🌈 Redshift and Doppler Shift — 2D Wave Fronts and Shifted Spectral Lines

2D companion of the redshift and Doppler sim: moving-source wave fronts, relativistic Doppler factor against the classical approximation, shifted H-alpha, H-beta, Na D and Ca K lines on a spectrum bar, and a Hubble diagram with an independent crest-arrival numerical check.

2D · HTML5 Canvas 2D · 60 FPS target · runs fully client-side, no install