Teaching demo
Supersonic
A plane makes pressure ripples that spread at the speed of sound. What happens when the plane flies faster than they do?
Why supersonic jet intakes are pointy
The wedge above is designed for Mach 2.0 — drag its flight-speed slider and watch the shock angle move off the cowl lip. Engines can only swallow slow air, so the intake's job is to use the shock itself as a brake — and that only works if the shock lands exactly on the lip. Concorde used flat adjustable ramps and the SR-71 slid its spikes in and out for exactly this reason: the geometry must chase the shock angle as Mach changes.
Model: ripples spread at the speed of sound (sin μ = 1/M for the cone); the intake shock uses the real oblique-shock θ–β–M relation for an 8° wedge (γ = 1.4). Scene not to scale — real booms come from ~11 km up.