How Much Physics Can You Feasibly Learn When Self-Studying?

[gibberingmouther]

i started out learning physics for fun with maxwell's equations because partially i wanted to expand my understanding of electronics. i spiderwebbed around on the internet trying to learn the math to understand the equations. i learned some things but i still didn't have it all down before i decided last Friday to start going through a physics textbook i own. I've been making good progress since then working on it each day. i make sure to understand the derivation (algebraically, graphically, and conceptually - whatever that may mean exactly) before i move on to the next thing. so far i have gotten to the section on conservation of momentum and collisions. I've still got momentum (lol) so I'm going to keep going. it's fun! and i still have to take physics for my major so it'll help with that as well.

i'm on page 263 of an approximately 1500 page textbook. i know there's a lot to learn. after you've studied a certain amount of physics and math you develop a familiarity with it. i guess people who go on to do original work in physics (like for a phd) develop that familiarity and know just enough to extrapolate and do some new research? that's kind of how i imagine it working would you guys who know say that is accurate?

anyway, the idea for this thread came from those considerations and finally from looking at this link that contains a list of equations: https://physics.info/equations/

i mean, holy crap! that's a lot of equations. how much of it is feasible to learn? do you skip certain parts of it, like optics let's say, because you don't really need to know it?

 

[Borek]

holy crap! that's a lot of equations.

It is not. Many of them are quite easy to derive from the basic principles. Some of them are plain stupid IMHO, it doesn't make sense to list two different forms when one is perfectly sufficient, as the other follows from the definition of the average value.

You don't have to remember how much is 345*876, it is enough to learn the basic multiplication table and methods to multiply any two numbers.

At the same time - there are way more equations, as many problems can be tackled using different methods. As long as they give the same result they are perfectly valid, but they can be quite different when it comes to methodology and calculations, and sometimes choosing the right approach is half of the success. But I doubt anyone knows them all, in every branch o physics, that's where specialization comes into play.

 

[Dishsoap]

Most graduate students I know keep a copy of major undergrad textbooks in their offices - there are always equations and concepts that you don't know, but that you can look up if necessary. I would partially agree that people who do "original work" in physics do have a familiarity with physics, but it's not some vague familiarity with the field in general, but a solid knowledge of the basics.

Here's an example - yesterday, for some work I'm doing, I was reading up on piezoelectric materials (their electrical properties change if you squeeze them, for instance). Because in undergrad I learned about how electric dipoles work and how atoms are arranged in different materials, understanding the concept took me 30 seconds. If I didn't have a firm knowledge of the basics, then encountering something outside my field of study would have crippled me.

I'm curious, can you tell us which textbook you are using? There are a standard few textbooks that we recommend here at PF for self-studying physics, and you might be making your life more difficult than necessary :)

 

[gibberingmouther]

I'm curious, can you tell us which textbook you are using? There are a standard few textbooks that we recommend here at PF for self-studying physics, and you might be making your life more difficult than necessary :)

i'm using Sears and Zemansky's "University Physics with Modern Physics". i like it a lot so far. i still use the internet for some things, like if i need more context about a derivation. I've done some of the problems (there are good already solved example problems in the book as well as many other suggested exercises). it seems like if you understand the concepts and equation derivations, doing the problems is not hard.

 

[BvU]

holy crap! that's a lot of equations

I agree with Borek: it's not much. And if you keep going the way you do you'll agree after a while. It's like learning languages: you don't read dictionaries from cover to cover, and a grammar isn't pleasant reading either. You laern a few things that help you learn other things and gradually you can read simple texts, then more complicated stuff. But the best way is to listen and talk -- projected on physics: read the text and do the exercises. PF is here for you when you get stuck

Hats off for your enterprise !

Good luck !

 

[Integral]

You should have a calculus book as well. Calculus is the language of physics, learn it.