[HN Gopher] So you want to learn physics (2021) ___________________________________________________________________ So you want to learn physics (2021) Author : weird_science Score : 277 points Date : 2023-08-20 16:28 UTC (6 hours ago) (HTM) web link (www.susanrigetti.com) (TXT) w3m dump (www.susanrigetti.com) | EvgeniyZh wrote: | 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 | qsort wrote: | 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 problems you lack the intuition that | ties together theory. | belugacat wrote: | 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 subject I know as a | practitioner (typically something tech/programming related) | from watching YouTube videos/listening to podcasts. | | Because they've heard hours and hours from experts, they have a | feeling of deep understanding. But talking to them about this | topic is extremely frustrating because their knowledge clearly | has never had to be applied to the real world, and is grounded | in nothingness, so they misunderstand lots, but they feel like | they know what they're talking about as much as you do. | civilitty wrote: | _> 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._ | | That mirrors the trajectory of all humankind, doesn't it? | From lofty Platonic ideals to nitty gritty empiricism and | experimentation. | tourgen wrote: | [dead] | antegamisou wrote: | > The most frustrating is when I have friends who have | derived their entire understanding of a subject I know as a | practitioner (typically something tech/programming related) | from watching YouTube videos/listening to podcasts. | | > Because they've heard hours and hours from experts, they | have a feeling of deep understanding. But talking to them | about this topic is extremely frustrating because their | knowledge clearly has never had to be applied to the real | world, and is grounded in nothingness, so they misunderstand | lots, but they feel like they know what they're talking about | as much as you do. | | You just gave the most accurate description of HN userbase in | two paragraphs. | beltsazar wrote: | >> Solving problems is the only way to understand physics. | There's no way around it. | | The reason is that you think you understand what you read, but | as Richard Feynman said: | | > The first principle is that you must not fool yourself, and | you are the easiest person to fool. | | You think you understand 90% of what you read, but in reality | it's probably only 20-30%. By doing the exercises, at the very | least you'll know that you don't know that much. And if you | then reread the materials a few pages before, you'll realize | that you have skimmed (or worse, skipped) some parts because | you mistakenly thought you already understood it. | | Another tips from my personal experience: When you're reading a | textbook, keep asking in your mind questions with the types of | "what if" and "how about," which are sometimes not yet | explained in the section you're reading. Also, keep associating | what you've recently learned with what you've already known | (days ago, years ago). | | Be curious and validate that you really understand what you | think you understand. | markus_zhang wrote: | 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. | Qem wrote: | > 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. | javajosh wrote: | 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 this! | Now that they know they need it, and why, you can give them the | tool that fits the bill. For example, I think calculus is | probably better learned _after_ trying to write down some force | laws, and perhaps doing some numerical analysis. Then when you | learn them you realize those nice closed-form solutions aren 't | busywork, they are _huge_ labor saving tools that eliminate ad | hoc labor intensive analysis. | | I would also _deemphasize_ the more mathy parts of calculus - | do you really need a deep dive into continuity or the | fundamental theorem of calculus? Eventually, yes. But it 's | just like programming: you're not going to need to understand | language theory or ADTs or category theory or lambda calculus | to write your first program. Or your second. And, IMHO, you | should only reach for this understanding when you realize you | need it. Otherwise, it won't integrate well into your toolkit. | whartung wrote: | > 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 lance and rushed at this | windmill from assorted directions, I quickly run into my | limitations that prevent the problem being solved. I run into | vocabulary problems with the math, the fact that I simply | don't have the math to approach the problem (which appears to | be some vector calculus -- I think. "No, you idiot, it's XYZ | instead", but I don't know enough to know that it's not | vector calculus, if, indeed, it isn't). I try to apply basic | kinematics to the problem, but I don't know if that's enough. | And, finally, it could be all of those things plus, oh, some | optimization issues and, also, would you like to be | introduced to the several different techniques for computing | numeric integration and the differential equation solvers? | | "Eeep!" | | To quote the film "Addams Family Values": | Wednesday: Pugsley, the baby weighs 10 pounds, the cannonball | weighs 20 pounds. Which will hit the stone walkway first? | Pugsley: I'm still on fractions. | | So, yea, that's me, I'm Pugsley. It seems I need 2+ years of | mechanics, calculus, and differential equations, and, | probably, some time with computer based simulation all to | chart the course for a spaceship to a planet for a 40 year | old role playing game. Of course, I don't know what the, | perhaps, abbreviated path I could take through those domains | to get to be able to answer my question. That might knock a | year off the study, but, unlikely. "Better to have all of the | foundation" and all that. Which is true, but I'm kind of | after the "reward" part here, not so much the "journey". | projectileboy wrote: | You might dig "The Theoretical Minimum" by Susskind, as | well as his follow-on books. And he has associated lectures | on YouTube. | brightlancer wrote: | > 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, then it rightfully | destroys trust. | | I never taught at the university level, but with middle and | high school math students I taught them to how (re)discover | the solutions, rather than teaching them the solutions | directly. | | As a practical matter, many of my college classes went too | quickly to do anything _but_ teach the solution -- or tell us | to learn it between classes and bring questions back. | javajosh wrote: | I don't think it breaks trust, if you tell them what's | going on. "Hey kids, I'm going to give you a problem that | went unsolved until Newton. I don't expect you to find his | answer, which I'll teach you later, but I want you to try | to solve it your own way." | aleph_minus_one wrote: | > 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). | BenFranklin100 wrote: | 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. | ak_111 wrote: | That is some dedication, well done. Interesting to know more | about your career and where this lead to if you continued | down the physics path. | BenFranklin100 wrote: | I went on to earn a doctorate in biophysics and then began | a career developing instrumentation for biomedical | research. While I no longer work directly in the field of | physics, the physical intuition and reasoning abilities | honed by a physics education has allowed me to successfully | lead teams consisting of electrical and mechanical | engineers, while serving as the liaison to biologists and | doctors. I regard a physics education as a modern-day | 'liberal arts' technical degree. | shanusmagnus wrote: | 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? | BenFranklin100 wrote: | We were required (by the state I believe) to take a | comprehensive test assessing our competency at physics. I | struggled with test and was disheartened that four years of | strenuous effort would be all for naught. I knew I needed | to do something to shore up my understanding of physics if | I was going to retain the knowledge decades onwards. The | other reason was a simple love for the beauty and | underlying simplicity of the subject. | [deleted] | remote_phone wrote: | 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't | important because everyone eventually figure it out. It's the | ones who can do the problems and get good marks that succeed in | the end. | froggit wrote: | This is kind of interesting to hear because I was the other | way around. I found the best way to understand something was | to teach it to others. That way I took what I already | understood and was able to see what other people | misunderstood, which was often something I'd never expected | to be an issue, and add their experience in learning the | topic on to what I already knew which expanded my overall | understanding. | | Then again, in the process of teaching I always found myself | teaching people to work problems, which required me to be | able to work the problems myself. In a way, it's kind of | impressive you managed to avoid doing that. | javajosh wrote: | 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. | TheCleric wrote: | 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). | ChuckMcM wrote: | Totally 100% with this. When younger I thought I could read the | material and say "Oh, okay that makes sense I understand this." | Only to fail miserably when on a test or somewhere I had to | apply what I "knew" and realizing I didn't actually know it. I | lean strongly toward autodidacticism and learned that if I | could solve problems with the technique _then_ I knew it. | ecshafer wrote: | My calculus 1 professor gave the advice that the best way to | study is to do every problem in the book, then go and get | another book and do every problem in that book, and keep | doing that until you look at a problem and know exactly every | step to do immediately. | ChuckMcM wrote: | Time consuming but I can see this being really really | effective. | SpaceManNabs wrote: | I see no mention of Landau and Lifshitz! On a less joking tone, I | don't know many of these books. I was kinda surprised. guess i am | outdated. | gaze wrote: | Landafschitz is kinda hard to self teach from. Fantastic | supplement, though | cgh wrote: | 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. | rollinDyno wrote: | This post comes in at a very good time because I have recently | begun to become interested in particle physics and have so far | only resorted to watching YouTube videos. This is a sign that it | is maybe time for me to jump into a textbook. | | However, I seem to be interested in a few particular questions | about particle physics as a science rather than facts about | particle physics. For instance, I am interested in the | instruments and methods that physicists use to verify their | theoretical claims empirically. I am also interested in how | theorists are able to come up with theories so early on, such | that they are confirmed by evidence many years later. What are | the assumptions that they were able to make? I am curious about | where they derived the creativity to be able to bring in so many | assumptions together and the come up with their models. Now that | I write this, I realize that before theories were validated there | were probably competing models. | | Therefore, I am not exactly sure I want to study particle physics | per se, or whether a book on the history of particle physics will | do. I am ok with having a popular understanding of the subject, I | mostly want to gain inspiration from following the work of famous | scientists. | deepsquirrelnet wrote: | Even though Susan Rigetti says you don't _need_ to learn calculus | first, I would recommend it --- or learn it concurrently with the | introductory mechanics course. Mechanics is so much more | enriching when you learn the mathematical language that was | created to describe it. | | You'll already be one step ahead by the time you get to the | second course, which is good, because you can strongly benefit | from learning vector calculus at that time. I really enjoyed the | text "Div, Grad, Curl and all that". | ghaff wrote: | One problem with approaching physics without any calculus is | that you're more or less in the place in which most people | taking high school physics are. Here are a bunch of formulas. | Memorize them and don't worry about why they are what they are | or how they relate to all the other formulas that you also have | to memorize. | DigitalNoumena wrote: | [dead] | [deleted] | cb321 wrote: | Rather than 27 (or however many) books, an ambitious student | _may_ be able to use _just one_ big-ish book: Ian D. Lawrie 's "A | Unified Grand Tour Of Theoretical Physics". This even has a | little 18 page "Snapshots of the Tour" which might be a trip down | memory lane for those who studied physics long ago. | | Of course, it might also be impenetrable if you haven't had prior | exposure to most of the material.. I have zero experience trying | to teach physics from it. | libraryofbabel wrote: | It will be impossible to learn physics from this book, even in | the unlikely event that you already have all the requisite | mathematical background (partial differential equations, vector | calculus, tensors, etc.). Degree of "ambition" doesn't come | into it; you just can't start out with special and general | relativity and spacetime and quantum fields; you need to solve | a lot of problems in newtonian mechanics and electromagnetism | and thermodynamics and get a solid foundation in classical | physics first. There is no royal road to this stuff: Susan's | list lays out the standard curriculum and it's really the only | way we know to produce physicists. | | That said, this book does look like a great text for someone | with a graduate level physics knowledge who wants to refresh | their memory. | fcatalan wrote: | 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. | monster_group wrote: | 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. | computerfriend wrote: | Excellent discipline. What topic are you focussing on? | monster_group wrote: | I have been working on quantum physics since March of this | year and am hoping to complete the whole text book | (Townsend) by end of the year. Then on to special | relativity -> classical field theory in 2024, general | relativity and QFT in 2025 and 2026 - at least that's the | plan. | markus_zhang wrote: | I'm preparing to do something similar but attack a lesser beast | that is the general relativity. I had a Master's degree in | Statistics but unfortunately 1) Statistics does not really | match Pure Mathematics and 2) I forgot most of it. | | A beast it still is, I think it is contained in its own walls. | I can skip any topic in Quantum Physics and others that is | irrelevant. | | I'm wondering if it's helpful to you too to focus on something | smaller. | ahelwer wrote: | Using math to model a system instead of learning math qua math | does wonders for ease of understanding. Derivates and integrals | become easy if you're using them to model the relationship | between position/velocity/acceleration. I don't think I really | got linear algebra until using it to learn quantum computing. | growingkittens wrote: | Brushing up on high school maths is easy using Khan Academy, if | that's all that's stopping you. | nologic01 wrote: | The title should probably be: "So you want to learn _theoretical_ | physics ". | | While generally little known and appreciated among modern | theorists and mathematical physicists, physics is actually an | _empirical_ science. In other words, every single section of that | reading list is based directly or indirectly on a diverse and | sophisticated set of devices and measurement configurations (aka | experiments). Also, most progress in our understanding the | physical universe follows simply from inventing ever better | probes and opening new observation windows. | | A computer analogy of the theoretical/empirical physics relation | might be fun: You can spend your whole life writing application | software and never even know what digital devices you are | actually using. That's totally legit. But if you want to write a | new computer language (= a new theory) you most likely will have | to dig into memory architectures and caches and all that stuff. | If you want to dramatically increase the speed of computation (= | a new observation window) you have to design a new chip. And if | you want to go really deep and invent new computing paradigms, | well then you need to learn quantum mechanics :-) | | In fairness, she does have a final sentence about that weird | place called _laboratory_ (= a place of labor). | | > And, finally, a note on learning in a laboratory vs. learning | from textbooks. Physics is both an experimental and theoretical | science, and while research happens in laboratories and on | blackboards and computers, the majority of any physics education | does not take place in a laboratory but in lecture classes that | teach from textbooks and assign homework problems that are found | in textbooks. | | My recommendation for a comprehensive intro into theoretical | physics is _The Road to Reality by Roger Penrose_. Alas there is | no such profound review of all experimental physics. | lanza wrote: | She just lists the standard curriculum through undergraduate | and graduate degrees. I clicked the links to all the books and | my Amazon has the purchase dates from when I took those | courses. It's not specific at all to theoretical physics. | staunton wrote: | [dead] | xrayarx wrote: | The author is aka Susan Fowler and author of three books and has | a degree in physics. | | The Post is basically about how to get a degree or at least the | equivalent and would require an effort of years. | | https://en.wikipedia.org/wiki/Susan_Rigetti | kingkongjaffa wrote: | 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. | Avshalom wrote: | I have a B.S. Physics from NMT graduated in 2009 (they changed | some of the courses a year or two after my cohort) but the main | series progression was Modern Physics -> Waves -> Classical | Mechanics, E/M/Optics -> Quantum -> Thermo. Never really did | much of anything fluids-wise other than some viscosity/drag | stuff in Mechanics | lanza wrote: | Former theoretical physicist here (quantum gravity). TBH I | don't know what Navier-Stokes is. | ghaff wrote: | Consider yourself lucky :-) Fluid dynamics and I never got | along very well--probably mostly the math (partial | differential equations mostly as I recall). | disentanglement wrote: | Thermodynamics is usually (and rightfully so) taught together | with statistical physics for which quantum mechanics is | essential, so the order does make sense. | carabiner wrote: | NS is too applied and seems akin to including the beam | equation. | kingkongjaffa wrote: | Would you also say Maxwell's equations are "too applied"? | | They're both pretty firmly physics things rather than applied | or engineering things, in their purest forms... | btrettel wrote: | 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 the most important | principles. In an extraterrestrial civilization, the boundaries | between engineering, physics, and chemistry may be entirely | different. | | Dismissing Navier-Stokes as just a consequence of Newton's laws | and thus unimportant can be extended further towards dismissing | a large fraction of what's taught in physics degree programs. | An undergraduate physics student may get more education on | Bose-Einstein condensates (which are just a consequence of | quantum mechanics :-) than they do on Navier-Stokes. The | Navier-Stokes equations are a lot more important than Bose- | Einstein condensates in my view. | lanza wrote: | 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 generating physics PhDs | in the 2000s and beyond. | | 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). | btrettel wrote: | > 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. | lanza wrote: | > 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. | | It was an exaggeration given that it never came up during | my studies once. And I think that's a fantastic | assessment of their value that I made it through most of | a decade of studies without having to know a thing about | fluid dynamics. | | > 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. | | ...why? You're commenting on a physics line of education | here. We don't use fluid dynamics and we _extensively_ | use group theory. | staunton wrote: | The physics curriculum prepares people to do research on | stuff that is published in "physics journals". You may | not think that should be the goal but it is. Doing work | on Navier-Stokes lands you in a math journal on PDEs. | | On a more important note, the actual topics are | completely irrelevant. What's important is learning to | "think like a physicist". That's what has value even for | those who don't go on to do academic research, which is | most students. For any given physics topic that is | relevant to real-life applications, there are engineers | who _actually_ know how to use it, something that would | be ridiculous to expect from the superficial treatment a | physics degree _has to_ give any one topic. | superposeur wrote: | As a physicist, fluid mechanics was the most glaring gap in my | undergraduate preparation, despite its centrality to most | physics applications. Somehow it is always a "time permitting" | topic at the end of an already-cramped curriculum. | | I first encountered the Euler equation in the context of GR -- | absurd. In another decade or two, I suspect its rightful place | early in the physics curriculum will be emphasized. | _dain_ wrote: | >can you tell me if you can really get a physics degree without | bumping into Bernoulli or Navier-Stokes? | | Bernoulli principle was covered in my bachelor degree but | Navier Stokes wasn't; true-blue fluid dynamics was either an | optional course that I didn't take or a grad student course, I | don't remember now. | elashri wrote: | I am writing my physics PhD thesis and I did not study fluid | mechanics (other than the few chapters in the standard general | physics). | | It will really be dependent on what is your physics field but | you can definitely survive in physics without deep knowledge of | fluid mechanics except when your study require it | | PS: I am a particle physicist. | jwuphysics wrote: | A professor remarked that it was a bit sad that physics | students nowadays have a better understanding of quantum | field theory than fluid mechanics. He mentioned this while | lecturing on QFT. | [deleted] | tekla wrote: | But fluid mechanics is haarrddddd (Aeronautical Engineer). | Compressible fluids can go suck it. I rue the day Navier- | Stokes became a thing. | elashri wrote: | There is a more practical reason for that. QFT has become | essential to learn for many Condensed matter physicists. | And they always are with particle physicists which will | span most of the physics community, at least comparing with | whose work involve in-depth knowledge of fluid mechanics. | Not to mention that QFT seems easy in comparison. | pclmulqdq wrote: | That is a very "pure physics" way to approach physics, and I | think it's right if you want to build up the underlying | principles. That was how my college taught physics, and it | helped to make many otherwise unintuitive parts of | thermodynamics understandable. | | Also, physicists don't necessarily include fluid dynamics as a | core discipline. It is almost mechanical engineering to them. | I'm not surprised to see it missing. | carabiner wrote: | yeah NS is just newton's laws, which is part of mechanics | mhh__ wrote: | Newton's laws and centuries worth of intuition about fluids | but sure. | | Also stating the equation isn't the same thing as studying | it. | cli wrote: | 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. | abhayhegde wrote: | This guide does contain the books that are usually recommended in | a university course setting! So, it will require significant | amount of time and effort to master it. One of the series of | books that physicists religiously stick to is Landau and | Lifschitz. But my experience has been that it's worth it only if | you already have some basic understanding. | joe__f wrote: | I never got on very well with Landau and Lifschitz it's pretty | intense. I mostly used pdf lecture notes from different | courses. They can be a bit mixed but many are very good quality | and you can easily pick up a couple for the same topic if you | don't understand some part of one of them | ajkjk wrote: | Landau and Lifschitz are terrible books, pedagogically | speaking. They're good only in that they're exhaustive and | rigorous. | amluto wrote: | 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. | | Hydraulics are _everywhere_. Ever used a sink? Flushed a toilet? | Contemplated an air filter? Felt both sides of a small fan? | Wondered how, exactly, a utility pump causes water to go in the | inlet and out the outlet, and tried to read the manufacturer's | spec? Contemplated that the ripples when you throw a rock in an | actual pond really don't resemble the average "look I made water | in WebGL" animation very much? | | And more fancily, and very much in "Physics", cosmological models | usually model the universe as being full of a spatially varying | _continuous fluid_. Stars are plasma or weirder things, and those | are fancy fluids. | | Yet, for some reason, the basics are missing from "Physics". You | can sometimes find them in mechanical engineering departments, | and Feynman covers it a bit in his lectures. | meristem wrote: | Do you have text/other sources suggestions for this? I agree | with you, would like to learn more. | antegamisou wrote: | 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). | srameshc wrote: | I love HN for thing like these that I wouldn't have otherwise | found out. I used to think often about physics but not seriously | enough to search for resources on how to get started and learn. | But now that I have this guide (thank you Susan), I think I will | start and no longer wonder or plan for learning physics in the | future. | projectileboy wrote: | 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. | gleenn wrote: | 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? | projectileboy wrote: | 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. | tayo42 wrote: | > 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, | applying it interesting ways. Doing that within so many of the | areas of study is still gated behind academics. | | 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. But to do anything | interesting physics, astronomy, philosophy too you need to be in | school. sucks | thrwaway99956 wrote: | > 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. | quantum_state wrote: | " But to do anything interesting physics, astronomy, philosophy | too you need to be in school." Why would you say that? I am | curious. Imagine you are into a specific physics subject and | knows what to do with some of contemporary problems that are | puzzling people, work on it to provide your solution, etc., and | publish your findings. I would think no one could prevent you. | Right? | sebg wrote: | Previous posts, if you want to take a look at the comments there: | | https://news.ycombinator.com/from?site=susanrigetti.com | dang wrote: | Thanks! Macroexpanded: | | _So You Want to Learn Physics (2016)_ - | https://news.ycombinator.com/item?id=24088985 - Aug 2020 (124 | comments) | | _So You Want to Learn Physics (2016)_ - | https://news.ycombinator.com/item?id=18374994 - Nov 2018 (122 | comments) | | _So You Want to Learn Physics_ - | https://news.ycombinator.com/item?id=12691963 - Oct 2016 (129 | comments) | elashri wrote: | > Classical Electrodynamics by Jackson (essential). This is the | bible of classical electrodynamics, and everyone who works | through either loves it or hates it (I loved it). | | I agree that there is a division between who loves that book | (like the author) and the majority of the graduate students who | had nightmares (and sometimes still gets). I like this goodreads | review of the book [1] | | > A soul crushing technical manual written by a sadist that has | served as the right of passage for physics PhDs since the dawn of | time. Every single one of my professors studied this book, and | every single one of them hates it with a passion. While I've no | intention of becoming a professor, I still wonder, will my | colleagues also inflict this torture on their students? Will the | cycle be perpetuated ad infinitum? How many more aspiring | physicists will we leave battered and bruised at the gates of | insanity before switching to a textbook that seeks to make | electrodynamics clear and intuitive rather than a mind-numbing | trip through the seventh circle of hell? | | [1] https://www.goodreads.com/review/show/1266180525 | | * personal note: If this book is really the bible of classical | mechanics, then I'm atheist. | libraryofbabel wrote: | Well yes, but curious what book you would recommend instead for | graduate electrodynamics? Note that she already recommends | first studying Griffith's _Introduction to Electrodynamics_ at | the undergraduate level (and that one is a true pleasure to | read imho). | elashri wrote: | I'm happy that many professors start to use Zangwill's Modern | Electrodynamics [1] textbook. It seems more focused on | explaining things and don't assume that you know too much | (which you usually have no idea if you should have known | something or you just an idiot) like Jackson. | | [1] https://www.amazon.com/dp/0521896975/ | jore wrote: | It is interesting that 2 years later the same reviewer changes | their mind a bit: | | > Now, a few years after writing that review, I must return to | say that as much as I hate this book, it's probably the best | textbook that I have. I constantly return to it to reteach | myself basic concepts or math. The problem with the text is | that in order for it to be useful, you pretty much have to | already understand the material. It's a dense, technical manual | that, when paired with an easier to understand text such as | Griffiths, grants tremendous power. Don't get me wrong, if | there is a hell, I personally hope John David Jackson is | burning in it right now, but I also have to tip my hat to him | LYK-love wrote: | After reading this blog, I'm ashamed. I just graduated from | college. In my high school, the education of physics was so | boring and tiresome that I even hated it at one point. For this | reason, I chose computer science rather than physics as my major | in college. Later, I gradually became interested in physics, | however, due to the lack of good enough study habits, atmosphere | and courage (which is a self-deprecating way of saying cowardice | and laziness), until now I have not taken a step forward. This is | the decision I regret most in my life. I am going to the United | States to study for a master's degree in CS. Maybe I can learn | some physics during the freetime of the two-year program because | the educational resources in the United States are more | abundant(perhaps). | ChrisArchitect wrote: | (2021) | | anything new here? | cal85 wrote: | All of it, to the users who haven't seen it posted here before. | chucksmash wrote: | It was mentioned in another comment thread[0] this morning. | These things happen[1]. | | [0]: https://news.ycombinator.com/item?id=37199307 | | [1]: https://news.ycombinator.com/item?id=32795559 | ahelwer wrote: | Undergraduate physics hasn't changed much in the past two | years. ___________________________________________________________________ (page generated 2023-08-20 23:00 UTC)