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I believe this could be interesting to many people here who are interested in quantum theory but are not (yet) professional physicists:
http://lanl.arxiv.org/abs/1803.07098
http://lanl.arxiv.org/abs/1803.07098
Best regardsLeonard Susskind said:A number of years ago I became aware of the large number of physics enthusiasts out there who have no venue to learn modern physics and cosmology. Fat advanced textbooks are not suitable to people who have no teacher to ask questions of, and the popular literature does not go deeply enough to satisfy these curious people. So I started a series of courses on modern physics at Stanford University where I am a professor of physics. The courses are specifically aimed at people who know, or once knew, a bit of algebra and calculus, but are more or less beginners.
Maybe it's not a valid assumption for an average high school student. But I don't think that average high school students would be interested in those lectures in the first place.One thing the lectures do not seem to explain is complex numbers; they start out by assuming the students already know about those. Is that a valid assumption for high school students?
To me, that's one thing which I think is wrong with modern physics. I never understood how people can make such a sharp distinction between what's "phsyics" and what's "philosophy". It degrades physics into bookkeeping.I think it is weak on interpretation.
"There are many interpretations of quantum mechanics. These interpretations are not scientifically testable, since there is no way to distinguish one from the other, and thus they are in the realm of philosophy, not science"
In Holland it sure isn't, as far as I can tell :DOne thing the lectures do not seem to explain is complex numbers; they start out by assuming the students already know about those. Is that a valid assumption for high school students?
No, that's pretty strong, because it's true. Don't destract beginners with philosophy from the physics, is a good advice always!I think it is weak on interpretation.
"There are many interpretations of quantum mechanics. These interpretations are not scientifically testable, since there is no way to distinguish one from the other, and thus they are in the realm of philosophy, not science"
Photons as bullets are ok, as long as one is also taught the limitations of the model. The textbook by Grynberg and colleagues does say that some single photon states "might be referred to as quasi-particle states, because they are the quantum states whose properties most closely resemble those of an isolated particle propagating at the speed of light, just as the classical state is the quantum state closest to a classical electromagnetic wave." https://books.google.com.sg/books?id=l-l0L8YInA0C&source=gbs_navlinks_s (p375)The worst was indeed the QM section: Photons as little bullets, photo-electric and Compton effects as proof for photons, the Bohr model of the hydrogen atom; in relativity still the velocity-dependent mass etc. etc.
That is laudable but a losing battle, when even Hawking hypes AI http://www.bbc.com/news/technology-30290540.I think, it's of utmost importance to develop better ideas on how to catch high-school students with the beauty of the natural sciences since not only because the interest in STEM subjects is necessary from an economic point of view (unfortunately nearly the only point of view that is nowadays advocated by science and education politicians) but also to have an educated society that understands at least on a qualitative level how modern technology works and what are its advantages and what may be causing problems, etc. etc.
In Australia - yes. It would be taught is grade 10 in the advanced math stream. Even if not in that stream early on in grade 11 as part of Math C or IB Math HL. For those taking an accelerated course that complete normal math grade 11 and do uni subjects grade 12 probably done in grade 9. I think such accelerated students is what this paper is aimed at.One thing the lectures do not seem to explain is complex numbers; they start out by assuming the students already know about those. Is that a valid assumption for high school students?
Yeah, 50 years ago... It's 2018, time to move on with what's really used amongst scientists.Purcell and Feynman were among those who used the velocity-dependent mass.
I was shocked that Susskind as unaware that "The Law of Large Numbers" is a theorem, especially the weak law.There is also this course taught by Leonard Susskind : http://theoreticalminimum.com/courses/quantum-mechanics/2012/winter
http://theoreticalminimum.com/home
Best regards
Patrick
We obviously disagree about this. One should not teach outdated concepts like velocity-dependent mass, even when Feynman (with the greatest didactics in physics after Sommerfeld) uses this concept. Purcell's textbook in the Berkeley physics course series is the only textbook I explicitly discourage students to read, because it's more confusing than helpful. The best book with the same aims, i.e., to teach electrodynamics at the undergrad level relativistically from the very beginning is, Melville Schwartz's book Principles of Electrodynamics (he's a Nobel laureate as Purcell by the way).Photons as bullets are ok, as long as one is also taught the limitations of the model. The textbook by Grynberg and colleagues does say that some single photon states "might be referred to as quasi-particle states, because they are the quantum states whose properties most closely resemble those of an isolated particle propagating at the speed of light, just as the classical state is the quantum state closest to a classical electromagnetic wave." https://books.google.com.sg/books?id=l-l0L8YInA0C&source=gbs_navlinks_s (p375)
Velocity-dependent mass is not wrong, so it is wrong to teach that the velocity-dependent mass is wrong. Purcell and Feynman were among those who used the velocity-dependent mass.
Use of the photo-electric effects etc as proof for photons is wrong, since alternative models exist. Aspect still uses it in his public lectures, but he is careful to say that it does not prove photons, only that all existing models require quantization of either matter or light.
I've no clue, what this has to do with physics didactics. I'm sure it's worth thinking carefully about possible problems of any new technology, but this has nothing to do with physics didactics. It's of course true that to enable people to think about dangers of technology it's mandatory to offer them a good education in the natural sciences and math.That is laudable but a losing battle, when even Hawking hypes AI http://www.bbc.com/news/technology-30290540.
I think "old quantum physics" shouldn't be taught in a physics course at all. One must not teach outdated models but the modern ones to avoid to build up unnecessarily wrong intuitions like photons as little bullets (sorry, I don't see any sense in which the modern concept of photons is compatible with particle-like paradigms at all) or orbits of electrons around a nucleus as a model of atoms. Rightfully, nobody ever discusses to teach Aristotelian physics before teaching Newtonian mechanics. I cannot understand, why one should teach the Bohr model of atoms or why one needs wrong ideas on photons to introduce QT.But to be a bit more serious and to tie in quantum mechanics and thermodynamics like Hawking did, what's your view on teaching "old quantum physics" like Planck's quantization and blackbody radiation? It is of course notable that Planck knew that it did not imply the quantization of light.
...or if you're a Bohmian adherent :P Guided bullets, that is ;)Photons as bullets are ok, as long as one is also taught the limitations of the model...
I still do not understand how electromagnetic spectrum with different wavelengths of a photon particle can be explained as a particle with a wave function, separate but from the same particle. If both mechanical and quantum are both true. There has to be a resolution to those opposing ideas. If the mass of the photon is so infinitesimal to not have a relevant value in mathematical calculations, then is it the energy that the photon results from that causes the different wavelengths.Photons as bullets are ok, as long as one is also taught the limitations of the model. The textbook by Grynberg and colleagues does say that some single photon states "might be referred to as quasi-particle states, because they are the quantum states whose properties most closely resemble those of an isolated particle propagating at the speed of light, just as the classical state is the quantum state closest to a classical electromagnetic wave." https://books.google.com.sg/books?id=l-l0L8YInA0C&source=gbs_navlinks_s (p375)
Velocity-dependent mass is not wrong, so it is wrong to teach that the velocity-dependent mass is wrong. Purcell and Feynman were among those who used the velocity-dependent mass.
Use of the photo-electric effects etc as proof for photons is wrong, since alternative models exist. Aspect still uses it in his public lectures, but he is careful to say that it does not prove photons, only that all existing models require quantization of either matter or light.
https://arxiv.org/abs/1312.4057I think "old quantum physics" shouldn't be taught in a physics course at all. One must not teach outdated models but the modern ones to avoid to build up unnecessarily wrong intuitions like photons as little bullets (sorry, I don't see any sense in which the modern concept of photons is compatible with particle-like paradigms at all) or orbits of electrons around a nucleus as a model of atoms. Rightfully, nobody ever discusses to teach Aristotelian physics before teaching Newtonian mechanics. I cannot understand, why one should teach the Bohr model of atoms or why one needs wrong ideas on photons to introduce QT.
Yes, I agree, that's what I mean by teaching old quantum physics (and that's how I was taught it too).On the other hand, it's also important to teach some history of science and how modern science has been developed, and this should include also the history of quantum theory (in fact, it's hard to motivate the quite abstract formulation of modern quantum theory without arguing with the historical development of the subject) and thus "old quantum mechanics", but it should be taught as the way how modern quantum theory has been finally discoved in 1925/26 and that the physicists at the time were forced to give up the classical-physics intuitions by observations and experiments. It's also good to know that the great physicists involved with it, among them Bohr and Einstein, knew very well that "old quantum mechanics" is not satisfactory. Einstein even didn't think that modern quantum theory is satisfactory at all, and until the end of his live he tried to get a more satisfactory picture about "photons" and of course to formulate all of physics in a unified classical field theory with no success, and today the best theory we have is quantum theory. That it is not the final theory is also pretty probable. However, we have no clue, how a better theory might look. The irony is that so far the standard model of particle physics is too successful in describing all outcomes of experiments at the available energies (including the LHC) to get a handle on physics beyond the standard model.
Interesting! I'll have a look. Concerning the didactics, I'd say there's some justification for not teaching Aristotelian physics but Newtonian physics in the abstract:https://arxiv.org/abs/1312.4057
Aristotle's Physics: a Physicist's Look
Carlo Rovelli
Well, our highschool teacher told us from the very beginning that she has to teach it, because it's part of the mandatory curriculum. She also let no doubt about what opinion she had concerning this curriculum ;-)). Of course, one must say, that she was a postdoc in atomic physics before she became a highschool teacher, and that's why she also taught us the Schrödinger equation, including some of the most simple cases for energy-eigenvalue problems like the rigid box and the harmonic oscillator. She was the best teacher in highschool I had, and I guess it's much because of her that I studied finally physics rather than electrical engineering, which I wanted to do first, because I liked tinkering with simple electronics ;-))).Yes, I agree, that's what I mean by teaching old quantum physics (and that's how I was taught it too).
I guess one runs into trouble concerning, among others, Newton-Wigner localisation, right?I've not yet seen any convincing application of the Bohmian interpretation of QT to relativistic QFT, particularly not one with photons, i.e., massless spin-1 fields.
They aren't. The photon is not a "particle".If both mechanical and quantum are both true
Photons as bullets are ok, ...
atyy I know how you feel. I was recently criticized by the NRA for saying bullets are like big phat photons. They have wave properties and disperse, interfering with innocent bystanders.wrong intuitions like photons as little bullets
Do you mean Melvin Schwartz's Principles of Electrodynamics?Melville Schwartz's book Principles of Electrodynamics