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Perpetual Motion Machines (PMMs)

"Nothing occurs locally, nor globally in the universe, without mass-energy exchange/conversion and entropy production. 

It is crystal-clear (to me) that all confusions related to the far-reaching fundamental Laws of Thermodynamics, and especially the Second Law (Abstract & FULL paper), are due to the lack of their genuine and subtle comprehension." > Sadi Carnot's Reflections <*> Clausius Theory of Heat <

Perpetual Motion Machine (PMM) of the First Kind (PMM1) would be one to violate the 1st Law of Thermodynamics, to permanently produce useful energy (work) without any energy source, or to produce more 'energy' than consumed (thus generate energy from nowhere); and Perpetual Motion Machine of the Second Kind (PMM2) would be one to violate the 2nd Law of Thermodynamics, to permanently produce useful energy (work) from a single reservoir in equilibrium only, or to produce more 'useful energy' than consumed, i.e., to has higher efficiency than the ideal Carnot cycle (thus generate useful-energy/non-equilibrium from nowhere and destroy entropy).        The name, "perpetual motion (PM)"  is somewhat misleading, since everything in Nature is in perpetual motion, but PM machine (PMM) means a machine (engine) producing a useful energy (work), i.e., moving under load (extracting work, load important). A friction-less pendulum or wheel (or electrons around a nucleus, or planets around a star, etc.) will permanently move but without extracting (producing) work, thus NOT violating any Law and not being PMM. 

Of course, neither PMM1 nor PMM2 are possible (will violate conservational- and forced-transformational existence, respectively) , although we may be mislead to believe so due to lack of our proper and full observation and/or comprehension of coupled energy transfers and conversions from the surroundings and/or within interacting system(s).

 To 'scoop' the useful-energy (for use or storage) require forcing by transferring the useful-energy from elsewhere or even more since in part it will be dissipated (converted) into thermal energy with generation of entropy. It cannot be 'scooped' from within an equilibrium alone nor obtained more than transferred, thus resulting in impossible entropy destruction (i.e., a wishful process without due forcing).    


* The 2nd Law defines forced directional displacement of useful/available mass-energy transfer in time, thus all processes, from higher to lower energy density/potential, due to its non-equilibrium (non-uniformity) in space, towards equilibrium (force-flux cause-and-effect phenomena), while part of the energy (up to the whole) is irreversibly converted to thermal energy (dissipated via heat) and thereby generated entropy, equal to the generated thermal energy per absolute temperature. The process cannot proceed spontaneously in opposite direction against the forcing and thus create non-equilibrium and destroy entropy, however the non-equilibrium (useful energy or work potential which is cause of process forcing) could be re-arranged/transferred and in limit conserved (in reversible processes, including forcing advantage potential). The original Clausius and Kelvin-Plank statements are the special cases related to the thermo-mechanical energy conversions. Due to reversible equivalency of all types of (coupled) energy conversions, all different statements of the Second Law (2nd Law) are equivalent...also...and.

   There is 'energy' (or 'mass-energy' as the building block of all existence) which is conserved while transferred during forced interactive displacement (subject of the First Law of Thermodynamics: energy cannot be destroyed nor generated from nowhere; and, there is 'useful energy' or 'work potential' as measure of non-equilibrium (an autonomous concept) which is the cause-end-effect of forcing energy transfer (all processes) from higher to lower energy density/potential (subject of the Second Law of Thermodynamics: non-equilibrium is irreversibly dissipated/lost in time towards equilibrium and cannot be generated from nowhere, i.e., the useful work potential is irreversibly converted to heat, and thus entropy is always generated, only in limit it may be conserved but cannot be destroyed, the latter not to be confused with local entropy decrease on the expense of increase elsewhere).

    During forced energy transfer a part (and ultimately all) of the useful energy is dissipated (irreversibly converted to thermal energy with the corresponding entropy generation), but in limit, the non-equilibrium (work potential) may be conserved during reversible processes, including localized increase of energy potential on the expense of decrease elsewhere (forcing advantage). See also Perpetual Motion Machines.

►There is no such thing as a unidirectional force or a force that acts on one body only (no imaginary boundary vector-forces). Put it very simply: a forcing (force-flux cause-and-effect phenomena) acts between an interface of pair of objects (forced interaction: action-reaction, including process-inertial forces), and not on a single object. The Newton Laws and the Laws of Thermodynamics imply that all forces are mass-energy interactions (forced displacements with momentum and energy transfer and conservation) between different particulate bodies due to non-equilibrium (available energy or work potential, cause of forcing) towards the equilibrium.

►Mass-energy is directionally displaced/transferred from its higher to lower density/potential while conserved in time due to forced displacement caused by its non-equilibrium (non-uniform) distribution in space, in an irreversible process approaching equilibrium until its distribution equalize in all directions (equi-partition of mass-energy).

Laws of Thermodynamics and Nature and Selected Links>Perpetual motion-Wikipedia * The Museum of Unworkable Devices