The eternal engine, 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 supply of energy to it.
The laws of thermodynamics
To understand whether mobile perpetum is possible or impossible, one should recall the first two laws of thermodynamics:
- The first law of thermodynamics says: "Energy is not created and is not destroyed, it can only go 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 over time." This law indicates in which direction the thermodynamic process will occur spontaneously. In addition, the impossibility of the transfer of energy from one type to another without loss follows from this law.
Perpetual motion machine of the first and second kind
The perpetual motion machine, or in Latin perpetuum mobile, is of two kinds:
- The perpetual motion machine of the first kind is a machine that constantly works without supplying external energy and at the same time does some work. That is, perpetum mobile of the first kind contradicts the first law of thermodynamics, therefore, 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 energy into electric energy and vice versa, without any losses during this conversion. That is, the perpetual motion machine (perpetuum mobile) of the second kind contradicts the second law of thermodynamics.
Impossibility of existence
The perpetual motion machine of the first kind contradicts the fundamental law of physics on the conservation of the energy of an isolated system, and therefore cannot exist. As for the perpetuum mobile of the second kind, it is also impossible, since in any running engine there is atomization of energy in various ways, mainly in the form of heat.
Given that the laws of thermodynamics have been tested for 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 a variety of religious circles, in which there are beliefs about endless sources of energy and so on.
In addition, from time to time various mental “paradoxes” appear, which, it would seem, demonstrate the performance of various perpetual mobiles. In all these cases, we are talking about errors in understanding the laws of physics, so such mental "paradoxes" are instructive.
The 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 working machine cannot transfer energy from one state to another with a coefficient of efficiency equal to 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 to this day have searched and continue to search 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 projects of such machines consist in the use of different weights, angles, physical or mechanical properties of specific substances, which can move constantly and even create an excess of useful energy. Speaking about modern time and its enormous energy needs, we can understand the importance of perpetum mobile, which would become a real revolution in the development of mankind.
Returning to history, it should be said that the first known projects of perpetual motion machines began to appear in medieval Europe. It is believed that the first model of the perpetual motion machine was the corresponding invention in Bavaria in the 8th century AD.
Famous projects of perpetual motion in the Middle Ages
Unfortunately, to date, nothing is known about the existence of perpetum mobile projects in societies until the Middle Ages. No information was preserved that the ancient Greeks or Romans created such machines.
The most ancient invention of the perpetual motion machine, which is known to mankind, is the magic wheel. Although no images of this invention have been preserved, historical written sources say that it dates back to the existence of the Merovingian Empire on the territory of modern Bavaria in the 8th century. However, some historians say that this machine did not exist in reality 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 works on differential equations precede, for 5 centuries, the similar works of Newton and Leibniz. Around 1150, Bhaskara came up with a wheel that was supposed to rotate forever. Unfortunately, this invention was never constructed, but it is the first undoubted evidence of attempts to create perpetual motion.
The first invention of the perpetual motion machine in Europe is the car of the famous French freemason and 13th century architect Villard de Onnekur. It is not known exactly whether his invention was constructed, but in the diaries of Villard de Onnekur find an image of his perpetuum mobile.
Leonardo da Vinci, the legendary engineer and inventor from Florence, also created several machines - perpetual motion machines, and in this regard he was several centuries ahead of his time. These machines, of course, turned out to be inoperative, and the scientist concluded that it was impossible for perpetual motion machines to exist in physics.
The eternal engines of modern times
With the advent of modern times, the invention of the perpetual motion machine became a popular activity, and many inventors spent their time creating such a machine. This boom is associated primarily with success in the development of mechanics.
So, the Italian inventor of the XVI century, 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 theme of the perpetual motion machine.
Thought experiments
In theoretical physics, often use mental experiments with which they try to verify the fundamental physical laws. Regarding the theme of perpetual motion, you can name the following projects:
- The demon of Maxwell. It is a violation of the second law of thermodynamics when a hypothetical demon shares a mixture of gases. This thought experiment allows us to understand the essence of the entropy of the system.
- The perpetual motion machine of Richard Feynman, which performs work due to thermal fluctuations and therefore can work 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 dead?
We cannot say with certainty that a mechanism will never be invented that can work forever, since humanity still does not know much about the Universe in which it lives. Perhaps a species of exotic matter will be discovered, for example, black matter in space, about which almost nothing is known. The behavior of this matter can make us reconsider the laws of thermodynamics. These laws are so fundamental that any change in their scale will be similar to the influence of Albert Einstein's theory on the laws of classical mechanics by Isaac Newton and on the development of physics as a whole. It is also possible that perpetual motion exists in objects whose behavior obeys quantum mechanics.