Quantum Could you finish a course in QM (using Griffiths) with another book?

[solklar]

Hello!

I was wondering if there'd be any problems using another QM book (like Shankar, Ballentine etc) in a course where the standard literature is Griffiths Introduction to Quantum Mechanics? By that I mean is there ever any disadvantages to going to a more advanced textbook (assuming you still understand it well) at the point where it could become difficult to finish the course?

I was wondering mainly over the difference between wave-function approach and state approach. Do you think there are a lot of things regarding wave-functions that is not covered in a state based book? I'm asking this because 6 months after this course I will read another course that is using more advanced books and I don't want to buy both books if I could get away using one.

Edit: Assume I could comprehend a more advanced book

 

[Dr Transport]

the instructor picked a text for a reason, you should use it and not wanting to purchase both texts isn't a reason.

 

[mpresic3]

Perhaps you could get Griffith second-hand or from a library, if you do not like the cost. I had a quantum mechanics prof who refused to use Griffith because he also felt it cost too much. He asked the graduates in his class to recommend another textbook for the next semester when he would be teaching undergrads.

Your prof will probably assign problems out of Griffith or follow the text, so there may be no way around it. Perhaps you can ask the professor about why Griffith is chosen, and express the problems you are having in preferring the state space approach over wave-function. (S)He may even appreciate that you are interested enough and familiar enough with the subject to realize that higher level QM deals mostly with state space.

Do not worry about learning about wavefunctions though. When I went to school >40 years ago, many of us undergrads were so anxious to learn QM, we took physical chemistry from the chemistry department to learn it a semester sooner. Physical chemistry was mostly baby QM, (mainly because it was not the whole semester). That used the wavefunction approach. I never felt learning a little extra was a bad thing.

 

[Vanadium 50]

I'm confused - is your position that you can use a more advanced textbook because you already know what's going to be taught? If that's the case, why do you care? Or are you saying you don't know the material, but want to learn it from a text that assumes you already do. That's not likely to work either.

 

[solklar]

the instructor picked a text for a reason, you should use it and not wanting to purchase both texts isn't a reason.

Probably he chose it because it's an easy introduction and the majority of people in the class won't go on to take the second course (won't go into theoretical physics) so they don't want it too advanced. In none of my classes have I ever felt a very strong need to use the exact textbook the professor recommends, but that may be because I'm not in the US either and our textbook industry is not the same as yours. However in other classes most textbooks uses the exact same approach.

We have a lot of lectures and get printed assigned problems even if we don't buy the book.

I'm confused - is your position that you can use a more advanced textbook because you already know what's going to be taught? If that's the case, why do you care? Or are you saying you don't know the material, but want to learn it from a text that assumes you already do. That's not likely to work either.

No my position is that I was not asking about wether or not I could understand another book, because I felt that would derail the discussion. Instead I was only worrying about what you could possibly miss if you start out with a state-based approach instead of wave function. I know it's perfectly legitimate to start learning the state version, so I was wondering what the major differences could be in problem solving.

This is a general class at my university (although only STEM) and it includes people who won't go on to study physics, and those who do will take another class 6 months later that is more rigorous and using states. I have also heard negative opinions about Griffiths, so that's why I would rather get another book.

Edit: I have also had a large Modern Physics course where we learned about wave functions and solved the hydrogen atom etc, so this won't be the first time I see wave functions. We also have a really strong math department so most of us are proficient in (abstract) linear algebra and ODE/PDEs.

 

[vanhees71]

I would advise to read a 2nd textbook on the side as soon as Griffiths starts to get confusing. I don't know the book too well, but judging from the confusion it causes students participating in this forum because of too much sloppiness, I guess it's a good idea to read a 2nd textbook on the side.