The Miracle of Migration in Animals

Gaussmeter, Earth’s magnetic field, airfoil shape, and wing tip vortex may be meaningless terms for many people. They may not know that the Earth consists of a solid inner and a liquid outer core, which move around each other, creating the magnetic field that makes a compass needle point north. Probably no one except aviation engineers or those with a keen interest in the subject would know that fans—and the wings and propellers of aircraft—have an airfoil shape; and that the flow of air ar...