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This looks really nice. But can someone recommend something more like "The Practical Experiments of Quantum Mechanics"? I've read some articles and seen some v

by audunw 8y ago

This looks really nice. But can someone recommend something more like "The Practical Experiments of Quantum Mechanics"? I've read some articles and seen some video courses on Quantum Mechanics, and it seems that there's always way more focus on the mathematics and abstract/simplified physics, and not much description of the actual experiments. I get that the main challenge of teaching it is understanding the mathematics, but it's hard to stay focused when - even though I understand the equations - I'm not sure what the mathematics describes physically. Or when I do understand it, that I have no idea how one would go about preparing the state. I think I've gotten a half decent understanding of the Stern–Gerlach experiment, but that's about it.

SiempreViernes 8y ago
Famously there is no consensus of how to interpret the equations of quantum mechanics, which naturally restricts introductory discussion to the mathmatical aspects.
- forkandwait 8y ago
  I think there is a ton of consensus on how the equations predict lab results, however, and I would be very happy with that.
  - jabl 8y ago
    For practical uses the "shut up and calculate" interpretation of QM works just fine. For a recent head-scratcher, though, see https://www.nature.com/articles/s41467-018-05739-8 https://www.nature.com/articles/s41467-018-05739-8
    - kgwgk 8y ago
      There was some discussion about that paper here: https://news.ycombinator.com/item?id=18023452 https://news.ycombinator.com/item?id=18023452 I think it's much less interesting than it seems at first sight. Related (and clearer): In Defense of a "Single-World" Interpretation of Quantum Mechanics (Jeffrey Bub) https://arxiv.org/abs/1804.03267 https://arxiv.org/abs/1804.03267
- kgwgk 8y ago
  I'm not sure the lack of consensus is the reason. One can learn QM and use it for a whole career without ever worrying about these issues. I'm not sure why do you mean by "introductory discussion" but I think "popular science" books focus mostly on the controversial parts. At the university level, at least in my experience, you study a lot of classical physics, early quantum physics (1900-1925), and mathematical physics before taking a first look at Quantum Mechanics (Schroedinger/Heisenberg). And you may never be exposed to the relativistic extensions.
  - SiempreViernes 8y ago
    I meant the discussion in the intro courses; Griffiths just plonks down the Schrodinger equation on page one and you just have to eat it. In contrast a textbook about thermodynamics will be all steam engines at the start, or maybe talk about a thermometer. Solid, sensible things and no talk about Gibbs free energy or any of the deep theory that exists. You could start a QM book talking about the double slit experiment, but would have to write a lot of "one interpretation" and "some views say this". Or you could just brazenly pretend there is no controversy and make every reader that knows of it very suspicious indeed.
    - andrepd 8y ago
      >You could start a QM book talking about the double slit experiment That is indeed how my favorite QM book starts: Cohen-Tannoudji. See also Landau for one that starts from experiment and not theory.
      - kgwgk 8y ago
        Yes, but it quickly cuts to the meat :-) (I mean C-T/D/L, that’s the book I was talking about in a sibling comment)
    - kgwgk 8y ago
      I’m not familiar with that book. I learnt QM from a 2-volume, 1500 pages book that gives you Schroedinger’s equation 10 pages in. But that book made no claim of being “introductory” and I previously had a “quantum physics” course including the different things that lead to Schroedinger’s equation (Plank, Rutherford, Bohr, etc). In any case introductory books that discuss the physics and not just the mathematics do also exist, like vol 3 in Feynman’s lectures. Edit: I’m looking at Griffiths’ book and after defining Schroedinger’s equation in section 1.1 he devotes three pages to discussing its statistical interpretation in section 1.2 and mentions different interpretations, the Bell inequalities and the measurement problem. He comes back to these philosophical issues at the end of the book in a 12-page afterword.
deleted 8y ago
[deleted]
forkandwait 8y ago
I would love to get a lab manual to accompany Griffith's book on QM. I actually find it bizarre how little information there is, and I have looked. My gut tells me someone with an M.A. in physics, $5,000, and a lot of time could set up a hobby lab in her or his garage to validate everything through QED... As for interpetation of QM, I don't think that's the problem since one can just set up an experiment based on prediction from the mathematical models. Sure, you will have make multiple runs to show the predicted distribution of the non-deterministic, umm, stuff, but that isn't a problem.
kgwgk 8y ago
Maybe you will find some introductory stuff on quantum optics interesting. Check Nicolas Gisin's book "Quantum Chance". A few articles about the experimental violation of Bell’s inequalities: https://static.scientificamerican.com/sciam/assets/media/pdf/197911_0158.pdf https://static.scientificamerican.com/sciam/assets/media/pdf... https://qudev.phys.ethz.ch/phys4/studentspresentations/epr/aspect.pdf https://qudev.phys.ethz.ch/phys4/studentspresentations/epr/a... http://drchinese.com/David/Aspect.pdf http://drchinese.com/David/Aspect.pdf http://www.rpi.edu/dept/phys/Courses/PHYS4510/AspectNature.pdf http://www.rpi.edu/dept/phys/Courses/PHYS4510/AspectNature.p...
CamperBob2 8y ago
This looks really nice. But can someone recommend something more like "The Practical Experiments of Quantum Mechanics"? You might have a look at https://www.amazon.com/Exploring-Quantum-Physics-through-Projects-ebook/dp/B00HLFTYI6 https://www.amazon.com/Exploring-Quantum-Physics-through-Pro... . This book stops short of covering molecular beams, though.
jostylr 8y ago
Quantum Mechanics, An Experimentalist Approach: https://www.amazon.com/gp/product/110706399X/ https://www.amazon.com/gp/product/110706399X/ If one wants to get into some of the philosophy about it, then try: Foundations of Quantum Mechanics: An Exploration of the Physical Meaning of Quantum Theory https://www.amazon.com/gp/product/3319658662 https://www.amazon.com/gp/product/3319658662
mathgenius 8y ago
Feynman volume III: it's very wordy, and concrete. http://www.feynmanlectures.caltech.edu/III_toc.html http://www.feynmanlectures.caltech.edu/III_toc.html You might also like John Bell's original papers. Feynman doesn't do entanglement. Conway's "free will" paper is good aswell.

by audunw 8y ago

SiempreViernes 8y ago

Famously there is no consensus of how to interpret the equations of quantum mechanics, which naturally restricts introductory discussion to the mathmatical aspects.

forkandwait 8y ago
I think there is a ton of consensus on how the equations predict lab results, however, and I would be very happy with that.
- jabl 8y ago
  For practical uses the "shut up and calculate" interpretation of QM works just fine. For a recent head-scratcher, though, see https://www.nature.com/articles/s41467-018-05739-8 https://www.nature.com/articles/s41467-018-05739-8
  - kgwgk 8y ago
    There was some discussion about that paper here: https://news.ycombinator.com/item?id=18023452 https://news.ycombinator.com/item?id=18023452 I think it's much less interesting than it seems at first sight. Related (and clearer): In Defense of a "Single-World" Interpretation of Quantum Mechanics (Jeffrey Bub) https://arxiv.org/abs/1804.03267 https://arxiv.org/abs/1804.03267
kgwgk 8y ago
I'm not sure the lack of consensus is the reason. One can learn QM and use it for a whole career without ever worrying about these issues. I'm not sure why do you mean by "introductory discussion" but I think "popular science" books focus mostly on the controversial parts. At the university level, at least in my experience, you study a lot of classical physics, early quantum physics (1900-1925), and mathematical physics before taking a first look at Quantum Mechanics (Schroedinger/Heisenberg). And you may never be exposed to the relativistic extensions.
- SiempreViernes 8y ago
  I meant the discussion in the intro courses; Griffiths just plonks down the Schrodinger equation on page one and you just have to eat it. In contrast a textbook about thermodynamics will be all steam engines at the start, or maybe talk about a thermometer. Solid, sensible things and no talk about Gibbs free energy or any of the deep theory that exists. You could start a QM book talking about the double slit experiment, but would have to write a lot of "one interpretation" and "some views say this". Or you could just brazenly pretend there is no controversy and make every reader that knows of it very suspicious indeed.
  - andrepd 8y ago
    >You could start a QM book talking about the double slit experiment That is indeed how my favorite QM book starts: Cohen-Tannoudji. See also Landau for one that starts from experiment and not theory.
    - kgwgk 8y ago
      Yes, but it quickly cuts to the meat :-) (I mean C-T/D/L, that’s the book I was talking about in a sibling comment)
  - kgwgk 8y ago
    I’m not familiar with that book. I learnt QM from a 2-volume, 1500 pages book that gives you Schroedinger’s equation 10 pages in. But that book made no claim of being “introductory” and I previously had a “quantum physics” course including the different things that lead to Schroedinger’s equation (Plank, Rutherford, Bohr, etc). In any case introductory books that discuss the physics and not just the mathematics do also exist, like vol 3 in Feynman’s lectures. Edit: I’m looking at Griffiths’ book and after defining Schroedinger’s equation in section 1.1 he devotes three pages to discussing its statistical interpretation in section 1.2 and mentions different interpretations, the Bell inequalities and the measurement problem. He comes back to these philosophical issues at the end of the book in a 12-page afterword.

deleted 8y ago

[deleted]

forkandwait 8y ago

I would love to get a lab manual to accompany Griffith's book on QM. I actually find it bizarre how little information there is, and I have looked. My gut tells me someone with an M.A. in physics, $5,000, and a lot of time could set up a hobby lab in her or his garage to validate everything through QED... As for interpetation of QM, I don't think that's the problem since one can just set up an experiment based on prediction from the mathematical models. Sure, you will have make multiple runs to show the predicted distribution of the non-deterministic, umm, stuff, but that isn't a problem.

kgwgk 8y ago

Maybe you will find some introductory stuff on quantum optics interesting. Check Nicolas Gisin's book "Quantum Chance". A few articles about the experimental violation of Bell’s inequalities: https://static.scientificamerican.com/sciam/assets/media/pdf/197911_0158.pdf https://static.scientificamerican.com/sciam/assets/media/pdf... https://qudev.phys.ethz.ch/phys4/studentspresentations/epr/aspect.pdf https://qudev.phys.ethz.ch/phys4/studentspresentations/epr/a... http://drchinese.com/David/Aspect.pdf http://drchinese.com/David/Aspect.pdf http://www.rpi.edu/dept/phys/Courses/PHYS4510/AspectNature.pdf http://www.rpi.edu/dept/phys/Courses/PHYS4510/AspectNature.p...

CamperBob2 8y ago

This looks really nice. But can someone recommend something more like "The Practical Experiments of Quantum Mechanics"? You might have a look at https://www.amazon.com/Exploring-Quantum-Physics-through-Projects-ebook/dp/B00HLFTYI6 https://www.amazon.com/Exploring-Quantum-Physics-through-Pro... . This book stops short of covering molecular beams, though.

jostylr 8y ago

Quantum Mechanics, An Experimentalist Approach: https://www.amazon.com/gp/product/110706399X/ https://www.amazon.com/gp/product/110706399X/ If one wants to get into some of the philosophy about it, then try: Foundations of Quantum Mechanics: An Exploration of the Physical Meaning of Quantum Theory https://www.amazon.com/gp/product/3319658662 https://www.amazon.com/gp/product/3319658662

mathgenius 8y ago

Feynman volume III: it's very wordy, and concrete. http://www.feynmanlectures.caltech.edu/III_toc.html http://www.feynmanlectures.caltech.edu/III_toc.html You might also like John Bell's original papers. Feynman doesn't do entanglement. Conway's "free will" paper is good aswell.