Sonic booms arise from the same mechanism as boat wakes

Evidence

The reason for the sudden boom, and the angle the cone makes with the path of the object, can be seen in figure 7.32. Each moment in time that the object disturbs the air at a new point, that point becomes the center of a spherical surface of sound expanding at the speed of sound. Imagine holding an eyedropper over a pool of water, with droplets falling at regular intervals. If the eyedropper is moved across the surface at constant speed, three scenarios are possible: either the speed of the dropper is slower than the wave that moves out in a circle from each new drop, or it is the same speed, or it is faster (supersonic). If it is faster, a V-shaped envelope of the wavefronts from each droplet will form. This is not unlike the familiar V-shaped wake of a speedboat, which travels much faster over the water than any of the waves it generates. — Eric J. Heller, Why You Hear What You Hear- An…, 635

Categorization

• DEFINE: Explains the sonic boom mechanism via the eyedropper/boat-wake analogy, connecting the abstract wavefront envelope to a familiar everyday phenomenon.
• XREF: Links to other wave-physics treatments of bow shocks and wakes; the eyedropper analogy appears throughout physics pedagogy.