The same kind of condensation is sometimes seen above the wings of jet aircraft at low altitude in high-humidity conditions. The top of a wing is a curved surface. The curvature (and increased air velocity) causes a reduction in air pressure, as given by Bernoulli's Law. This reduction in air pressure causes cooling, and when the air cools past its dew point, water vapour condenses out of the air, producing droplets of water, which become visible as a white cloud. In technical terms, the "Wilson cloud" is also an example of the Prandtl–Glauert singularity in aerodynamics.