Perpetual Motion Machines

1659 Words7 Pages
Perpetual motion Machines The motion of a theoretical mechanism that, without any losses due to friction or other forms of dissipation of energy, would continue to operate indefinitely at the same rate without any external energy being applied to it. This is called “Perpetual motion” Perpetual motion describes hypothetical machines that operate or produce useful work indefinitely and, more generally, hypothetical machines that produce more work or energy than they consume, whether they might operate indefinitely or not. There is undisputed scientific consensus that perpetual motion in a closed system would violate the first law of thermodynamics and/or the second law of thermodynamics. Machines which extract energy from seemingly perpetual sources—such as ocean currents—are indeed capable of moving "perpetually" (for as long as that energy source itself endures), but they are not considered to be perpetual motion machines because they are consuming energy from an external source and are not closed systems. Similarly, machines which comply with both laws of thermodynamics but access energy from obscure sources are sometimes referred to as perpetual motion machines, although they also do not meet the standard criteria for the name. Despite the fact that successful closed system perpetual motion devices are physically impossible in terms of our current understanding of the laws of physics, the pursuit of perpetual motion remains popular. Basic principles There is an undisputed scientific consensus that perpetual motion in a closed system violates either the first law of thermodynamics, the second law of thermodynamics, or both. The first law of thermodynamics is essentially a statement of conservation of energy. The second law can be phrased in several different ways, the most intuitive of which is that heat flows spontaneously from hotter to colder places;
Open Document