Ask HN: What is the best way to get into Physics as a coder?

I'm a fellow programmer who has been self-learning physics for the past few months. My opinion is that a programming background is largely irrelevant to the "learning physics" part. It might help depending on what you want to do with the physics after you learn it, if that involves writing simulations or something like that. But really learning physics mostly involves reading books and solving physics problems.

I think the most important advice is don't try to skip ahead. It's tempting to jump straight into the cool modern physics topics like quantum mechanics and general relativity before you have the necessary background. I've gone down that route and didn't really learn anything that way.

If you haven't taken any physics at the university level, you probably want to start with one of the big calculus-based intro books like Young's University Physics. Calculus, differential equations, and linear algebra are really important, so you might want to pick up separate textbooks on those (or a single volume Engineering Mathematics textbook) unless you have already learned these subjects. Everyone speaks highly of the Feynman Lectures, but some say that they're only really beneficial after you already have a decent understanding of the subjects being covered. I believe I heard Sean Carroll say this once on a podcast, and I trust his opinion on physics matters.

The core subjects in undergraduate physics are classical mechanics, electrodynamics, special relativity, quantum mechanics, and statistical mechanics/thermodynamics. You will learn all of these subjects from an intro textbook as a first pass. After that, you'll return to each subject and essentially relearn it at a more advanced level with dedicated textbooks for each (except SR which is covered in electrodynamics). General relativity and quantum field theory are usually taught at the graduate level or as upper-level undergraduate electives, so those are best to save for last.

Having forgotten a lot of the math I learned a decade ago, I've found that having one of those Mathematical Methods books nearby at all times is indispensable. I went with Riley/Hobson/Bence, but Boas also gets good reviews. These books are a bit terse if you're learning a subject for the first time, but they're great as a reference and contain pretty much all the math you will ever need to know unless you plan on doing research-level physics.

Don't forget about YouTube. There are lots of lectures available from top universities, as well as independent content creators. I haven't looked much into physics channels yet, but on the math side I highly recommend 3Blue1Brown, especially his series "Essence of Calculus" and "Essence of Linear Algebra".

This is a good roadmap to guide your study path and has good textbook recommendations: https://www.susanrigetti.com/physics

Make simulators. Anything. Finite elements, diffusions

soon enough you'll learn about gradients, curls, and how to implement them

Oh, and play kerbal space programs

You might be thinking of this: https://www.susanrigetti.com/physics

Hang out at places like Barnes and Noble while you code and drink coffee.

Pick up books from subjects that you think might interest you while you hang. Read a few chapters and decide if the book/subject is for you.

If you really love it; buy the book and take it home.

I did this for a number of years, and absorbed a lot from coding, general physics, quantum mechanics, and even tried to dabble in Astro physics.

For that matter, graphics in computer games are informed by physics in the sense that many methods like rendering, raytracing, NeRF, Gaussian Splatting try to simulate light fields.