What are you reading now? (STEM only)

[gentzen]

Trying to read about Logic, which I never covered in much depth as a physicist. Currently on "First Steps in Modal Logic" by Sally Popkorn. I really recommend Schechter's "Classical and Nonclassical Logics: An Introduction to the Mathematics of Propositions"

Frank Pfenning's Automated Theorem Proving Handouts are a nice easily accessable resource for many topics in Logic from a non-philosophical engineering point of view.

 

[Demystifier]

Frank Pfenning's Automated Theorem Proving Handouts are a nice easily accessable resource for many topics in Logic from a non-philosophical engineering point of view.

By engineering, do you mean applied mathematician?

 

[gentzen]

By engineering, do you mean applied mathematician?

software engineering ... automation ... optimization
and don't forget that an important application of automated theorem proving is checking the logic of digital chips before go into mass production

I never thought about the meaning of applied mathematics. Of course, it doesn't share the goals of pure mathematics, but that doesn't help too much with clarifying its own meaning and goals.

 

[romsofia]

After realizing I've never read any works of Fock's, I decided to check out his book on gravitation, so I'm currently reading "Theory of Space, Time and Gravitation" by Vladimir Fock. I actually enjoy his approach to relativity so far. Pretty clean, seems almost like the "correct" way to teach introduction courses on it.

I also found it funny how he had to bring up his disdain for calling it "General relativity", in which he concludes the introduction with a rant on it, "We call the theory of Einstein space the Theory of Gravitation, not the "general theory of relativity ", because the latter name is nonsensical." In the preceding paragraphs, he argues there is actually no "relativity" in "general relativity", and by doing so, it somehow leads to misunderstandings of the theory (which I'm sure he will make clear on the chapters involving gravitation).

 

[vanhees71]

When was the book written? The "philosophical remarks" by Fock may well be to prevent from getting into trouble in showing, that the theory is compatible with dialectical materialism, because otherwise it would have been even dangerous to work publicly about it. I also did this for quantum theory. You can find such phrases in many Russian textbooks. A "nice" summary is the appendix of the quantum-mechanics textbook by Blokhintsev.

 

[AndreasC]

When was the book written? The "philosophical remarks" by Fock may well be to prevent from getting into trouble in showing, that the theory is compatible with dialectical materialism, because otherwise it would have been even dangerous to work publicly about it. I also did this for quantum theory. You can find such phrases in many Russian textbooks. A "nice" summary is the appendix of the quantum-mechanics textbook by Blokhintsev.

Fok however was interested in such subjects both before and after Zhdanovschina. Not to say that it didn't play its part, since I see he very specifically mentions Mach in that book. However it's not the whole story.

 

[romsofia]

When was the book written? The "philosophical remarks" by Fock may well be to prevent from getting into trouble in showing, that the theory is compatible with dialectical materialism, because otherwise it would have been even dangerous to work publicly about it. I also did this for quantum theory. You can find such phrases in many Russian textbooks. A "nice" summary is the appendix of the quantum-mechanics textbook by Blokhintsev.

Ah, I hadn't considered that. It was in the early 1950s, so it makes more sense from that POV.

I enjoy the history of physics, so I should probably find a book that talks about how scientists worked in the USSR during this time period as I am now curious!

 

[Gavinn]

I am reading this book:
https://www.worldscientific.com/worldscibooks/10.1142/0494#t=aboutBook
A tough one

 

[vanhees71]

I only know some papers, because I was stumbling over this appendix in Blokhintsev's book, which sounded very bizarre to me. Well, that's my usual reaction to "philosophy of physics" anyway, but I was surprised that scientists like Fock, you only vaguely know from how their achievements are quoted in textbooks (in this case the Fock space in QFT), could come to such strange conclusions as stating that already Lenin head quantum-mechanical ideas ;-)). Here's a review:

https://www.sps.ch/artikel/geschich...efense-of-modern-theories-in-soviet-union-13/

 

[AndreasC]

I only know some papers, because I was stumbling over this appendix in Blokhintsev's book, which sounded very bizarre to me. Well, that's my usual reaction to "philosophy of physics" anyway, but I was surprised that scientists like Fock, you only vaguely know from how their achievements are quoted in textbooks (in this case the Fock space in QFT), could come to such strange conclusions as stating that already Lenin head quantum-mechanical ideas ;-)). Here's a review:

https://www.sps.ch/artikel/geschich...efense-of-modern-theories-in-soviet-union-13/

This is a good article, I read that a while ago. Fock is indeed very interesting. Though I don't think he ever said Lenin had "quantum mechanical ideas", but rather that dialectical materialism (which predates Lenin, it was first formulated by Engels) is not incompatible with the new advances. At the time there were philosophers attacking dialectical materialism based on its supposed incompatibility with them, and, (worse for Fock) philosophers in the USSR who attacked the new advances for their incompatibility with diamat.

I think Fock had two things in his mind. On the one hand, he though diamat was indeed a good philosophical framework to interpret and depthen knowledge of nature. On the other hand, he wanted to defend the new advances from attacks coming from the "diamat philosopher" camp, which in the USSR was official philosophy, and at the time of the Zhdanov doctrine you could actually get in real deep trouble for things like that (or, on the flip side, you could get promoted to stardom peddling pseudoscience, like Lysenko). So he also wanted to separate to some degree the content of the new theories from the philosophical debates, while also demonstrating that diamat is compatible and can be used fruitfully to further investigations.

As an aside, while most Marxist USSR philosophers at the time were attacking Bohr vigorously for positivist views, his closest, most loyal ally from the start was Leon Rosenfeld, who was, get this, a high profile Marxist and member of the French Communist Party, who tried to use his influence to block Marxist critics of complementarity and Copenhagen interpretation etc. In the course of doing that, he also tried to block David Bohm, who was again a Marxist. To what extent Bohm's Marxist views incentivized him to try and develop a realist view of QM, I don't know. But it would be interesting to read about. But it's very interesting how closely these seemingly unrelated political debates tracked advancements, even though traditional history of physics tends to erase them.

 

[Demystifier]

To what extent Bohm's Marxist views incentivized him to try and develop a realist view of QM, I don't know.

In his view of QM Bohm was influenced by some eastern philosophy, and by eastern I don't mean Soviet.

 

[AndreasC]

In his view of QM Bohm was influenced by some eastern philosophy, and by eastern I don't mean Soviet.

Yeah, I know he engaged with Hindu philosophy etc, but to my understanding that was mostly later. Don't know any more details though.

 

[AndreasC]

In his view of QM Bohm was influenced by some eastern philosophy, and by eastern I don't mean Soviet.

The following paper I found seems to talk about the issue: https://arxiv.org/abs/2307.05611

 

[haushofer]

I was curious about Schwichtenberger's No Nonsense QFT book,

https://www.amazon.com/dp/3948763011/?tag=pfamazon01-20

It contains some nice insights, but my god, literally every step is explicitly spelled out and it's a bit surreal to be reminded of what an integral or complex number is after several hundred pages (it's like arriving at an Arabic learning book at page 400 and be reminded how to pronounce the alif). I'm also sceptical about what readers actually learn from such an "layed back" approach without any exercises. Because of the vast space of explicitness (and topics; e.g. why treat special relativity as if it's the reader's very first encounter? Why all those explicit exposure to examples with ordinary vectors?) some crucial topics aren't covered (why not a nice exposition of e.g. the i-epsilon usage which can be confusing? Where's the QED calculation of the electron's magnetic moment? etc)

Don't get me wrong: the book is nicely written, refreshing in its (intuitive) approach, and contains really nice insights, especially for a very first encounter. It's just a bit cumbersome to find them sometimes, especially if you already have some background, and some of the notation was confusing to me. To me, the overly done explicitness made it sometimes a bit annoying instead of enlightening, and I missed some topics. Leaving one with the didactic question: what does a reader really learn after reading al those explicit calculations spit out in excruciating detail without having done any exercises? I'm not sure that's understanding "to be proud of", as the back of the book promises. But maybe I'm not the right public to start with.

 

[AndreasC]

I am reading Padmanabhan's Cosmology and Astrophysics through Problems. The idea is to teach the subject through exercises, without much explicit instruction.

My understanding is that he intended this book for people who already know the basics of astrophysics. This is probably the audience that makes the most sense to teach through this method. I don't really know astrophysics beyond absorbing some things here and there. I thought I could manage by general physics background, but the exercises are *HARD*. Even the ones that are ranked 1/3 in difficulty. Maybe it's just these ones I tried already that seem so hard to me because I am not very familiar with their subject. But yeah, it is NOT a good resource for an intro, unless hints are provided. I will persevere a bit more but there's really very few things there I can solve completely on my own in a rasonable time frame (although it is very satisfying when I manage it).

As a mild criticism, I would say it needs fewer "show that" exercises and more "find" exercises if it wants to be consistent with its target. But probably make them a bit easier. Or even better, come up with exercises which ask you something like "calculate quantities of x type", where some of them are easy, some are medium and some are hard. This way it doesn't shut off less advanced people completely, but it can also be pushed. In my opinion, hard exercises are better when you at least know where to start.

 

[apostolosdt]

I only know some papers, because I was stumbling over this appendix in Blokhintsev's book, which sounded very bizarre to me. Well, that's my usual reaction to "philosophy of physics" anyway, but I was surprised that scientists like Fock, you only vaguely know from how their achievements are quoted in textbooks (in this case the Fock space in QFT), could come to such strange conclusions as stating that already Lenin head quantum-mechanical ideas ;-)). Here's a review:

https://www.sps.ch/artikel/geschich...efense-of-modern-theories-in-soviet-union-13/

Interesting reading, although my only contact with Fock's physics was through Hartree-Fock approximation during my graduate years. Thanks for pointing out this paper.

The following paper I found seems to talk about the issue: https://arxiv.org/abs/2307.05611

I only knew Bohm from the Aharonov–Bohm effect. I happened to be doing some research work (early 1990s) at the same university where Bohm was an emeritus professor (but not in the same college). I knew he was at Birkbeck, which I occasionally visited, but I never met him. Ironically, I've learned a lot more about him by reading various posts in this Forum, but mostly by reading about Bohm the scientist because of those posts.

But then, I came across an article, cited below, by Christian Forstner, of the Max Planck Institute, that outlines a rather "acute" image of Bohm the philosopher. Hopefully, some comments by more knowledgeable members would clarify Forstner's article.

https://www.mpiwg-berlin.mpg.de/sites/default/files/Preprints/P303.pdf

 

[vanhees71]

I also know Bohm's very good quantum-mechanics textbook, written before he dealt with de Broglie's idea of pilot waves. I think writing this book triggered Bohm's interest in finding a so-called "realistic interpretation".

 

[apostolosdt]

I also know Bohm's very good quantum-mechanics textbook, written before he dealt with de Broglie's idea of pilot waves. I think writing this book triggered Bohm's interest in finding a so-called "realistic interpretation".

You sound quite positive in describing Bohm's QM book. So, I won't find myself reading "interpretation" stuff, if I, out of curiosity, try to thumb through it, is that right? (My acquaintance of QM is with more standard textbooks.)

 

[vanhees71]

This book is very conventional Copenhagen. It was published in 1951 before Bohm invented his pilot-wave interpretation.

 

[Demystifier]

So, I won't find myself reading "interpretation" stuff, if I, out of curiosity, try to thumb through it, is that right?

There is some interpretation stuff in the book, but in the Copenhagen spirit. But most of the book is not about interpretations.

 

[gmax137]

I'm halfway through Boltzmann's Atom by David Lindley
https://www.amazon.com/s?k=boltzmann's+atom&ref=nb_sb_noss

This is closer to a biography, certainly not a text book. It has driven me to dust off my Berkeley Volume 5 "Statistical Physics" which I now plan to go through for fun.

I found Lindley's discussions of the resistance to the "atomic theory" enlightening. I always wondered why Mach, Planck, and those guys didn't "believe" in atoms. As described, their issue centered on the disconnect between Thermo II (entropy increases) and the reversibility of Newtonian mechanics.

 

[haushofer]

I found Lindley's discussions of the resistance to the "atomic theory" enlightening. I always wondered why Mach, Planck, and those guys didn't "believe" in atoms. As described, their issue centered on the disconnect between Thermo II (entropy increases) and the reversibility of Newtonian mechanics.

Can you elaborate a bit on that? :)

 

[AndreasC]

Can you elaborate a bit on that? :)

Planck believed the second law was impossible to violate. Boltzmann's statistical theory derived the law as valid only statistically, since atomic physics were considered to be governed by the reversible laws of classical mechanics. Planck sided with the "energeticists" who believed a continuous view of matter was correct, because he did not accept the second law as only approximately emergent.

Interestingly, it was exactly because he was insistent on an absolute second law of thermodynamics that he got interested in black body radiation. In fact the Rayleigh-Jeans law had nothing to do with it, despite what is usually claimed in historical recountings. The Rayleigh-Jeans law rested on the equipartition theorem and some flavor of atomic theory, which Planck didn't believe in anyways. Planck simply guessed an expression for the entropy of a harmonic oscillator just so that it could fit Wien's law and experiments. In fact he did this twice, the first time with results that were eventually disproven experimentally. The second time they were fine, but at some point he realized that if he wanted a more fundamental prediction and not just a guess, he needed to stop ignoring Boltzmann's interpretation of entropy.

It turned out that after all that, you could deduce this way that each oscillator had a discrete energy spectrum, but it doesn't appear even Planck gave it much thought, and he didn't seem to believe he was going anywhere beyond classical physics. Not only that, but he wasn't even making the identification of oscillators with atoms. It was only later that others such as Lorentz and Einstein appreciated these aspects of his theory. Planck was simply reverse engineering the entropy of harmonic oscillators from Wien's law.

 

[vanhees71]

It turned out that after all that, you could deduce this way that each oscillator had a discrete energy spectrum, but it doesn't appear even Planck gave it much thought, and he didn't seem to believe he was going anywhere beyond classical physics. Not only that, but he wasn't even making the identification of oscillators with atoms. It was only later that others such as Lorentz and Einstein appreciated these aspects of his theory. Planck was simply reverse engineering the entropy of harmonic oscillators from Wien's law.

Planck was well aware that this conclusion of his radiation law was not compatible with classical physics, and that's why he looked for some way out of his "act of desparation" that forced him to introduce the "energy quanta".

Indeed, Planck found his radiation law first by interpolating the entropy of his harmonic oscillators such that it fulfilled Wien's and the Rayleigh-Jeans law in the corresponding limits, where the results of Rubens, Kurlbaum et al from the measurements of the black-body spectrum at the Reichsanstalt agreed with them. Then Planck figured out that indeed he could only derive this within statistical physics by assuming the energy quantization.

 

[AndreasC]

Planck was well aware that this conclusion of his radiation law was not compatible with classical physics, and that's why he looked for some way out of his "act of desparation" that forced him to introduce the "energy quanta".

But Planck by his own admission did not pay much attention to the implications of his assumption, as it was "a purely formal assumption and I really did not give it much thought except that no matter what the cost, I must bring about a positive result".

It's clear that he did not think he had gone beyond classical physics at the time. In the following few years he did not write anything more on that subject. He also did not clearly state the discrete relation for the energy spectrum of the oscillators anywhere in his original papers. And 6 years afterwards, he presented a continuous theory of matter that didn't say anything about discrete harmonic oscillator energies and whatnot. He did not accept atomic theory and championed a continuous theory of matter for a long time after his 1900 and 1901 papers. By quantizing the energies, Planck probably thought at the time he had made some kind of approximation that would be smoothed out eventually.

 

[vanhees71]

Of course, he introduced the quantized energy quanta $\epsilon=h \nu$ in his famous paper of Dec. 14, 1900, and for the rest of his live he looked for possibilities to derive his radiation law within classical physics, without success of course.

That he was reluctant to accept his own finding is also clear from this paper. Here's a nice review about these historical questions:

https://doi.org/10.1119/1.4955146

 

[gmax137]

Can you elaborate a bit on that? :)

See post 653 and ...

 

[haider]

Got this really pretty used copy of Boas from a relative in the US (hardcover costs like 15 times the amount here in India). Plan to work through some chapters over Christmas. Also found this post-it still inside :)

 

[Frabjous]

Just picked up “Ballistics in the Seventeenth Century” by Hall (1952).

 

[Nik_2213]

"How to build a habitable planet" by CH Langmuir & W. Broecker (2nd, much revised & expanded Edition)
'Terraforming' by MJ Fogg. (My classic 1995 Edition, dug out of storage...)

Yes, I'm writing another space-story, the sequel to 'Chaparral', #17 in fiction section...
https://www.physicsforums.com/threads/the-short-story-thread-post-yours-here.914630/