Module 1
Classical Electromagnetism & The Medium
Maxwell's equations, dielectrics, refraction, phase vs group velocity, and caustics.
Before engaging with OFT's vacuum-as-medium arguments, you need to remember how light behaves in macroscopic media. This is the bedrock of the wave sector — OFT Alpha through OFT 2.
Concepts to Cover
Maxwell's Equations (Conceptual Review) Focus on the wave equation derivation and the relationship between electric and magnetic fields. You do not need to re-derive everything from scratch — you need to be able to hold the physical picture in your head: oscillating E and B fields propagating through space, each driving the other.
Dielectrics and Refraction How and why light slows down in a medium. Review the index of refraction (n = √(εμ)), permittivity (ε), and permeability (μ). The vacuum itself has ε₀ and μ₀ — this is not nothing. This is the foundation of OFT's vacuum-as-medium claim.
Phase Velocity vs. Group Velocity The distinction between how fast a wave crest moves and how fast information (or energy) moves. Crucial for the later arguments about causality, signal propagation, and the muon g-2 anomaly.
Caustics and Branched Flow The optics of wave propagation through weakly structured random media — soap films, ocean waves, the ionosphere. Where the medium has small random variations, waves focus into bright filaments (caustics) and dark voids. This is the mechanism behind OFT's resolution of the double-slit experiment. You do not need the maths — you need the visual intuition.
Resources
Stanford / Leonard Susskind — Electromagnetism (The Theoretical Minimum)
Unmatched for an unhurried, first-principles reconstruction of Maxwell's equations. Susskind strips away engineering busywork to focus directly on the physical meaning of the vector fields, divergence, and curl. Watch this if you want the foundations rebuilt properly.
▶ Watch the playlist on YouTube
PBS Space Time — Optics and Wave Physics
Search their channel for videos on phase velocity vs. group velocity, wave packets, and refraction. Their animations provide the visual scaffolding needed to hold complex wave dynamics in mind.