What is gyro compass?
A gyrocompass is similar to a gyroscope. It is a compass that finds true north by using an (electrically powered) fast-spinning wheel and friction forces in order to exploit the rotation of the Earth. Gyrocompasses are widely used on ships. They have two main advantages over magnetic compasses: * they find true north, i.e., the direction of Earth’s rotational axis, as opposed to magnetic north, * they are not affected by ferrous metal in a ship’s hull. (No compass is affected by nonferrous metal, although a magnetic compass will be affected by non-ferrous wires with current running through them.) A gyrocompass is essentially a gyroscope, a spinning wheel mounted on gimbals so that the wheel’s axis is free to orient itself in any way. Suppose it is spin up with its axis pointing in some direction other than the celestial pole. Because of the law of conservation of angular momentum, such a wheel will maintain its original orientation. Since the Earth rotates, it appears to a stationary o
