Source
Wavefronts
Observer
Pressure at observer (N-wave)
This 2D companion to the site's 3D sonic boom simulation strips the phenomenon down to its geometry: a source flies left to right at a chosen Mach number while a fixed-speed circular wavefront expands from every point it has ever occupied. Below Mach 1 those circles stay nested and spread apart — ordinary Doppler-shifted sound. Push the speed slider past Mach 1 and the circles visibly pile up into a V-shaped Mach cone trailing the source, its half-angle shrinking as θ = arcsin(1/M) with increasing speed. A ground observer marker sits below the flight path; every time the expanding wavefronts reach it, the small chart underneath plots the resulting pressure — a single sharp compression-then-rarefaction N-wave once the cone is sweeping past supersonically, versus a gentler, more spread-out ripple at subsonic speed. An altitude slider raises or lowers the flight path relative to the observer, changing how spread out or concentrated the boom arrival is.