# Memorizing Equations

1. Aug 16, 2014

### pierce15

Hello. I'm not quite sure where to post this, so sorry if this is the wrong place. I come to you today as a self-studier of quantum mechanics. If I want to be a good physicist, should I commit all of the equations to memory? (e.g. wavefunctions for all the different common potentials and the associated energy spectra.)

Edit: this goes for all of physics, not just QM; my recent studies have pushed my capabilities, so before I proceed to memorize everything I would like to know whether it is considered most professional to do so.

Last edited: Aug 16, 2014
2. Aug 17, 2014

### ShayanJ

No. Memorizing equations doesn't help in anything!
You should understand the equations deeply and learn how to use them.

3. Aug 17, 2014

### Simon Bridge

No.

You will find the equations you use a lot will end up memorized anyway - but it is not something you should be primarily worried about. Professionalism has nothing to do with it - it's just not practical: there's thousands of the things!

If you are good at memorizing, then memorize the physics: the relationships.
The maths should be thought of as a language for describing physics - not as a bunch of equations and formulae to be applied to the appropriate situations.

Of course, professionally speaking, if you are being paid to work in a field, you will be expected to have the basic tools of that field at your fingertips.

4. Aug 17, 2014

### voko

As Simon Bridge said, physics has a language. And that language is mathematics. Using classical mechanics as a simpler example, a minimal understanding of it requires the knowledge of momentum, energy, Newton's laws. These are all expressible as equations, but they can also be stated verbally without much problem, so one could argue that mathematics is avoidable at that level. A more advanced level of knowledge needs the least-action principle and the Euler-Lagrange equations; these, while can be formally "specified verbally", do not make any sense at all (regardless of the amount of hand-waving involved) unless dealt with as equations. Not knowing the latter equations means simply that one does not possess the advanced understanding of classical mechanics, plain and simple.

The bottom line: you can know some physics without memorizing any equations; but knowing more advanced physics requires memorizing some equations. With some practice and with a decent textbook, it is usually fairly clear what is worth memorizing.

5. Aug 17, 2014

### ZealScience

No, I don't think so, especially for the wavefunctions which are only specific solutions. In terms of doing a proper exam, they might help to save you some time...but since you are self-studying, it would only be a waste of time. However, I do suggest that you have some sense of the general form of the wavefunctions so that certain interpretations could be made more easily.

For the actual equations, I think it would be handy to memorize the important ones; this is only for the pragmatic purpose of efficiency so that you don't have to rederive them every time. Usually, by reading sufficient materials you would become familiar with them spontaneously.

6. Aug 17, 2014

### pierce15

All right. Thanks a lot for the input, everyone.