Cybernetics is the study of communication and feedback control in machines and humans. Cybernetics analyzes the ability of humans, animals and some machines to respond to or make adjustments based upon sensory input from the environment. This process of response or adjustment is called feedback or automatic control. For example, the household thermostat uses feedback when it turns a furnace on or off based on its measurements of temperature. The earliest known feedback control mechanism, the centrifugal governor, was developed by Scotsman James Watt in 1788. Watt's steam engine governor contained two weighted arms that were hurled outward by centrifugal force as engine speed increased. Once the arms reached a certain point, they triggered a mechanical link which closed a valve, thus preventing engine from exceeding a certain speed, keeping it at a constant rate. The principles of feedback control were first clearly defined by Norbert Wiener (1894-1964), a...