Gyroscope

just about everyone is familiar with one gyroscope instrument --the child's spinning top developed independently in ancient civilizations around the world. why does it go on spinning? inertia. A moving object will persist in its motion along the same axis,unless a force acts to change or stop it.

In 1852 French physicist Leon Foucault created a precision gyroscope and gave the instrument name made up of Greek words meaning essentially rotation watcher while holding his gyroscope cage steady,Foucault showed that the angle of the inner disk's rotation seemed  to change very gradually on its own in fact it  was an early demonstration of  own rotation on its axis.

Once in motion,the gyroscope's inner wheel maintains the orientation of its rotation even as its outer frame is tilted. because of this, the gyroscope is a tremendously useful tool in setting or maintaining direction in a number of application, from aircraft navigation to missile missle guidance to tunnel mining.