"King of the Experimenters"
To mark the 210th anniversary of M. Faraday's birth and the 170th anniversary of his discovery of the law of electromagnetic induction
Michael Faraday was born on September 22, 1791, in a suburb of London, in the family of a blacksmith. Financial difficulties forced the father to send his 13-year-old son to work in a bookstore. At first, the boy was a messenger, and then became an apprentice bookbinder. He worked from five in the morning until seven in the evening, and in his spare time he read books that he bound.
Michael's childhood habit of working, natural intelligence, curiosity, and desire to explain natural phenomena, which he learned about from books, allowed him to later become a great scientist.
Young Faraday sought to fill in the gaps in his education on his own. He was particularly interested in physics and chemistry. One of the bookbinding workshop's clients drew attention to the talented young man, who presented him with tickets to lectures by G. Davy, a well—known professor at the Royal Institute. The lectures on electrochemistry made a huge impression on Michael, and he asked Davy to hire him. The scientist responded to this request by arranging for Faraday as a laboratory assistant.
In 1813. Davy takes Michael on a trip to Europe. Faraday participates in chemical and physical experiments that Davy conducts in laboratories in Italy and France. After returning to London in 1815, Michael worked as an assistant at the Royal Institute. The main aspiration of Faraday in the initial period of his scientific activity was to master the art of experimentation. And he understood it so perfectly that he later earned the fame of the "king of experimenters" in the scientific world.
Scientific activity completely captured Faraday. He spent all his days in the institute's laboratory. His range of scientific research was extremely wide: work on the liquefaction of gases, the production of new organic hydrocarbon compounds (in particular, benzene and butylene), the development of a method for the identification of a new group of substances — sulfonic acids used for the manufacture of dyes and certain drugs. But Faraday was most interested in electromagnetic phenomena.
In 1821, while preparing an article on these phenomena, he read about the discovery made in 1820 by the Danish physicist X. By Oersted. The Dane discovered that a magnetic needle held up to a current conductor is deflected, i.e. he discovered the relationship between electricity and magnetism. Faraday also got acquainted with the works of the French physicist A. Ampere, who in the same year, 1820, discovered the phenomenon of the interaction of two conductors with a current: their attraction or repulsion from each other, depending on the direction of the currents flowing through them. This phenomenon served as the basis of electrodynamics.
In the laboratory of the Royal Institute, Faraday repeated all these experiments, for the first time detecting the rotation of a magnet around a current conductor, and the latter around a magnet.
Based on the results of his scientific research, Faraday published a number of articles in the Proceedings of the Royal Society of London, and in 1824 he was elected a member of this society. In 1825, he was appointed director of the laboratory of the Royal Institute.
In 1827, Faraday published the book "Chemical Experiments", where he summarized the materials of his research. For his contribution to science, Faraday was elected a professor at the Royal Institute. The highest skill and thoroughness of conducting experiments, the ability to summarize their results have created a well-deserved authority in the scientific world for the "king of experimenters".
Professor G. Davy, Faraday's first scientific supervisor, liked to repeat to his friends at the end of his life (he died in 1829): "I have made several important discoveries for science in my life, but the biggest of them is my discovery of Faraday." If Mr. Davy had lived a little longer and learned about his student's subsequent work, he might have been even more proud of the discovery of such a brilliant scientist, as Faraday rightfully was. It was in the early 30s of the XIX century
The great physicist made the most significant discoveries. The most important of them (1831) is the law of electromagnetic induction, which bears his name.
The experiment that led to this discovery was described by Faraday in the article "On the induction of electric currents": "A copper wire was wound on a wide wooden coil ..., between its coils was another wire of the same length and insulated from the first. One of the coils was connected to a galvanometer, and the other to a voltaic battery. When the circuit was closed, it was observed... the galvanometer needle deflected, and the same effect was observed when the current stopped."
On September 17, 1831, Faraday received an electric current using a magnet: "One end of a cylindrical magnetic rod... it is brought to the very edge of a cylindrical spiral of wire, after which the rod is pushed into the spiral for the entire length — the galvanometer needle starts moving, the rod is abruptly pulled out — the arrow starts moving again, but in the opposite direction. This effect is observed whenever a magnet is pushed in or out, and therefore an electric wave is generated."
Faraday reported on another experiment on October 28, 1831. "I made a copper disk rotate between the poles of a large horseshoe-shaped magnet of the Royal Society. The axis and the point on the edge of the disk were connected to the galvanometer. As the disk rotated, the galvanometer needle began to move." This "Faraday wheel" was the world's first electric generator.
On November 24, 1831, Faraday delivered an extensive report to the Royal Society: "Experimental studies on electricity" on the experiments carried out. His discoveries were highly appreciated by scientists and were of great importance for the development of science and technology. They formed the basis of electrical engineering, being the starting point for the creation of electric generators and electric motors. Just three years later, the Russian scientist B. Jacobi, having familiarized himself with the works of Faraday, created a "magnetic motor", and already in 1838 he used it for electric traction (see "Locomotive" No. 9 for the current year).
The first attempts to use traction electric motors in railway transport were made in the same year in England and the USA. However, the chemical power sources of the motors, such as galvanic batteries, turned out to be low—power, bulky and inconvenient to operate. Therefore, electrical engineers from various countries, based on Faraday's discoveries, worked to create a powerful source of electricity — a generator. Their efforts were successfully completed in 1871, when the electrical engineer 3. Gram, a Belgian by nationality, presented to the Paris Academy of Sciences a sample of the world's first dynamo he had created. Two years earlier, he had patented a circuit for an annular armature that provides electromotive force and a constant-direction current.
After this invention, electric machines began to compete successfully with steam engines and gradually replace the latter. Electric traction began to receive rapid development on the railways. As early as 1879, V. Siemens demonstrated at an industrial exhibition in Berlin a sample of the first electric railway, and the following year F. Pirotsky in St. Petersburg and V. Siemens near Berlin demonstrated the first electric tram cars. Faraday's ideas and discoveries were materialized in transportation and in many other industries.
But let's go back to the 1830s and 1840s, when Faraday continued his research in the field of electromagnetism. He found out the dependence of induction currents on the magnetic properties of the medium, investigated the phenomenon of self-induction, and studied the mechanism of electrical conductivity in various media.
To explain electromagnetic phenomena, Faraday introduced the concept of a field, a space filled with lines of force. His ideas about electric and magnetic fields and the wave process of electromagnetic interactions were developed and put into mathematical form by the outstanding English physicist D. Maxwell (ironically, he was born in 1831, the year Faraday discovered the law of electromagnetic induction). Maxwell highly appreciated the merits of Faraday, the simplicity and clarity of the explanation of the phenomena he discovered. Here is how he wrote about it in an article published in the Encyclopedia Britannica: "... the practical applications of Faraday's discovery have increased and continue to increase every year in terms of their number and value ... Faraday's original formulation of the law remains to this day the only one ... by which the theory of phenomena can be presented so that it is accurate and It is quantitatively correct, while remaining within the framework of simple presentation methods."
In the course of further experiments, Faraday established links between magnetic and optical phenomena, suggesting the electromagnetic nature of light. These ideas were later confirmed and developed by Maxwell in his electromagnetic theory of light.
Along with his work on electromagnetism, Faraday studied discharges in gases, finding out their electrical properties. Trying to identify the nature of electricity, Faraday came to the idea of the unity of the "forces" of nature (different types of energy). Based on the principle of conservation of energy, he argued that in a chemical source of electrical current, A. Volta, chemical energy is converted into electrical energy. From this, Faraday concluded that it was possible to reverse the conversion of electrical energy into chemical energy.
He conducted a series of experiments on electrolysis. By passing an electric current through various solutions (electrolytes), Faraday established quantitative relationships between substances formed as a result of the decomposing effect of electric current and the strength of the current. He discovered and formulated the basic laws of electrolysis, and also introduced terminology that has been preserved to this day, for example, the terms: anode, cathode, electrolysis and electrode. The physical constant, the Faraday number, is still widely used in electrochemical calculations today.
02.07.2023, 14:16
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