Perpetual motion machine
What is a perpetual motion machine
There is an electromagnetic coil on a permanent magnet. Then the potential energy generated by the electromagnetic coil using a certain amount of work is equal to the permanent The magnetic force of a magnet is proportional to its size. A perpetual motion machine refers to an unachievable engine that violates the basic laws of thermodynamics. A machine that can do work forever without consuming energy violates the first law of thermodynamics, so it is called the "first type of perpetual motion machine". A machine that continuously absorbs heat from seawater or air in nature and continuously converts it into mechanical energy without a temperature difference. It violates the second law of thermodynamics, so it is called a "second type of perpetual motion machine." The term perpetual motion machine is not very appropriate. For example, once a flywheel starts to move, it can continue to move forever if there is no frictional resistance. Although this is not easy to achieve in practice, it makes sense in theory and can be regarded as a practical limit situation. The so-called perpetual motion machine does not refer to this situation. It is not an attempt to maintain eternal motion, but an expectation to continuously obtain useful work without external energy supply, that is, without consuming any fuel or power. If this kind of perpetual motion machine can really be made, then infinite power can be obtained out of nothing without using any natural energy. Before people had grasped the basic laws of nature, this idea once tempted many people with outstanding creative talents, who devoted a lot of wisdom and labor to pursue the realization of this dream. However, no perpetual motion machine has ever been actually built, and no perpetual motion machine design has withstood scientific scrutiny.
The reason why perpetual motion cannot exist
According to the laws of the universe, any matter in the universe and on the earth must go through the process of creation and destruction, and must be completed with external forces as conditions Self-transformation, for example, human beings need to eat and other very natural things. Everything in the universe will die, it's just a matter of time. The perpetual motion machine violates this law, so matter that violates the formula of the law cannot exist. Human inventions are just the trial of rules and formulas, and humans cannot feel it themselves. However, we find that what humans "invent" are phenomena that already exist in nature, but humans use formulas + labor to unlock them. Therefore, we cannot violate the laws of the universe, we can only follow it.
The dream of a perpetual motion machine
The idea of ??a perpetual motion machine originated in India. Around 1200 AD, this idea spread from India to the Islamic world, and from here to the West. In Europe, the most famous early perpetual motion machine design was proposed by a Frenchman named Hennecaut in the 13th century. As shown in the picture: there is a rotating shaft in the center of the wheel, and 12 movable short rods are installed on the edge of the wheel. An iron ball is installed at one end of each short rod. The designer of the scheme believes that the ball on the right is farther from the axis than the ball on the left, so the rotational torque generated by the ball on the right is greater than the rotational torque generated by the ball on the left. In this way, the wheel will rotate endlessly in the direction pointed by the arrow, and drive the machine to rotate. This design has been copied by many people in different forms, but it has never achieved non-stop rotation. If you analyze it carefully, you will find 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 perform work on the outside. It will only swing a few times and then stop at the position drawn in the picture on the right. Later, Leonardo da Vinci (1452-1519) in Renaissance Italy also built a similar device. When he designed it, he believed that the heavy ball on the right was farther from the center of the wheel than the heavy ball on the left. The unbalanced effect on both sides will cause the wheel to rotate continuously in the direction of the arrow, but the experimental result is negative. Leonardo da Vinci keenly concluded from this: perpetual motion is impossible to achieve. In fact, according to the principle of lever balance, in the above two designs, although each weight on the right exerts a greater rotational effect on the wheel, the number of weights is smaller. Accurate calculations can prove that there will always be an appropriate position where the rotational effects (moments) exerted by the weights on the left and right sides on the wheel in opposite directions are exactly equal and cancel each other out, causing the wheel to reach equilibrium and come to rest. The height difference of flowing water can push the hydraulic turbine to provide external power. Can running water be used to design a perpetual motion machine? In the 1670s, an Italian machinist Steer proposed a design for a perpetual motion machine.
When designing, he believed that the water flowing out from the upper tank would impact the rotation of the water wheel. While the water wheel drove the water mill to rotate, it would also drive the spiral water pump through a set of gears to lift the water in the reservoir to the upper tank again. middle. He thought that the entire device could keep running like this and effectively perform work on the outside. In fact, less and less water flowed back into the tank, and soon all the water in the tank flowed into the reservoir below, and the turbine stopped rotating. Buoyancy is also a good helper in designing perpetual motion machines. It is a famous buoyancy perpetual motion machine design. A series of balls, wound around two wheels, can rotate like a chain. Some balls on the right are placed in a container filled with water. The designer believes that if there was no water container on the right side and the number of balls on the left and right sides was equal, the chain would be balanced. However, now that the balls on the right are immersed in water, they will be pushed upward by the water due to the buoyancy of the water, which will also drive the entire string of balls to rotate around the upper and lower wheels. There is a ball above the water. There is a ball below that passes through the bottom of the container and is replenished. Such a perpetual motion machine has not yet been made. Is it because the ball below can pass through the bottom of the container without allowing water to leak out, which is technically difficult to manufacture? Technical difficulties are not the main problem, the main problem lies in the principle of design. When the ball below passes through the bottom of the container, it, like the bottom of the container, has to withstand the pressure of the water above, and because it is at the bottom of the water, it experiences great pressure. This downward pressure will offset the buoyancy of the balls above, and the water machine will not be able to 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, etc. to obtain effective power, but they have all failed without exception. In fact, in all perpetual motion machine designs, we can always find an equilibrium position. In this position, all the forces cancel each other out, and there is no longer any driving force to make it move. All perpetual motion machines will inevitably come to rest at this equilibrium position and become immobile. Since the Gothic era, there have been more and more such design schemes. During the 17th and 18th centuries, people proposed various designs of perpetual motion machines. Some used a "spiral water pump", some used the inertia of the wheel, the buoyancy of water or capillary action, and some used the repulsion between magnetic poles of the same sex. of. The court was filled with all kinds of designers trying to make money from this illusory invention. Both learned and unlearned people believed that a perpetual motion machine was possible. This task attracted researchers like a mirage, but all these plans ended in failure without exception. They go around in circles for years and years without achieving anything. Through continuous practice and experimentation, people gradually realize that any machine that does work on the outside world consumes energy. A machine cannot do work without consuming energy. At this time, some famous scientists such as Stavin and Huygens began to realize that it was impossible to create a perpetual motion machine using mechanical methods.
The disillusionment of the dream of perpetual motion machines
In the mid-19th century, a series of scientific workers made great contributions to the correct understanding of the relationship between the conversion of thermal functions and the conversion of other forms of material motion. Soon after The great laws of conservation and transformation of energy were discovered. People realize that all substances in nature have energy, and energy comes in various forms. It can be converted from one form to another, and transferred from one object to another. In the process of transformation and transfer, energy changes. The sum remains the same. The transformation law of energy conservation provides a more precise and rich scientific basis for dialectical materialism. It effectively attacks those idealistic views that believe that material motion can be created and destroyed at will, and it completely breaks the illusion of perpetual motion. After all attempts to create the first type of perpetual motion machine failed, some people dreamed of creating another kind of perpetual motion machine, hoping that it would not violate the first law of thermodynamics and be both economical and convenient. For example, this kind of heat engine can directly absorb heat from the ocean or atmosphere and turn it completely into mechanical work. Since the energy of the ocean and atmosphere is inexhaustible, this heat engine can run endlessly and perform work. It is also a kind of perpetual motion machine. However, based on a large amount of practical experience, the British physicist Kelvin proposed a new universal principle in 1851: It is impossible for a substance to absorb heat from a single heat source and turn it completely into useful work without producing other effects. In this way, the idea of ??the second type of perpetual motion machine also went bankrupt. The endless designs of perpetual motion machines have all failed under the rigorous scrutiny of science and the ruthless testing of practice.
In 1775, the French Academy of Sciences announced that "the undergraduate academy will no longer review all designs related to perpetual motion machines." This shows that the scientific community at that time had realized from long-term accumulated experience that the attempt to create a perpetual motion machine had no hope of success. The idea of ??a perpetual motion machine has lasted for hundreds of years in human history. The refutation of this myth will not only help people correctly understand science, but also help people correctly understand the world. Energy can neither be created nor destroyed out of thin air. It can only be converted from one form to another or transferred from one object to another. During the process of transformation and transfer, the total amount of energy does not change. This is the law of conservation of energy. So first A quasi-perpetual motion machine cannot be made. The transformation and transfer of energy are directional, just like heat can spontaneously transfer from a hot object to a cold object, but it cannot spontaneously transfer from a cold object to a hot object without causing other changes, so the second type is always Motives cannot be created either.
In history, many people have tried to design a machine that does not consume energy, but can rotate continuously and even perform work continuously. 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 is an illusion that will never succeed because it violates one of the most universal laws of nature, which is the law of energy transformation and conservation. The famous scientist Leonardo da Vinci proposed the idea of ??the impossibility of a perpetual motion machine as early as the 15th century. He once designed a runner, as shown in the figure, with a series of containers installed on the edge of the runner, and the containers were filled with some mercury. , he thought that the movement of mercury in the container might cause the wheel to rotate forever, but after careful study, he came to a negative conclusion. He realized from many similar designs that his attempt at a perpetual motion machine was doomed to fail. He wrote: "Fantasyists of eternal motion! How futile your explorations are! Just be gold diggers!" However, for several hundred years after the 15th century, the activity of creating perpetual motion machines never stopped. For example: In the 17th century, there was a British prisoner named Malkis who was imprisoned under the Tower of London. He built a "perpetual motion machine" that could rotate, as shown in the picture. The diameter of the runner is 4.3 meters, and 40 steel balls each weighing 23 kilograms move along the outside of the spokes of the runner, which increases the torque. When it reaches a high place, the steel balls will automatically roll toward the center. He is said to have 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 motion. 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 toward the end of the extended arm, increasing the torque. Turn to the other side and the soft arm begins to bend, moving closer to the axis. The designers thought this would allow the machine to gain torque. However, he did not expect that although the moment arm was shortened, the resistance increased, and the wheel could only stop in place. Archimedean Screw Perpetual Motion Machine In 1681, a famous British doctor, Vlad, put forward a suggestion to use the Archimedean screw (pictured) to lift the water in the pool to a high place, and then let the rising water drive the turbine. , In addition to driving the water mill to do work, the hydraulic turbine can also make the Archimedes spiral rotate to continuously lift water. If this goes on and on, wouldn't it mean that there is no need to worry about drought and water shortage? For a time, there were many people in the National People's Congress who responded to him, and various automatic water turbines were proposed one after another, and there was a craze. Magnetic perpetual motion machine Around 1570, an Italian professor named Tesniers proposed that a perpetual motion machine could be realized using the attraction of magnets. His design is as shown in the figure. A is a magnet. The iron ball C is attracted by the magnet and can roll up the slope. It rolls to the upper end E, falls from the small hole B, returns through the curved surface BFC, and is attracted by the magnet again. The iron ball It can continue to move along the spiral path. Probably he had not established Coulomb's law at that time and did not know that the magnitude of magnetic force changes inversely with the square of the distance. As long as you think about it carefully, the absurdity will be obvious. There are many similar examples, which will not be described in detail here. We only need to name a few to illustrate how widespread and tempting this futile activity is. 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 creating perpetual motion machines, scientists have gradually realized the objective regularities of nature from the study of basic theories of mechanics.
Following Leonardo da Vinci, Steven wrote "Fundamentals of Statics" in 1568. When discussing the decomposition of forces on an incline, he clearly put forward the view that perpetual motion is impossible. The illustration he used is drawn on the title page of the book, as shown in the picture. Above the picture is written: "Magic is actually not magical." Thread 14 small balls of equal weight evenly with thread to form a ball chain connected end to end, and place it On an incline, he believed that the "movement without end" of the chain was absurd, so the two sides should be balanced. In 1775, French scientists solemnly passed a resolution refusing to examine perpetual motion machines. The book "History of the French Academy of Sciences" has the following record: "In this year, the Academy of Sciences passed a resolution and decided to refuse to consider the answers to the following questions: doubling the cube, trisecting the angle, finding the square with the same area as the circle, and expressing eternity. "Any machine that moves." And explained: "The construction of a perpetual motion machine is absolutely impossible. Even if the friction and resistance in the middle do not eventually destroy the original power, this power cannot produce an effect equal to the cause; and imagine that the power can be continuous. If the friction and resistance are reduced, the initial motion can often continue, but it cannot interact with other objects. In this assumption (impossible to exist in nature), The only possible eternal motion would be of no use to the purposes of the builders of perpetual motion machines. The disadvantage of these studies was that they were extremely expensive, and more than ruined a family, they often wasted technicians who might have rendered a great service to the public. Tools, time and ingenuity.” However, even under such clear warnings from the French Academy of Sciences, various activities to create perpetual motion machines have not yet converged. In the mid-19th century, the law of conservation of energy had been established. In 1861, a British engineer named Derkes collected a large amount of information and wrote a book called "Perpetual Motion Motion in the 17th and 18th Centuries", warning people not to gain fame and good luck from the gift of eternal motion. However, Derkes's "warning words" failed to prevent the continued proliferation of perpetual motion machines. At the end of the 19th century, someone in Pennsylvania, USA, wanted to use magnets to replace the pendulum's hammer, and tried to use magnetic power to replace the clockwork. They thought it would be possible to automatically maintain the swing without the clockwork. The result was a futile effort with no results. Entering the 20th century, more complex and specious designs continued to be proposed. For example, some people want to "invent" automatic cars, some people want to "create" automatic washing machines, some people want to use the "molecular attraction" in water to make "automatic" pumps, and some people want to make generators purely from permanent magnets, especially in the "energy crisis" Stimulated by the epidemic, such activities have continued unabated and emerged one after another. Another type of perpetual motion machine is also often proposed and is quite confusing. For example, in the 1880s, an inventor in the Washington area, Gamuer, designed a zero-degree engine (Zeromotor) that used liquid ammonia as the working substance to absorb heat from the surrounding environment. The ammonia changed from liquid to gaseous state at 0 A pressure of 4 atmospheres is generated at ℃, which can push the piston to do work. It seems that this does not require the use of fuel. He further explained that the ammonia gas expands and cools after driving the piston, and will automatically condense in the container, so it can continue to work in a cycle. In 1881, his design actually received support from the Chief Engineer of the U.S. Navy and was officially praised. Even the then President of the United States watched the design model with great interest. They may think that if this engine is really successful, the U.S. fleet will not need a coaling station and can obtain endless heat energy from the ocean. However, as long as we analyze it scientifically, we will find that Gamuer's design is a heat engine with a single heat source. It violates the second law of thermodynamics. This is the second type of perpetual motion machine that cannot be realized. If the "invention" of perpetual motion machines is of some benefit to mankind, it is that people can learn a lesson from it: all "creations" that violate natural laws such as the law of energy transformation and conservation are doomed to fail.
After reading these stories about the invention of perpetual motion machines, what do you think? Scientific laws cannot be violated. If you violate them, you will hit a wall. Don't do that kind of futile thing! The development of science and technology should be used to minimize unnecessary energy loss, rather than developing a perpetual motion machine that can never be realized.
The Enlightenment of Perpetual Motion Machines
The failure of various perpetual motion machine designs and the shattering of the dream of creating a perpetual motion machine are a big blow to everyone looking for perpetual motion machines.
However, reflecting on this failed exploration process, it has enlightened mankind from the negative side. Some scientists began to think from this negative conclusion and raised the question: Does the impossibility of making a perpetual motion machine mean that there is a law in nature? , which makes it impossible for us to get energy out of nothing? That is to say, there is a certain transformation relationship between various energies in nature. Thinking in this regard is one of the clues to the establishment of the principles of energy transformation and conservation. The famous German physicist and physiologist H. Helmholtz (1821-1894) started from the fact that perpetual motion machines are impossible to realize and discovered the principles of energy conversion and conservation. He wrote in the paper: "In view of the failure of previous experiments, people no longer ask how I can use the known and unknown relationships between various natural forces to create an eternal motion, but ask if eternal motion It is impossible. What kind of relationship should exist between various natural forces?" In the mid-19th century, the principles of energy conversion and conservation were generally recognized by the scientific community. This principle points out that all substances in nature have energy, corresponding to different forms of motion. Energy also has different forms, such as kinetic energy and potential energy of mechanical motion, internal energy of thermal motion, electromagnetic energy of electromagnetic motion, and chemical motion of chemical motion. etc., they are represented by state parameters specific to various forms of motion. When the form of motion changes or the amount of motion is transferred, energy is also converted from one form to another, and transferred from one system to another; the total energy remains unchanged during transformation and transfer. There is another very wonderful fantasy that does not violate the principles of energy transformation and conservation. If all the heat energy in the air or seawater can be converted into the mechanical work we need through an ingenious machine, this can become an inexhaustible energy source. The idea of ??inventing this kind of machine is much smarter than the previous idea of ??generating energy out of thin air. If this kind of machine can really be invented, there will be another advantage. On the one hand, we can take out the heat energy in an object to do work, and at the same time, it will also reduce the temperature of the object. In this way, we can set up some huge factories on the ocean to use the thermal energy in seawater to perform various tasks, such as using it to generate electricity. A ship can use the heat in seawater without burning coal or oil. Isn’t it a wonderful thing to be able to sail around the world? This can be called the second kind of perpetual motion machine, which is also impossible to achieve because it violates the second law of thermodynamics. The second law of thermodynamics is an objective law proven by countless practices. It can be expressed as: "It is impossible to absorb heat from a single heat source and turn it into useful work without causing other effects." This means that the heat engine cannot be 100% efficient. While part of the heat absorbed by the heat source is converted into useful work, the other part of the heat is transferred to the low-temperature heat source. Pursuing the failure experience of perpetual motion machines can give us two insights: First, the experience of failure also has positive scientific research value. The failure of various design plans of perpetual motion machines has aroused people's reflection and inspired the ideas of energy transformation and conservation. It becomes one of the thinking clues for the establishment of energy conversion and conservation principles; secondly, we must act in accordance with scientific laws. People who pursued perpetual motion machines in history did not do so because they did not have good intentions, nor did they lack the spirit of hard work, but because they were doing work that violated objective laws. Before people understood the laws of energy transfer and transformation, we can only regret the failure of those efforts to seek perpetual motion machines. However, if anyone still designs a perpetual motion machine today, then he is stupid. Those who violate scientific laws will never succeed. When humans use nature, they must abide by the laws of nature, rather than develop a perpetual motion machine that can never be realized.
Perpetual Motion Scam
In history, countless people have been obsessed with the design and manufacture of perpetual motion machines. Before the establishment of the thermodynamic system, some of these people were scientists, and some hoped to become famous and rich through this. Speculators, and after the establishment of the thermodynamics system, in addition to "citizen scientists" who hope to break the existing scientific system, those who are committed to the design of perpetual motion machines are also scammers who make money in the name of perpetual motion machines. The famous perpetual motion machine scams in history include: △Automatic wheel scam: In 1714, the German Orfilius claimed to have invented a perpetual motion machine called the automatic wheel. This machine rotated sixty revolutions per minute and could turn the A 16-kilogram object rose to a considerable height. When he announced the news and conducted a public experiment, he became famous throughout Germany.
In 1717, a governor from Poland sent troops to guard the house after inspecting the room where the automatic wheel was placed. After 40 days, he found that the automatic wheel was still rotating, and issued an appraisal certificate to Orfilius. Orfilius made a lot of money by exhibiting the automatic wheel, and Russian Tsar Peter I even reached a purchase agreement with him worth 100,000 rubles. In the end, due to a dispute between Orfilius's wife and the maid, the maid was angry and exposed. It turned out that the automatic wheel relied on the maid hidden in the wall of the room to pull the cable. The whole incident was a scam. △Wang Hongcheng scam: Wang Hongcheng, a native of Harbin, China, proposed a perpetual motion machine in 1984. He used the perpetual motion machine he designed to drive his own washing machines, fans and other devices. Soon the scam was exposed. The perpetual motion model he made was made of hidden An electric motor is driven by a button battery, and the electrical wiring that supplies the washing machine and fan is hidden underground. In 1998, another of Wang Hongcheng's scams, "Water to Oil," was exposed, and he himself was imprisoned. In addition, at the Paris Exposition in the 1980s, a "perpetual motion device" was exhibited: This device is a large wheel that keeps rotating. Visitors to the exposition were very curious about this perpetual motion machine and pushed the wheel in the opposite direction of rotation. disc to prevent the wheel from turning. The designer of this perpetual motion device took advantage of the curiosity of the audience, allowing them to turn the wheel backwards to wind up the perpetual motion machine and keep the device running. In addition, Huang Wei, the former commander of the 12th Corps of the Kuomintang Army, was captured at the Xubeng Battle of the Kuomintang Civil War in 1948 and sent to the Gongdelin War Criminals Management Center to undergo "reformation." Until his release in 1975, he ignored everyone Objection, he devoted himself to the development of perpetual motion machines in the institute, which is very famous. Of course it ended in failure. The principle of perpetual motion. Perpetual motion magnetism is force. Do an experiment. Attach a magnet to each end of a stick. Mount the stick on a stand so that it can be rotated. Then install magnets under the magnets, the left one makes the magnet run upward, and the right one makes the magnet run downward. We can design the magnetic poles to achieve this movement.
What do you think after reading these stories about the invention of perpetual motion machines? Scientific laws cannot be violated. If you violate them, you will hit a wall. Don't do that kind of futile thing! The development of science and technology should be used to minimize unnecessary energy loss, rather than developing a perpetual motion machine that can never be realized.
The first type of perpetual motion machine
Many people in history have had such a beautiful wish: to create a machine that does not require power, which can continuously perform work on the outside world. In this way, huge wealth can be created out of nothing. In the history of science, no perpetual motion machine has ever been successful. The discovery of the law of conservation of energy made people realize that any machine can only convert energy from one form to another. A form, rather than creating energy out of nothing. Therefore, it is impossible to create a perpetual motion machine at all. It violates the first law of thermodynamics: the increase in the internal energy of an object is equal to the sum of the heat absorbed by the object from the outside world and the work done by the object to the outside world.
The second type of perpetual motion machine
Some people once designed a type of machine, hoping that it would absorb heat from a high-temperature heat reservoir (such as a boiler) and use it to do work without discharging it to a low-temperature heat reservoir. heat. Can’t the efficiency of this kind of machine reach 100%? This kind of machine does not violate the law of conservation of energy, but none of them succeeded. People call this type of perpetual motion machine that only absorbs heat from a single heat reservoir and performs work uninterruptedly the second type of perpetual motion machine. This kind of perpetual motion machine cannot be made because the conversion of mechanical energy and internal energy is directional: mechanical energy can be converted into internal energy, but all internal energy cannot be converted into mechanical energy without causing other changes.