History Main / PerpetualMotionMachine

* In Creator/RobertReed's novel, ''An Exaltation Of Larks'', time travelers from the [[TheStarsAreGoingOut heat death of the universe]] have been steadily making their way back to the Big Bang (at 15 month intervals) in order to tweak the laws of physics to make the ''entire universe'' a perpetual motion machine - rather than slowly succumbing to entropy, the universe will periodically [[ApocalypseHow collapse]] and then expand again.

* In Creator/RobertReed's novel, ''An Exaltation Of Larks'', time travelers from the [[TheStarsAreGoingOut heat death of the universe]] have been steadily making their way back to the Big Bang (at 15 month intervals) in order to tweak the laws of physics to make the ''entire universe'' a perpetual motion machine - rather than slowly succumbing to entropy, the universe will periodically [[{{ApocalypseHow collapse]] and then expand again.

* ''WesternAnimation/TheSimpsons'', "The PTA Disbands": Lisa is going crazy while the teachers are on strike and creates a [[http://www.youtube.com/watch?v=Xy0UBpagsu8 perpetual motion machine]]. Homer later told Lisa that no physics law should be broken in his home.

* In one episode of {{Recess}}, Gretchen invented one for a school project, and it was immediately confiscated by the government.

** In the book, Psychlo's atmosphere has the same implausible property. But, there, it's implied that the Psychlos are actually from a different universe with different physical laws.

->"''Lisa! In this house, we obey the laws of thermodynamics!''"

[[AC:Advertising]]
* A Toyota commercial demonstrates a car with regenerative braking, which attempts to recapture a portion of the energy lost as the car brakes. The actor in the commercial imagines applying this same technology to a roller coaster to create a [[http://www.youtube.com/watch?v=r8iFqz1Ogig "self-sustaining amusement park."]] Unfortunately, he is talking about creating a perpetual motion machine. No matter how perfect the machine, heat, friction, gravity, and air resistance guarantee that this is impossible. The flaw in his idea comes from the fact that the energy expended to cause the roller coaster to start will always be greater than the energy regained from the breaks, in much the same way that hybrid cars need gas.

* The main focus of the first episode of {{The Chronicles of Professor Jack Baling}} is what happens to an engineering professor when he encounters a working perpetual motion machine. Specifically, an overbalanced wheel [[http://www.lhup.edu/~dsimanek/museum/machines/machines.htm]].

* In ''DwarfFortress'' the mechanical energy needed to pump water up one story is only one tenth the amount generated when the water comes back down and powers a water wheel. Power the pump with the water wheel, prime it once with manual labor, and it will endlessly generate power.
* ''VideoGame/{{Portal}}'' fans proposed several ideas for perpetual motion machines using the portal technology. Most of them revolve around the fact that if one portal is on the ceiling and the other is on the floor, any object thrown in would fall indefinitely.

* The Reapers in ''MassEffect'' somehow work without fuel. In ''MassEffect3'' Codex it is outright stated how strange and impossible this should be, as well as the fact that without need for resources and capable of replenishing their foot-soldiers from enemy ranks, the Reapers need absolutely no supply lines in war.

-->-- '''Homer Simpson''', ''TheSimpsons'', "The PTA Disbands"

* A couple of [[SCPFoundation SCP's]] are noted they could be used as perpetual motion machines, although they would either A. produce power very slowly or B. to dangerous to use.

* ''TheSimpsons'', "The PTA Disbands": Lisa is going crazy while the teachers are on strike and creates a [[http://www.youtube.com/watch?v=Xy0UBpagsu8 perpetual motion machine]]. Homer later told Lisa that no physics law should be broken in his home.

* Technically, do to conservation of Angular momentum, if you had a spinning wheel in empty space and no force acts on it at all, it would spin forever. However, if you try to do anything useful with it, it will start to slow down.

* Discussed in the VorkosiganSaga novel ''Komarr''. One of the physicists Miles calls in to consult determines that the device he's asking her about ''looks'' like a perpetual motion machine. Since she's a competent physicist who doesn't believe in such things, she concludes that it must be drawing energy from the deep structure of the wormholes it gets pointed at -- because there's nowhere else it could be coming from.

* In the second ''Literature/JimButton'' book by MichaelEnde, the protagonists invent it. Essentially, their version is based on a magnet which you can switch on and off, which pulls their locomotive.

* ''{{Portal}}'' fans proposed several ideas for perpetual motion machines using the portal technology. Most of them revolve around the fact that if one portal is on the ceiling and the other is on the floor, any object thrown in would fall indefinitely.

Obviously, a SubTrope of YouFailPhysicsForever: a PerpetualMotionMachine contradicts the First Law of Thermodynamics, which states, roughly, "You can't get something for nothing." Of course, this didn't stop some people from believing in a PMM - [[IRejectYourReality they just insist that obviously, the First Law has to be wrong.]]

Obviously, a SubTrope of YouFailPhysicsForever. To be precise, a PerpetualMotionMachine contradicts the First Law of Thermodynamics or in other words in this case, "You can't get something for nothing." Of course, this didn't stop some people from believing in a PMM - [[IRejectYourReality they just insist that obviously, the First Law has to be wrong.]]

This is pretty much NoConservationOfEnergy applied to machines.

Obviously, a SubTrope of YouFailPhysicsForever. To be precise, a PerpetualMotionMachine contradicts the Second Law of Thermodynamics or in other words in this case, "You can't get something for nothing." Of course, this didn't stop some people from believing in a PMM - [[IRejectYourReality they just insist that obviously, the Second Law has to be wrong.]]