## Friday, October 07, 2016

### Friday Science: Classifying Physics

So I've taken a shot at categorizing math and chemistry. Today's physics.

1. What do physics majors take?
• I didn't really find many university catalogs very helpful.
• So there's a first semester introductory course, typically covering Mechanics, then advanced mechanics later
• Then there's a second semester course, perhaps covering Thermodynamics, then advanced thermodynamics later, statistical mechanics
• Then there's a third introductory course, usually Electromagnetism, then more advanced electromagnetism later
• Optics
• Quantum physics, particle physics, and relativity
• Electronics
• Computational physics
• Astrophysics
2. Here are the classifications of Dewey and the Library of Congress:

So the Library of Congress adds geophysics and meteorology. I suppose fluid mechanics wasn't exactly mentioned above either.

3. Then there are physics textbooks. Here are the units in one I have:
• Mechanics
• Waves
• Thermodynamics
• Electromagnetism
• Optics
• Modern Physics
4. OK, so here's my recombobulation, with the math cross-overs I can think of:

I. Classical Mechanics
• Kinematics - describing motion, including rotational motion
• Dynamics - the forces that cause motion
• The math required to do these well includes basic algebra, trig, differential and integral calculus; there is at least some minimal treatment of vectors, radian measurement, partial differential equations
• wave mechanics (mechanical, fluid, sound)
• add logarithms to the math of sound waves
II. Thermodynamics and Statistical Mechanics
• Great deal of overlap here with those aspects of chemistry relating to changes of states.
• zeroth, first and second laws of thermodynamics
• natural logarithms and e pop up occasionally
• statistical mechanics gets into summation functions and probabilistic functions
• I suppose meteorology and geophysics go here.
III. Electromagnetism and Optics
• Maxwell's four laws and beyond
• Not much new mathematically, surface integrals
IV. Modern Physics
• relativity, special and general
• Relativity required some new math, especially non-Euclidean geometry
• cosmic physics
• quantum mechanics
• Quantum mechanics involves a lot of linear algebra, including matrix algebra. It involves complex analysis, that is, extensive use of complex numbers. There is e.
V. Tools and Equipment
• There is of course the standard and exotic equipment, including everything from particle accelerators to voltmeters to the Hubble Space telescope.
• Computers have increasingly played a role in doing physics, to where computational physics is an important piece of the puzzle