Changes

Another type of perpetual motion machine simply uses its initial energy to remain in motion perpetually.  If entropy is always increasing, even in closed (and isolated) systems, then indefinite motion is impossible because an increase in the disorder of the system will inevitably disrupt the motion.  The [[Second Law of Thermodynamics]] predicts that a perpetual motion machine in this sense is impossible, and none has ever been created.

Another type of perpetual motion machine simply uses its initial energy to remain in motion perpetually.  If entropy is always increasing, even in closed (and isolated) systems, then indefinite motion is impossible because an increase in the disorder of the system will inevitably disrupt the motion.  The [[Second Law of Thermodynamics]] predicts that a perpetual motion machine in this sense is impossible, and none has ever been created.