Yes I know it!—Part 2

This post directly continues from my last post. The content here was meant to be an update to my last post, but it grew, and so, I am noting it down as a separate post in its own right.


Thought about it [I mean my last post] a lot last night and this morning. I think here is a plan of action I can propose:

I can deliver a smallish, informally conducted, and yet, “official” sort of a seminar/talk/guest lecture, preferably at an IIT/IISER/IISc/similar institute. No honorarium is expected; just arrange for my stay. (That too is not necessary if it will be IIT Bombay; I can then stay with my friend; he is a professor in an engineering department there.)

Once arranged by mutual convenience, I will prepare some lecture notes (mostly hand-written), and deliver the content. (I guess at this stage, I will not prepare Beamer slides, though I might include some audio-visual content such as simulations etc.)

Questions will be OK, even encouraged, but the format will be that of a typical engineering class-room lecture. Discussions would be perfectly OK, but only after I finish talking about the “syllabus” first.

The talk should preferably be attended also by a couple of PhD students or so (of physics/engineering physics/any really relevant discipline, whether it’s acknowledged as such by UGC/AICTE or not). They should separately take down their notes and show me these later. This will help me understand where and how I should modify my notes. I will then myself finalize my notes, perhaps a few days after the talk, and send these by email. At that stage, I wouldn’t mind posting the notes getting posted on the ‘net.

Guess I will think a bit more about it, and note about my willingness to deliver the talk also at iMechanica. The bottom-line is that I am serious about this whole thing.

A few anticipated questions and their answers (or clarifications):

  1. What I have right now is, I guess, sufficient to stake a claim. But I have not taken the research to sufficiently advanced stage that I can say that I have all the clarifications worked out. It’s far more than just a sketchy conceptual idea, and does have a lot of maths too, but it’s less than, say, a completely worked out (or series of) mathematical theory. (My own anticipation is that if I can do just a series of smaller but connected mathematical models/simulations, it should be enough as my personal contribution to this new approach.)
  2. No, as far as QM is concerned, the approach I took in my PhD time publications is not at all relevant. I have completely abandoned that track (I mean to say as far as QM is concerned).
  3. However, my PhD time research on the diffusion equation has been continuing, and I am happy to announce that it has by now reached such a certain stage of maturation/completion that I should be writing another paper(s) on it any time now. I am happy that something new has come out of some 10+ years of thought on that issue, after my PhD-time work. Guess I could now send the PhD time conference paper to a journal, and then cover the new developments in this line in continuation with that one.
  4. Coming back to QM: Any one else could have easily got to the answers I have. But no, to the best of my knowledge, none else actually has. However, it does seem to me now that time is becoming ripe, and not to stake a claim at least now could be tantamount to carelessness on my part.
  5. Yes, my studies of philosophy, especially Ayn Rand’s ITOE (and Peikoff’s explanations of that material in PO and UO) did help me a lot, but all that is in a more general sense. Let me put it this way: I don’t think that I would have had to know (or even plain be conversant with) ITOE to be able to formulate these new answers to the QM riddles. And certainly, ITOE wouldn’t at all be necessary to understand my answers; the general level of working epistemology still is sufficiently good in physics (and more so, in engineering) even today.  At the same time, let me tell you one thing: QM is very vast, general, fundamental, and abstract. I guess you would have to be a “philosophizing” sort of a guy. Only then could you find this continuous and long preoccupation with so many deep and varied abstractions, interesting enough. Only then could the foundations of QM interest you. Not otherwise.
  6. To formulate answers, my natural proclivity to have to keep on looking for “physical” processes/mechanisms/objects for every mathematical idea I encounter, did help. But you wouldn’t have to have the same proclivity, let alone share my broad convictions, to be able to understand my answers. In other words, you could be a mathematical Platonist, and yet very easily come to understand the nature of my answers (and perhaps even come to agree with my positions)!
  7. To arrange for my proposed seminar/talk is to agree to be counted as a witness (for any future issues related to priority). But that’s strictly in the usual, routine, day-to-day academic sense of the term. (To wit, see how people interact with each other at a journal club in a university, or, say, at iMechanica.)
  8. But, to arrange for my talk is not to be willing to certify or validate its content. Not at all.
  9. With that being said, since this is India, let me also state a relevant concern. Don’t call me over just to show me down or ridicule me either. (It doesn’t happen in seminar talks, but it does happen during job interviews in Pune. It did happen to me in my COEP interview. It got repeated, in a milder way, in other engineering colleges in SPPU (the Pune University). So I have no choice but to note this part separately.)
  10. Once again, the issue is best clarified by giving the example. Check out how people treated me at iMechanica. If you are at an IIT/IISc/similar institute/university and are willing to treat me similarly, then do think of calling me over.

More, may be later. I will sure note my willingness to deliver a seminar at an IIT (or at a good University department) or so, at iMechanica also, soon enough. But right now I don’t have the time, and have to rush out. So let me stop here. Bye for now, and take care… (I would add a few more tags to the post-categories later on.)

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Yes I know it!

Note: A long update was posted on 12th December 2017, 11:35 IST.


This post is spurred by my browsing of certain twitter feeds of certain pop-sci. writers.

The URL being highlighted—and it would be, say, “negligible,” but for the reputation of the Web domain name on which it appears—is this: [^].


I want to remind you that I know the answers to all the essential quantum mysteries.

Not only that, I also want to remind you that I can discuss about them, in person.

It’s just that my circumstances—past, and present (though I don’t know about future)—which compel me to say, definitely, that I am not available for writing it down for you (i.e. for the layman) whether here or elsewhere, as of now. Neither am I available for discussions on Skype, or via video conferencing, or with whatever “remoting” mode you have in mind. Uh… Yes… WhatsApp? Include it, too. Or something—anything—like that. Whether such requests come from some millionaire Indian in USA (and there are tons of them out there), or otherwise. Nope. A flat no is the answer for all such requests. They are out of question, bounds… At least for now.

… Things may change in future, but at least for the time being, the discussions would have to be with those who already have studied (the non-relativistic) quantum physics as it is taught in universities, up to graduate (PhD) level.

And, you have to have discussions in person. That’s the firm condition being set (for the gain of their knowledge 🙂 ).


Just wanted to remind you, that’s all!


Update on 12th December 2017, 11:35 AM IST:

I have moved the update to a new post.

 


A Song I Like:

(Western, Instrumental) “Berlin Melody”
Credits: Billy Vaughn

[The same 45 RPM thingie [as in here [^], and here [^]] . … I was always unsure whether I liked this one better or the “Come September” one. … Guess, after the n-th thought, that it was this one. There is an odd-even thing about it. For odd ‘n” I think this one is better. For even ‘n’, I think the “Come September” is better.

… And then, there also are a few more musical goodies which came my way during that vacation, and I will make sure that they find their way to you too….

Actually, it’s not the simple odd-even thing. The maths here is more complicated than just the binary logic. It’s an n-ary logic. And, I am “equally” divided among them all. (4+ decades later, I still remain divided.)… (But perhaps the “best” of them was a Marathi one, though it clearly showed a best sort of a learning coming from also the Western music. I will share it the next time.)]


[As usual, may be, another revision [?]… Is it due? Yes, one was due. Have edited streamlined the main post, and then, also added a long update on 12th December 2017, as noted above.]

 

 

Busy, busy, busy… And will be. (Aka: Random Notings in the Passing)

Have been very busy. [What’s new about that? Read on…]


First, there is that [usual] “busy-ness” on the day job.


Then, Mary Hesse (cf. my last post) does not cover tensor fields.

A tensor is a very neat mathematical structure. Essentially, you get it by taking a Cartesian product of the basis vectors of (a) space(s). A tensor field is a tensor-valued function of, say, the physical (“ambient”) space, itself a vector space and also a vector field.

Yes, that reads like the beginning paragraph of a Wiki article on a mathematical topic. Yes, you got into circles. Mathematicians always do that—esp. to you. … Well, they also try doing that, on me. But, usually, they don’t succeed. … But, yes, it does keep me busy. [Now you know why I’ve been so busy.]


Now, a few other, mostly random, notings in the passing…


As every year, the noise pollution of the Ganapati festival this year, too, has been nothing short of maddening. But this year, it has not been completely maddening. Not at least to me. The reason is, I am out of Pune. [And what a relief it is!]


OK, time to take some cognizance of the usual noises on the QM front. The only way to do that is to pick up the very best among them. … I will do that for you.

The reference is to Roger Schlafly’s latest post: “Looking for new quantum axioms”, here [^]. He in turn makes a reference to a Quanta Mag article [^] by Philip Ball, who in turn makes a reference to the usual kind of QM noises. For the last, I shall not provide you with references. … Then, in his above-cited post, Schlafly also makes a reference to the Czech physicist Lubos Motl’s blog post, here [^].

Schlafly notes that Motl “…adequately trashes it as an anti-quantum crackpot article,” and that he “will not attempt to outdo his [i.e. Motl’s] rant.” Schlafly even states that he agrees with him Motl.

Trailer: I don’t; not completely anyway.

Immediately later, however, Schlafly says quite a remarkable thing, something that is interesting in its own regard:

Instead, I focus on one fallacy at the heart of modern theoretical physics. Under this fallacy, [1] the ideal theory is one that is logically derived from postulates, and [2] where one can have a metaphysical belief in those postulates independent of messy experiments.” [Numbering of the clauses is mine.]

Hmmm…

Yes, [1] is right on, but not [2]. Both the postulates and the belief in them here are of physics; experiments—i.e. [controlled] observations of physical reality—play not just a crucial part; they play the “game-starting” part. Wish Schlafly had noted the distinction between the two clauses.

All in all, I think that, on this issue of Foundations of QM, we all seem to be not talking to each other—we seem to be just looking past each other, so to say. That’s the major reason why the field has been flourishing so damn well. Yet, all in all, I think, Schlafly and Motl are more right about it all than are Ball or the folks he quotes.

But apart from it all, let me say that Schlafly and Motl have been advocating the view that Dirac–von Neumann axioms [^] provide the best possible theoretical organization for the theory of the quantum mechanical phenomena.

I disagree.

My position is that the Dirac-von Neumann axioms have not been done with due care to the scope (and applicability) of all the individual concepts subsuming the different aspects of the quantum physical phenomena. Like all QM physicists of the past century (and continuing with those in this century as well, except for, as far as I know, me!), they confuse on one crucial issue. And that issue is at the heart and the base of the measurement/collapse postulate. Understand that one critical issue well, and the measurement/collapse postulate itself collapses in no time. I can name it—that one critical issue. In fact, it’s just one concept. Just one concept that is already well-known to science, but none thinks of it in the context of Foundations of QM. Not in the right way, anyway. [Meet me in person to learn what it is.]


OK, another thing.

I haven’t yet finished Hesse’s book. [Did you honestly expect me to do that so fast?] That, plus the fact that in my day-job, we would be working even harder, working extra hours (plus may be work on week-ends, as well).

In fact, I have already frozen all my research schedule and put it in the deep freeze section. (Not even on the back-burner, I mean.)

So, allow me to go off the blog once again for yet another 3–4 weeks or so. [And I will do that anyway, even if you don’t allow.]


A Song I Like:

[The value of this song to me is mostly nostalgic; it has some very fond memories of my childhood associated with it. As an added bonus, Shammi Kapoor looks slim(mer than his usual self) in this video, the so-called Part 2 of the song, here [^]—and thereby causes a relatively lesser irritation to the eye. [Yes, sometimes, I do refer to videos too, even in this section.]]

(Hindi) “madahosh hawaa matawaali fizaa”
Lyrics: Farooq Qaisar
Singer: Mohammed Rafi
Music: Shankar-Jaikishan

[BTW, did you guess the RD+Gulzar+Lata song I had alluded to, last time? … May be I will write a post just to note that song. Guess it might make for a  good “blog-filler” sometime during the upcoming several weeks, when I will once again be generally off the blog. … OK, take care, and bye for now….]

What am I thinking about? …and what should it be?

What am I thinking about?

It’s the “derivation” of the Schrodinger equation. Here’s how a simplest presentation of it goes:

The kinetic energy T of a massive particle is given, in classical mechanics, as
T = \dfrac{1}{2}mv^2 = \dfrac{p^2}{2m}
where v is the velocity, m is the mass, and p is the momentum. (We deal with only the scalar magnitudes, in this rough-and-ready “analysis.”)

If the motion of the particle occurs additionally also under the influence of a potential field V, then its total energy E is given by:
E = T + V = \dfrac{p^2}{2m} + V

In classical electrodynamics, it can be shown that for a light wave, the following relation holds:
E = pc
where E is the energy of light, p is its momentum, and c is its speed. Further, for light in vacuum:
\omega = ck
where k = \frac{2\pi}{\lambda} is the wavevector.

Planck hypothesized that in the problem of the cavity radiation, the energy-levels of the electromagnetic oscillators in the metallic cavity walls maintained at thermal equilibrium are quantized, somehow:
E = h \nu = \hbar \omega
where \hbar = \frac{h}{2\pi}  and \omega = 2  \pi \nu is the angular frequency. Making this vital hypothesis, he could successfully predict the power spectrum of the cavity radiation (getting rid of the ultraviolet catastrophe).

In explaining the photoelectric effect, Einstein hypothesized that lights consists of massless particles. He took Planck’s relation E = \hbar \omega as is, and then, substituted on its left hand-side the classical expression for the energy of the radiation E = pc. On the right hand-side he substituted the relation which holds for light in vacuum, viz. \omega = c k. He thus arrived at the expression for the quantized momentum for the hypothetical particles of light:
p = \hbar k
With the hypothesis of the quanta of light, he successfully explained all the known experimentally determined features of the photoelectric effect.

Whereas Planck had quantized the equilibrium energy of the charged oscillators in the metallic cavity wall, Einstein quantized the electromagnetic radiation within the cavity itself, via spatially discrete particles of light—an assumption that remains questionable till this day (see “Anti-photon”).

Bohr hypothesized a planetary model of the atom. It had negatively charged and massive point particles of electrons orbiting around the positively charged and massive, point-particles of the nucleus. The model carried a physically unexplained feature of the stationary of the electronic orbits—i.e. the orbits travelling in which an electron, somehow, does not emit/absorb any radiation, in contradiction to the classical electrodynamics. However, this way, Bohr could successfully predict the hydrogen atom spectra. (Later, Sommerfeld made some minor corrections to Bohr’s model.)

de Broglie hypothesized that the relations E = \hbar \omega and p = \hbar k hold not only just for the massless particles of light as proposed by Einstein, but, by analogy, also for the massive particles like electrons. Since light had both wave and particle characters, so must, by analogy, the electrons. He hypothesized that the stationarity of the Bohr orbits (and the quantization of the angular momentum for the Bohr electron) may be explained by assuming that matter waves associated with the electrons somehow form a standing-wave pattern for the stationary orbits.

Schrodinger assumed that de Broglie’s hypothesis for massive particles holds true. He generalized de Broglie’s model by recasting the problem from that of the standing waves in the (more or less planar) Bohr orbits, to an eigenvalue problem of a differential equation over the entirety of space.

The scheme of  the “derivation” of Schrodinger’s differential equation is “simple” enough. First assuming that the electron is a complex-valued wave, we work out the expressions for its partial differentiations in space and time. Then, assuming that the electron is a particle, we invoke the classical expression for the total energy of a classical massive particle, for it. Finally, we mathematically relate the two—somehow.

Assume that the electron’s state is given by a complex-valued wavefunction having the complex-exponential form:
\Psi(x,t) = A e^{i(kx -\omega t)}

Partially differentiating twice w.r.t. space, we get:
\dfrac{\partial^2 \Psi}{\partial x^2} = -k^2 \Psi
Partially differentiating once w.r.t. time, we get:
\dfrac{\partial \Psi}{\partial t} = -i \omega \Psi

Assume a time-independent potential. Then, the classical expression for the total energy of a massive particle like the electron is:
E = T + V = \dfrac{p^2}{2m} + V
Note, this is not a statement of conservation of energy. It is merely a statement that the total energy has two and only two components: kinetic energy, and potential energy.

Now in this—classical—equation for the total energy of a massive particle of matter, we substitute the de Broglie relations for the matter-wave, viz. the relations E = \hbar \omega and p = \hbar k. We thus obtain:
\hbar \omega = \dfrac{\hbar^2 k^2}{2m} + V
which is the new, hybrid form of the equation for the total energy. (It’s hybrid, because we have used de Broglie’s matter-wave postulates in a classical expression for the energy of a classical particle.)

Multiply both sides by \Psi(x,t) to get:
\hbar \omega \Psi(x,t) = \dfrac{\hbar^2 k^2}{2m}\Psi(x,t) + V(x)\Psi(x,t)

Now using the implications for \Psi obtained via its partial differentiations, namely:
k^2 \Psi = - \dfrac{\partial^2 \Psi}{\partial x^2}
and
\omega \Psi = i \dfrac{\partial \Psi}{\partial t}
and substituting them into the hybrid equation for the total energy, we get:
i \hbar \dfrac{\partial \Psi(x,t)}{\partial t} = - \dfrac{\hbar^2}{2m}\dfrac{\partial^2\Psi(x,t)}{\partial x^2} + V(x)\Psi(x,t)

That’s what the time-dependent Schrodinger equation is.

And that—the “derivation” of the Schrodinger equation thus presented—is what I have been thinking of.

Apart from the peculiar mixture of the wave and particle paradigms followed in this “derivation,” the other few points, to my naive mind, seem to be: (i) the use of a complex-valued wavefunction, (ii) the step of multiplying the hybrid equation for the total energy, by this wavefunction, and (iii) the step of replacing \omega \Psi(x,t) by i \dfrac{\partial \Psi}{\partial t}, and also replacing k^2 \Psi by - \dfrac{\partial^2 \Psi}{\partial x^2}. Pretty rare, that step seems like, doesn’t it? I mean to say, just because it is multiplied by a variable, you are replacing a good and honest field variable by a partial time-derivative (or a partial space-derivative) of that same field variable! Pretty rare, a step like that is, in physics or engineering, don’t you think? Do you remember any other place in physics or engineering where we do something like that?


What should I think about?

Is there is any mechanical engineering topic that you want me to explain to you?

If so, send me your suggestions. If I find them suitable, I will begin thinking about them. May be, I will even answer them for you, here on this blog.


If not…

If not, there is always this one, involving the calculus of variations, again!:

Derbes, David (1996) “Feynman’s derivation of the Schrodinger equation,” Am. J. Phys., vol. 64, no. 7, July 1996, pp. 881–884

I’ve already found that I don’t agree with how Derbes uses the term “local”, in this article. His article makes it seem as if the local is nothing but a smallish segment on what essentially is a globally determined path. I don’t agree with that implication. …

However, here, although this issue is of relevance to the mechanical engineering proper, in the absence of a proper job (an Officially Approved Full Professor in Mechanical Engineering’s job), I don’t feel motivated to explain myself.

Instead, I find the following article by a Mechanical Engineering professor interesting: [^]

And, oh, BTW, if you are a blind follower of Feynman’s, do check out this one:

Briggs, John S. and Rost, Jan M. (2001) “On the derivation of the time-dependent equation of Schrodinger,” Foundations of Physics, vol. 31, no. 4, pp. 693–712.

I was delighted to find a mention of a system and an environment (so close to the heart of an engineer), even in this article on physics. (I have not yet finished reading it. But, yes, it too invokes the variational principles.)


OK then, bye for now.


[As usual, may be I will come back tomorrow and correct the write-up or streamline it a bit, though not a lot. Done on 2017.01.19.]


[E&OE]