Hi all, I am a student in Mathematics who has recently discovered a small interest in Physics. I will be graduating next semester, but I will have the opportunity to take an extra class of my choosing. I have already completed the year-long Physics I and Physics II sequence covering elementary Classical Mechanics & Electromagnetism that most engineers take. I would like to ask what class would be the most interesting or useful to a soon-to-be Math graduate student. If it matters, I will likely be doing computational math or numerical analysis in graduate school, but I greatly enjoy pure math. I also like earth-science and chemistry a decent amount. Mechanics - This course is an undergraduate course in classical mechanics at the level of the textbook by Fowles and Cassidy. The course includes particle dynamics in one, two, and three dimensions; oscillatory systems including normal modes; conservation laws; dynamics of a system of particles; motion of rigid bodies; central force problems; Lagrangian and Hamiltonian Mechanics. Electromagnetism - This course is an undergraduate course in electromagnetism at the level of the textbook by Griffith. The course includes electrostatics; Laplace's equation; the theory of dielectrics; magnetostatic fields; electromagnetic induction; magnetic fields of currents; Maxwell's equations. Thermodynamics - Concept of temperature, equations of state; the first and the second law of thermodynamics; entropy; change of phase; the thermodynamics functions. Modern Physics - Foundations of the atomic theory of matter; kinetic theory; elementary particles; radiations; atomic model; atomic structure; atomic spectra and energy levels; quantum theory of radiation; x-rays; special theory of relativity. At the moment, I am leaning towards electromagnetism, as I found it to be more interesting than mechanics. I am not too sure. Any suggestions are appreciated.