The gyroscope is capable of measuring how quickly the phone is being turned. It measures the rate of rotation of the phone and returns values in radians per second about the x axis, the y axis and the z axis. This rate of rotation is also known as the Angular Velocity, so the gyroscope can tell us the speed of rotation of the phone. By extension, if the speed of rotation is any number greater than 0, we can infer that the phone is being turned.