Other What are you reading now? (STEM only)

[Demystifier]

B. Zwiebach, Mastering Quantum Mechanics (2022)
https://www.amazon.com/dp/026204613X/?tag=pfamazon01-20

New excellent QM textbook, very pedagogic, suitable for beginners, yet very complete (about 1100 pages long) and containing many modern topics which other textbooks rarely discuss.

 

[haushofer]

Can you give some examples of such topics?

 

[Frabjous]

B. Zwiebach, Mastering Quantum Mechanics (2022)
https://www.amazon.com/dp/026204613X/?tag=pfamazon01-20

New excellent QM textbook, very pedagogic, suitable for beginners, yet very complete (about 1100 pages long) and containing many modern topics which other textbooks rarely discuss.

The TOC is here
https://mitp-content-server.mit.edu/books/content/sectbyfn?collid=books_pres_0&id=12259&fn=toc.pdf

 

[dextercioby]

Only 3 chapters worth a read: 18, 22, 23.

 

[Demystifier]

Only 3 chapters worth a read: 18, 22, 23.

Provided that you already know everything else.

 

[Demystifier]

Can you give some examples of such topics?

See post #484 by @dextercioby.

 

[haushofer]

I guess I'll buy it; his string theory book was remarkable.

I once took a course on Double Field Theory from him; he's also an excellent teacher, and was really interested in our research topics.

 

[vanhees71]

Quote from the book:

2.4 Photoelectric Effect
In this and in the following section, we will discuss some foundational experiments relating to
photons. e first is the photoelectric effect. The second is Compton scattering. Together, these two
experiments convinced physicists that photons are quanta of light.

Really? :-(((

Historically that may be right, but neither the PE nor Compton scattering prove the necessity for quantization of the em. field. This is really well-known now. Why do textbook writers, particularly of QM intro textbooks, always just copy the mistakes from the tradition?

Besides, where are the postulates clearly stated?

 

[andresB]

Quote from the book:Really? :-(((

Historically that may be right, but neither the PE nor Compton scattering prove the necessity for quantization of the em. field. This is really well-known now. Why do textbook writers, particularly of QM intro textbooks, always just copy the mistakes from the tradition?

Besides, where are the postulates clearly stated?

I know about the photoelectric effect using classical waves in the Schrödinger equations. but I'm unaware of a wavy explanation of the Compton scattering

 

[vanhees71]

It's a classical em. wave scattering on an electron (described quantum mechanically with the Dirac equation), i.e., in semiclassical approximation. That's how Klein and Nishina explained the Compton effect quantum mechanically for the first time.

https://doi.org/10.1007/BF01366453 (it's, however in German ;-)).

 

[Frabjous]

Historically that may be right, but neither the PE nor Compton scattering prove the necessity for quantization of the em. field.

What demonstrated the necessity of the quantization of the em field?

 

[Demystifier]

Historically that may be right, but neither the PE nor Compton scattering prove the necessity for quantization of the em. field. This is really well-known now. Why do textbook writers, particularly of QM intro textbooks, always just copy the mistakes from the tradition?

Obviously, it's not known well enough.

Besides, where are the postulates clearly stated?

Sec. 5.3.

 

[Demystifier]

What demonstrated the necessity of the quantization of the em field?

Spontaneous emission, I would say.

 

[vanhees71]

What demonstrated the necessity of the quantization of the em field?

E.g., Spontaneous emission and the HOM effect

https://en.wikipedia.org/wiki/Hong–Ou–Mandel_effect

 

[vanhees71]

Obviously, it's not known well enough.Sec. 5.3.

Ok, well. Where can I find an hermitean operator to measure in the lab? Maybe I ask my experimental colleagues on Monday ;-))... Then there's an "instantaneous collapse". The question is, why does one need another 1000+x-page sloppy book on QM? :-((

 

[Demystifier]

Then there's an "instantaneous collapse". The question is, why does one need another 1000+x-page sloppy book on QM? :-((

Who is worried about philosophical quibbles now?

 

[vanhees71]

It's not philosophical. I don't bother too much about the "instantaneous collapse" postulate without even mentioning that it's highly problematic. That you may indeed see as a philosophical detail, I'll never would bother to discuss with beginners in QM, but as far as I could see glancing over the book, it's sloppy also in the math (and thus also in the physics). Admittedly, I have a few points I check to see whether I want to buy a new QM physics book.

(1) How are states defined: the author states its given by the state ket. That's too sloppy for my taste, because it's very important to identify a ray (or equivalently the projection operator $|\psi \rangle \langle \psi|$) with a (pure) state and not $|\psi \rangle$ itself. Without this, there'd be no non-relativistic QM (the unitary representations of the Galilei group don't lead to physically useful quantum theories), no half-integer spin, and many more problems.

(2) The operators representing observables must be essentially self-adjoint; Hermitean is not sufficient. Also one measures not an Hermitean (or self-adjoint) operator in the lab but real-world "objects", but the latter is again maybe a bit philosophical, but I've never understood what people mean when they state they'd measure an abstract mathematical entity like a self-adjoint operator in Hilbert space. I've never seen one around me ;-)).

(3) Is the question, why orbital angular momenta have only integer and not half-integer eigenvalues (properly) addressed? As expected from (1) and (2), of course not. Already Pauli knew in 1925/26 that of course the claim that a wave function must be unique as a classical field is not a valid argument. The lack of realizing this is of course due to the sloppiness with regard to item (1) above.

(4) Is the photon picture used at least qualitatively correct, if it is used at all in a beginners-QM (non-relativistic QM)? The answer is definitely no here too.

 

[andresB]

(2) The operators representing observables must be essentially self-adjoint; Hermitean is not sufficient. Also one measures not an Hermitean (or self-adjoint) operator in the lab but real-world "objects", but the latter is again maybe a bit philosophical, but I've never understood what people mean when they state they'd measure an abstract mathematical entity like a self-adjoint operator in Hilbert space. I've never seen one around me ;-)).

I don't get the claim. It is true that the physically relevant QM representation of the Galilei group is not faithful but projective. Yet, it is a unitary projective representation.

 

[vanhees71]

Sure, but why should you look for projective representations in the first place if the absolute phase of the state ket were physically significant?

 

[Hamiltonian]

@vanhees71 I have seen you dislike most popular intro QM books, eg. Griffths QM and now Zwiebach's new book. What book do you usually recommend to a complete novice?
or do you simply believe there is no one good intro QM book :(

 

[martinbn]

@vanhees71 I have seen you dislike most popular intro QM books, eg. Griffths QM and now Zwiebach's new book. What book do you usually recommend to a complete novice?
or do you simply believe there is no one good intro QM book :(

Laundau Lifshitz

 

[vanhees71]

@vanhees71 I have seen you dislike most popular intro QM books, eg. Griffths QM and now Zwiebach's new book. What book do you usually recommend to a complete novice?
or do you simply believe there is no one good intro QM book :(

Sakurai, Ballentine, Weinberg, Messiah, Landau and Lifschitz vol. 3, Dirac. There are many good into books.

 

[MathematicalPhysicist]

Sakurai, Ballentine, Weinberg, Messiah, Landau and Lifschitz vol. 3, Dirac. There are many good into books.

No list can be complete without Cohen-Tanoudji's books...
P.S
I really should start reading this book, reminds me of Courant-Hilbert or Courant-John in calculus.
I only read parts, and it's good I read Cohen-Tanoudji that once I took an exercise in an undergraduate QM1, there was a question on Glauber something. No one in class knew how to answer this exercise but me, cause I gave a look at the book's index.

Good for me...

 

[Demystifier]

Sakurai, Ballentine, Weinberg, Messiah, Landau and Lifschitz vol. 3, Dirac.

But some of those say that there is collapse.

 

[Demystifier]

HOM effect
https://en.wikipedia.org/wiki/Hong–Ou–Mandel_effect

I've just noticed that this effect is also discussed in the Zwiebach's book, another topic that can rarely be found in other general QM textbooks.

 

[vanhees71]

But some of those say that there is collapse.

Sure, if you look for books, where they don't mention collapse, the list will be very short ;-).

 

[George Jones]

Admittedly, I have a few points I check to see whether I want to buy a new QM physics book. ...

These are interesting criteria. What is the set of books satisfies these four criteria, and also is suitable for a first undergrad quantum mechanics course (beyond Modern Physics) at a typical North American university? It wouldn't surprise if it's the empty set.

 

[haushofer]

For me, no textbook is perfect. I'm happy to get some misrepresentations; basically every book has them and no author is God. I prefer writing style and topic selection. The very first reason I read textbooks is because I'm in love with physics and mathematics, and if an author resonates with that in his writing style, much can be forgiven.

 

[vanhees71]

These are interesting criteria. What is the set of books satisfies these four criteria, and also is suitable for a first undergrad quantum mechanics course (beyond Modern Physics) at a typical North American university? It wouldn't surprise if it's the empty set.

Well, Sakurai is pretty close. My favorite intro textbook is unfortunately not available in English: E. Fick, Einführung in die Grundlagen der Quantentheorie, Aula-Verlag Wiesbaden (1979)

 

[MidgetDwarf]

Well, Sakurai is pretty close. My favorite intro textbook is unfortunately not available in English: E. Fick, Einführung in die Grundlagen der Quantentheorie, Aula-Verlag Wiesbaden (1979)

Someone give Vanhees a large annual salary, so that he can translate German math/physics books!