But why would light "slow down"? | Visualizing Feynman's lecture on the refractive index
The phenomenon of light slowing in a medium is formally defined not by a reduction in particle velocity (which remains $c$), but by the macroscopic phase shift resulting from the superposition of incident electromagnetic waves with secondary spherical waves generated by bound charged particles within the material. This mechanism, governed by the interaction between an external driving frequency and the resonant frequencies of these charges modeled as damped harmonic oscillators, fundamentally explains the origin of refractive index dispersion where specific spectral components experience varying degrees of phase retardation based on their proximity to resonance.
But why would light "slow down"? | Visualizing Feynman's lecture on the refractive index
The phenomenon of light slowing in a medium is formally defined not by a reduction in particle velocity (which remains $c$), but by the macroscopic phase shift resulting from the superposition of inc…