Asked by: Ofosu Antwi Kenneth, Ghana
Everything in the Universe is in motion because forces exist in the Universe. The gravitational force and the electromagnetic force ensure large objects are in motion while the weak and strong nuclear forces ensure the quantum world is constantly in motion. If there were no forces, there would be no motion.
The question of why there are forces in the Universe is currently unanswerable by science. They appear to be fundamental and demonstrable facts but there may not be an ultimate reason for their existence, just as there may not be a root cause for the existence of the Universe itself.