Portal:Physics/Selected picture/Week 3, 2007

Image credit: Ensign John Gay, U.S. Navy

The Prandtl–Glauert singularity, the point at which a sudden drop in air pressure occurs, is generally accepted as the cause of the visible condensation cloud that often surrounds an aircraft traveling at transonic speeds, though there remains some debate. It is an example of a mathematical singularity in aerodynamics.