Most important undergraduate physics course?

Question

I'm curious what the most important physics course likely to be taken by a physics major might be. By important, I mean the course/topic that has the farthest reaching and most significant implications in the sort of physics that is currently being researched today.

If I had to guess just one, I'd say statistical mechanics, since thermodynamics is explained by it and quantum theory is dependent on it.

Any thoughts?

Answer 1

I would have said that the most important course for an undergraduate physicist is the mathematics course! However, classical mechanics with its Hamiltonian and Lagrangian formulations is the key to quantum mechanics. Then again, statistical mechanics is a key to many areas of solid state physics, gas physics, and thermodynamics. At the end of the day, all of the physics courses provide a scaffold of structure upon which they all inter-depend.

For modern physics perhaps the most far reaching course, in an undergraduate programme, would group theory and special unitary matrices, along with Lie groups. This form of mathematics is key to the standard gauge model of particle physics.

Physics is such a broad subject that it is impossible to be absolute on which course is the most important!  

Answer 2

I really want to help, but in doing so, I'd like to go off the grid here and point to mathematics.

In my experience as a physics student and teacher, I have found that the biggest barrier to understanding physics is often mathematics.

So I would say that you should master:

Calculus (relevant for classical physics and some relativity)

Linear Algebra (critical for theoretical quantum work and often overlooked) -- EDIT -- specifically matrices and matrix mechanics

Statistics (calculus based)

Again, if you are a math whiz, just ignore me, but as you progress in your career, it would be unfortunate to be unable to grasp the physics concepts due to being unable to "translate" the meaning of mathematical expressions. (This is the what I often see happening with students)

I know you asked for physics courses, but I hope you appreciate my answer is intended to respond to the "most important" part of your question.

Respectfully,

Toddio

Answer 3

I doubt if anything classifies as "most important", but if you ask what course(s) would be the building blocks for the future courses, these would be:

- Mechanics

This would be kinematics, dynamics, classical mechanics (Lagrangian/Hamiltonian formulations), rotational dynamics (moment of inertia etc.), fluid mechanics (Eulerian, Lagrangian descriptions), Elasticity (Stress tensor etc.)

- Electromagnetism

Maxwell's equations and their application including optics.

- Statistical Physics

Ergodic hypothesis, partition function, application to different things, perhaps with a segue into information theory (since information is negative entropy).

The reason I mention these is that these don't require mathematics beyond calculus slightly beyond high school level (assuming that the student takes a parallel or prerequisite course in differential equations etc.)

Notions like Relativity and QM involve assumptions that are much more difficult to swallow, since many questions that were addressed by the postulates would become familiar only after going through the above material.

For example, consider Bohr's hypothesis on quantization of angular momentum. One can see that independently from the notion of quantization of phase space as well, but in order to raise the question as to *why* the quantization was even proposed, one needs to know that accelerating charges emit electromagnetic waves (and hence, lose energy), which would raise the question as to why electrons don't simply fall into the nucleus.

The above courses will also strengthen your mathematical/physical intuition. For example, Einstein's gravitation notions involve tensors. If you know about the Elastic property relating stress and strain or the dielectric constant as tensors, you will get a "feel" for them, which is very, very important because otherwise, you will only have a "mathematical" feel for them.

That's why, I would include only the ones I did: a thorough grounding in mechanics (including fluid mechanics), electromagnetism and statistical physics. Those themselves would probably take a good two or three semesters at least.

Here's wishing you the best if you are about to embark on a major in Physics!

Answer 4

I think it depends on what you do. I used to think quantum was the most important when I was doing atomic physics research, but now that I am doing plasma physics I think E&M was.