Do I need Classical mechanics and waves in order to understand Quantum mechanics????

Robert1986

As a math guy, allow me to give my two cents. First of all, it makes no sense to teach QM to students who are not physics majors (that is, of course, unless they WANT to take it, then they can just sign up.) It is far more sensible to teach us uninitiated folks the classical stuff, since, as someone pointed out, we can touch blocks in a way that is difficult to do with atoms. My two semesters of Physics gave me a pretty good understanding of classical stuff. That being said, I plan to take QM as a grad student.

Secondly, to me, teaching QM then Classical stuff is a bit like teaching Analysis and then Calculus. In principle, it can be done, but analysis requires a certain amount of mathematical maturity just as QM requires a certain amount of "physical maturity."

Jorriss

Quote by Robert1986

Secondly, to me, teaching QM then Classical stuff is a bit like teaching Analysis and then Calculus. In principle, it can be done, but analysis requires a certain amount of mathematical maturity just as QM requires a certain amount of "physical maturity."

Imo, this is a very well put comparison.

bpatrick

I don't see anything wrong with the current system, but I also think there are many ways to go about learning that can be just as effective. I was fine with learning loads of math and chemistry concurrently, then simply jumping into "upper level undergraduate" physics.

I had multivariable calc, statistics, linear algebra, ODEs, PDEs, and combinatorics/graph theory ... then took quantum mechanics and statistical mechanics in the same semester without having taken any physics courses other than a high school algebra physics overview.

I didn't have much trouble learning physics that way. I guess there were a few things that were harder for me to tackle since it was the first time I was seeing much of the material. My chemistry background helped out a bit for that, but not as much as a physics sequence would have. At least I had the necessary math preparation, there were some guys in the course who struggled due to issues they were having with their mathematics preparation.

Mike H

Quote by Robert1986

It is far more sensible to teach us uninitiated folks the classical stuff, since, as someone pointed out, we can touch blocks in a way that is difficult to do with atoms.

Perhaps this is an argument for more thoughtfully devised physics/chemistry laboratory experiences & courses for students.

One of the most memorable scientific experiences I had an as an undergraduate was doing ESR studies of organic dyes bound to proteins (admittedly, this was in the lab where I did my undergraduate research and not in a standard laboratory course), and being able to predict (qualitatively) spectral changes using a simple "particle in a box" model. When it actually panned out, I was rather excited.

Einstein Mcfly

Quote by Einstein Mcfly

Sorry to dig up such an old thread, but I found this discussion really interesting. I've long thought that the way things are taught is a relic of some earlier time and (at least with chemistry) you end up teaching a lot of things to young undergrads that are dumbed down or made slick for the purposes of comprehension that they will have to basically unlearn later on in their undergraduate (or certainly graduate) career. Things like the Bohr atom that does nothing but cater to their classical prejudices and give exactly the wrong idea of how to best picture an electron are kept around only to make life harder for the poor graduate TAs that end up spending all the time telling them that what what they "know" is just a silly cartoon.

Anyway, I'm interested in two things: 1) How to best avoid teaching things in this way in a era when lessons are constrained by standardized tests that expect students to be ready for plug and chug type questions involving semi to totally incorrect concepts and 2) what's a good textbook (advance undergrad or graduate level is fine) that discusses classical mechanics as the macroscopic limit of QM?

Thanks for any help.

Anyone?

homeomorphic

Quantum mechanics seems kind of "out of left field" to me without knowing something about Hamiltonian mechanics and waves. Schrodinger's equation has a Hamiltonian operator in it that comes from quantizing a classical Hamiltonian. So, yes, I think you have to know classical mechanics to understand quantum mechanics. Otherwise, you'll be missing a lot of motivation, I think.

Similar Threads for: Do I need Classical mechanics and waves in order to understand Quantum mechanics????
Thread	Forum	Replies
hydrogen atom obeying classical mechanics rather than quantum mechanics	Introductory Physics Homework	6
Quantum mechanics vs Classical mechanics	General Physics	5
Classical vs Quantum Mechanics	General Physics	1
classical and quantum mechanics	General Physics	6

homeomorphic	Quantum mechanics seems kind of "out of left field" to me without knowing something about Hamiltonian mechanics and waves. Schrodinger's equation has a Hamiltonian operator in it that comes from quantizing a classical Hamiltonian. So, yes, I think you have to know classical mechanics to understand quantum mechanics. Otherwise, you'll be missing a lot of motivation, I think.