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Perpetual Motion and why its not possible, Perpetual motion: the motion of a hypothetical machine that, once activated, would run forever unless subject to an external force or to wear.produces work without the input of energy, a machine which spontaneously converts thermal energy into mechanical work Examples of perpetual motion devices: an electric car that charges itself when it drives, A clock that winds itself as tells time. Why isn't it possible? These thing are governed by the first two laws of thermodynamics. The first law of thermodynamics: ∆U = q+w, ∆(delta)U The change internal energy of the system, and (q)The heat transferred into/out of the system and (w) The work done by/on the system. ΔU=q+w simply states that energy can be neither created nor destroyed (conservation of energy). Thus power generation processes and energy sources actually involve conversion of energy from one form to another, rather than creation of energy from nothing. Example of the first law: Battery=chemical energy to electrical Photosynthesis= Optical energy to Chemical energy The Second law of thermos dynamics: dS=∂Q/T The infinitesimal change in entropy of a system (dS) is calculated by measuring how much heat has entered a closed system (∂Q) divided by the common temperature (T) at the point where the heat transfer took place. The Second Law of Thermodynamics is commonly known as the Law of Increased Entropy. While quantity remains the same (First Law), the quality of matter/energy deteriorates gradually over time. HuH? Usable energy is inevitably used for productivity, growth and repair. In the process, usable energy is converted into unusable energy. Thus, usable energy is irretrievably lost in the form of unusable energy. With this information you can see why perpetual motion is not an option. There is a bit more to this due do the three categories of "Perpetual devices." Here are some perpetual device images to give you an idea.
