Energy
Windmill – A Rondo (but not a perpetuum mobile)
Our world is based on entropy; it causes that some of energy is unavailable for work in the thermodynamic processes in machines or living systems. Perpetuum mobile (which in Latin means perpetual motion) refers to movement that goes on forever (Webster Online, 2012). An object would move infinitely, according to Newton's first law of motion, in a perfect vacuum with no forces acting at it. In reality, space is filled with low-density plasma.
https://www.google.com/search?q=plasma&aq=f&oq=plasma&aqs=chrome.0.57j0j5j0.2749j0&sourceid=chrome&ie=UTF-8
(Every machine would lose energy to friction and air resistance. Moreover, perpetual machine would deliver more energy than was put into it, which would violate the law of conservation of energy, which states that energy can never be created or destroyed. For this reason it is impossible to build a perpetual motion machine that would work infinitely without the input of energy from the external sources. Physicists and philosophers performed for ages the thought experiments about interaction between entropy, information, quantum fluctuations of energy, thermal effects, magnetism, gravity, etc. Proponents of the perpetual machine have been working from the ancient times on thousands of various solutions and were often so confident about their success that in 1775 the Royal Academy of Sciences in Paris, and then the United States Patent and Trademark Office and many other patent offices started to officially reject all patent applications. This theme is constantly present in literature, music, and film.
While taking into account all the above remarks, here comes an idea, or a semi-practical model for a rondo, a sequence of actions, where one event proceeds from another and can even be seen as never-ending events or cycles. For example, how a windmill pumps water to water the ground, watering allows corn to grow, corn produces gas, gas powers machinery, machinery digs the oil, oil serves for digging coal through surface mining, which allows for a hydropower production, which in turn may be used to water the ground.