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BIOGRAPHIES OF GREAT SCIENTISTS
Hertz Heinrich Rudolf. Biography of the scientist
Directory / Biographies of great scientists
In the history of science, there are not many discoveries that you have to come into contact with every day. But without what Heinrich Hertz did, it is already impossible to imagine modern life, since radio and television are a necessary part of our life, and he made a discovery in this area. Heinrich Rudolf Hertz was born on February 22, 1857 in the family of a lawyer who later became a senator. The boy was weak and sickly, but he successfully overcame the unusually difficult first years of his life, and, to the delight of his parents, he evened out, became healthy and cheerful. Everyone believed that he would follow in his father's footsteps. And indeed, Heinrich entered the Hamburg real school and was going to study law. However, after they began classes in physics at their school, his interests changed dramatically. Fortunately, the parents did not interfere with the boy's search for his vocation and allowed him to go to the gymnasium, after graduating from which he received the right to enter the university. Having received a matriculation certificate, Hertz left in 1875 for Dresden and entered the Higher Technical School. At first he liked it there, but gradually the young man realized that a career as an engineer was not for him. On November 1, 1877, he sent a letter to his parents, where there were such words: “I used to often say to myself that being a mediocre engineer is preferable to me than a mediocre scientist. And now I think that Schiller is right when he said: will not succeed in it. "And this excessive caution of me would be madness on my part." Therefore, he left the school and went to Munich, where he was accepted immediately into the second year of the university. The years spent in Munich showed that university knowledge was not enough; for independent scientific studies, it was necessary to find a scientist who would agree to become his supervisor. That is why, after graduating from university, Hertz went to Berlin, where he got a job as an assistant in the laboratory of the largest German physicist of that time, Hermann Helmholtz. Helmholtz soon noticed a talented young man, and good relations were established between them, which later turned into close friendship and at the same time into scientific cooperation. Under the guidance of Helmholtz, Hertz defended his thesis and became a recognized specialist in his field. Helmholtz, in his obituary, recalls the beginning of Hertz's scientific career, when he proposed to him a topic for student work in the field of electrodynamics, "being sure that Hertz would become interested in this issue and solve it successfully." Thus, Helmholtz introduced Hertz to the area in which he subsequently had to make fundamental discoveries and immortalize himself. Describing the state of electrodynamics at that time (summer 1879), Helmholtz wrote: "... the field of electrodynamics turned into a roadless desert at that time. Facts based on observations and consequences from very dubious theories - all this was interspersed interconnected." It was in this year that Hertz was born as a scientist. The aspiring scientist was completely captured by the work on the doctoral dissertation, which is mandatory for a university graduate, which he wanted to complete as soon as possible. On February 5, 1880, Heinrich Hertz was crowned with the degree of Doctor of Science with a rare in the history of the University of Berlin, and even with such strict professors as Kirchhoff and Helmholtz, the predicate - with honors. His thesis "On induction in a rotating ball" was theoretical, and he continued to engage in theoretical research at the Physics Institute at the university. But Heinrich Hertz began to doubt, since he believed that the theoretical works he published were accidental for him as a scientist. He was more and more attracted to experiments. On the recommendation of his teacher, in 1883 Hertz received a position as assistant professor in Kiel, and six years later became professor of physics at the Technische Hochschule in Karlsruhe. Here, Hertz had his own experimental laboratory, which provided him with the freedom of creativity, the opportunity to do what he felt interested and recognized. Hertz realized that what interested him most in the world was electricity, the rapid electrical oscillations he had worked on as a student. It was in Karlsruhe that the most fruitful period of his scientific activity began, which, unfortunately, did not last long. In an 1884 paper, Hertz shows that Maxwellian electrodynamics has advantages over conventional electrodynamics, but considers it unproven that it is the only possible one. Subsequently, Hertz, however, settled on the compromise theory of Helmholtz. Helmholtz borrowed from Maxwell and Faraday the recognition of the role of the medium in electromagnetic processes, but, unlike Maxwell, he believed that the action of open currents should be different from the action of closed currents. This question was studied in the laboratory of Helmholtz by N. N. Schiller in 1876. Schiller did not discover the difference between closed and open currents, as it should have been according to Maxwell's theory! But, apparently, Helmholtz was not satisfied with this and suggested that Hertz once again start testing Maxwell's theory. Hertz's calculations showed that the expected effect, even under the most favorable conditions, would be too small, and he "refused to develop the problem." However, since that time he did not stop thinking about possible ways to solve it, and his attention "was sharpened in relation to everything connected with electrical vibrations." By the beginning of Hertz's research, electrical oscillations had been studied both theoretically and experimentally. Hertz, with his keen attention to this subject, while working at the Karlsruhe Higher Technical School, found a pair of induction coils in the physics room intended for lecture demonstrations. “It struck me,” he wrote, “that in order to obtain sparks in one winding, it was not necessary to discharge large batteries through another and, moreover, that small Leyden jars and even discharges of a small induction apparatus were sufficient for this, if only the discharge pierced the spark gap” . Experimenting with these coils, Hertz came up with the idea of his first experience. Hertz described the experimental setup and the experiments themselves in an article published in 1887 entitled "On Very Fast Electrical Oscillations". Hertz describes here a method for generating oscillations "about a hundred times faster than those observed by Feddersen." “The period of these oscillations,” writes Hertz, “determined, of course, only with the help of theory, is measured in hundred-millionths of a second. Consequently, in terms of duration, they occupy a middle place between the sound vibrations of weighty bodies and the light vibrations of the ether.” But Hertz does not talk about any electromagnetic waves with a length of about three meters in this work. All he did was to construct a generator and a receiver of electrical oscillations by studying the inductive action of the oscillatory circuit of the generator on the oscillatory circuit of the receiver, with a maximum distance of three meters between them. In On the Actions of the Current, Hertz moved on to studying phenomena at a greater distance, working in an auditorium 14 meters long and 12 meters wide. He found that if the distance of the receiver from the vibrator is less than one meter, then the nature of the distribution of the electric force is similar to the dipole field and decreases inversely as the cube of the distance. However, at distances exceeding three meters, the field decreases much more slowly and is not the same in different directions. In the direction of the axis of the vibrator, the action decreases much faster than in the direction perpendicular to the axis, and is hardly noticeable at a distance of four meters, while in the perpendicular direction it reaches distances greater than twelve meters. This result contradicts all laws of the long-range theory. Hertz continued research in the wave zone of his vibrator, the field of which he later calculated theoretically. In a number of subsequent works, Hertz irrefutably proved the existence of electromagnetic waves propagating at a finite speed. "The results of my experiments on fast electrical oscillations," Hertz wrote in his eighth article in 1888, "showed me that Maxwell's theory has an advantage over all other theories of electrodynamics." The field in this wave zone at different moments of time was depicted by Hertz using a picture of lines of force. These drawings by Hertz were included in all electricity textbooks. Hertz's calculations formed the basis of the theory of antenna radiation and the classical theory of radiation of atoms and molecules. Thus, in the course of his research, Hertz finally and unconditionally switched to Maxwell's point of view, gave a convenient form to his equations, supplemented Maxwell's theory with the theory of electromagnetic radiation. Hertz obtained experimentally the electromagnetic waves predicted by Maxwell's theory and showed their identity with the waves of light. In 1889, at the 62nd Congress of German Naturalists and Physicians, Hertz delivered a report "On the relationship between light and electricity." Here he sums up his experiments in the following words: "All these experiments are very simple in principle, but, nevertheless, they entail the most important consequences. They destroy any theory that considers that electric forces jump space instantly. They mean a brilliant victory Maxwell's theory ... How unlikely her view of the essence of light seemed earlier, it is now so difficult not to share this view. In 1890, Hertz published two articles: "On the basic equations of electrodynamics in bodies at rest" and "On the basic equations of electrodynamics for moving bodies." These articles contained research on the propagation of "electric force rays" and, in essence, gave the canonical exposition of Maxwell's theory of the electric field, which has since become part of the educational literature. Hertz's experiments caused a huge resonance. Particular attention was drawn to the experiments described in the work "On the rays of electric force." “These experiments with concave mirrors,” Hertz wrote in the “Introduction” to his book “Investigations on the Propagation of Electric Force,” “quickly attracted attention, they were often repeated and confirmed. They received a positive assessment, which far exceeded my expectations.” Among the numerous repetitions of Hertz's experiments, a special place is occupied by the experiments of the Russian physicist P. N. Lebedev, published in 1895, the first year after Hertz's death. In the last years of his life, Hertz moved to Bonn, where he also headed the department of physics at the local university. There he made another major discovery. In his work "On the Influence of Ultraviolet Light on an Electric Discharge", received by the "Protocols of the Berlin Academy of Sciences" on June 9, 1887, Hertz describes an important phenomenon discovered by him and later called the photoelectric effect. This remarkable discovery was made due to the imperfection of the Hertzian method of detecting oscillations: the sparks excited in the receiver were so weak that Hertz decided to place the receiver in a dark case to facilitate observation. However, it turned out that the maximum spark length in this case is much less than in an open circuit. Removing the walls of the case in succession, Hertz noticed that the interfering effect was exerted by the wall facing the spark of the generator. Investigating this phenomenon carefully, Hertz established the cause that facilitates the spark discharge of the receiver - the ultraviolet glow of the generator spark. Thus, purely by chance, as Hertz himself writes, an important fact was discovered that had no direct relation to the purpose of the study. This fact immediately attracted the attention of a number of researchers, including A. G. Stoletov, a professor at Moscow University, who studied the new effect, which he called actinoelectric, with particular care. Hertz did not have time to study this phenomenon in detail, since he suddenly died of a malignant tumor on January 1, 1894. Until the last days of his life, the scientist worked on the book "Principles of Mechanics, set forth in a new connection." In it, he sought to comprehend his own discoveries and outline further ways to study electrical phenomena. After the untimely death of the scientist, this work was completed and prepared for publication by Hermann Helmholtz. In the preface to the book, he called Hertz the most talented of his students and predicted that his discoveries would determine the development of science for many decades to come. Helmholtz's words turned out to be prophetic and began to come true a few years after the scientist's death. And in the XNUMXth century, almost all areas of modern physics arose from the work of Hertz. Author: Samin D.K.
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