Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Ask HN: How to self-study physics?

news.ycombinator.com

Post reply on HN
Print view View original

161–170 of 194 posts

Re: Ask HN: How to self-study physics?

#161

Post by throwqwerty »

hriir0 wrote: post #135
throwqwerty wrote: post #129

Earlier quoted context omitted.

academic virtue signaling. like people recommending TAOCP to people that don't know how to program or rudin (either one!) to people that don't know any math.

Interesting. To me that’s just a subjective list the author likes. The replies seem a bit on the level of “...but everyone knows really.” I always took notions like “expert” virtue signaling to mean experts seem convinced we should all learn via the timelines they did. Uni students versed in textbook physics, linear timelines for learning cause that’s how society taught them, are also experts in working cognitive the…

>To me that’s just a subjective list the author likes.

but the prompt isn't "list some books you like" but "how should I learn" so there's obviously intent in picking those books.

Re: Ask HN: How to self-study physics?

#162

Post by op03 »

andrepd wrote: post #97
petermcneeley wrote: post #84

Earlier quoted context omitted.

"I'd suggest not actually trying to simulate physical systems on a computer" I cannot disagree enough with this statement. I am double major in Physics and CS. There are two kinds of physics, Math and Physics. Most of what you learn in uni physics is Math. But the Math is only one (outdated) description of the nature of physical law. Leonard Susskind himself has said on multiple occasions that the equations of physic…

And I cannot disagree enough with your comment. > There are two kinds of physics, Math and Physics. Most of what you learn in uni physics is Math. But the Math is only one (outdated) description of the nature of physical law. Lord knows what you mean by this. By "math physics" do you mean theoretical, and by "physics physics" the experimental part? Even then, this doesn't make any sense. Every physics course teaches…

Faraday did a lot of "self studying of Physics". He was a book binder who didn't know any Math (had to drop out of school at 13). The reason he got into it was not because he read a Physics or Math textbook or worked out math problems, but because some one liked the way he bound books and gave him a ticket to a Humphrey Davy talk at the Royal Institution. Thats all it took to get into Physics.

Without him dreaming up his experiments and tinkering away, god knows when Maxwell's equations would have been discovered.

Why did we have to wait for a Faraday to show up to do his simple experiments? How come all the natural philosophers and mathematicians of the age, around the whole planet, had not thought to do them?

If Faraday had asked that bunch how do I self-study physics the answers wouldn't have been too different to what we see today.

Today's version of Faraday could very well be some kid hacking away at some computer game, dreaming up scenarios, exercising imagination and cooking up experiments in the same way Faraday did.

Re: Ask HN: How to self-study physics?

#163

Post by abdullahkhalids »

mindcrime wrote: post #152
abdullahkhalids wrote: post #149

Earlier quoted context omitted.

I disagree with you. I teach physics. Everyone interested in physics should read the Feynman lectures, but they are neither sufficient or necessary to understand physics. They are merely oomph on top of already good understanding. Let's imagine physics=boxing. No amount of reading boxing books, or watching boxing videos is going to teach you any boxing. To learn boxing you have to throw 10,000 punches. To learn physi…

Let's imagine physics=boxing. No amount of reading boxing books, or watching boxing videos is going to teach you any boxing. To learn boxing you have to throw 10,000 punches. To learn physics, you need to solve 1000s of questions. I'm not sure that this is a very good analogy. You can buy a heavy bag, and go out in your garage and throw 10000 punches - with no instruction - and still not know how to throw a proper pu…

> learn some technique,

Exactly. Feynman lectures tell you what the laws are, and why they make intuitive sense. They don't tell you how to apply the laws to a wide variety of scenarios, even those not discussed in the book. Physics textbooks like Haliday & Resnick do exactly this; briefly state the law and then teach you how to apply the law.

But merely reading those textbooks won't help you either. You still have to turn to the exercises and solve a bunch of questions correctly to actually learn.

Re: Ask HN: How to self-study physics?

#164

Post by AnthonBerg »

abdullahkhalids wrote: post #149
AnthonBerg wrote: post #111

Earlier quoted context omitted.

We all learn differently. Please don't deal in pedagogical certainties that may close doors unventured. Feynman's lectures were crucially eye-opening for me and many others.

I disagree with you. I teach physics. Everyone interested in physics should read the Feynman lectures, but they are neither sufficient or necessary to understand physics. They are merely oomph on top of already good understanding. Let's imagine physics=boxing. No amount of reading boxing books, or watching boxing videos is going to teach you any boxing. To learn boxing you have to throw 10,000 punches. To learn physi…

> Everyone interested in physics should read the Feynman lectures, but they are neither sufficient or necessary to understand physics

We actually agree, almost perfectly.

I contend that for some, including myself, they are an incredibly powerful tool for building an intuition. Not only after other studies, but during and before as well.

You say your part as someone who teaches, and that's important. Conversely, I say my part as someone who has learned and is learning.

But we are in almost perfect agreement.

Re: Ask HN: How to self-study physics?

#165

Post by dorchadas »

Hasz wrote: post #127

I would like to add one of my favorite mathematical "cookbooks" -- "Mathematical Methods in the Physical Sciences" by Mary Boas. Bad Integrals? Tensor Analysis? Fancy functions and special polynomials? PDE tricks? Boas has solutions! Methods are practically explained and succinct. It's my favorite book to brush up on a old technique or learn some new methods. Wolfram's Mathworld is also a good reference, but not as m…

This is the book we started to use in my Mathematical Methods in Physics course. It was good, but the professor decided (rightly, in my opinion) to focus more on working from linear algebra/differential equations textbooks so I never went through it. Might pull it back out and do that.

Re: Ask HN: How to self-study physics?

#166

Post by madhadron »

gaze wrote: post #80
scottlocklin wrote: post #74

For the love of God, don't use Feynman lectures to learn physics. That's something you read after you know physics, for relaxation and conceptual stuff. Resnick & Halliday is a much better freshman/sophomore book. Susskind's "theoretical minimum" is actually pretty good. http://theoreticalminimum.com/courses Fowler gives a pretty conventional undergraduate physics curriculum (adding Feynman in there somehow). If it w…

HRK is for learning physics, feynman is for feeling like you're learning physics when you aren't, and ll is for feeling like you're understanding nothing. LL and Feynman are definitely nice to look back upon though.

L&L assumes a particular set of steps and shared reading culture. I had the good fortune to have a professor take me through volume 1 in a classical mechanics class. Thereafter other volumes became very straightforward to read and taught me a lot of physics.

Re: Ask HN: How to self-study physics?

#167

Post by CBLT »

stared wrote: post #54
perczel wrote: post #13

I thought I would also add my two cents, though there have been many excellent responses already. I recently defended my PhD in Physics (MIT '18). First of all - great idea! It is never too late to learn math and physics! In fact, with hard work and commitment, anybody can muster them to a high level. (1) Reading =/= understanding in math and physics. You understand a topic only if you can solve the problems. (2) Wor…

A lot of good pieces of advice (especially on problem-solving, timescale, and moving on). However, some points are IMHO superfluous, for example: > Not all topics are equally important. Focus on the important parts. These statements are correct and general, and most people would agree with (even having no idea the topic), but are rarely actionable (or even: make sense for a newcomer). Vide most of the motivational qu…

The introduction or author's foreword usually covers that in my experience. They'll say which chapters you can skip, and sometimes lay out a map of the key milestone chapters.

Re: Ask HN: How to self-study physics?

#168

Post by kyuudou »

jacobolus wrote: post #26
perczel wrote: post #13

I thought I would also add my two cents, though there have been many excellent responses already. I recently defended my PhD in Physics (MIT '18). First of all - great idea! It is never too late to learn math and physics! In fact, with hard work and commitment, anybody can muster them to a high level. (1) Reading =/= understanding in math and physics. You understand a topic only if you can solve the problems. (2) Wor…

> (8) Counterintuitive: If you get completely stuck, move on! Learning often happens in non-linear ways. If you hit an insurmountable roadblock, just keep going. When you return in a few days/weeks, things will almost certainly be clearer. This is something our education system does a poor job at. My observation from watching a 3.5-year-old all the time is that bootstrapping most skills (e.g. riding a 2-wheeled scoot…

>as the brain has apparently been churning away at the problem in the background without any obvious deliberate effort in between.

This is so fundamental. I picked up a similar concept from a passionate english teacher in 7th grade. He said, after a certain point you've done all that you can do, so let your subconscious work on it, sleep on it and the next day or week you'll find your idea coming together. Paraphrased of course.

Sleep is a very important component of this IMO. It doesn't work as well if you are in poor health and sleep-deprived.

It's like some kind of garbage collection and backend processing happens that we just don't fully understand yet as part of the learning process.

Similarly, I found back in college that concepts processed and stored in short-term memory needed to be "slept on" to fully and solidly store into long-term memory and "stick".

Control the input, carefully imagine and focus on the desired output and your brain will take care of much of the rest. Let it.

Re: Ask HN: How to self-study physics?

#169

Post by gaze »

madhadron wrote: post #166
gaze wrote: post #80

Earlier quoted context omitted.

HRK is for learning physics, feynman is for feeling like you're learning physics when you aren't, and ll is for feeling like you're understanding nothing. LL and Feynman are definitely nice to look back upon though.

L&L assumes a particular set of steps and shared reading culture. I had the good fortune to have a professor take me through volume 1 in a classical mechanics class. Thereafter other volumes became very straightforward to read and taught me a lot of physics.

Yeah I think that's right. LL is now something I look back upon frequently for reference... but you have to have been introduced properly.

Re: Ask HN: How to self-study physics?

#170

Post by godelski »

rguzman wrote: post #92
scottlocklin wrote: post #74

For the love of God, don't use Feynman lectures to learn physics. That's something you read after you know physics, for relaxation and conceptual stuff. Resnick & Halliday is a much better freshman/sophomore book. Susskind's "theoretical minimum" is actually pretty good. http://theoreticalminimum.com/courses Fowler gives a pretty conventional undergraduate physics curriculum (adding Feynman in there somehow). If it w…

context: former theoretical physics grad student, dropped out ABD to start a company. this comment is right on the money on several fronts: - the Feynman lectures are great after you already understand some of the mechanics of "doing" physics and have some other exposure to the topics, Halliday & Resnick is a better place to start on any one topic - with infinite time, i'd always follow the approach of learning the m…

I'll second Griffiths for E&M, Quantum, and Particle. I think everyone that has gone through a physics undergrad will swear by Griffiths. He is just such a delight.

But I'll suggest Marion and Thornton [0] for Classical. With Griffiths for E&M and Thornton for Classical you should be able to get a really good grasp on most of "physics". I'll also say that these series are upper division for undergrads. Given OP's background I think these would be fine starting points. If not, start with Halliday[1].

For grad level, the gold standard is Goldstein for Classical [2] and Jackson for Electrodynamics[3].

These types of books will give you a very strong base in physics and should enable you to branch out. Given your ML background you may be very interested in thermodynamics and statistical mechanics.

I'll also add an "out there" idea. Sign up for physics classes at your local community college if they offer labs. I say this as someone who went Physics -> CS and is doing HPC + ML. Labs really stress and force you to do analysis. Lower division labs won't ask too much, but if you go in with this intent I think you can get a lot out of it. I'm sure that if you did these lower div labs and talked to a professor at your local uni they would allow you to sit in on upper division labs (you would NEED to show that you are serious first, because these labs can be dangerous! Happy to help you learn doesn't mean happy to babysit and make sure you don't electrocute yourself or making sure you don't take a laser to the eye. TAing undergrad labs I saw enough people get electrocuted, including myself... more than once).

[0] https://smile.amazon.com/Classical-Dynamics-Particles-System...

[1] https://www.smile.amazon.com/Fundamentals-Physics-10th-David...

[2] https://smile.amazon.com/Classical-Mechanics-Goldstein-Poole...

[3] https://smile.amazon.com/Classical-Electrodynamics-Third-Dav...

Post reply on HN