What is a perpetual motion machine

There is an electromagnetic coil above a permanent magnet, so the potential energy generated by the electromagnetic coil with a certain amount of work is proportional to the magnetic force of the permanent magnet. Perpetual machine refers to an engine that violates the basic laws of thermodynamics and cannot be realized. A machine that can do work forever without consuming energy violates the first law of thermodynamics, so it is called "the first kind of perpetual motion machine". In the absence of temperature difference, a machine that continuously absorbs heat from seawater or air in nature and continuously converts it into mechanical energy violates the second law of thermodynamics, so it is called "the second kind of perpetual motion machine". The term perpetual motion machine is not very appropriate. Such as a flywheel, once it starts to move, it can continue to move permanently without friction and resistance, which is not easy to realize in practice, but it makes sense and can be regarded as a practical limit situation. The so-called perpetual motion machine does not refer to this situation, not trying to keep eternal motion, but expecting to get useful work continuously without external energy supply, that is, without consuming any fuel and power. If this perpetual motion machine can really be made, then we can get infinite power out of nothing without using any natural energy. When people haven't mastered the basic laws of nature, this idea once lured many people with outstanding creative talents, who paid a lot of wisdom and labor to pursue the realization of this dream. However, no perpetual motion machine has been actually manufactured, and no design scheme of perpetual motion machine can withstand scientific examination.

The reason why perpetual motion machine can't exist

According to the laws of the universe, everything in the universe and on the earth has to go through the process of production and extinction, and it is only natural that human beings need to eat and so on. Everything in the universe will die out, only a matter of time. The perpetual motion machine violates this law, so the matter that violates the law formula cannot exist. The invention of human beings is just a trial of the law formula, and human beings can't feel it, but we find that what human beings "invent" is a phenomenon that already exists in nature, but human beings use formula+labor to unlock it. Therefore, we can't violate the laws of the universe, we can only follow it.

Dream of perpetual motion machine

The idea of perpetual motion machine originated in India, and it spread from India to the Islamic world around 12 AD, and from here to the west. In Europe, one of the most famous designs of perpetual motion machine in the early days was put forward by a Frenchman named Hennecau in the 13th century. As shown in the figure: there is a rotating shaft in the center of the wheel, and 12 movable short rods are installed at the edge of the wheel, and one end of each short rod is equipped with an iron ball. The designer of the scheme thinks that the ball on the right is farther from the axis than the ball on the left, so the rotating torque generated by the ball on the right is greater than that generated by the ball on the left. In this way, the wheel will turn endlessly in the direction indicated by the arrow and drive the machine to turn. This design has been copied by many people in different forms, but it has never been turned endlessly. After careful analysis, it will be found that although the torque generated by each ball on the right is large, the number of balls is small, and the torque generated by each ball on the left is small, but the number of balls is large. Therefore, the wheel will not continue to rotate and do work outside, but will only swing a few times and stop at the position drawn on the right. Later, Leonardo da Vinci (1452-1519) of Renaissance Italy also built a similar device. When he designed it, he thought that the heavy ball on the right was farther away from the wheel center than the heavy ball on the left, and the wheel would rotate endlessly in the direction of the arrow under the unbalanced action of both sides, but the experimental results were negative. Leonardo da Vinci keenly concluded that perpetual motion machine is impossible to realize. In fact, according to the principle of lever balance, in the above two designs, although each weight on the right exerts a large rotating effect on the wheel, the number of weights is small. Accurate calculation can prove that there will always be a proper position, so that the rotating action (torque) exerted by the weights on the left and right sides on the wheel in the opposite direction is just equal and offset each other, so that the wheel can reach a balance and come to a standstill. The drop of running water can push the turbine to provide power to the outside. Can the running water be used to design a perpetual motion machine? In the 167s, an Italian mechanic, Stell, put forward a design scheme of perpetual motion machine. In his design, he thought that the water flowing out of the upper tank would impact the rotation of the water wheel. While driving the water mill to rotate, the water wheel would drive the spiral pump through a set of gears to lift the water in the reservoir to the upper tank again. He thought that the whole device could keep running like this and do work effectively. In fact, less and less water flows back to the tank, and soon all the water in the tank flows into the reservoir below, and the turbine stops running. Buoyancy is also a good helper in designing perpetual motion machines. It is a famous design scheme of buoyancy perpetual motion machine. A series of balls, wound around the upper and lower wheels, can rotate like a chain. Some balls on the right are put in a container full of water. The designer thinks that if there is no water container on the right, the number of balls on the left and right sides is equal, and the chain will be balanced. However, now these balls on the right are immersed in the water, and when they are buoyed by the water, they will be pushed upward by the water, which will drive the whole string of balls to rotate around the upper and lower wheels. There is a ball above the water. There is a ball below that goes through the bottom of the container and is added. Such a perpetual motion machine has not been made, is it because it is technically difficult to make the ball below pass through the bottom of the container without letting water leak out? The technical difficulty is not the main problem, but the principle of design. When the ball below passes through the bottom of the container, it bears the pressure of the water above, just like the bottom of the container, and because it is at the bottom of the water, it is under great pressure. This downward pressure will offset the buoyancy of the above balls, and the hydrodynamic machine will not move forever. In addition, people have also proposed various designs of perpetual motion machines that use the inertia of wheels, capillary action of thin tubes, electromagnetic force and so on to obtain effective power, but they all failed without exception. In fact, in the design of all perpetual motion machines, we can always find a balanced position, in which the forces just cancel each other out and there is no longer any driving force to make it move. All perpetual motion machines are bound to stop at this equilibrium position and become unmotivated. Since the Gothic era, there have been more and more such designs. In the 17th and 18th centuries, people put forward various designs of perpetual motion machines, some of which used "spiral water pumps", some used the inertia of wheels, buoyancy or capillary action of water, and some used the repulsion between same-sex magnetic poles. The court gathered all kinds of scheme designers who tried to make money with this illusory invention. Both learned and uneducated people believe that perpetual motion is possible. This task attracts researchers like a mirage, but all these schemes ended in failure without exception. They have been spinning around in the same place for years, and they can't create any results. Through constant practice and trial, people gradually realize that any machine that does work to the outside world will consume energy. Machines can't do work without consuming energy. At this time, some famous scientists, such as Stevin and Huygens, began to realize that it was impossible to make a perpetual motion machine by mechanical methods.

the dream of perpetual motion machine is shattered

in the middle of 19th century, a series of scientific workers made great contributions to correctly understand the mutual transformation relationship between thermal function transformation and other material motion forms, and soon the great law of energy conservation and transformation was discovered. People realize that all substances in nature have energy, and energy has various forms, which can be transformed from one form to another and transferred from one object to another, and the sum of energy remains unchanged in the process of transformation and transfer. The transformation law of energy conservation provides a more accurate and richer scientific basis for dialectical materialism. It has effectively dealt a blow to the idealistic view that material movement can be created and destroyed at will, and it has completely broken the dream of perpetual motion. After all the attempts to make the first kind of perpetual motion machine failed, some people dreamed of making another kind of perpetual motion machine, hoping that it would not violate the first law of thermodynamics and be economical and convenient. For example, this kind of heat engine can directly absorb heat from the ocean or atmosphere and turn it into mechanical work. Because the energy of the ocean and atmosphere is inexhaustible, this kind of heat engine can work endlessly and is also a perpetual motion machine. However, on the basis of a lot of practical experience, the British physicist Kelvin put forward a new general principle in 1851: it is impossible for matter to absorb heat from a single heat source and turn it into useful work without other effects. In this way, the idea of the second kind of perpetual motion machine also went bankrupt. The endless stream of perpetual motion machine design schemes all failed under the strict examination of science and the ruthless test of practice. In 1775, the French Academy of Sciences announced that "undergraduate colleges will no longer review all the designs of perpetual motion machines". This shows that at that time, the scientific community had realized from the long-term accumulated experience that there was no hope of success in the attempt to make a perpetual motion machine. The idea of perpetual motion machine has lasted for hundreds of years in human history. The refutation of this myth is not only conducive to people's correct understanding of science, but also conducive to people's correct understanding of the world. Energy can neither be produced out of thin air nor disappear out of thin air, but can only be transformed from one form to another or transferred from one object to another. In the process of transformation and transfer, the sum of energy remains unchanged, which is the law of conservation of energy, so the first type of perpetual motion machine cannot be made. The transformation and transfer of energy is directional, just as heat can be spontaneously transferred from a hot object to a cold object, but it cannot be spontaneously transferred from a cold object to a hot object without causing other changes, so the second type of perpetual motion machine cannot be made.

In history, many people tried to design a machine that can rotate endlessly and even do work continuously without consuming energy. This is what people call a perpetual motion machine. Despite the hard work of many people, it turns out that they all failed without exception. Perpetual motion machine is an illusion, which will never succeed, because it violates one of the most common laws in nature, that is, the law of energy transformation and conservation. Leonardo da Vinci, a famous scientist, put forward the idea that perpetual motion machine is impossible as early as the 15th century. He once designed a kind of runner, as shown in the figure, and installed a series of containers on the edge of the runner, which were filled with some mercury. He thought that the movement of mercury in the containers might make the runner rotate forever, but after careful study, he came to a negative conclusion. He realized from many similar design schemes that the attempt of perpetual motion machine was doomed to failure. He wrote: "visionaries of eternal movement! How futile your exploration is! Still go to be a gold digger! " However, for hundreds of years after the 15th century, the activities of making perpetual motion machines never stopped. For example, in the 17th century, there was a prisoner named Marchis who was imprisoned under the Tower of London in England. He made a rotating "perpetual motion machine", as shown in the figure. The diameter of the runner is 4.3 meters, and 4 steel balls, each weighing 23 kilograms, move along the outer side of the spoke wing to increase the torque. When the runner is turned to a high place, the steel balls will automatically roll to the center. It is said that he once performed this device to King Charles I of England. The king was very happy and pardoned him. In fact, this machine relies on inertia to maintain short-term movement. Soft-arm perpetual motion machine In the 19th century, someone designed a special mechanism, as shown in the figure. Its arms can bend. There is a groove on the arm, and the ball rolls along the groove to the extended arm end, which increases the torque. Turning to the other side, the soft arm begins to bend and move closer to the axis. The designer thinks that this can make the machine get torque. However, he didn't expect that although the moment arm was shortened, the resistance increased, and the runner could only stop in place. Archimedes spiral perpetual motion machine In 1681, a famous doctor in Britain, Vlad, put forward a suggestion, using the archimedes spiral (as shown in the figure) to lift the water in the pool to a high place, and then let the rising water drive the turbine. The turbine can not only drive the water mill to do work, but also make the archimedes spiral to continuously lift water. If this goes on and on, can you not worry about the drought and dry water? At that time, there were many people who responded to him, and all kinds of automatic turbines were put forward one after another, and there was a craze. In about 157, an Italian professor named Tesniers proposed that a perpetual motion machine could be realized by the attraction of a magnet. His design is shown in the figure. A is a magnet, and the iron ball C can be attracted by the magnet to roll up along the inclined plane, to the upper E, to fall from the small hole B, to return through the curved surface BFC, and to be attracted by the magnet again, so that the iron ball can move continuously along the spiral path. Probably he had not established Coulomb's law at that time, and he didn't know that the magnitude of magnetic force was inversely proportional to the square of distance. As long as he thought about it seriously, his absurdity would be clear at a glance. There are many similar examples, which will not be described in detail here. As long as we list some names, it is enough to show how extensive and attractive such futile activities are. For example: surface tension perpetual motion machine, buoyancy perpetual motion machine, permanent magnet perpetual motion machine, automatic car, automatic washing machine, etc. While some people are keen on making perpetual motion machines, scientists have gradually realized the objective laws of nature from the study of basic mechanics theories. After Leonardo da Vinci, Steven wrote a book "Fundamentals of Statics" in 1568, in which when discussing the decomposition of forces on inclined planes, he clearly put forward the view that perpetual motion machines could not be realized. The illustration he used is painted on the title page of the book, as shown in the figure, which reads at the top: "Magic is not magic." 14 small balls of equal weight are evenly threaded to form a ball chain connected end to end and placed on an inclined plane. He thinks that the chain's "endless movement is absurd", so both sides should be balanced. In 1775, French scientists solemnly passed a resolution refusing to try perpetual motion machines. In the book History of the French Academy of Sciences, it is recorded as follows: "This year, the Academy of Sciences passed a resolution and decided to refuse to hear the answers to the following questions: cubic, angle trisection, square with the same area as the circle, and any machine that shows eternal motion." And explained: "the construction of perpetual motion machine is absolutely impossible, even if the friction and resistance in the middle do not eventually destroy the original power, this power can not produce the effect equal to the cause;" If we imagine that power can work continuously, the effect will be infinitely small within a certain period of time. If the friction and resistance are reduced, the initial motion will often continue, but it can't interact with other objects. In this assumption (nature can't exist), the only possible eternal motion will be useless to achieve the purpose of the perpetual motion builder. The disadvantage of these studies is that they are extremely expensive, not only destroying a family, but technicians who could have provided a lot of services to the public often wasted their tools, time and intelligence. " However, even under such a clear warning from the French Academy of Sciences, the activities of creating perpetual motion machines have not yet converged. In the mid-19th century, the law of conservation of energy has been established. In 1861, a British engineer, Delks, collected a lot of information and wrote a book entitled "Perpetual Motion in the 17th and 18th centuries", warning people not to dream of gaining fame from the gift of eternal movement.