Introduction
    Overview
    A brief history of quaternions
    Multiplying quaternions the easy way
    Inner and outer products
    Algebraic tools is an HTML document
    Understanding a Mathematica notebook

Classical Mechanics
    F = ma
    4 tests of a conservative force
    The simple harmonic oscillator and wave equation

Special Relativity
    An alternative algebra for boosts

    PS1: Kinematic effects of relativity
    PS2: More kinematic effects
    PS3: The Lorentz transformation and the addition of velocities
    PS4: The Doppler effect, 4-vector invariants, and the twin paradox
    PS5: Energy, Mass and Momentum
    PS6: The Compton effect and the threshold collision problems

Electricity and Magnetism
    Classical electrodynamics
    Quantum electrodynamics
    The Maxwell equations in the Lorenz gauge
    The Lorentz Force
    Gauge transformations

Quantum Mechanics
    Bracket notation & quaternions: quaternions as a complete inner product space
    Polar representations
    Multiplying quaternion exponentials (without Campbell-Hausdorff)
    Commutators and the uncertainty principle
    The Schrödinger equation
    The Klein-Gordon equation
    Time reversal

Gravity
    Please see my current work to unify gravity and EM at the top of the quaternions.com page.
    Answering question in quantum gravity
    Gravitational redshift experiments
    The length of a quaternion in curved spacetime

Conclusions
    A (very brief) summary of physics equations written as quaternions
    Conclusions