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So you want to learn physics (2021)

susanrigetti.com

51–60 of 170 posts

Re: So you want to learn physics (2021)

#51

So happy to see the love for Griffith’s Intro to Electrodynamics. I know it gets dinged for not being sufficiently rigorous, but I’ve never read another math or science textbook that did as good a job of getting a beginner to truly understand the subject.

In what way is it not rigorous? I've never read it but it definitely seems interesting to have a "good" but non-rigorous science book. Does it just hand-wave over some things to get to other important topics?

Re: So you want to learn physics (2021)

#52

Earlier quoted context omitted.

Yes, and I'd take it further. What I'd like to see more of in physics texts is presenting a problem before offering the solution. Too often you get what amounts to a laundry list of techniques and ideas, which are the components to the answers to hard problems, but the student isn't motivated to learn them. If you present the hard problem first, the student may flail around and realize: I need something to help with…

> If you present the hard problem first, the student may flail around and realize: I need something to help with this! I suffer from this. Sure, I'd like to learn physics, but what I don't want to do is learn all of it. Right now. Because what I'd rather learn is what I need to solve the problem I have. It's a silly problem, it's not real world, but it's my problem that I'd like solved. As I've grabbed my horse and l…

You might dig “The Theoretical Minimum” by Susskind, as well as his follow-on books. And he has associated lectures on YouTube.

Re: So you want to learn physics (2021)

#53
post #51

So happy to see the love for Griffith’s Intro to Electrodynamics. I know it gets dinged for not being sufficiently rigorous, but I’ve never read another math or science textbook that did as good a job of getting a beginner to truly understand the subject.

In what way is it not rigorous? I've never read it but it definitely seems interesting to have a "good" but non-rigorous science book. Does it just hand-wave over some things to get to other important topics?

I didn’t think so, but it’s the text I used as an undergrad, so I don’t have a basis for comparison. I just have seen that criticism pop up on HN when this topic has arisen in the past.

Re: So you want to learn physics (2021)

#54

I dropped out of Physics back in the day, because I loved computers a bit more, and now that I'm kind of fed up with computers I'd like to remove the thorn and do something like this. But I find that so much time has passed that I would need to brush up parts of my high school maths first, and this kind of discourages me before even starting.

I decided to start self learning theoretical physics late last year. I have been now studying physics every day for almost a year (before and after work). I did have to brush up on calculus and matrices but it came back very quickly (within a few days) after a 25 year gap so I'd say don't let that discourage you.

Excellent discipline. What topic are you focussing on?

Re: So you want to learn physics (2021)

#55

It’s a decent list but thermodynamics is introduced way too late in the list (after modern and quantum wtf) and fluid dynamics and fluid mechanics including aerodynamics is entirely missing. If you have a physics education (I have an engineering education) can you tell me if you can really get a physics degree without bumping into Bernoulli or Navier-Stokes? At least just to see the lay of the land.

The order seems fine to me.

Thermodynamics/statistical mechanics was taught as a junior level class at my undergraduate alma mater. During that year, students would take electrodynamics, classical mechanics, and statistical mechanics as separate classes in some loose order, although of course simpler versions of these topics would have been introduced in first year physics.

The lack of fluid mechanics also, unfortunately, tracks with my experience.

Re: So you want to learn physics (2021)

#56
post #3

A point that's rightfully emphasized by the author: > Solving problems is the only way to understand physics. There's no way around it. This generalizes well to other fields. I don't want to discourage anybody from trying to educate themselves in a difficult field (be it physics or something else), but that's a very common and immediately visible problem with autodidacts. If you haven't worked through enough hard pro…

In college, I was always the first one out of my friends to “get” a concept, like fast Fourier transforms, anything with signal processing or even coding or any labs we had to do etc so I would spend time teaching them in the library. However I never did any of the exercises, mostly due to laziness and not arrogance. They would get A’s and I would get C’s and D’s. I emphasize this story to my kids because knowing isn…

I think this shows a lack of self-doubt, which can be deadly. Those problems acted as verification to yourself that you understood the theory and its application. If you truly understood the material, then the problems would be zero effort. However, if you struggled with them it's a signal that you don't know what you think you know.

Re: So you want to learn physics (2021)

#57
Surprised to not find Tong's notes for qft [1] (his other notes are great too). That's the only clear source of introductory QFT (and I have none for advanced QFT). Of course the only real way to learn QFT is to learn it multiple times from various sources, but you usually have exam after the first one, and Tong may get you through it.

[1] https://www.damtp.cam.ac.uk/user/tong/qft.html

Re: So you want to learn physics (2021)

#58

It’s a decent list but thermodynamics is introduced way too late in the list (after modern and quantum wtf) and fluid dynamics and fluid mechanics including aerodynamics is entirely missing. If you have a physics education (I have an engineering education) can you tell me if you can really get a physics degree without bumping into Bernoulli or Navier-Stokes? At least just to see the lay of the land.

Thermodynamics is usually (and rightfully so) taught together with statistical physics for which quantum mechanics is essential, so the order does make sense.

Re: So you want to learn physics (2021)

#59
post #50

> they are and have been dreadfully underserved and underestimated by the academic physics community (who do not take them seriously because they aren’t studying at colleges and universities) This stuck out, pretty rigorous if all you want to satisfy your curiosity. If you want to actually apply any of the hard work you put in, you need a degree. I think that is the most interesting part of learning anything, applyin…

> That killed my motivation for putting effort into most things, pretty much except computer science where we are still ok with trusting self taught people for some reason.

100% same, except computers bore me to death now. I would even be willing to go back to school at this point if it wasn’t tens of thousands of dollars.

Re: So you want to learn physics (2021)

#60
post #3

A point that's rightfully emphasized by the author: > Solving problems is the only way to understand physics. There's no way around it. This generalizes well to other fields. I don't want to discourage anybody from trying to educate themselves in a difficult field (be it physics or something else), but that's a very common and immediately visible problem with autodidacts. If you haven't worked through enough hard pro…

It used to pose as a difficulty for self leaners because they did not have access to assignments, exams and solutions unless they register for classes.

Nowadays it's a lot easier when there are so many free materials from top school online. And stack exchange and reddit is available almost 24-7 if one ever has a question.

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