## How important are derivations and proofs?

InquilineKea
Posts: 301
Joined: Sun Mar 21, 2010 9:07 pm

### How important are derivations and proofs?

Derivations are, of course, very important for basic classical mechanics.

But what about things beyond that? What about derivations for the solutions of the hydrogen atom? Or other upper-level derivations/proofs?

grae313
Posts: 2296
Joined: Tue May 29, 2007 8:46 pm

### Re: How important are derivations and proofs?

Important to what?

HappyQuark
Posts: 762
Joined: Thu Apr 16, 2009 2:08 am

### Re: How important are derivations and proofs?

InquilineKea wrote:Derivations are, of course, very important for basic classical mechanics.

But what about things beyond that? What about derivations for the solutions of the hydrogen atom? Or other upper-level derivations/proofs?
Important to a balanced breakfast? Crucial

Important to physics? Not really.

Or maybe I've mixed the two up, again.

InquilineKea
Posts: 301
Joined: Sun Mar 21, 2010 9:07 pm

### Re: How important are derivations and proofs?

Okay sorry, I meant, important for doing well on the Physics GRE.

i mean, most of the time, you're just plugging in equations you've memorized. Deriving them takes valuable time, and it's better to memorize the core equations just for the test. But sometimes it might be helpful to derive something?

The_Duck
Posts: 41
Joined: Tue Nov 16, 2010 12:04 pm

### Re: How important are derivations and proofs?

It's a multiple-choice test on which you have less than two minutes to get a numerical answer to each question, except for a couple of conceptual questions. You better not be working through very many derivations during the test.

Working through derivations in your studying is very good because you see why the formulas come out the way they do, and you're more likely to remember them. E.g., If you've worked through the solutions to the hydrogen atom and harmonic oscillator and infinite square well on your own, you'll easily be able to answer the inevitable questions about their energy levels.

Posts: 233
Joined: Sun Jul 05, 2009 9:17 am

### Re: How important are derivations and proofs?

InquilineKea wrote:Okay sorry, I meant, important for doing well on the Physics GRE.
If your aim is "just" to fair well on the physics GRE, tell the proofs to go to hell. But if your aim is to be a physicist, there is no shortcut. Choose wisely!

physics_auth
Posts: 163
Joined: Sat Jul 18, 2009 7:24 pm

### Re: How important are derivations and proofs?

InquilineKea wrote:Okay sorry, I meant, important for doing well on the Physics GRE.

i mean, most of the time, you're just plugging in equations you've memorized. Deriving them takes valuable time, and it's better to memorize the core equations just for the test. But sometimes it might be helpful to derive something?

If you spend time reading derivations and proofs ... I guess that you don't know how to prepare yourself for that test. You have to be as abstractive as possible if you want to survive!

grae313
Posts: 2296
Joined: Tue May 29, 2007 8:46 pm

### Re: How important are derivations and proofs?

I hope you're aware that you shouldn't be deriving anything at the actual test in which case I'll interpret your question as "are derivations a useful studying tool for the pGRE". I would say yes, if you have the time. As has already been pointed out, memorization changes to knowing (always superior) when you understand really well the why's and how's of something. In addition, if you know where certain terms in an equation are coming from, you'll be able to modify the equation if a new variation on the old situation comes up. If you're short on time, no way. Work practice problems.