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So you want to learn physics (2021)

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Re: So you want to learn physics (2021)

#81

Post by meristem »

amluto wrote: post #65

This has the same omission that my undergrad program had: continuum mechanics. Even just the very basics (pressure, velocity, etc in a moving, non-equilibrium system) and translating between the terminology used by different science and engineering fields (static pressure, total pressure, velocity pressure, stagnation pressure, hydrostatic pressure, dynamic pressure, plain old pressure, head, oh my!) is very useful.…

Do you have text/other sources suggestions for this? I agree with you, would like to learn more.

Re: So you want to learn physics (2021)

#82

Post by aleph_minus_one »

brightlancer wrote: post #66
javajosh wrote: post #24

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…

> What I'd like to see more of in physics texts is presenting a problem before offering the solution. Yes. > If you present the hard problem first, the student may flail around and realize: I need something to help with this! Now that they know they need it, and why, you can give them the tool that fits the bill. No. If an instructor deliberately gives a student a problem that they know the student _cannot_ solve, th…

> If an instructor deliberately gives a student a problem that they know the student _cannot_ solve, then it rightfully destroys trust.

This does not destroy trust, but gives the student an important lesson: we only have the techniques to solve, say, 0.0000001% of the problems. So you have to learn brutally hard for the next many years (or rather decades) to have the minimal qualifications to be able to invent whole new techniques that no person has ever come up in history before to increase this ratio from, say,to 0.000000100000000001% (even this would trigger a whole new aera in the history of science).

Re: So you want to learn physics (2021)

#83

Post by cgh »

To help with some of the math required by general relativity, there's a good series on YouTube by the user "eigenchris" on tensor calculus, which I found helpful for a geometric intuition of what's going on. He also has a series on GR itself, which I haven't watched yet. If you're interested in learning GR and want specific information on the area of differential geometry you'll need to understand it, then this series is a great start.

Re: So you want to learn physics (2021)

#84

Post by btrettel »

lanza wrote: post #77
btrettel wrote: post #31

Earlier quoted context omitted.

I've noticed before that "physics" as in what is taught for a physics degree has gaps which make little sense to me as a mechanical engineer. Continuum mechanics (including both fluid and solid mechanics) is unfortunately nearly entirely absent aside from some basic things like Hooke's law and Bernoulli's principle. In my view, what's taught for a physics degree is more of a historical accident than a selection of th…

A physics undergraduate degree is different than a lot of degrees in that it's 100% incomplete for the purpose of training towards a real profession. Nobody hires physics bachelors. It's just the four year mark of your studies to be a 8+ year trained physicist. And for that purpose of being an intermediate degree to becoming a physics PhD, Navier-Stokes isn't relevant. You don't use it in most fields that are generat…

> You don't use [Navier-Stokes] in most fields that are generating physics PhDs in the 2000s and beyond.

That's because physics degrees don't include much on fluid dynamics. If someone wants to get a PhD in fluid dynamics, they probably get a PhD in some variety of engineering. This goes back to what I said about the physics curriculum seeming weird to me, as it it's not about "physics" in itself. It's more a random selection of topics that exists for historical reasons.

> There's only so much time to teach somebody in four years and there are significantly more important things that are also being left out (e.g. more thorough courses on group theory).

In another comment, you said that you don't know what the Navier-Stokes equations are. Given that, I don't think you're in a good position to judge their value.

I have a couple of group theory books myself, and I don't agree with your assessment that group theory should get priority over fluid dynamics.

Re: So you want to learn physics (2021)

#85

Post by shanusmagnus »

BenFranklin100 wrote: post #26
qsort wrote: 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…

I only became reasonably proficient in physics when I took the summer off between undergrad and graduate school and spent three months, six days a week, ten hours a day, doing nothing but working through four years of undergraduate physics curriculum by solving problems from my textbooks. There is no substitute for solving problems.

Like another commenter, I'm curious what drove you to this. Seems like clearly A Good Idea I Could Have Benefited From, but my attitude was always: I finished the class, whatever I need to learn through application, life will point me toward. Yet I wish I had done something similar to what you did. What gave you the impetus?

Re: So you want to learn physics (2021)

#86

Post by antegamisou »

meristem wrote: post #81
amluto wrote: post #65

This has the same omission that my undergrad program had: continuum mechanics. Even just the very basics (pressure, velocity, etc in a moving, non-equilibrium system) and translating between the terminology used by different science and engineering fields (static pressure, total pressure, velocity pressure, stagnation pressure, hydrostatic pressure, dynamic pressure, plain old pressure, head, oh my!) is very useful.…

Do you have text/other sources suggestions for this? I agree with you, would like to learn more.

Halliday & Resnick Fundamentals of Physics is what we used in AP as well as in freshman year at college. Covers most sections one needs to be familiar with to be physics literate (solid/fluid mechanics, waves, thermo, electromagnetism, optics, relativity).

Re: So you want to learn physics (2021)

#87

Post by TheCleric »

javajosh wrote: post #56
remote_phone wrote: post #46

Earlier quoted context omitted.

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.

As someone who had an a similar experience to whom you are replying to, this was definitely not the case. The problems were easy, but were not "zero effort". Even if it takes you only a few minutes to do the steps and show the work per problem, then that could still take you 30-60 minutes to complete the assignment. That was time I'd spend doing things I wanted to do (fun in the short term, a nightmare in the long term).

Re: So you want to learn physics (2021)

#88

Post by antegamisou »

belugacat wrote: post #22
qsort wrote: 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…

That’s a POV I’ve grown to adopt as I got older (like many, perhaps). I used to heavily privilege theory, believing that everything could (and maybe should) be derived from first principles. Now I place the concrete over everything else; theory is nice when it can illuminate why the practice works. Otherwise, it’s just words. The most frustrating is when I have friends who have derived their entire understanding of a…

[flagged]

Re: So you want to learn physics (2021)

#89

Post by Qem »

markus_zhang wrote: post #60
qsort wrote: 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.

> 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.

Many textbooks still employ the deplorable practice of not presenting the answer to all exercises at the end, unfortunately.

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