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There are a few themes that physics revolves around: 1. Action Principle: A lot of problems in mechanics can be boiled down to writing down the correct Lagrang
by orbifold 7y ago
There are a few themes that physics revolves around:
1. Action Principle: A lot of problems in mechanics can be boiled down to writing down the correct Lagrangian.
2. Statistical physics, this teaches you about to think in terms of "Zustandssummen" and is the starting point for deriving lots of interesting laws like black body radiation.
3. Field (Gauge) Theory, turns out you can write down and derive interesting Lagrangians for Electrodynamics, Fluid Dynamics and General Relativity as well.
3.1. Noethers Theorem and Symmetries allow you to get a unified view of conserved quantities.
4. Spinors, they are fundamental for understanding the quantum behaviour of matter
5. Path Integrals necessary to understand Feynman diagrams and Calculations in Quantum Field Theory.
6. Do the harmonic oscillator in as many different ways as possible, a lot of physics can be understood by solving the harmonic oscillator or coupled oscillators. Once you've understood why this is the case and the situations in which it isn't true, you will have understood a lot of physics.
I would recommend a depth first instead of breadth first approach. Pick something advanced that really interests you and work backwards what prerequisites you need to understand it. There are parts of classical physics that are super interesting but barely anyone learns about them anymore (I skimmed through Sommerfeld's lectures on theoretical physics once, they contain all kinds of super interesting problems with spinning billiard balls, tops and so on, this was at a time when Quantum Mechanics was in its infancy).
- thatcherc 7y agoI think points 1-6 apply best to someone with an undergrad degree (and maybe even an undergrad degree in physics), since it's hard to grasp ie the action principle and Noether's theorem without having seen at least a bit of Newtonian and classical mechanics and E&M. Certainly my high school self would have struggled here. I really like the idea of "depth first and work backwards" though. I finished undergrad with a degree in physics about a year ago, focused mostly on AMO, but since then I've seen all these headlines about AdS-CFT correspondence and cool quantum gravity papers and trying to read them is wayyy over my head. What I realized was that to read these papers, I needed to backtrack. I kinda needed to be familiar with some of the toy models for black holes in a quantum setting, which requires quantum field theory, which requires classical field theory, which I never got around to in school. So now I'm reading a set of classical field theory notes and loving it! Plus I get to look forward to the eventual dig all the way back down to AdS-CFT.
- peter_d_sherman 7y ago"A lot of problems in mechanics can be boiled down to writing down the correct Lagrangian." There's something that intuitively sounds very right about that... This list seems very interesting... I will have to explore all of these areas in greater detail... I'm not a physicist by profession, but I find most of your list's topics fascinating...
- deleted 7y ago[deleted]
- throw1234651234 7y agoIf you were writing a good guide on how to scare off a beginner from physics, congratulations.
- QuesnayJr 7y agoI think this is a good list. I think if you are interested in physics just for intellectual breadth, and not to become a physicist, it makes sense to focus on "big picture" ideas. Analytical mechanics and Noether's theorem are appealing big picture ideas.