A perpetual motion machine, or in Latin "perpetum mobile", is a hypothetical machine that could function forever after giving it an initial impulse and without the need for subsequent energy supply to it.
The laws of thermodynamics
To understand whether a perpetum mobile is possible or impossible, one should remember the first two laws of thermodynamics:
- The first law of thermodynamics says: "Energy is neither created nor destroyed, it can only pass into different states and types." That is, if work is done on a given system or it exchanges heat with the external environment, then its internal energy changes.
- The second law of thermodynamics. According to him, "the entropy of the universe tends to increase with time." This law indicates in which direction the thermodynamic process will proceed spontaneously. In addition, this law implies the impossibility of energy transfer from one type to another without loss.
Perpetual motion machine of the first and second kind
Perpetuum mobile, or in Latin perpetuum mobile, is of two kinds:
- A perpetual motion machine of the first kind is a machine that constantly works without the supply of external energy and at the same time does some work. That is, the perpetum mobile of the first kind contradicts the first law of thermodynamics, which is why, by the way, it was called the engine of the first kind.
- A perpetual motion machine of the second kind is any machine that works with periodic cycles, converting one type of energy into another, for example, mechanical to electrical and vice versa, without any losses in the process of this transformation. That is, a perpetual motion machine (perpetuum mobile) of the second kind contradicts the second law of thermodynamics.
Impossibility of existence
A perpetual motion machine of the first kind contradicts the fundamental law of physics about the conservation of energy in an isolated system, therefore it cannot exist. As for perpetuum mobile of the second kind, it is also impossible, since in any running engine, energy is dispersed in various ways, mainly in the form of heat.
Given that the laws of thermodynamics have been verified by several centuries of experiments and experiments and have never failed, we can safely say that any projects of perpetual motion machines are a hoax. Such projects often arise in various religious circles, in which there are beliefs about endless sources of energy and so on.
Furthermore, various mental"paradoxes", which, it would seem, demonstrate the efficiency of certain perpetuum mobiles. In all these cases, we are talking about errors in understanding the laws of physics, so such mental "paradoxes" are instructive.
Historical search for perpetual motion machines and their importance for the development of mankind
The laws of thermodynamics were finally established in the second half of the 19th century. According to them, any running machine cannot transfer energy from one state to another with an efficiency of 100%, not to mention the constant supply of energy to other systems without supplying it to the machine itself.
Despite this, many people in the course of history and to this day have been looking for and continue to look for various designs of working perpetual motion machines, which can be compared with a kind of "elixir of youth" in the field of mechanics.
All designs of such machines are based on the use of different weights, angles, physical or mechanical properties of specific substances that can move constantly and even create an excess amount of useful energy. Speaking about modern times and its huge energy needs, one can understand the importance of the perpetum mobile, which would become a real revolution in the development of mankind.
Going back in history, the first known designs of perpetual motion machines began to appear in medieval Europe. It is believed that the corresponding invention in Bavaria in the 8th century became the first model of a perpetual motion machine.century AD.
Famous designs of perpetual motion machines in the Middle Ages
Unfortunately, nothing is known about the existence of perpetum mobile projects in societies before the Middle Ages. No information has been preserved that the ancient Greeks or Romans built such machines.
The most ancient invention of the perpetual motion machine known to mankind is the magic wheel. Although no pictures of this invention have been preserved, historical written sources say that it dates back to the time of the existence of the Merovingian Empire in the territory of modern Bavaria in the 8th century. However, some historians say that this machine did not really exist and that all information about it is a legend.
Bhaskara was a famous Indian mathematician who is recognized as the most influential scientist of the Middle Ages on his continent. His work on differential equations predates similar work by Newton and Leibniz by 5 centuries. Around 1150, Bhaskara invented a wheel that was supposed to turn forever. Unfortunately, this invention was never constructed, but it is the first undoubted evidence of attempts to create perpetual motion.
The first invention of a perpetual motion machine in Europe is the car of the famous French freemason and architect of the 13th century Villard de Honnecourt. It is not known for sure whether his invention was constructed, but in the diaries of Villard de Honnecourt they find an image of his perpetuum mobile.
Legendary engineer and inventor from Florence, Leonardo da Vinci also created several machines - perpetual motion machines, and in this respect he was several centuries ahead of his time. These machines, of course, turned out to be inoperable, and the scientist concluded that perpetual motion machines cannot exist in physics.
Perpetual motion machines of the New Age
With the advent of modern times, the invention of the perpetual motion machine became a popular pastime, and many inventors spent their time creating such a machine. This boom is primarily due to the success in the development of mechanics.
Thus, the 16th-century Italian inventor Mark Zimara designed an ever-working mill, and the Dutchman Cornelius Drebbel dedicated one of these inventions to the English king. In 1712, engineer Johann Bessler analyzed more than 300 such inventions and decided to create his own perpetum mobile.
As a result, in 1775, members of the Royal Academy of Sciences in Paris issued a decree that they would not accept any inventions that are associated with the subject of a perpetual motion machine.
Thought experiments
In theoretical physics, thought experiments are often used to try to test fundamental physical laws. Regarding the theme of perpetual motion machines, the following projects can be mentioned:
Maxwell's Demon. We are talking about a violation of the second law of thermodynamics, when a hypothetical demon separates a mixture of gases. This thought experiment allowsunderstand the essence of the entropy of the system
Richard Feynman's perpetual motion machine that does work by thermal fluctuations and can therefore run forever. In fact, it will work as long as the environment has a higher temperature than the engine itself
Is the hope of creating a perpetual motion machine finally dead?
We cannot say with certainty that a mechanism capable of working forever will never be invented, since humanity still does not know much about the Universe in which it lives. Perhaps a species of exotic matter will be discovered, such as black matter in space, about which almost nothing is known. The behavior of this matter may force us to reconsider the laws of thermodynamics. These laws are so fundamental that any change in their scope will be similar to the influence of Albert Einstein's theory on the laws of classical mechanics of Isaac Newton and on the development of physics in general. It is also possible that perpetual motion exists in objects whose behavior is governed by quantum mechanics.
