Course Name
Paradigms in Physics: Central Forces
Course Number
ph426
Year/Term
Spring-2026
Course Credits
4
Class meeting times
8 hours of lecture/discussion per week for five weeks.
Prerequisites
PH213, PH425, PH422
Course description
Gravitational and electrostatic forces; angular momentum and spherical harmonics, separation of variables in classical and quantum mechanics, hydrogen atom.
Topic/Day
Activities
Resources
Homework Due
W1 D1: Math Bits
Unit: Math Bits (PDEs)
Introduction to the Unit
Learning Outcomes
Unit Learning Outcomes: Partial Differential Equations (Math Bits)
Unit: Math Bits (Power Series Solutions of ODEs)
Introduction to the Unit
Learning Outcomes
Unit Learning Outcomes: Power Series Solutions of ODEs (Math Bits)
W1 D2: Math Bits
W1 D3: Math Bits
Vector Spaces/Inner Products (Review)
Legendre Polynomial Series
Guessing Legendre Coefficients Expanding a Function in Legendre Polynomials.
W1 D4: Math Bits
Separation of Variables
Curvilinear
Separation of Variables - Spherical Harmonics
Legendre's Associated Equation
Theorems about Power Series Solutions
W1 D5: Math Bits
Series Solutions for Legendre Polynomials
W2 D1
Separation of Variables
Rectangular (Review)
Unit: Classical Mechanics Orbits
W2 D2
Systems of Particles
GCF: Systems of Particles
Taylor Chap. 3 (Optional)
Central Force Lagrangians
Reduced Mass
GCF: Reduced Mass
Taylor 8.2
W2 D3
Solutions of the Harmonic Oscillator Equation (Review)
Angular Momentum
Angular Momentum SWBQ Planar Orbit
Conservation of
Classical Angular Momentum
W2 D4
Equations of Motion
Change of Variables
Polar Graphs
Circles, Ellipses, Hyperbolas
Orbit Shape
Spherical/Polar Coordinates
(Review)
Curvilinear Coordinates Introduction Curvilinear Basis Vectors
GCF: Coordinates
Video: Basis Vectors (Review from PH 335/422)
W2 D5
W3 D1
More Effective Potentials
Effective Potentials
Acting Out Effective Potentials Effective Potentials
Taylor 8.4 (Optional)
GCF: Effective Potentials
Inverse Square Forces:
Kepler's First Law
W3 D2
Kepler's Second Law
Kepler's Second Law Effective Potential Diagrams, version 1 Free Particle Effective Potential
Orbits Summary
Introduction to the Unit
Learning Outcomes
Unit Learning Outcomes: Classical Mechanics Orbits
Unit: Quantum Mechanics on the Ring
Introduction to the Unit
Learning Outcomes
Unit Learning Outcomes: Quantum Mechanics on a Ring
W3 D3
Time Dependence Review
Time Evolution Refresher (Mini-Lecture) Time Evolution of the ISW
Introduction to Particle on a Ring
Intro to Particle on a Ring
Separating out Center-of-Mass: Quantum
GCF: Reduced Mass
McIntyre 7.1
Eigenstates on a Quantum Ring
GCF: Motion on a Ring
McIntyre 7.5
W3 D4
Normalization of Eigenstates on the Ring
W3 D5
Time Dependence on a Ring
Time Dependence for a Quantum Particle on a Ring Part 1 Visualization of Quantum Probabilities for a Particle Confined to a Ring
Meaning of the Wave Function
Wavefunctions on a Quantum Ring
W4 D1
MEMORIAL DAY
No Class
Unit: Angular Momentum in Quantum Mechanics
Introduction to the Unit
Learning Outcomes
W4 D2
Quantum Ring with Separation of Variables
McIntyre 7.5
Schrödinger's Equation:
Spherical Symmetry
W4 D3
Spherical Harmonics:
Properties
Spherical Harmonics
GCF: Spherical Harmonics
McIntyre 7.6.4
W4 D4
Quantum States of the Rigid Rotor
Quantum Systems Reference Sheet Probabilities for a Quantum Particle on a Unit Sphere in Spherical Harmonic Functions
W4 D5
Spherical Harmonics:
Visualization
Spherical Harmonics on a Balloon
Rigid Rotor Probabilities & Degeneracy
Probabilities for a Quantum Particle on a Unit Sphere in Spherical Harmonic Functions
W5 D1
Symmetries, Parity, Degeneracy
Time Dependence
Quantum Particle on a Unit Sphere in Dirac Notation
McIntyre 7.6.3
Unit: Quantum Mechanics of the Hydrogen Atom
Introduction to the Unit
Learning Outcomes
W5 D2
Commutation Relations
Angular Momentum Commutation Relations: Lecture
The Radial Equation
McIntyre 8.1-8.4
GCF: The Radial Equation
W5 D3
W5 D4
Visualizing Radial Functions
Visualizing Radial Wave Functions
Radial Functions
Radial Functions for a Hydrogenic Atom
Hydrogen Atom Wave Functions
Calculations on Hydrogen Atom States
Quantum Calculations on the Hydrogen Atom Hydrogen Probabilities in Matrix Notation
Hydrogen Spectra
McIntyre 8.3
Hydrogen Atom Visualization of Probability Densities
Visualization of Quantum Probabilities for the Hydrogen Atom
W5 D5
Review
Classical Orbits Equation Sheet Quantum Ring Equation Sheet Quantum Systems Reference Sheet Spherical Harmonics Radial Functions for a Hydrogenic Atom
Learning outcomes
Unit Learning Outcomes: Partial Differential Equations (Math Bits) Unit Learning Outcomes: Power Series Solutions of ODEs (Math Bits) Unit Learning Outcomes: Classical Mechanics Orbits Unit Learning Outcomes: Quantum Mechanics on a Ring Unit Learning Outcomes: Angular Momentum in Quantum Mechanics Unit Learning Outcomes: Quantum Mechanics of the (Unperturbed) Hydrogen Atom
Final Exam
FINAL EXAM