7 ms·

Review of Jean Bricmont's book "Making Sense of Quantum Mechanics"

71 points by mathgenius 9y ago

jostylr 9y ago
As a proponent of de Broglie-Bohm theory, or pilot wave theory, (particles have definite positions and are being guided by the wave function of QM), I am pleased to hear of the book and enjoyed the review. The reviewer was actually on my thesis committee and he always had an air of excitement with regards to this material as well as clarity with regards to both the philosophy and mathematics. As someone familiar with the material, I can hear within the book the very common themes that proponents of dBB often have to say. Without having read it, I can't comment on the book's clarity of presentation, but it certainly sounds like all the elements are there and more perspectives are always welcome. The issue has always been in getting people to try to accept that both standard QM and several of its alternatives really do not have an adequate description of reality in them and that this is a problem. I imagine the chapter that gives an in-depth discussion about what one wants from science is the most important novel contribution from the book to the field. If you are curious about the strangeness of QM, then you should read the review and probably the book. Just a note, as I have written elsewhere, that dBB is a theory that has been proven to have existence and uniqueness of solutions, handles identical particles in a very natural way, handles spin simply, generalizes to the Dirac equation, generalizes to QFT settings, has numerous proposals on integrating with relativity, and, quite recently, has led to some promising directions in resolving the issue of divergences associated with renormalization. Oh, and cats are always alive until they are not. There is no both alive and dead situation.
- Synaesthesia 9y ago
  >Oh, and cats are always alive until they are not. There is no both alive and dead situation. Of course not, this is why it’s called a paradox.
  - woodandsteel 9y ago
    I think what he meant is that the theory can explain what we observe without having to make that very strange assumption.
    - Synaesthesia 9y ago
      Yeah I realized that in retrospect. I still subscribe to the view that the status of the cat is undecidable at that point.
- mathgenius 9y ago
  I suspect that, for many physicists, the de Broglie-Bohm medicine is worse than the disease itself. It reminds me of Scott Aaronson's work "The Ghost in the Quantum Turing Machine" [1] where he sets up the boundary conditions of the universe to somehow encode free-will. But then, even the author doesn't seem to want to take this medicine. [1] https://arxiv.org/abs/1306.0159 https://arxiv.org/abs/1306.0159
- akvadrako 9y ago
  Bohm's interpretation is definitely one of the more reasonable ones and I think it's a fine picture to have in your head. But it suffers from two major flaws. 1. There is no need for the particle It's superfluous structure, which has no effect on the dynamical evolution or predictions. Only the pilot wave is needed, so that's a straightforward violation of Occam's razor. 2. It has FTL influences They may not be exploitable to us, but the primitive ontology of the theory requires it. This is seriously against the spirit of special relativity. In my view, Bohm's theory is only suitable as a visual aid or for those who are in denial about the consequences of pure unitary dynamics.
  - szemet 9y ago
    suitable as a visual aid Especially the somewhat related silicon droplet videos on youtube, e.g.: https://www.youtube.com/watch?v=WIyTZDHuarQ https://www.youtube.com/watch?v=WIyTZDHuarQ
  - alien_at_work 9y ago
    >so that's a straightforward violation of Occam's razor. I'm probably missing something but I don't get this objection entirely. I've long considered Occam's razor just a thing you can say. It doesn't have any predictive power as far as I can tell. The complex answer is just as likely to be correct as the simple one [1]. [1] http://neuralnetworksanddeeplearning.com/chap3.html http://neuralnetworksanddeeplearning.com/chap3.html Search for "Occam's razor"
    - akvadrako 9y ago
      It's not about complex vs simple, but about adding unnecessary assumptions. At least, that's the strict form of Occam's razor which I'm using here. If I have two theories: 1. which says that the Earth orbits the Sun and predicts when seasons and sunrises occur 2. the same as 1, plus undetectable pink elephants are floating through space Then Occam's razor says we should discard the second, because it just adds an assumption without adding predictive power. Or more plainly, if my axioms are a = 2b and a = b^2 then adding the axiom sqrt(a) = b creates a strictly inferior theory.
fernly 9y ago
https://www.amazon.com/Making-Sense-Quantum-Mechanics-Bricmont-ebook/dp/B01AJHYA7M https://www.amazon.com/Making-Sense-Quantum-Mechanics-Bricmo... $55 to buy, $30 to rent.
- mathgenius 9y ago
  You can also find it on libgen, if you are so inclined.
  - wensheng 9y ago
    thank you
mathgenius 9y ago
> Denials of an objective reality are, in the opinion of the author, and also of the reviewer, aberrations of human thought, plain and simple. I found this sentence rather disappointing, although I can sympathize. It really does seem like there is an objective reality out there, and humanity has certainly benefited greatly from our collective power over the natural world. However, if this "reality" is mathematical in nature, and mathematics is incomplete, then I don't see what is the big deal with giving up the idea of an objective reality. The founders of QM seemed to be much more open to these ideas, eg. Heisenberg and Bohr.
- jamesrcole 9y ago
  Why do you think incompleteness means non-objectivity? One reason I ask is that, as I understand it, incompleteness concerns the ability to prove certain characteristics rather than meaning a system has/hasn't got those characteristics.
  - antonvs 9y ago
    > incompleteness concerns the ability to prove certain characteristics rather than meaning a system has/hasn't got those characteristics. That's right. I like the way Gregory Chaitin puts it, "some mathematical facts are true for no reason, they are true by accident, or at random." I also don't see any connection to objective reality. Ignoring mathematics, we know that the universe contains things that are true by accident, but that doesn't undermine the idea of objective reality.
  - mathgenius 9y ago
    You can go on adding new axioms to your incomplete system, in an attempt to complete it. This to me looks like measurement processes in quantum mechanics. Mathematicians gave up on the idea of the "one true" mathematics, but it seems physicists still hope for the "one true" reality. Maybe this is a facile analogy. I'm still pondering if there are deeper things to be said about this.
- soVeryTired 9y ago
  I think the biggest problem with the “objective reality is mathematical” point of view is that there are many non-equivalent ways of interpreting the mathematics (e.g. wavefunction collapse vs. many worlds). It’s also the case that two non-equivalent mathematical formalisms can describe the same phenomenon. I’m not a physicist, but I think classical vs. Hamiltonian mechanics fits the bill there. Also possibly quantum vs. Bohmian mechanics (but I’m far too naïve in physics to be able to judge that one properly).
ivan_ah 9y ago
Nice. The book seems like a good review of foundations. It's good to see the topic discussed by someone expert, because otherwise QM education is left in the hands of gurus and popular science who totally butcher the subject. See this excerpt for my attempt to explain QM from first principles: https://minireference.com/static/excerpts/noBSguide2LA_preview.pdf#page=125 https://minireference.com/static/excerpts/noBSguide2LA_previ... (content warning: contains math equations)
Synaesthesia 9y ago
I actually found this Amazon review of the book to be particularly enlightening https://www.amazon.com/gp/aw/review/3319258877/R36M2YLHIMTBL1/ref=cm_cr_dp_mb_rvw_2?ie=UTF8&cursor=2 https://www.amazon.com/gp/aw/review/3319258877/R36M2YLHIMTBL...
lisper 9y ago
Almost twenty years ago now I had an "aha" moment about QM courtesy of John Preskill (http://www.theory.caltech.edu/people/preskill/ http://www.theory.caltech.edu/people/preskill/) that made it all come together for me: entanglement and measurement are the same physical phenomenon. Once you understand that, everything else makes perfect sense, and QM is no more difficult to understand than relativity. See: http://www.flownet.com/ron/QM.pdf http://www.flownet.com/ron/QM.pdf for the writeup I did at the time. There's also a Google tech talk: https://www.youtube.com/watch?v=dEaecUuEqfc https://www.youtube.com/watch?v=dEaecUuEqfc It's dismaying to me that even 20 years later QM is still presented as a deep mystery. It's not.
- majewsky 9y ago
  > I had an "aha" moment [...] that made it all come together for me: entanglement and measurement are the same physical phenomenon. Wait... that's not common knowledge amongst physicists?!? I arrived at that same conclusion in my sixth semester of physics (and third semester of quantum mechanics lectures), when the notion of weak measurements was introduced. > QM is no more difficult to understand than relativity. This is a nice quote when taken out of context, because it makes it sound like relativity is considered simple. :)
  - tpeo 9y ago
    Missing out on things you think you know, for whatever reason, is a thing. So we sometimes end up surprised even when traveling through well trodden paths.
  - lisper 9y ago
    > Wait... that's not common knowledge amongst physicists?!? Not only is it not common knowledge, there are still some who vehemently deny it is true, insisting that the Copenhagen interpretation or Bohmiam mechanics are still tenable, and that the "measurement problem" is still a problem. To this day I regularly fool even card-carrying physicists with the EPRG puzzle. Yes, it's shocking. > it sound like relativity is considered simple Conceptually, it is simple, but even relativity is often presented incorrectly. It is not that the speed of light is the universal speed limit, it is that it is the universal reference. Everything is always moving at the speed of light through space-time. The only thing that changes is what component of that velocity is moving through space and what component is moving through time.
fermigier 9y ago
Why did the author publish with Springer, at such a high price, and not some more mainstream, and cheaper, publisher ? Also, it seems Bricmont has an upcoming title, still with Springer, but at a more reasonable price, and probably more mainstream (judging only by the cover): https://www.amazon.fr/Quantum-Sense-Nonsense-Jean-Bricmont/dp/3319652702 https://www.amazon.fr/Quantum-Sense-Nonsense-Jean-Bricmont/d...
- gumby 9y ago
  > Why did the author publish with Springer, at such a high price, and not some more mainstream, and cheaper, publisher ? All the summary is is an answer to your question: 'This is an invited review of Jean Bricmont's book "Making Sense of Quantum Mechanics."'
  - fermigier 9y ago
    By "the author" I meant Bricmont, sorry for the confusion.
    - gumby 9y ago
      It makes sense for an academic book to be published in an academic press. A mainstream press probably wouldn't be interested; the academic press would have the relationships with the academic bookshops which is more likely to reach the likely audience.
Luc 9y ago
Meanwhile, Lubos Motl sure doesn't like it! https://www.amazon.com/gp/customer-reviews/R3NWAU0FI5RP3L/ref=cm_cr_arp_d_rvw_ttl?ie=UTF8&ASIN=3319258877 https://www.amazon.com/gp/customer-reviews/R3NWAU0FI5RP3L/re... (the whole thread of comments under the review is quite good! Sort by oldest first)
ivan_ah 9y ago
related article on interpretations: https://www.newscientist.com/article/2097199-seven-ways-to-skin-schrodingers-cat/ https://www.newscientist.com/article/2097199-seven-ways-to-s...

71 points by mathgenius 9y ago

As a proponent of de Broglie-Bohm theory, or pilot wave theory, (particles have definite positions and are being guided by the wave function of QM), I am pleased to hear of the book and enjoyed the review. The reviewer was actually on my thesis committee and he always had an air of excitement with regards to this material as well as clarity with regards to both the philosophy and mathematics. As someone familiar with the material, I can hear within the book the very common themes that proponents of dBB often have to say. Without having read it, I can't comment on the book's clarity of presentation, but it certainly sounds like all the elements are there and more perspectives are always welcome. The issue has always been in getting people to try to accept that both standard QM and several of its alternatives really do not have an adequate description of reality in them and that this is a problem. I imagine the chapter that gives an in-depth discussion about what one wants from science is the most important novel contribution from the book to the field. If you are curious about the strangeness of QM, then you should read the review and probably the book. Just a note, as I have written elsewhere, that dBB is a theory that has been proven to have existence and uniqueness of solutions, handles identical particles in a very natural way, handles spin simply, generalizes to the Dirac equation, generalizes to QFT settings, has numerous proposals on integrating with relativity, and, quite recently, has led to some promising directions in resolving the issue of divergences associated with renormalization. Oh, and cats are always alive until they are not. There is no both alive and dead situation.

Synaesthesia 9y ago
>Oh, and cats are always alive until they are not. There is no both alive and dead situation. Of course not, this is why it’s called a paradox.
- woodandsteel 9y ago
  I think what he meant is that the theory can explain what we observe without having to make that very strange assumption.
  - Synaesthesia 9y ago
    Yeah I realized that in retrospect. I still subscribe to the view that the status of the cat is undecidable at that point.
mathgenius 9y ago
I suspect that, for many physicists, the de Broglie-Bohm medicine is worse than the disease itself. It reminds me of Scott Aaronson's work "The Ghost in the Quantum Turing Machine" [1] where he sets up the boundary conditions of the universe to somehow encode free-will. But then, even the author doesn't seem to want to take this medicine. [1] https://arxiv.org/abs/1306.0159 https://arxiv.org/abs/1306.0159
akvadrako 9y ago
Bohm's interpretation is definitely one of the more reasonable ones and I think it's a fine picture to have in your head. But it suffers from two major flaws. 1. There is no need for the particle It's superfluous structure, which has no effect on the dynamical evolution or predictions. Only the pilot wave is needed, so that's a straightforward violation of Occam's razor. 2. It has FTL influences They may not be exploitable to us, but the primitive ontology of the theory requires it. This is seriously against the spirit of special relativity. In my view, Bohm's theory is only suitable as a visual aid or for those who are in denial about the consequences of pure unitary dynamics.
- szemet 9y ago
  suitable as a visual aid Especially the somewhat related silicon droplet videos on youtube, e.g.: https://www.youtube.com/watch?v=WIyTZDHuarQ https://www.youtube.com/watch?v=WIyTZDHuarQ
- alien_at_work 9y ago
  >so that's a straightforward violation of Occam's razor. I'm probably missing something but I don't get this objection entirely. I've long considered Occam's razor just a thing you can say. It doesn't have any predictive power as far as I can tell. The complex answer is just as likely to be correct as the simple one [1]. [1] http://neuralnetworksanddeeplearning.com/chap3.html http://neuralnetworksanddeeplearning.com/chap3.html Search for "Occam's razor"
  - akvadrako 9y ago
    It's not about complex vs simple, but about adding unnecessary assumptions. At least, that's the strict form of Occam's razor which I'm using here. If I have two theories: 1. which says that the Earth orbits the Sun and predicts when seasons and sunrises occur 2. the same as 1, plus undetectable pink elephants are floating through space Then Occam's razor says we should discard the second, because it just adds an assumption without adding predictive power. Or more plainly, if my axioms are a = 2b and a = b^2 then adding the axiom sqrt(a) = b creates a strictly inferior theory.

fernly 9y ago

https://www.amazon.com/Making-Sense-Quantum-Mechanics-Bricmont-ebook/dp/B01AJHYA7M https://www.amazon.com/Making-Sense-Quantum-Mechanics-Bricmo... $55 to buy, $30 to rent.

mathgenius 9y ago
You can also find it on libgen, if you are so inclined.
- wensheng 9y ago
  thank you

mathgenius 9y ago

> Denials of an objective reality are, in the opinion of the author, and also of the reviewer, aberrations of human thought, plain and simple. I found this sentence rather disappointing, although I can sympathize. It really does seem like there is an objective reality out there, and humanity has certainly benefited greatly from our collective power over the natural world. However, if this "reality" is mathematical in nature, and mathematics is incomplete, then I don't see what is the big deal with giving up the idea of an objective reality. The founders of QM seemed to be much more open to these ideas, eg. Heisenberg and Bohr.

jamesrcole 9y ago
Why do you think incompleteness means non-objectivity? One reason I ask is that, as I understand it, incompleteness concerns the ability to prove certain characteristics rather than meaning a system has/hasn't got those characteristics.
- antonvs 9y ago
  > incompleteness concerns the ability to prove certain characteristics rather than meaning a system has/hasn't got those characteristics. That's right. I like the way Gregory Chaitin puts it, "some mathematical facts are true for no reason, they are true by accident, or at random." I also don't see any connection to objective reality. Ignoring mathematics, we know that the universe contains things that are true by accident, but that doesn't undermine the idea of objective reality.
- mathgenius 9y ago
  You can go on adding new axioms to your incomplete system, in an attempt to complete it. This to me looks like measurement processes in quantum mechanics. Mathematicians gave up on the idea of the "one true" mathematics, but it seems physicists still hope for the "one true" reality. Maybe this is a facile analogy. I'm still pondering if there are deeper things to be said about this.
soVeryTired 9y ago
I think the biggest problem with the “objective reality is mathematical” point of view is that there are many non-equivalent ways of interpreting the mathematics (e.g. wavefunction collapse vs. many worlds). It’s also the case that two non-equivalent mathematical formalisms can describe the same phenomenon. I’m not a physicist, but I think classical vs. Hamiltonian mechanics fits the bill there. Also possibly quantum vs. Bohmian mechanics (but I’m far too naïve in physics to be able to judge that one properly).

ivan_ah 9y ago

Nice. The book seems like a good review of foundations. It's good to see the topic discussed by someone expert, because otherwise QM education is left in the hands of gurus and popular science who totally butcher the subject. See this excerpt for my attempt to explain QM from first principles: https://minireference.com/static/excerpts/noBSguide2LA_preview.pdf#page=125 https://minireference.com/static/excerpts/noBSguide2LA_previ... (content warning: contains math equations)

Synaesthesia 9y ago

I actually found this Amazon review of the book to be particularly enlightening https://www.amazon.com/gp/aw/review/3319258877/R36M2YLHIMTBL1/ref=cm_cr_dp_mb_rvw_2?ie=UTF8&cursor=2 https://www.amazon.com/gp/aw/review/3319258877/R36M2YLHIMTBL...

lisper 9y ago

Almost twenty years ago now I had an "aha" moment about QM courtesy of John Preskill (http://www.theory.caltech.edu/people/preskill/ http://www.theory.caltech.edu/people/preskill/) that made it all come together for me: entanglement and measurement are the same physical phenomenon. Once you understand that, everything else makes perfect sense, and QM is no more difficult to understand than relativity. See: http://www.flownet.com/ron/QM.pdf http://www.flownet.com/ron/QM.pdf for the writeup I did at the time. There's also a Google tech talk: https://www.youtube.com/watch?v=dEaecUuEqfc https://www.youtube.com/watch?v=dEaecUuEqfc It's dismaying to me that even 20 years later QM is still presented as a deep mystery. It's not.

majewsky 9y ago
> I had an "aha" moment [...] that made it all come together for me: entanglement and measurement are the same physical phenomenon. Wait... that's not common knowledge amongst physicists?!? I arrived at that same conclusion in my sixth semester of physics (and third semester of quantum mechanics lectures), when the notion of weak measurements was introduced. > QM is no more difficult to understand than relativity. This is a nice quote when taken out of context, because it makes it sound like relativity is considered simple. :)
- tpeo 9y ago
  Missing out on things you think you know, for whatever reason, is a thing. So we sometimes end up surprised even when traveling through well trodden paths.
- lisper 9y ago
  > Wait... that's not common knowledge amongst physicists?!? Not only is it not common knowledge, there are still some who vehemently deny it is true, insisting that the Copenhagen interpretation or Bohmiam mechanics are still tenable, and that the "measurement problem" is still a problem. To this day I regularly fool even card-carrying physicists with the EPRG puzzle. Yes, it's shocking. > it sound like relativity is considered simple Conceptually, it is simple, but even relativity is often presented incorrectly. It is not that the speed of light is the universal speed limit, it is that it is the universal reference. Everything is always moving at the speed of light through space-time. The only thing that changes is what component of that velocity is moving through space and what component is moving through time.

fermigier 9y ago

Why did the author publish with Springer, at such a high price, and not some more mainstream, and cheaper, publisher ? Also, it seems Bricmont has an upcoming title, still with Springer, but at a more reasonable price, and probably more mainstream (judging only by the cover): https://www.amazon.fr/Quantum-Sense-Nonsense-Jean-Bricmont/dp/3319652702 https://www.amazon.fr/Quantum-Sense-Nonsense-Jean-Bricmont/d...

gumby 9y ago
> Why did the author publish with Springer, at such a high price, and not some more mainstream, and cheaper, publisher ? All the summary is is an answer to your question: 'This is an invited review of Jean Bricmont's book "Making Sense of Quantum Mechanics."'
- fermigier 9y ago
  By "the author" I meant Bricmont, sorry for the confusion.
  - gumby 9y ago
    It makes sense for an academic book to be published in an academic press. A mainstream press probably wouldn't be interested; the academic press would have the relationships with the academic bookshops which is more likely to reach the likely audience.

Luc 9y ago

Meanwhile, Lubos Motl sure doesn't like it! https://www.amazon.com/gp/customer-reviews/R3NWAU0FI5RP3L/ref=cm_cr_arp_d_rvw_ttl?ie=UTF8&ASIN=3319258877 https://www.amazon.com/gp/customer-reviews/R3NWAU0FI5RP3L/re... (the whole thread of comments under the review is quite good! Sort by oldest first)

ivan_ah 9y ago

related article on interpretations: https://www.newscientist.com/article/2097199-seven-ways-to-skin-schrodingers-cat/ https://www.newscientist.com/article/2097199-seven-ways-to-s...