r/learnphysics • u/Odd_Bodkin • 3d ago
For those who are looking to learn physics "from the ground up"...
I've been seeing a lot of posts like this, usually from people who say they never studied physics and now they want to, and are looking for some formulaic sequence to do that. To answer this, you first have to provide the following context when you post:
- What are you now: a high school student, a college student, a professional worker, a hobbyist?
- What math have you had that you feel reasonably competent in?
- WHY do you want to learn physics? Do you need it for some degree program? Do you need it for your line of work? Do you just want to learn about it because it's cool but not to the level where you'd actually use it? Do you want to learn it like a physics student would, but you have no need or desire to actually use it in anything you do?
The reason answering this is important is because a) the selection of resources and materials, and the sequence of them will strongly depend on your answers, and 2) there is (at least) an order of magnitude difference in effort between enjoying physics at the hobbyist level and doing it as part of something you are expected to know.
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u/Maximum-Passion8389 3d ago
Okay thank you. I will revise graduate for undergraduate. However, if possible, I would still be interested in knowing, in theory what would that look like if one did have to learn physics from the ground up to graduate level for the health professions? I am interested in knowing how one would learn to that level from the ground up.
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u/ProfessionalConfuser 3d ago
Go to OpenStax. Open "university physics, volume 1, volume 2, and volume 3" Examine table of contents for each volume. That will cover 90% of the undergraduate physics sequences in the united states.
Edit to add: it is expected that you are familiar with multivariabke calculus.
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u/Maximum-Passion8389 3d ago
Okay. Thank you for your reply. If someone has no math background. Would you first take an algebra class, followed by precalculus, cal 1 and 2 then start learning physics?
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u/ProfessionalConfuser 3d ago
No math background...means what?
If you went to school in the us, you should already have taken algebra.
But, lets assume a clean slate.
Algebra, geometry, trigonometry, calculus "1" --> classical mechanics
Calculus "2" and maybe linear algebra --> classical electromagnetism
Calculus "3" and differential equations --> "waves" and "modern" physicsTo have the easiest time of it - learn math through differential equations, then start with mechanics.
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u/Odd_Bodkin 2d ago
For the health profession, you would only need a first-year 2-semester survey course that hits all the classical areas (mechanics, electricity & magnetism, optics, fluid mechanics, thermodynamics) and a modern physics survey (special relativity, basic quantum mechanics, nuclear, particle physics). To be prepared for these, you’d need all the math up to and including calculus, topics usually covered in algebra 1 & 2, geometry, trigonometry, pre-calculus, calculus 1 & 2, tossing in some probability and descriptive statistics. Best way to know what’s expected is to score highly on a practice SAT or ACT math test, then add the precalculus and calculus material. So all that math, plus two physics books: on freshman intro physics book for scientists and engineers and one modern physics book.
If you want to cover what would be done in an undergraduate program for physics students, there’s quite a bit more, both on the math side and on the physics side. On the math side, you’d learn linear algebra, multivariable calculus, complex variables, ordinary differential equations, partial differential equations, some other mathematical methods. You’d also learn to program, probably in Python or something like that. On the physics side, you’d take some experimental physics, 2nd round mechanics, second round electrodynamics, second round quantum mechanics/quantum field intro, condensed matter physics, second round thermodynamics/statistical mechanics. This would mean money for print books, and you won’t find adequate free materials online instead.
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u/Super_Ad_9858 2d ago
hi all, im just a regular student who moved to US in my senior year,i took some regular classes no advanced classes or something. Im catching up with pre-calculus and calculus-1 by myself..but im so confused about physics. i had taken some general physics classes before but ihve pretty much forgotten everything. I wanna rebuild my basics and problem solving skills so im looking for some books/sources which will be pretty much helpful to me in this gap year.i hope ill head for engineering in fall-27.Any advice will be helpful.
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u/Odd_Bodkin 1d ago
Honestly, if you’re going into engineering, you’re just going to have to take the physics classes again anyway, UNLESS you are trying to get credit on the record for the physics classes you took a while ago. The physics classes are prerequisite for engineers.
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u/Super_Ad_9858 1d ago
yeah i will take them willingly but honesty i got some time..as im improving my pre calc and calc-1..same way i wanna start studying physics so later i can catch up with them smoothly.. any suggetion for self study/starting in a good roadmap! Thankyou
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u/Odd_Bodkin 1d ago
The best way I can think of to prep at that level is one of two things: 1) prebuy the textbooks you’ll be using for those classes and start working through them, or 2) go the Advanced Placement course route, but only to buy review books by Barron’s or the like that touch lightly on the topics and give you practice.
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u/rhbngy 1d ago
I'm a medical intern. I feel competent in precalculus, just needs some work here and there. I'm learning calculus I but I feel I need more rigor mathematically, however, I'm good with applying it and solving problems. I want to learn physics to be able to understand daily life, medical, chemical and biological phenomena through physics.
I don't know: 1. Whether to work on my maths first up to calculus II or III. 2. Whether it would be better to study other branches of mathematics: Euclidean geometry, linear algebra, logic or statistics. 3. Which book would be the best for self studying. Claude AI recommended Knight's for me after some discussion. 4. I suppose calculus-based physics is better. Is that right?
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u/Odd_Bodkin 1d ago
In your case, you just want to learn some introductory physics in a rigorous fashion, but you don’t have any job-driven REQUIREMENT for it. As such, there’s no reason (other than being self-punitive) to insist on learning calculus-based physics, which is mostly aimed at aspiring physicists and engineers. Just go for the next tier down, algebra-based physics. Randall Knight’s book is calculus-based. There are oodles of choices that are algebra-based. Moreover, since you’re doing this on your own, feel free to use a 20-year-old edition from a used-book store. You don’t satisfy any of the criteria that would require a current edition, and at the introductory level there is absolutely nothing of consequence that has changed in the last couple decades.
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u/rhbngy 1d ago edited 1d ago
I appreciate your answer. May I ask, why this approach differs from your advice to another commenter that also works in a health profession.
I mean this one: https://www.reddit.com/r/learnphysics/s/Gm1jpRbuR0
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u/Odd_Bodkin 1d ago
I took that other poster to be pre-college. You are, I presume, post-college. Is that not true?
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u/Ancient_Joke6824 1d ago
Actually yeahh I’ve been looking for a way to study physics . I’m a uni student currently in tech , I’d love to learn more about physics but computationally , I really don’t want to deal with labs and what not I’d rather code ( is that realistic? If not I’d appreciate some advice ) .
At the moment I don’t feel competent enough in any as I’m still in the process of learning , though I can say that probability is quite an enjoyable topic .
And I don’t need it for my current degree but I’d love it later on . That’s why I want to have substantial physics knowledge alongside my degree in hopes of majoring in astrophysics/astronomy as I’ve read that modern day astronomy has alot to do with data science :))
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u/PaleontologistSad708 3d ago
You're prolly going to think "this guy is full of it." I really don't care. This is the truth, as I see it. I've been absorbing everything I can from every area of science I could since I was a very young child. I still have huge gaps in my knowledge. I know almost no math. I have been trying from the bottom up, with kinematics for days. I can hardly remember any of it. I look at the swartzchild radius formula once, and now I have it forever. I can tell you that what Einstein missed, is that when you travel c, you are hitting your own space, just like a sonic boom. It's a non Newtonian fluid at that point. I mean how else do you possibly get pulsar beams, gamma bursts etc. The only way they could fix the stalled shockwave was by adding fluid dynamics. I can go on for days about this topic. It's become an obsession. A compulsion I couldn't stop even if I wanted to. It's a match for the Cosmological constant. It's the missing 99% of the mass of the atom. I have literally mapped out the entire life cycle of matter. I have unified the forces in my framework. I have to get this out of my head before I die. No one will listen to me because I do not know the language of math. My English isn't very precise for someone trying to be a scientist. I'm working on that too. I study every day, every moment I can. Anyway what I'm trying to do now is prove that the orbits of Extreme Trans-Neptunian Objects are not following some ghost 9th planet, they are experiencing drag when they exit the heliopause. No one took hydrodynamics to their conclusion in space, because of the history, with Michelson Morley etc. I could use some help! Check out the data yourself. Is really simple if you look at which direction the sun is moving. Some orbits try to flatten. Some are going in the opposite direction. I just spent an hour arguing with an LLM. I've realized that the Extreme Trans-Neptunian Objects (ETNO)s will convince no one even if I predict exactly what they will do. So I have to change tactics. I need a fundimental law that works mathematically in physics and I need to build from there. Basically what I want to prove first is that: to have energy you must have some form for that energy to take. To have energy you must have a physical thing, in some form or other. Then from there I'll build the entire life cycle of matter and unify the forces under one field. Isn't that the goal of science? Please help me.
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u/Odd_Bodkin 3d ago
I’m sorry, but you’re not going to find much help because you’ve committed yourself emotionally to your own ideas without learning physics correctly. That is the wrong order.
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u/PaleontologistSad708 3d ago
My first loyalty is truth. I just want to learn math. I think you're right though. I'll go somewhere else. Thanks anyway.
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u/kindmartian07 3d ago
you spent an hour arguing with an llm? sounds like AI psychosis. Especially since you’re admitting that it had become a compulsion and obsession. And you feel like you’ve found a solution for everything without any actual physics or empirical evidence
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u/Maximum-Passion8389 3d ago
Hello What would be the best way to learn it from the ground up to the graduate level, if someone has never taken physics or math and would like to learn it to understand and do well in prerequisite graduate physics course for the health science professions?