XII Международная студенческая научная конференция Студенческий научный форум - 2020

Alessandro Volta (1745-1827) was an Italian physicist, one of the authors of the theory of electricity, a famous physiologist and chemist. His discovery of "contact electricity" created a deep premise for studying the nature of current and searching for directions for its practical use.

Childhood and youth

Alessandro Volta was born on February 18, 1745 in the Italian town of Como, located near Milan. His parents Filippo and Maddalena were middle-class, so they could create a good life for the child. In early childhood, the boy was raised by a nurse who paid little attention to the child's development. The future scientist began to speak only at the age of four, with difficulty pronouncing sounds. Then everything indicated a certain mental retardation of the child who uttered the first word "No".

Only by the age of seven did the boy acquire a full speech, but soon lost his father. Alessandro was raised by his own uncle, who made it possible for his nephew to get a good education at the Jesuit school. He studied history, Latin, and mathematics with avidity, absorbing all knowledge. Volta's passion for physical phenomena was revealed almost immediately. For this purpose, he arranged a correspondence with the then famous author and demonstrator of physical experiments, the Abbe Jean-Antoine nollet.

In 1758, Earthmen once again observed the approach of Halley's comet to the planet. Volt's inquisitive mind immediately took a great interest in this phenomenon, and The young man began to study the scientific legacy of Isaac Newton. He was also interested in the works of Benjamin Franklin and based on one of them built a lightning rod in his city, which announced the surrounding area with the sound of bells during a thunderstorm.

After completing his studies, Alessandro stayed on to teach physics at the Como gymnasium. However, the role of a modest teacher did not match the level of Volta's talent and a few years later he became a Professor of physics at one of the oldest universities in Pavia (a city in Northern Italy in the region of Lombardy). After moving here, Volta traveled widely in Europe, visiting many capitals with his lectures. In this position, the scientist will work for 36 years, and in 1815, he headed the faculty of philosophy at the University of Padua.

The first opening

Even during the years of teaching Volta completely devoted himself to science and actively engaged in the study of atmospheric electricity, conducting a series of experiments on electromagnetism and electrophysiology. The first notable invention of the Italian was a capacitor electroscope equipped with diverging straws. This device was much more sensitive than its predecessors with balls suspended on a string.

In 1775, Alessandro invented an electrophor (electric induction machine) capable of generating static electricity discharges. The device was based on the phenomenon of electrification by induction. It consists of two metal disks, one of which is coated with resin. In the process of rubbing it, a charge of negative electricity occurs. When you bring another disk to it, the latter is charged, but if you take an unrelated current to the ground, the object will get a positive charge. By repeatedly repeating this cycle, you can significantly increase the charge. The author claimed that his device does not lose its effectiveness even three days after charging. During one of the boat trips on the lake, Volta was able to make sure that the gas at the bottom is well lit. This allowed him to design a gas burner and suggest the possibility of building a wire signal transmission line. In 1776, a scientist managed to create an electro-gas gun ("Volta gun"), the action of which is based on the explosion of methane from an electric spark.

Voltaic pile

The scientist came to his most famous discovery by studying the experiments of his compatriot Luigi Galvani, who managed to detect the effect of contraction of muscle fibers in a prepared frog during the interaction of its opened nerve with two dissimilar metal plates. The author of the discovery explained the phenomenon by the existence of "animal" electricity, but Volta offered a different interpretation. In his opinion, the experimental frog acted as a kind of electrometer, and the source of current was the contact of dissimilar metals. The muscle contraction was caused by a secondary effect of the electrolyte, a liquid found in the frog's tissues.

To prove the correctness of the conclusions Volta conducted an experiment on himself. To do this, he placed a tin plate on the tip of his tongue and a silver coin parallel to his cheek. The items were connected by a small wire. As a result, the scientist felt a sour taste on his tongue. Later, he complicated his experience. This time, Alessandro placed the tip of a pewter leaf over his eye and placed a silver coin in his mouth. Objects came into contact with each other using metal points. Each time he made contact, he felt a lightning-like glow in his eye.

In 1799, Alexandro Volta finally came to the conclusion that "animal electricity" does not exist, and the frog reacted to the electric current generated by the contact of dissimilar metals.

This conclusion was used by Alessandro in developing his own theory of "contact electricity". First, he proved that when two metal plates interact, one gets more stress. In the course of a further series of experiments, Volta became convinced that a single contact of dissimilar metals is not enough to produce serious electricity. It turns out that for the appearance of a current, a closed circuit is necessary, the elements of which are conductors of two classes – metals (the first) and liquids (the second).

In 1800, a scientist designed a Voltaic pole – the simplest version of a DC power source. It was based on 20 pairs of metal circles made of two types of material, which were separated by paper or fabric layers, moistened with an alkaline solution or salt water. The author explained the presence of liquid conductors by the presence of a special effect, according to which a certain "electromotive" force appears during the interaction of two different metals. Under its influence, the electricity of opposite signs is concentrated on different metals. However, Volta could not understand that the current occurs as a result of chemical processes between liquids and metals, so he presented a different explanation.

If you add up a vertical row of pairs of different metals (for example, zinc and silver without gaskets), then a zinc plate charged with a current of one sign will interact with two silver plates that are charged with electricity of the opposite sign. As a result, the vector of their joint action will be reset to zero. To ensure the summation of their actions, it is necessary to create a contact of the zinc plate with only one silver plate, which can be achieved with the help of second-class conductors. They effectively differentiate metal pairs and do not interfere with current flow. Volta reported his discovery to the Royal society of London in 1800. Since that time, the direct current sources invented by Volta have become known to the entire physical community. Despite certain scientific limitations, Alessandro came close to creating a galvanic cell, which is associated with the transformation of chemical energy into electrical energy. In the future, scientists repeatedly conducted experiments with the voltaic column, which led to the discovery of chemical, light, heat, and magnetic effects of electricity. One of the most notable variants of the voltaic column design can be recognized as V. Petrov's galvanic battery.

As an experiment, you can create a Volta pole with your own hands from improvised tools. Other invention

Sometimes Volta is considered the Creator of the prototype of a modern spark plug, without which it is impossible to imagine a car. He was able to make a simple structure consisting of a metal rod that was inside a clay insulator. He also created his own electric battery, which he called the "crown of vessels". It consists of successively connected copper and zinc plates, which are located inside the vessels with acid. Then it was a solid source of current, which today would be enough to power a low-power electric bell.

Volta created a special device designed to study the properties of burning gases, which was called the eudiometer. It was a vessel filled with water, which in an inverted form is lowered into a special bowl with liquid. After a long pause in 1817, voltu published the theory of hail and the frequency of thunderstorms.

Family life

The wife of the Italian scientist was Countess Teresa Peregrini, who gave birth to three sons.In 1819, a scientist in years left public life and retired to his estate. Alessandro Volta died on March 5, 1827 in his own estate of Camnago and was buried on its territory. Subsequently, it received a new name Kamnago-Volta.

After his death, fate played a cruel trick on the scientist. During the exhibition dedicated to the centenary of the creation of the Voltaic pole, a large fire occurred, almost completely destroying his personal belongings and appliances, and the cause of the fire was called a malfunction of electrical wires.

Interesting fact

-While in the library of the Academy, Napoleon Bonaparte read the inscription on the Laurel wreath: "to the Great Voltaire" and removed the last two letters from it, leaving the option "to the Great Volta".

Napoleon was well disposed to the great Italian and once likened the "Voltaic pole" he invented to life itself. The French Emperor called the device the spine, the kidneys the positive pole, and the stomach the negative. Subsequently, by order of Bonaparte, a medal would be issued in Volta's honor, he would be given the title of count, and in 1812 he would be appointed President of the electoral College.

- At the initiative of Volta, the concepts of electromotive force, capacitance, circuit and voltage difference were approved in science. Its proper name is the unit of measurement of electric voltage (since 1881).

- In 1794, Alessandro organized an experiment under the grim name "Quartet of the dead". It involved four people with wet hands. One of them was touching the zinc plate with his right hand, and the other was touching the tongue with his left. He, in turn, touched the eye of the third, who held the dissected frog by the legs. The latter touched the body of the frog with his right hand, and in his left hand held a silver plate that touched the zinc one. During the last touch, the first person started violently, the second felt a sour taste in his mouth, the third felt a glow, the fourth experienced unpleasant symptoms, and the dead frog seemed to come to life, fluttering its body. This sight shocked all the witnesses to the depths of their souls.

-Volta the scientific award for the achievements of scientists in the field of electricity is named after Volta.

-Volta died on the same day and hour as the famous French mathematician Pierre-Simon Laplace.

- The portrait of the scientist was depicted on an Italian banknote.

-In the Italian city of Como, there is a Museum of Alessandro valta-it was opened in 1927 to mark the centenary of the scientist's death.

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