Question What would be the point of a perpetual motion machine?
Lets say that someone invents a perpetual motion machine. One that is possibly realistic and is 100 percent efficient. What could you possible use it for other than possibly as a battery but even then the transfer from the machine to the outside world would come at a cost of efficiency, since if you take any energy out of it it will promptly stop being a perpetual motion machine. So then why do people try to create them when even if you could make one it would be pretty much useless.

Best Answer If you had the use of a perpetual motion machine you could increase the energy deficit that is created by other attempts to harvest energy sources. The reason a perpetual motion machine doesn't exist at this point is because of friction and gravity. These two, if eliminated, could allow for much more efficient machinery. A gasoline-driven vehicle, even, would see an efficiency increase of over 50%. It would cut down on energy costs, fuel consumption, and wear-and-tear on machined parts.

Question How does a perpetual motion machine reverse entropy or time?
I know it's not possible but, if you built a perpetual motion machine how would it reverse entropy or time? How would the process go about? negative comments aren't allowed. Please provide good sources and info. Thank you.

Best Answer In the mid 1800s, the concept of the perpetual motion machine became fashionable. Basically, it is a machine that when once started, will continue to produce useful work with no further addition of or input of additional energy. The US patent office was overwhelmed with patent applications for such machines, and there were a lot of hard feelings and wasting of time and energy in the arguing over the rejection of all of these patent applications. Until the US patent director had a brainstorm. He started requiring all applicants to submit a functioning working model. Patent applications for perpetual motion machines dropped to ZERO!! This is because they are impossible(duh). You simply cannot continue to extract useful work from something that requires no additional energy input. Energy is a commodity like water or copper or oxygen or anything else. All so-called perpetual motion machines will run down and stop. You can't make a bottle that gives an unlimited supply of water; you can't make an oil well that gives an unlimited supply of gasoline, and you can't make a car that goes forever without adding any additional fuel to the gas tank. It is stupid to think that you can. Even the Sun will burn out some day.

Question How can there be no such thing as a perpetual motion machine?
Theoretically, it sounds so simple, but in reality, it is increasingly difficult. Why? And why is creating a "close-to-perpetual-motion" machine so damn easy? I said creating a "close-to-perpetual-motion" machine was easy. I never said creating an actual perpetual motion machine was easy.

Best Answer Creating a perpetual motion machine is easy........ provided you have an infinite supply of energy, (which is obviously impossible......) Thermodynamics says that (except on a subatomic scale,) no physical process can be 100% energy efficient. That means that without an *external source of energy*, friction, and other internal processes will eventually bring the activity of any machine to a halt, no matter the circumstances. This would still be true, even if it were possible to completely eliminate friction, such as levitating a magnet over a superconductor in a vacuum. In a more abstract sense, the second law of thermodynamics says that the amount of "entropy" in any self contained system can only *increase*, never decrease. Exactly what "entropy" is, is hard to define in in colloquial terms, but it can be variously described as "disorder", "chaos", or "homogeneousness." Thus, any "organized motion" within a machine, must eventually be all converted into "disorganized motion".........i.e. heat. Hope that makes sense, ~W.O.M.B.A.T.