn out to be a wrong idea. Now, after watching this video, I know that it is a wrong idea.

However, precisely for the same reason (i.e., coming to know what they actually have in mind, and also, how they are going about it), I am not going to attack them, their research program. … Not necessary… I am sure that they would want to give up their program on their own, once (actually, some time after) I publish my ideas. I think so. … So, there…


“Video: Quantum mechanics isn’t weird, we’re just too big” YouTube video at: [^]

The speaker is Dr. Phillip Ball; the host is Dr. Zlatko Minev. Let me give some highlights of their bio’s: Ball has a bachelor’s in chemistry from Oxford and a PhD in physics from Bristol. He was an editor at Nature for two decades. Minev has a BS in physics from Berkeley and a PhD in applied physics from Yale. He works in the field of QC at IBM (which used to be the greatest company in the computers industry (including software)).

The abstract given at the YouTube page is somewhat misleading. Ignore it, and head towards the video itself.

The video can be divided into two parts: (i) the first part, ~47 minutes long, is a presentation by Ball; (ii) the second part is a chat between the host (Minev) and the guest (Ball). IMO, if you are in a hurry, you may ignore the second part (the chat).

The first two-third portion of the first part (the presentation) is absolutely excellent. I mean the first 37 minutes. This good portion (actually excellent) gets over once Ball goes to the slide which says “Reconstructing quantum mechanics from informational rules”, which occurs at around 37 minutes. From this point onward, Ball’s rigour dilutes a bit, though he does recover by the 40:00 minutes mark or so. But from ~45:00 to the end (~47:00), it’s all down-hill (IMO). May be Ball was making a small little concession to his compatriots.

However, the first 37 minutes are excellent (or super-excellent).

But even if you are absolutely super-pressed for time, then I would still say: Check out at least the first 10 odd minutes. … Yes, I agree 101 percent with Ball, when it comes to the portion from ~5:00 through 06:44 through 07:40.

Now, a word about the mistakes / mis-takes:

Ball says, in a sentence that begins at 08:10 that Schrodinger devised the equation 1924. This is a mistake / slip of the tongue. Schrodinger developed his equation in late 1925, and published it in 1926, certainly not in 1924. I wonder how come it slipped past Ball.

Also, the title of the video is somewhat misleading. “Bigness” isn’t really the distinguishing criterion in all situations. Large-distance QM entanglements have been demonstrated; in particular, photons are (relativistic) QM phenomena. So, size isn’t necessarily always the issue (even if the ideas of multi-scaling must be used for bridging between “classical” mechanics and QM).

And, oh yes, one last point… People five-and-a-half feet tall also are big enough, Phil! Even the new-borns, for that matter…

A personal aside: Listening to Ball, somehow, I got reminded of some old English English movies I had seen long back, may be while in college. Somehow, my registration of the British accent seems to have improved a lot. (Or may be the Brits these days speak with a more easily understandable accent.)


Status of my research on QM:

If I have something to note about my research, especially that related to the QM spin and all, then I will come back a while later and note something—may be after a week or two. …

As of today, I still haven’t finished taking notes and thinking about it. In fact, the status actually is that I am kindaa “lost”, in the sense: (i) I cannot stop browsing so as to return to the study / research, and (ii) even when I do return to the study, I find that I am unable to “zoom in” and “zoom out” of the topic (by which, I mean, switching the contexts at will, in between all: the classical ideas, the mainstream QM ideas, and the ideas from my own approach). Indeed (ii) is the reason for (i). …

If the same thing continues for a while, I will have to rethink whether I want to address the QM spin right at this stage or not…

You know, there is a very good reason for omitting the QM spin. The fact of the matter is, in the non-relativistic QM, the spin can only be introduced on an ad-hoc basis. … It’s only in the relativistic QM that the spin comes out as a necessary consequence of certain more basic considerations (just the way in the non-relativistic QM, the ground-state energy comes out as a consequence of the eigenvalue nature of the problem; you don’t have to postulate a stable orbit for it as in the Bohr theory). …

So, it’s entirely possible that my current efforts to figure out a way to relate the ideas from my own approach to the mainstream QM treatment of the spin are, after all, a basically pointless exercise. Even if I do think hard and figure out some good and original ideas / path-ways, they aren’t going to be enough, because they aren’t going to be general enough anyway.

At the same time, I know that I am not going to get into the relativistic QM, because it has to be a completely distinct development—and it’s going require a further huge effort, perhaps a humongous effort. And, it’s not necessary for solving the measurement problem anyway—which was my goal!

That’s why, I have to really give it a good thought—whether I should be spending so much time on the QM spin or not. May giving some sketchy ideas (rather, making some conceptual-level statements) is really enough… No one throws so much material in just one paper, anyway! Even the founders of QM didn’t! … So, that’s another line of thought that often pops up in my mind. …

My current plan, however, is to finish taking the notes on the mainstream QM treatment of the spin anyway—at least to the level of Eisberg and Resnick, though I can’t finish it, because this desire to connect my approach to the mainstream idea also keeps on interfering…

All in all, it’s a weird state to be in! … And, that’s what the status looks like, as of now…


… Anyway, take care and bye for now…


A song I, ahem, like:

It was while browsing that I gathered, a little while ago, that there is some “research” which “explains why” some people “like” certain songs (like the one listed below) “so much”.

The research in question was this paper [^]; it was mentioned on Twitter (where else?). Someone else, soon thereafter, also pointed out a c. 2014 pop-sci level coverage [^] of a book published even earlier [c. 2007].

From the way this entire matter was now being discussed, it was plain and obvious that the song had been soul-informing for some, not just soul-satisfying. The song in question is the following:

(Hindi) सुन रुबिया तुम से प्यार हो गया (“sun rubiyaa tum se pyaar ho gayaa”)
Music: Anu Malik
Lyrics: Prayag Raj
Singers: S. Jaanaki, Shabbir Kumar

Given the nature of this song, it would be OK to list the credits in any order, I guess. … But if you ask me why I too, ahem, like this song, then recourse must be made not just to the audio of this song [^] but also to its video. Not any random video but the one that covers the initial sequence of the song to an adequate extent; e.g., as in here [^].


History:
2021.04.09 19:22 IST: Originally published.
2021.04.10 20:47 IST: Revised considerably, especially in the section related to the principle of the least action (PLA), and the section on the current status of my research on QM. Also minor corrections and streamlining. Guess now I am done with this post.