Perpetual motion machines

Perpetual motion machines are hypothetical devices that aim to operate indefinitely without any energy input, producing work or energy continuously. According to the laws of physics, specifically thermodynamics, such machines are impossible because they would violate the conservation of energy and increase entropy. In real-world terms, they would need to generate energy forever without losing any, which contradicts scientific principles since all real systems experience energy losses like friction and resistance. Despite many attempts, no perpetual motion machine has ever been successfully built or demonstrated.