Planetary influences on electrical engineering

Abstract

The author describes how Maxwell's equations are indebted to observations of Mars, Jupiter, and Saturn. The electromagnetic relations were derived in terms of a medium with 'small but real density' and with the capability of yielding elastically, but the mechanical origin to which the curl and div equations trace back is a surprise to many engineering students. Maxwell developed his ability to deal with waves by starting his career with a four-year study of the rings of Saturn, which constitute a rare, elastic medium subject to internal inverse-square forces. Applying the laws of motion, Maxwell deduced that electricity and magnetism should combine to support what he called an electromagnetic wave, whose velocity in that medium he could calculate. Meanwhile, observations of Jupiter's satellites revealed that light has a finite velocity. Knowing this value, Maxwell was able to propose that light itself might be electromagnetic. These foundations of modern electrical engineering thus rest firmly on astronomical observation of Mars, Jupiter, and Saturn. Astronomy has continued to contribute to many branches of electrical engineering.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>