New book on the foundations of quantum mechanics

[ttn]

Some years ago now, I was a regular reader and poster here and had a lot of fun arguing about the meaning of Bell's theorem, the relative merits of different "interpretations" of QM, etc. I just popped in for the first time in a long time, and it is nice to see some familiar faces (and many new ones as well) still discussing and debating these issues!

I checked in mostly to share some exciting news. Last year I had the opportunity to teach a sophomore/junior-level physics course on the foundations of QM, and then edited the weekly handouts I wrote for that course into book chapters. The book has just been published and is available, for example, here:

https://www.amazon.com/dp/3319658662/?tag=pfamazon01-20

The book covers everybody's favorite topics in the foundations of QM (the measurement problem, the ontology problem, EPR, the copenhagen interpretation, the pilot-wave theory, Bell's theorem, spontaneous collapse theory, and the many-worlds theory) and is designed to be uniquely accessible to undergraduate students with a pretty minimal prior exposure to quantum mechanics. It is intended to be unusually readable as textbooks go (and hence suitable for self-study and/or just reading for pure geeky pleasure) but also to provide a systematic and fairly balanced intro-textbook-like survey of the topics covered. (You can read the Preface and check out the TOC using the "Look Inside" feature at the link above to get a more detailed sense of the coverage and level.)

Anyway, I hope you'll check it out if you're at all interested. I'll be following this thread so that, if anybody has questions or comments you can post them here and I'll do my best to address/discuss. (I hope that makes this a genuine thread-starter rather than a mere shamelessly self-promoting advertisement!)

 

[StevieTNZ]

Thanks for sharing!

 

[bhobba]

Some years ago now, I was a regular reader and poster here and had a lot of fun arguing about the meaning of Bell's theorem, the relative merits of different "interpretations" of QM, etc. I just popped in for the first time in a long time, and it is nice to see some familiar faces (and many new ones as well) still discussing and debating these issues!

Great news.

There is also one for free from here if anyone is interested:
http://quantum.phys.cmu.edu/CQT/

It covers the foundational issues from the consistent/decoherent histories viewpoint.

Thanks
Bill

 

[bhobba]

Anyway, I hope you'll check it out if you're at all interested. I'll be following this thread so that, if anybody has questions or comments you can post them here and I'll do my best to address/discuss. (I hope that makes this a genuine thread-starter rather than a mere shamelessly self-promoting advertisement!)

Well I did read the afterward which is posted in the look inside on amazon.

He mentions he did not cover the important area of decoherence properly. That's a shame because it has had a strong influence on modern interpretations. But did mention Schlosshauer as a good source for that. He is right - imho he wrote THE book on it:
https://www.amazon.com/dp/3540357734/?tag=pfamazon01-20

Thanks
Bill

 

[ttn]

He mentions he did not cover the important area of decoherence properly. That's a shame because it has had a strong influence on modern interpretations. But did mention Schlosshauer as a good source for that. He is right - imho he wrote THE book on it:
https://www.amazon.com/dp/3540357734/?tag=pfamazon01-20

Yeah, in a book for a slightly more advanced audience, it would definitely be good to include a chapter on decoherence for just the reason you state. However, this would be almost exclusively polemical -- explaining how, despite the apparently widespread belief to the contrary, decoherence does not solve/dissolve foundational questions and in particular the measurement problem. Or maybe, to be charitable, one could put it this way: the only people who think decoherence (alone) solves the measurement problem, are people who don't think there is a measurement problem in the first place.

Decoherence is relevant in the sense that it allows one to understand, for example, how/why the branching structure in Everett's theory is objective, or how/why sub-system wave functions effectively collapse in the de Broglie - Bohm pilot-wave theory. That is, decoherence is important for understanding how proposed solutions of the measurement problem work... but it does not itself constitute such a solution.

FWIW, in my book, I explain and address these applications (effective collapse in dBB, branching in Everett, etc.) but without getting into the technical details of decoherence. For an audience that hasn't already been browbeaten into accepting the dogma that decoherence renders things like dBB and Everett unnecessary, this is, in my opinion, perfect.

 

[bhobba]

That is, decoherence is important for understanding how proposed solutions of the measurement problem work... but it does not itself constitute such a solution.

No it doesn't and Schlosshauer explains why going deep into what it does explain, and what it doesn't. While not solving the measurement problem decoherence has morphed it a bit, again carefully explained by Schlosshauer.

IMHO you have done the right thing for a book with its intended audience - you mention decoherence has more to say on the issue and give the source, Schlosshauer, where it can be found.

That's all that can really be asked.

As an aside - from what I read on Amazon a nice book - might get a copy for my library. Trouble is I have a huge amount of stuff to read (my latest is Einsteins Mistakes by Ohanian) - it just seems never ending - but fun. Since posting here my knowledge of QM has gone ahead in leaps and bounds. I used to believe for example electrons are in many positions at the same time - plus other equally silly stuff. Its just what it really says never gets discussed much in textbooks - and also the textbooks I initially learned it from - Dirac and Von-Neumann. I now know that was a bad choice - but I also read a bit later Ballentine, after a sojourn into Rigged Hilbert Spaces to sort out that damnable Dirac Delta function that bedeviled Von-Neumann (he was scathing of it in his book) which was a much much better text.

Thanks
Bill

 

[Demystifier]

I got the Norsen's book and I am about to start reading.

 

[A. Neumaier]

I got the Norsen's book and I am about to start reading.

did you finish it?

 

[Demystifier]

did you finish it?

I didn't read the whole book (most of it doesn't seem new to me), but I finished with reading all what I wanted to read. Why?

 

[A. Neumaier]

I didn't read the whole book (most of it doesn't seem new to me), but I finished with reading all what I wanted to read. Why?

Because you found starting to read the book worth reporting. This makes sense only if you also inform us about the value of the book from what you read.

 

[DarMM]

It's very good as an introduction to Bohmian Mechanics, GWR and Many Worlds. Particularly in how it shows that their fully developed version is quite different from their naive form as a result of exploring certain ambiguities in the naive formulations.

However I found the discussion of the Copenhagen interpretation to be a bit vague.

 

[Demystifier]

However I found the discussion of the Copenhagen interpretation to be a bit vague.

That's because the author thinks that Copenhagen interpretation is vague.

 

[Demystifier]

Because you found starting to read the book worth reporting. This makes sense only if you also inform us about the value of the book from what you read.

I think this is a very good introduction to philosophical foundations of quantum mechanics from a realist point of view. On the other hand, quantum foundations experts, anti-realists and those who do not like philosophy will not find much value in this book.

 

[DarMM]

That's because the author thinks that Copenhagen interpretation is vague.

I can appreciate he might think that, but I think it is still possible to give a much clearer presentation of Copenhagen as one finds for example in Matt Leifer's lectures.

 

[Demystifier]

Today on facebook I received the following message from Travis Norsen, the author of the book:
"According to the publisher, there is a new system that will allow any professor/lecturer to get a free copy of my book (on the Foundations of QM) to examine for possible adoption in a course. The book is suitable as a secondary text for a physics QM course, or as a (or as one of several) primary text(s) for a philosophy of physics course. Just send me (by email or facebook message) your name, institution, and email address and I will arrange for the publisher to contact you."