Human nature is such that from time immemorial people have tried to create something that works by itself, without any external influences. Subsequently, this device was given the definition Perpetuum Mobile or Perpetual motion machine. Many famous scientists from different times have tried unsuccessfully to create it, including the great Leonardo da Vinci. He spent several years creating a perpetual motion machine, both by improving existing models and trying to create something fundamentally new. In the end, having figured out why nothing works, he was the first to formulate the conclusion that it was impossible to create such a mechanism. However, the inventors were not convinced by its formulation, and they are still trying to create the impossible.
Wheel of Bhaskar and similar designs of perpetual motion machines
It is not known for certain who and when the first tried to create a perpetual motion machine, but the first mention of it in manuscripts dates back to the 12th century. The manuscripts belong to the Indian mathematician Bhaskar. In them, a certain wheel is described in poetic form, with tubes attached to it along the perimeter, half filled with mercury. It was believed that due to the overflow of fluid, the wheel itself will rotate endlessly. Several more attempts were made to create a perpetual motion machine based on approximately the same principle. Unsuccessfully as usual.
Models built on the principle of the Bhaskar wheel
Perpetual motion machine from a chain of floats
Another prototype of a perpetual motion machine is based on the use of Archimedes' law. In theory, it was believed that the chain, consisting of hollow reservoirs, will rotate due to the buoyant force. Only one thing was not taken into account - the pressure of the water column on the lowest tank will compensate for the buoyancy force.
Perpetual motion machine working according to Archimedes' law
Perpetual motion machine by Simon Stevin
Another inventor of the perpetual motion machine is the Dutch mathematician Simon Stevin. According to his theory, a chain of 14 balls, thrown through a triangular prism, should start moving, because there are twice as many balls on the left side than on the right, and the lower balls balance each other. But even here the insidious laws of physics interfered with the plans of the inventor. Despite the fact that four balls are twice as heavy as two, they roll on a flatter surface, therefore, the force of gravity acting on the balls from the right is balanced by the force of gravity acting on the balls from the left, and the system remains in equilibrium.
Stevin's perpetual motion machine model and its implementation with a chain
Permanent magnet perpetual motion machine
With the advent of permanent (and especially neodymium) magnets, the inventors of perpetual motion machines became active again. There are many variations of electric generators based on magnets, and one of their first inventors, Michael Brady, even patented this idea in the 90s of the last century.
Michael Brady working on a permanent magnet perpetual motion machine in 2002
And the video below shows a fairly simple design that anyone can make at home (if you get enough magnets). It is not known how long this thing will spin, but even if we do not take into account the energy losses from friction, this engine can be considered only conditionally eternal, because the power of the magnets weakens over time. But all the same, the spectacle is mesmerizing.
Of course, we did not talk about all the variants of perpetual motion machines, because human imagination, if not endless, is very inventive. However, all existing models of perpetual motion machines are united by one thing - they are not eternal. That is why the Paris Academy of Sciences since 1775 decided not to consider projects of perpetual motion machines, and the US Patent Office has not issued such patents for over a hundred years. And yet, in the International Patent Classification, there are still sections for some types of perpetual motion machines. But this only concerns the novelty of design solutions.
Summing up, we can only say one thing: despite the fact that it is still believed that the creation of a truly perpetual motion machine is impossible, no one forbids trying, inventing and believing in the unrealizable.