André-Marie Ampère

Andre-Marie Ampere (fr. Andre-Marie Ampere, 1775-1836) is a famous French scientist, famous for his discoveries in the field of physics, mathematics and natural science. He was elected a member of many Academies of Sciences, including Paris and St. Petersburg. Ampère, the author of a theory explaining the relationship between electrical and magnetic phenomena, put forward a hypothesis about the origin of magnetism and introduced the terms "electric current" and "electrodynamics" into scientific circulation. The scientist owns the discovery of the influence of the Earth's magnetic field on current-carrying conductors that are in motion.

Childhood

André Marie Ampère was born in Lyon on January 22, 1775. His parents were hereditary artisans and, despite their working origins, had a fairly high cultural level. The father of the future scientist, Jean-Jacques Ampere, had a good education, spoke several ancient languages, had a rich library and was fond of the works of enlighteners popular at that time. Even the upbringing of his children, he built in the spirit of the pedagogical theory of Jean-Jacques Rousseau.

On the eve of the French Revolution, Jean-Jacques Ampère was appointed to the high position of the royal prosecutor and, despite the fall of the Bastille and the persecution of the royalists, who soon followed, supported the revolution. But he wasn't very lucky. A few years later, ultra-radical Jacobins came to power, who began to exterminate many objectionable people, including adherents of moderate views, which Father Andre Marie also adhered to. As a result, the arrest and a disappointing sentence - execution on the guillotine. The “razor of the revolution” took the life of a worthy citizen of France in November 1793, which was a terrible shock for the young man and all family members. The young man became discouraged and did not touch books for almost 1.5 years.

From early childhood, a talented boy had a huge craving for knowledge. He did not attend school, but he was able to master arithmetic and reading on his own. Already at the age of 12, Ampère was considered by many to be a mathematical genius, and his personal teacher could no longer teach him anything. By the age of 14, he had mastered the entire French Encyclopedia, but physical phenomena were of particular interest. Andre became a regular at the London College Library, where he actively mastered the literature available there. In order to read the books of Euler and Bernoulli, he specially learned Latin.

First independent steps

Due to the complete lack of money caused by the confiscation of family property, Ampère begins teaching mathematics in the private boarding school Duprat and Olivier, while simultaneously getting a job in a school in the small town of Bourg, located near Lyon. In 1802, he successfully passed an interview in the commission, which recognized him as fit to conduct classes.

The miserable life of a poor teacher only exacerbated Ampere's craving for science. It was during this period that the young scientist expressed a hypothesis explaining magnetic and electrical phenomena by similar principles. And once he voiced his guess in the presence of  Alessandro Volta himself at a meeting of the Lyon Academy.

The beloved mathematics, where Ampere is attracted by the theory of probability, does not go unnoticed. Soon he writes an essay "Reflections on the Mathematical Game Theory". In it, the author proves that a player will always lose to an opponent who has more money. Andre Marie was immediately noticed at the Academy of Sciences and invited to teach at the Lyceum Lyon. Career went uphill and in 1804 Ampère moved to Paris as a tutor at the local Polytechnic School. Before moving to the capital, another bitter event happened in his life - the death of his beloved wife and the beginning of loneliness, which spurred him to move.

After three years of tutoring, a period of self-study began, and soon André Marie became a professor of mathematical analysis and an examiner in mechanics. At the same time, he worked in the Advisory Bureau of Crafts and Arts, and in 1808 he assumed the duties of the chief inspector of the university, which forced him to travel on permanent business trips.

In 1814, Ampère was elected a member of the Paris Academy in the geometry section, which seemed to indicate his well-formed scientific interests. But life has made its own adjustments to this alignment.

Discovery of electromagnetism

In 1820, André Marie attended a meeting of the French Academy of Sciences, at which information was announced about the discovery  by Hans Oersted  of the influence of electricity on a magnetic needle. Most academicians took this as an ordinary event, but not Ampere. He immediately began experiments, turning his small room into a mini-laboratory, and even made a table himself, which has become a real relic. Within two weeks, he formulated his conclusions, which influenced many branches of science.

A fragment of the table that Ampère made for experiments

Since the time of Newton, the belief that electricity and magnetism are parallel has been established. Many were sure that each of these phenomena lives according to its own laws. The facts obtained by Oersted were interpreted as follows - the magnetization of the wire occurs as a result of the action of electricity, which caused the effect on the arrow. Ampere did not agree with the generally accepted interpretation and formulated a bold and somewhat provocative idea - there are no magnetic charges at all, there are only electric ones, and the phenomenon of magnetism comes from the movement of electric charges.

According to the scientist, magnetism arises from a huge number of tiny electrical atomic circuits. Each of them acts as a kind of "magnetic sheet" - the simplest magnetic two-terminal network. Therefore, it becomes clear why magnetic monopoles do not exist in nature, unlike electric ones. Ampere's version in such a bold formulation is not supported by all scientists, but there is no doubt that it has become the most important prerequisite for asserting the idea of ​​the unity of nature. This required an answer to some topical questions, in particular, to present a complete theory of the interaction of currents. Ampere himself did an excellent job with the task.

In 1820, Ampère's rule was formulated to determine the effect of a magnetic field on a magnetic needle. According to this conclusion, the north pole will be at the end of the rod, located to the left of the person, who moves in the direction of the current and is facing him. Soon the author confirmed the existence of an interaction between electric currents, called Ampère's law. It shows the strength of the magnetic field in relation to the conductor inside it. The Frenchmanifestly proved that parallel conductors begin to attract each other when the current moves in one direction and repel when it is passed in the opposite direction.

The direction of Ampère's force can be found out according to the left hand rule. We place the hand in such a way that the perpendicular vector of magnetic induction fits in the palm of the hand, and four fingers are in an extended position in the direction of movement of charged particles in the conductor. In this case, the thumb set aside at an angle of 90 ° indicates the direction of Ampère's force.

left hand rule

In 1822, André Marie described the magnetic effect of a solenoid. As Ampere himself stated, any electrical conductor creates a magnetic field next to it. Its lines of force form circles concentric with respect to the central line of the conductor, which are in planes normal to the elements of the conductor. An even greater magnetic effect of electricity can be observed by twisting a conducting wire into a series of parallel, mutually insulated rings.

The scientist called this form of conductor a solenoid. Conducting experiments with many materials, the author was convinced that iron completely loses its magnetic properties at zero current, and steel retains magnetism for a long time. But the greatest effect was demonstrated by specially designed electromagnets, essentially iron rods in a wire winding through which an electric current was passed.

André Marie outlined all the conclusions obtained in his own scientific work, which was published in 1826 and called "The Theory of Electrodynamic Phenomena Derived Exclusively from Experience."

Telegraph Ampere

The first meaningful attempts to create a device capable of transmitting certain signals over a distance began to be made at the end of the 18th century. The pioneers in this business were Alain-Rene Lesage, who created the simplest design of two receivers and 24 insulated wires. Contributed to the development of this direction and Ampere. In 1829, he proposed the idea of ​​a telegraph, which was based on the discovery of Oersted. The scientist developed a transmitting device consisting of fifty wires and 25 magnetic needles attached to the axes. However, this project did not find a wide application, as it was rather impractical. It was assumed that a separate wire and arrow would be intended for each sign.

We can say that Andre Marie was able to get ahead of the time. At that time, there were no devices that could recognize an electrical signal. Stretching a wire for each letter, number or sign is very time consuming and uneconomical. However, there was still a benefit from this invention - today electromagnetic switches operate according to this principle.

Cybernetics and more

In his fundamental work, An Essay on the Philosophy of Sciences, Ampère gave the concept of a new science to cybernetics. He understood it as a doctrine of government for the provision of the common good. Its first part was published in 1834, and the second was published after the death of the author in 1843. Andre Marie called the theory of laws an important element of cybernetics. In his opinion, it should study the origin of laws, anticipating the consequences generated by them. The author emphasized the fundamental importance of the manager's personality, therefore he advocated the selection of the best candidates who are able to cope with their duties.

Ampere also brought out the need for the existence of another scientific direction, as an offshoot of cybernetics - cenolbology, that is, the science of public happiness. He set before her the task of determining the best living conditions for peoples in order to create an optimal economic system for this. In fact, André Marie raised the question of the rationality of human management, which should contribute to universal happiness.

Among the inventions of the scientist were things of a different nature. So, Ampère tried to create a new language of international communication, optimized the design of kites and planned to write an epic poem. The Frenchman was one of the first to consider partial differential equations, which began to be called after Monge-Ampere. In chemistry, independently of Amedeo Avogadro, Ampère was able to derive the law of molar volumes of gases. In addition, he made attempts to systematize the chemical elements according to their properties.

André Marie Ampère died of complications from pneumonia on June 10, 1836, while on another assignment as inspector general.

interesting facts

• Like many prominent scientists, Ampere introduced a number of new terms into scientific circulation, including electrodynamics, cybernetics and kinematics.
• In addition to mathematics and physics, André Marie excelled in other scientific fields. In particular, his merits are noted in chemistry, botany, linguistics and even philosophy.
• While reading a report by Ampere on the interaction of conductors with currents, one of the scientists exclaimed that he had not heard anything new. After all, if the currents affect the magnetic needle, then they are able to influence each other. From such an offensive, the speaker was completely confused, but his colleague Arago saved the situation. He took out two keys from his pocket and said that each of them affects the arrow, but does not affect each other.
• Ampère did not go to school for a single day, but thanks to his incredible craving for knowledge, he managed to become one of the most educated people of his time.
• The name André Marie is included in the list of the greatest scientists of France, which is located on the first floor of the Eiffel Tower.
• In 1881, at the first International Congress of Electricians, which was held in Paris, the unit of current was named after Ampère.