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You're probably selling yourself short. Differential equations isn't a bad course if you did well in Calculus and have the patience to grind out a ton of exampl

You're probably selling yourself short. Differential equations isn't a bad course if you did well in Calculus and have the patience to grind out a ton of examples. E&M, StatMech and/or Lagrangian Mechanics also ain't bad if it's taught well, but this is a case where you really have to do the diff eqs before you can do the physics piece. Diff Eqs is the language of most of physics; trying to wrap your brain around the other parts and differential equations at the same time is too big a lift even for a galaxy brain. It's like being asked to compile kernel modules without knowing how to use a mouse or keyboard. I've thought about trying to write something like Lenny Susskind's "theoretical minimum" book, assuming you have the prerequisites of differential equations and linear algebra. I mean, everyone struggles with the complicated problems, but more people should be able to appreciate the results. Meanwhile Susskind's book is pretty good!

rubidium 7y ago
I'll echo the grandparent that learning diff eq at the same time as the subject (e.g. mechanics) is "par for the course" for physics programs. There's many times throughout the progression to Physics PhD where "yes ideally you'd learn the math first" but there is only so much time. And some physics math is uniquely physics. I get your general point Scott, but I disagree with "trying to wrap your brain around the other parts and differential equations at the same time is too big a lift even for a galaxy brain". Learning both in the same course is doable.
- scottlocklin 7y ago
  The guy I was responding to, mikekchar, claimed that he was given advanced physics problems requiring diff eqs without having studied them before; this is absolutely not the case in any physics program I've ever heard of. By the time you get to Junior Year physics, you've had diff eqs, or at least an introduction to the ordinary diff eqs you get in late Calculus. You can probably learn them both in the same course; but only if the course is designed for this purpose (aka Boas based "math methods for physicists" or something). I do remember some guys in grad school who had never seen a Greens function before (I was doing them in sophomore years; guess I was lucky) encountering JD Jackson, but that's about the only disconnect I've seen.
  - rubidium 7y ago
    Just speaking from my own expedience, I had advanced (jr year) mechanics before diff eq... but admittedly was taking it early. It was doable but tough. Greens function were new to me in grad school. Grad school mechanics had be learning math I didn’t know before too... can’t recall what it was at the moment. And then the advanced AMO class had some more math I hadn’t seen.
  - psalminen 7y ago
    I was using diff eqs in mechanics a semester before taking Diff EQ, and this was following the standard course. In my experience, learning them through the lens of physics (which I had a more intrinsic understanding of) actually helped.

rubidium 7y ago

I'll echo the grandparent that learning diff eq at the same time as the subject (e.g. mechanics) is "par for the course" for physics programs. There's many times throughout the progression to Physics PhD where "yes ideally you'd learn the math first" but there is only so much time. And some physics math is uniquely physics. I get your general point Scott, but I disagree with "trying to wrap your brain around the other parts and differential equations at the same time is too big a lift even for a galaxy brain". Learning both in the same course is doable.

scottlocklin 7y ago
The guy I was responding to, mikekchar, claimed that he was given advanced physics problems requiring diff eqs without having studied them before; this is absolutely not the case in any physics program I've ever heard of. By the time you get to Junior Year physics, you've had diff eqs, or at least an introduction to the ordinary diff eqs you get in late Calculus. You can probably learn them both in the same course; but only if the course is designed for this purpose (aka Boas based "math methods for physicists" or something). I do remember some guys in grad school who had never seen a Greens function before (I was doing them in sophomore years; guess I was lucky) encountering JD Jackson, but that's about the only disconnect I've seen.
- rubidium 7y ago
  Just speaking from my own expedience, I had advanced (jr year) mechanics before diff eq... but admittedly was taking it early. It was doable but tough. Greens function were new to me in grad school. Grad school mechanics had be learning math I didn’t know before too... can’t recall what it was at the moment. And then the advanced AMO class had some more math I hadn’t seen.
- psalminen 7y ago
  I was using diff eqs in mechanics a semester before taking Diff EQ, and this was following the standard course. In my experience, learning them through the lens of physics (which I had a more intrinsic understanding of) actually helped.