Broglie (Broglie), Louis de( French physicist, Nobel Prize in Physics, 1929)
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Biography Broglie (Broglie), Louis de
August 15, 1892, Mr.. - March 19, 1987
French physicist Louis Victor Pierre Raymond de Broglie was born in Dieppe. He was the youngest of three children Victor de Broglie and nee Pauline de La Forest d'Armayl. As a senior man of aristocratic family, his father held the title of Duke. For centuries, the de Broglie served the nation in the military and diplomatic career, but Louis and his brother Maurice broke this tradition by becoming scientists.
Raised in a refined and privileged environment of the French aristocracy, B. even before entering the Lyceum Jeanson-de-Sayi in Paris, was fascinated by the various sciences. Of particular interest in him evoked history, the study by B. engaged in the Faculty of Arts and Letters, University of Paris, where he was in 1910. received a bachelor's degree. Under the influence of his elder brother Maurice B. more and more fascinated by physics and, in his own words, 'philosophy, generalizations and books [Henry] Poincare', the famous French mathematician. After a period of intensive training he was in 1913. got a degree in physics at the Faculty of Natural Sciences, University of Paris.
That same year, B. was called up for military service and enlisted in the French Corps of Engineers. After the start in 1914. First World War he served in the radio-telegraph division, and spent most of the war years in the wireless telegraph station at the Eiffel Tower. A year after the war, B. resumed his studies in physics at a private research laboratory of his brother. He studied the behavior of electrons, atoms, and X-rays.
It was an exciting time for physicists, when the riddles encountered at every step. In XIX. classical physics has achieved so much success that some scholars have begun to doubt whether remains unresolved at least some fundamental scientific problems. And only in the most recent years of the century made such astonishing discoveries as X-rays, radioactivity and the electron. In 1900, Mr.. Max Planck proposed his revolutionary quantum theory to explain the relationship between body temperature and he emitted radiation. Despite the time-honored notion of how, . that light propagates a continuous wave, . Planck suggested, . that electromagnetic radiation (just a few decades before it was proven, . that light is an electromagnetic radiation) consists of undivided portions, . energy is proportional to the frequency of radiation,
. New theory allowed Planck to solve the problem, on which he worked, but it was too unusual to be accepted. In 1905, Mr.. Albert Einstein showed that Planck's theory - not a mathematical trick. Using quantum theory, he offered a wonderful explanation of the photoelectric effect (emission of electrons of the metal surface under the action of the radiation incident on it). It was known that with increasing intensity of radiation emitted from the surface of the number of electrons increases, but their speed never exceeds a certain maximum. According to Einstein proposed an explanation, . each quantum transfers its energy to one electron, . pulling it from the metal surface: the more intense radiation, . the more photons, . that release more electrons, the energy of each photon is determined by its frequency and sets the speed limit of the electron emission,
. The merit of Einstein, not only in that it broadened the scope of quantum theory, but in confirmation of its validity. Light certainly has wave properties in a number of phenomena manifests itself as a particle.
. Further demonstration of quantum theory was followed in 1913, . When Niels Bohr proposed a model of the atom, . which connected the concept of Ernest Rutherford on the dense central core, . around which the electrons are treated, . with certain restrictions on the electron orbits,
. These restrictions allowed Bohr to explain the line spectrum of atoms, . which can be observed, . if light, . emitted substance, . located in an excited state during combustion or electric discharge, . pass through a narrow slit, . and then through a spectroscope - an optical instrument, . spatially separating the signal components, . corresponding to different frequencies or wavelengths (different colors),
. The result is a series of lines (the slit image), or range. The position of each spectral line depends on the frequency of certain components. The spectrum is entirely determined by the radiation of atoms or molecules of luminous matter. Bohr explained the emergence of the spectral lines of 'hopping' of electrons in atoms with one 'allowed' orbit to another, with lower energy. The difference between the orbits of the energy lost by the electron during the transition is emitted in quanta, or photons - light with a frequency proportional to the energy difference between the. Spectrum is a kind of coded record of the energy states of electrons. Bohr's model, thus reinforced, and the concept of the dual nature of light as a wave and particle flux.
. Despite the large number of experimental evidence, the idea of the dual nature of electromagnetic radiation, many physicists continue to raise doubts
. Besides the new theory discovered vulnerabilities. For example, Bohr's model 'approved' electron orbits in correspondence with the observed spectral lines. Orbits do not follow from the theory, and was fitted based on experimental data.
B. first realized that if the waves can behave like particles, and particles can behave like waves. He applied the theory of Einstein - Bohr on the particle-wave duality to material objects. Wave and the matter is considered to be quite different. Matter has rest mass. She can lie down or move with any speed. Light did not have rest mass: it is either moving at a certain speed (which may vary depending on the environment), or does not exist. By analogy with the relation between the wavelength of light and energy of the photon B. hypothesis of the existence of the relationship between wavelength and momentum (mass times the velocity of a particle). The momentum is directly related to the kinetic energy. Thus, the fast electron corresponds to the wave with higher frequency (shorter wavelength) than the slow electron. In what forms (wave or particle) shows a material object depends on the conditions of observation.
With extraordinary courage B. applied his idea to the model of the atom Bohr. The negative electron is attracted to the positively charged nucleus. In order to revolve around the nucleus at a certain distance, the electron must move at a certain speed. If the electron velocity changes, then changes the position of the orbit. In this case, the centrifugal force is balanced by the centripetal. The speed of an electron in a certain orbit, located at some distance from the nucleus, corresponding to a momentum (speed multiplied by the electron mass) and, consequently, by hypothesis, AB, specific wavelength of an electron. According to BA, 'allowed' orbits differ in that they fit into an integer number of wavelengths of the electron. Only on such a wave electron orbits are in phase (at a certain point of frequency cycle) with itself and not ruin their own interference.
In 1924, Mr.. B. presented his work 'Studies on the quantum theory' ( 'Researches on the Quantum Theory') as a doctoral dissertation Faculty of Natural Sciences, University of Paris. His opponents and members of the Academic Council were shocked, but are strongly skeptical. They considered the idea of B. a theoretical speculation, devoid of pilot. However, at the insistence of Einstein's doctoral degree B. yet been awarded. The following year, B. published his work in the form of an extensive article, which was greeted with respectful attention. Since 1926, Mr.. He became a lecturer in physics, University of Paris, and two years later was appointed Professor of Theoretical Physics, Institut Henri Poincare at the same university.
In Einstein's work B. impressed, and he advised many physicists to study it carefully. Erwin Schrodinger followed the advice of Einstein's ideas and put B. the basis of wave mechanics, summarized the quantum theory. In 1927, Mr.. wave behavior of matter was experimentally confirmed in studies of Clinton J. Davisson and Lester X. Germer, working with low-energy electrons in the United States, and George P. Thomson, who was using a high-energy electrons in England. Opening of the waves associated with electrons, which can be rejected in the right direction and focus, resulting in 1933. the establishment of Ernst Rusco electron microscope. The waves associated with material particles, now called the de Broglie waves.
In 1929, Mr.. 'for the discovery of the wave nature of electrons' B. was awarded the Nobel Prize in Physics. Introducing the winner at the awards ceremony, a member of the Royal Swedish Academy of Sciences KV. Oseen said: 'Based on the assumption that light is both wave motion and flow of corpuscles [particles], B. opened up entirely new dimension to the nature of matter, which previously no one had suspected ... Brilliant guess B. resolve longstanding disputes, finding that there are not two worlds, one - of light and waves, the other - matter and corpuscles. There is only one common world '.
B. continued his investigations into the nature of electrons and photons. Together with Einstein and Schrodinger he spent many years trying to find a formulation of quantum mechanics, which would report ordinary causal laws. However, the efforts of these outstanding scientists have not been successful, and it was experimentally proved that such theories are incorrect. In quantum mechanics the prevailing statistical interpretation based on the work of Niels Bohr, Max Born and Werner Heisenberg. This concept is often called the Copenhagen interpretation in honor of Bohr, who developed it in Copenhagen.
In 1933. B. was elected a member of the French Academy of Sciences, and in 1942. became its permanent secretary. The following year he founded the Center for Research in Applied Mathematics at the Institute Henri Poincare in order to strengthen ties between physics and applied mathematics. In 1945, after the Second World War, B. and his brother Maurice were appointed advisers to the French High Commission for Atomic Energy.
B. never married. He loved to make walking, reading, thinking and indulge in a game of chess. After the death of his brother in 1960. He inherited the ducal title. B. died in a Paris hospital on Mar. 19, 1987, Mr.. the age of 94.
In addition to the Nobel Prize, B. was awarded the first medal of Henri Poincare the French Academy of Sciences (1929), Grand Prix de Monaco Albert I (1932), the first UNESCO Kalinga Prize (1952) and Grand Prix Engineering Society of France (1953). He was the holder of honorary degrees from many universities and a member of many scientific organizations, including the Royal Society of London, U.S. National Academy of Sciences and the American Academy of Arts and Sciences. In 1945, Mr.. He was nominated to the French Academy of brother Maurice in recognition of his literary achievements.