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BASIC IDEAS OF DESCARTES' MECHANICS We have seen that the principle of conservation of work had the character of an axiom for Descartes. The principle of constancy of momentum had the same character for him. In his “Principles of Philosophy,” Descartes essentially did not substantiate it with anything other than a reference to

Curriculum Vitae

One of the creators of quantum mechanics, Louis de Broglie, is a world-famous scientist whose work in the field of theoretical physics, as well as his outstanding literary talent, profoundly changed modern physics and placed him on a par with the most outstanding scientists of our time.

De Broglie was born in Dieppe (France) in 1892 into one of the most aristocratic families. He graduated from the Lyceum in Paris and received a bachelor's degree in history from the University of Paris in 1909. However, having shown a penchant for exact sciences, he abandoned his career as a historian and paleontologist and in 1913 received a bachelor's degree in exact sciences from the same University of Paris.

After serving in the army during the First World War, he worked in the laboratory created by his brother Maurice de Broglie, where he was engaged in the experimental study of the highest frequency radiation that was available for spectroscopic research and where the problem of choosing between corpuscular and wave interpretation optical phenomena was especially acute. In 1924, Louis de Broglie defended his doctoral dissertation on “Research in Quantum Theory,” in which he attempted to build a bridge between these opposing theories. De Broglie associated a wave of a certain length with each moving particle. However, in the case of particles with significant mass, which classical mechanics deals with, the corpuscular properties. Wave properties are decisive for particles atomic sizes. Having at first retreated from the deep revolutionary content of his theory, de Broglie tried to preserve the traditional deterministic interpretation of classical physics with the help of various hypotheses. However, faced with enormous mathematical difficulties, he was forced to accept a probabilistic and indeterministic interpretation, in which classical mechanics became simply a special case of more general wave mechanics.

Experimental confirmation of these theories was obtained four years later by American physicists, employees of the Bell Telephone laboratory, who discovered that atomic particles such as electrons and protons, thanks to the wave associated with them, can, like light and X-rays, experience diffraction. Later, these ideas were put into practice in the development of magnetic lenses, which serve as the basis for an electron microscope.

The 1929 Nobel Prize winner in physics, Louis de Broglie, received the first-ever Henri Poincaré Medal from the French Academy of Sciences in the same year. In 1933 he was elected a full member of the French Academy of Sciences, and in 1942, replacing Emilie Picard, he became one of its permanent secretaries.

Finally, since 1926 he has been heavily involved in issues of education and scientific leadership. In 1928, after giving several lectures and courses at the Sorbonne, Paris and the University of Hamburg, de Broglie received the chair of theoretical physics at the Henri Poincaré Institute, where he organized a center for the study of modern theoretical physics. In 1943, trying to solve problems arising from the insufficient connection between science and industry, he founded a research department in applied mechanics at the Poincaré Institute. This interest in the practical application of science is reflected in his latest works, dedicated to particle accelerators, waveguides, atomic energy and cybernetics.

Louis de Broglie, together with his brother, published important scientific works on atomic particle physics and optics, adjacent to his early work, and also, in connection with fundamental research in wave mechanics, work on the physics of x-rays and γ-rays.

In his lectures and popular books, he discusses the philosophical aspects of the problems arising in these new theories. His most recent work in this area is “The History of the Development of Modern Physics from the First Solvay Congress of Physicists in 1911 to the Present.”

For his literary work he was honored with election to the French Academy in 1945. He is honorary president of the French Association of Scientific Writers and received the first Kalinga Prize in 1952 for high quality scientific works.

When the French government created the High Commission for Atomic Energy in 1945, Louis de Broglie was appointed its technical adviser, and after the reorganization of the Commission in 1951, he became a member of its Scientific Council.

Biography

Louis Victor Pierre Raymond - French theoretical physicist, one of the founders of quantum mechanics, Nobel Prize laureate in physics for 1929, member of the French Academy of Sciences (since 1933) and its permanent secretary (since 1942), member of the French Academy (since 1944 year).

Louis de Broglie is the author of works on fundamental problems of quantum theory. He developed a hypothesis about the wave properties of material particles (de Broglie waves, or waves of matter), which laid the foundation for the development of wave mechanics. He proposed an original interpretation of quantum mechanics (pilot wave theory, double solution theory), developed the relativistic theory of particles with arbitrary spin, in particular photons (neutrino theory of light), dealt with issues of radiophysics, classical and quantum field theories, thermodynamics and other branches of physics.

Origin and education

Louis de Broglie belonged to the famous aristocratic family of Broglie, whose representatives occupied important military and political positions in France for several centuries. The father of the future physicist, Louis-Alphonse-Victor (French Victor de Broglie; 1846-1906), 5th Duke of Broglie, was married to Pauline d'Armaille, granddaughter of Napoleonic general Philippe Paul de Segur. They had five children; in addition to Louis, these are: Albertine (1872-1946), later Marquise de Luppé; Maurice (1875-1960), later a famous experimental physicist; Philippe (1881-1890), who died two years before the birth of Louis, and Pauline, Countess de Pange (French Comtesse de Pange; 1888-1972), later a famous writer. Being the youngest child in the family, Louis grew up in relative solitude, read a lot, and was interested in history, especially political history. WITH early childhood he had a good memory and could accurately read an excerpt from a theatrical production or name a complete list of ministers of the Third Republic. He was predicted to have a great future in the public sphere. De Broglie lived in his villa in Dieppe or on his estates in Normandy and Anjou. In 1901, the family finally moved to Paris, where the father became a member of the National Assembly.

Young Louis de Broglie studied at home under the guidance of private priestly teachers - first Father Dupuis and then Father Chanet. After the death of the head of the family in 1906, the elder brother Maurice, who became the new Duke de Broglie, took care of the education of the younger one, sending him to the prestigious Lyceum Jeanson de Sailly. Here Louis, who inherited the title of prince of the Holy Roman Empire, studied for three years and in 1909 received bachelor's degrees (Baccalaureat) in philosophy and mathematics. He studied well in subjects such as French, history, physics, philosophy, showed average results in mathematics, chemistry and geography, had poor drawing skills and foreign languages. At the age of eighteen, Louis de Broglie entered the University of Paris, where he initially studied history and law, but soon became disillusioned with these disciplines and the methods of teaching them. At the same time, he was not attracted to the military or diplomatic career that was common in his family. According to the memoirs of Maurice de Broglie, during this crisis, his brother’s thoughts were directed towards unsolved problems of theoretical physics, closely related to the philosophy of science. This was facilitated by attending courses in “special mathematics”, reading the works of Henri Poincaré and studying the materials of the first Solvay Congress (1911), of which Maurice worked as one of the secretaries. As a result of reading the notes of the discussions that took place at this conference, as Louis de Broglie himself wrote many years later, he “decided to devote all his energies to clarifying the true nature of the mysterious quanta introduced into theoretical physics ten years earlier by Max Planck, the deep meaning of which is still unknown.” who understood." Turning his attention entirely to the study of physics, he graduated from the university in 1913 with a licentiate of science degree.

Military service. Scientific and teaching career

After completing his training, Louis de Broglie joined the engineering forces as a simple sapper to undergo compulsory service. It began in the fort of Mont Valérien, but soon, on the initiative of his brother, he was seconded to the Wireless Communications Service and worked on the Eiffel Tower, where the radio transmitter was located. Louis de Broglie remained in military service throughout the First World War, dealing with purely technical matters. In particular, together with Leon Brillouin and his brother Maurice, he participated in establishing wireless communications with submarines. Prince Louis was demobilized in August 1919 with the rank of non-commissioned officer (adjudant). Subsequently, the scientist spoke with regret about the six years of his life that passed in isolation from the fundamental problems of science that interested him.

After demobilization, Louis de Broglie continued his studies at the Faculty of Exact Sciences with the aim of obtaining a doctorate. Here he attended Paul Langevin's lectures on the theory of relativity, which made a great impression on him. It is also known that the young scientist regularly came to the School of Physics and Chemistry to discuss his results and thoughts with Langevin and Léon Brillouin. At the same time, Prince Louis began research in the private laboratory of his brother Maurice. The latter's scientific interests concerned the properties of x-rays and the photoelectric effect; Louis’s first works, written with his brother or independently, were devoted to this topic. In 1923, the younger de Broglie expressed his famous idea about the wave properties of material particles, which gave rise to the development of wave mechanics. After creating the formalism of this theory, the scientist took an active part in the discussion of its interpretation, proposing his own version. In subsequent years, he continued to develop various issues of quantum theory. Characterizing de Broglie's way of thinking, his student and closest collaborator Georges Lochak wrote:

Louis de Broglie is characterized by intuitive thinking through simple, concrete and realistic images inherent in three-dimensional physical space. ...aware of the power and rigor of abstract reasoning, he is at the same time convinced that the whole essence is still in concrete images, always unclear and unstable, endlessly revised and most often rejected as more or less false. ...it seems to me that there were two keys in de Broglie's work. The first of these is, obviously, History. He studied it so much that, as he once told me, he probably read more books on history than on physics... These studies were not for him a kind of curiosity or hobby of a cultured person, they were at the same time driving force his spirit and the fertile ground for his thoughts... The second key in his work was visibility... For de Broglie, to understand means to visualize.

J. Loshak. The evolution of Louis de Broglie’s ideas regarding the interpretation of wave mechanics // L. de Broglie. Heisenberg uncertainty relations and probabilistic interpretation of wave mechanics (With critical comments from the author). - M.: Mir, 1986. - S. 16, 21, 26.

In 1928, Louis de Broglie began his teaching career at the faculty natural sciences University of Paris, and in 1933 he headed the department of theoretical physics at the Henri Poincaré Institute (French: Institut Henri-Poincaré). He supervised the weekly seminar and scientific work of graduate students, although over the years, as he moved further and further away from the main direction of scientific development, the number of students became less and less. For many years (until his retirement in 1962), de Broglie gave courses of lectures on wave mechanics, its various aspects and applications; many of these courses have been published in book form. Noting the excellent qualities of these books, the famous physicist Anatole Abraham, however, wrote that

...as a lecturer in the classroom he was boring. Starting right on time, he read in his high voice and somewhat monotonously with large sheets, covered with shorthand symbols. He always stopped exactly at the end of the hour and left immediately. If anyone wanted to ask a question, he asked for a meeting, which was always granted and during which, it must be said, he made great efforts to clarify what was not clear. But few people took this step, and after a while, instead of attending lectures, preference was given to studying his beautifully written books.

In 1933, Louis de Broglie was almost unanimously (with the exception of only two votes) elected a member of the French Academy of Sciences. In 1942, he became its permanent secretary (Secrétaire Perpétuel) and held this position until 1975, when he resigned. The post of Honorary Permanent Secretary (Secrétaire Perpétuel d'Honneur) was created especially for him. On October 12, 1944, de Broglie was elected a member of the French Academy (his predecessor was the mathematician Émile Picard) and on May 31, 1945, he was solemnly accepted as one of the forty “immortals” by his own brother Maurice. In 1945 he was appointed advisor to the French Atomic Energy Commission. For his popular science works, UNESCO awarded him the first Kalinga Prize (1952). In 1973, the Fondation Louis de Broglie was founded to support research into fundamental problems in physics.

Louis de Broglie never married and rarely traveled abroad. After his mother's death in 1928, the family's large palace in Paris was sold and Louis settled in small house on Rue Perronet in Neuilly-sur-Seine, where he lived in seclusion for the rest of his life. He never owned a car, preferring to travel on foot or by metro, never went on vacation and spent every summer in Paris. In 1960, after the death of Maurice, who had no children, Louis de Broglie inherited the ducal title. As Abraham testifies, de Broglie was a shy man, never raised his voice and was polite to everyone. He was taciturn, but from his pen came large number scientific and popular science essays. The scientist died in Louveciennes on March 19, 1987 at the age of 95.

Scientific activities

Physics of X-ray radiation and photoelectric effect

Louis de Broglie's first works (early 1920s) were carried out in the laboratory of his older brother Maurice and concerned the features of the photoelectric effect and the properties of x-rays. These publications examined the absorption of X-rays and described this phenomenon using Bohr's theory, applied quantum principles to the interpretation of photoelectron spectra, and provided a systematic classification of X-ray spectra. Studies of X-ray spectra were important for elucidating the structure of the inner electronic shells of atoms (optical spectra are determined by the outer shells). Thus, the results of experiments carried out together with Alexandre Dauvillier made it possible to identify the shortcomings of existing schemes for the distribution of electrons in atoms; these difficulties were eliminated in the work of Edmund Stoner. Another result was the clarification of the insufficiency of the Sommerfeld formula for determining the position of lines in X-ray spectra; this discrepancy was eliminated after the discovery of electron spin. In 1925 and 1926, Leningrad professor Orest Khvolson nominated the de Broglie brothers for the Nobel Prize for their work on X-ray physics.

Waves of matter

Studying the nature of X-ray radiation and discussing its properties with brother Maurice, who considered these rays to be some combination of waves and particles, contributed to Louis de Broglie's awareness of the need to build a theory connecting corpuscular and wave concepts. In addition, he was familiar with the works (1919-1922) of Marcel Brillouin, in which a hydrodynamic model of the atom was proposed and an attempt was made to connect it with the results of Bohr's theory. The starting point in the work of Louis de Broglie was A. Einstein’s idea of ​​light quanta. In his first article on this topic, published in 1922, the French scientist considered black body radiation as a gas of light quanta and, using classical statistical mechanics, derived Wien’s radiation law within the framework of this concept. In his next publication, he tried to reconcile the concept of light quanta with the phenomena of interference and diffraction and came to the conclusion that it was necessary to associate some periodicity with quanta. At the same time, he interpreted light quanta as relativistic particles of very low mass.

It remained to extend wave considerations to any massive particles, and in the summer of 1923 a decisive breakthrough occurred. De Broglie outlined his ideas in a short note “Waves and Quanta” (Ondes et quanta, presented at a meeting of the Paris Academy of Sciences on September 10, 1923), which laid the foundation for the creation of wave mechanics. In this work, the scientist suggested that a moving particle with energy (\displaystyle E) E and speed (\displaystyle v) v, is characterized by some internal periodic process with frequency (\displaystyle E/h) E/h, where (\displaystyle h ) h - Planck's constant. To reconcile these considerations based on the quantum principle with the ideas of the special theory of relativity, de Broglie was forced to associate with a moving body a “fictitious wave” that propagates at a speed of (\displaystyle c^(2)/v) c^(2)/ v. Such a wave, later called a phase wave, or de Broglie wave, remains in phase agreement with the internal periodic process during the movement of the body. Having then examined the motion of an electron in a closed orbit, the scientist showed that the requirement of phase matching directly leads to the quantum Bohr-Sommerfeld condition, that is, to the quantization of angular momentum. In the next two notes (reported at meetings on September 24 and October 8, respectively), de Broglie came to the conclusion that the speed of a particle is equal to the group speed of phase waves, and the particle moves along the normal to surfaces of equal phase. In general, the trajectory of a particle can be determined using Fermat's principle (for waves) or the principle of least action (for particles), which indicates the connection between geometric optics and classical mechanics.

In an article combining the results of three notes, Louis de Broglie wrote that “perhaps every moving body is accompanied by a wave and that the separation of the movement of the body and the propagation of the wave is impossible.” Following these considerations, the scientist reconciled the phenomena of diffraction and interference with the hypothesis of light quanta. Thus, diffraction occurs when a particle of light passes through a hole whose size is comparable to the length of the phase waves. Moreover, these arguments, according to de Broglie, should also be valid for material particles, for example, electrons, which should have become an experimental confirmation of the whole concept. Evidence of electron diffraction was discovered by 1927, primarily through experiments by Clinton Davisson and Lester Germer in the United States and George Paget Thomson in England.

However, in 1924, Louis de Broglie's ideas about the wave properties of particles were only a hypothesis. He presented his results in expanded form in his doctoral dissertation, “Research on the Theory of Quantums,” which was defended at the Sorbonne on November 25, 1924. The examination committee, which included four famous scientists - physicists Jean Perrin, Charles Victor Mauguin, Paul Langevin and mathematician Elie Cartan, appreciated the originality of the results obtained, but could hardly understand their full significance. The exception was Langevin, who reported de Broglie's work at the Solvay Congress in April 1924. At his suggestion, a copy of the dissertation was sent to Albert Einstein. The latter's reaction in a letter to Langevin was encouraging: "He has lifted the corner of the great curtain (German: Er hat einen Zipfel der grossen Schleiers gelüftet)." The interest in this work of Einstein, who used it to justify his considerations in quantum statistics, attracted the attention of leading physicists to de Broglie's hypothesis, but few took it seriously at that time. The next step was taken by Erwin Schrödinger, who, starting from the ideas of the French physicist, at the beginning of 1926 developed the mathematical formalism of wave mechanics. The successes of Schrödinger's theory and the experimental discovery of electron diffraction led to widespread recognition of the merits of Louis de Broglie, as evidenced by the awarding of the Nobel Prize in Physics for 1929 to him with the wording “for the discovery of the wave nature of the electron.”

Interpretation of wave mechanics. Early works

After the publication of fundamental works on the theory of matter waves, Louis de Broglie published a number of small articles in which he developed and refined his ideas. These clarifications concerned such issues as the relativistic formulation of the relationship between particle energy and wave frequency, the explanation of the phenomena of interference and absorption of radiation by atoms due to the propagation of phase waves, and others. In his thesis he also applied his theory to the description of the Compton effect and the statistical equilibrium of gases and to the calculation of relativistic corrections for the hydrogen atom. However, the physical meaning of phase waves remained largely unclear. After Schrödinger's work on wave mechanics appeared in early 1926, the problem of interpreting the new theory became especially acute. By the end of 1927 she was in general outline the so-called Copenhagen interpretation was formulated, the basis of which was Born’s probabilistic interpretation of the wave function, Heisenberg’s uncertainty relations and Bohr’s principle of complementarity. Louis de Broglie, independently developing his ideas about waves associated with particles, came to a different interpretation, which was called the double solution theory.

The double solution theory was first presented in the article "Wave Mechanics and Atomic Structure of Matter and Radiation", published in the Journal de Physique in May 1927. In this work, particles were represented as "moving singularities" of a wave field described by a relativistic equation such as the Klein-Gordon equation. The speed of the singularity is equal to the speed of the particle, and the phase is determined by the action. Further, using the analogy between classical mechanics and geometric optics (the identity of the principle of least action and Fermat's principle), the author showed that the velocity of the singularity in the case of a free particle should be directed along the phase gradient. Continuous solutions of the wave equation, according to de Broglie, are associated with the case of an ensemble of particles and have the usual statistical meaning (density of the ensemble at each point). Such solutions can also be interpreted as the ensemble density possible solutions, determined by a set of initial conditions, so that the square of the amplitude of such a wave will determine the probability of detecting a particle in a given volume element (probability in the classical sense, as evidence of ignorance of the full picture). The next step was the so-called “double solution principle,” according to which the phases of the singular and continuous solutions are always equal. This postulate “assumes the existence of two sinusoidal solutions of the equation, having the same phase coefficient, with one solution representing a point singularity, and the other, on the contrary, having a continuous amplitude.” Thus, the singularity particle will move along the phase gradient (normal to surfaces of equal phases) of a continuous probability wave.

Having then considered the problem of the motion of a particle in an external potential and moving to the non-relativistic limit, de Broglie came to the conclusion that the presence of a continuous wave is associated with the appearance of an additional term in the Lagrangian of the particle, which can be interpreted as a small addition to the potential energy. This addition coincides with the so-called “quantum potential” introduced by David Bohm in 1951. Turning to the case of a many-particle system in a non-relativistic approximation, de Broglie wondered what the meaning of the Schrödinger equation was, and gave the following answer: the phase of solving the Schrödinger equation in configuration space, the number of dimensions of which is determined by the number of particles, sets the motion of each singularity particle in the ordinary three-dimensional space. The amplitude of the solution, as before, characterizes the probability density of detecting a system in a given location in the configuration space. Finally, in the last section of his article, de Broglie proposed a different view of the results obtained: instead of the “double solution principle,” which is difficult to substantiate, one can postulate the existence of two objects of different physical natures - a material particle and a continuous wave, with the latter directing the movement of the first. This wave is called the “pilot wave” (l’onde pilote). However, according to the scientist, such an interpretation could only be a preliminary measure.

Overall, de Broglie's work has not attracted much attention from the scientific community. The Copenhagen School considered it impossible to resolve fundamental difficulties by returning to the determinism of classical mechanics. Nevertheless, Wolfgang Pauli highly appreciated the originality of the French scientist's ideas. Thus, in a letter to Niels Bohr dated August 6, 1927, he wrote: “...even if this article by de Broglie misses the mark (and I hope that this is true), it is still very rich in ideas, very clear and written in much more high level than the childish articles of Schrödinger, who even today still thinks that he can... abolish material points." De Broglie failed to convince his colleagues of the validity of his ideas during the fifth Solvay Congress (October 1927), where he made a report on his preliminary theory of the pilot wave, only briefly touching on the idea of ​​a double solution. Based on the requirement of agreement with classical mechanics in the appropriate limit, he postulated the fundamental equation of motion in the form of proportionality of the particle speed to the phase gradient of the probabilistic pilot wave, described by the Schrödinger equation. He then considered a number of specific problems, including the case of a many-particle system.

Interpretation of wave mechanics. Later works

The causal theory of the pilot wave met with a cool reception among the participants at the Solvay Congress, which was partly due to its preliminary nature, which de Broglie himself emphasized. The majority preferred the simpler, purely probabilistic interpretation, and this unfavorable reaction, according to de Broglie, was one of the reasons for the refusal to develop his original ideas. In addition, he was unable to answer some important questions, in particular, to resolve the problems of measurement and the “reality” of the wave function. He found himself in a dead end and, as a result of a difficult internal struggle, switched to the point of view of his opponents. For many years, the scientist adhered to the standard Copenhagen interpretation in his lectures and writings. A new reason for revising views arose in 1951 with the appearance of the works of the American physicist David Bohm, which contained a new attempt to construct a quantum theory with “hidden parameters.” Bohm's theory essentially reproduces the ideas of the pilot wave theory in a slightly different formulation (for example, the equation of particle dynamics is written in the language of acceleration rather than velocity, so the corresponding “quantum potential” is introduced into the Newtonian equation). Bohm managed to advance much further than de Broglie in substantiating these views, in particular, to build a theory of measurements. The pilot wave theory, which has since often been called the de Broglie-Bohm theory, apparently allows one to obtain all the results of standard non-relativistic quantum mechanics consistently. It is consistent with Bell's inequalities and refers to nonlocal theories with hidden parameters. It is now often seen as an alternative (though rarely used) formulation of quantum theory.

Bohm's work prompted de Broglie to return to his ideas of a quarter century ago, but the object of his study was not the “preliminary” theory of the pilot wave, but what he believed was a more profound theory of the double solution (his attention was drawn to it by Jean-Pierre Vigier. De Broglie did not see how the properties of the wave function could be reconciled with Bohm’s assumption about the reality of the physical wave that this function describes. He believed that this contradiction could be resolved using the principle of double solution, which could give the wave an objective meaning, that is, make it an element of the physical. reality. “Thus, in the double solution theory, the unacceptable idea of ​​a particle, which is “piloted” by a certain distribution of probabilities of events, is replaced by the idea of ​​a singularity that is one with a physical wave, which in some sense “feels” the surrounding space and transmits. the corresponding information of the singularity, directing its movement.” The speed of the particle being driven by the wave with this approach is a hidden parameter that cannot be measured. Despite the great efforts made by the scientist to develop this theory, many unresolved difficulties remained in it. In particular, the Einstein-Podolsky-Rosen paradox remained unresolved.

De Broglie and his students used their ideas to develop problems of the motion of singularities and non-deformable wave packets (soliton solutions of nonlinear equations), quantum measurement theory, dynamics of particles with variable mass, and relativistic thermodynamics. The nonlinearity introduced into the wave equation was intended to explain not only the localization of particle energy on an extended wave, but also the nature of quantum transitions. In the early 1960s, de Broglie formulated the idea of ​​hidden thermodynamics of isolated particles, according to which a random element is introduced into the motion of an individual particle due to its interaction with a hidden “subquantum medium.” Thus, a quantum particle resembles a colloidal particle exhibiting Brownian motion due to collisions with invisible molecules of the medium. This allows, according to the scientist, to apply classical methods of the theory of fluctuations to the movement of a single particle.

Wave mechanics of the photon and other works

In the early 1930s, Louis de Broglie attempted to find a relativistic wave equation for the photon, similar in meaning to the equation derived by Paul Dirac for the electron. Assuming that a photon with spin 1 can be represented as a bound pair of particles with spin 1/2, the French scientist, starting from the Dirac equation, obtained the corresponding wave equation of the photon. The wave function of such a vector photon turned out to be similar to a Maxwellian electromagnetic wave. At the same time, de Broglie again introduced the assumption that the photon mass is finite. Thus, in 1934, he managed to obtain a wave equation for a particle with spin 1 and an arbitrary mass, which in 1936 was independently derived by the Romanian physicist Alexandru Proca and is called the Proca equation. Although the attempt to quantize the theory was unsuccessful (when moving to secondary quantization it ceases to be gauge invariant), this was the first equation describing the behavior of vector mesons. The theory developed by de Broglie is sometimes called the “neutrino theory of light,” since the neutrino appeared as a candidate for the role of the Dirac particles that make up the photon.

Over the next few years, Louis de Broglie, together with his students, worked to generalize the theory to particles with arbitrary spin, which were represented as complex systems consisting of the required number of elementary particles with spin 1/2. Many of the scientist’s publications are devoted to specific issues from various branches of physics. So, after the outbreak of World War II, de Broglie was entrusted with the collection and processing new information in radiophysics (radio wave propagation, waveguides, horn antennas, etc.). After the Second Armistice of Compiegne, French military engineers no longer needed this information, so in 1941 de Broglie published the resulting review in book form. Since 1946, the scientist has devoted a number of publications and courses of lectures to the problems of electron optics, thermodynamics (including relativistic), the theory of the atomic nucleus, and quantum field theory (attempts to eliminate the infinity of the electron’s own energy by introducing interaction with one or more meson fields).

Awards and Memberships

Foreign member of 18 academies of sciences around the world, including the Royal Swedish Academy of Sciences (1938), the US National Academy of Sciences (1948), the Royal Society of London (1953), and the USSR Academy of Sciences (1958).

Honorary doctorate from the universities of Warsaw, Bucharest, Athens, Lausanne, Quebec and Brussels.

Louis de Broglie was born on August 15, 1892 in Dieppe, France. Born into an aristocratic family. He was the youngest of three children of Victor de Broglie and née Pauline de la Forest d'Armaille. His father, as the eldest man of this aristocratic family, bore the title of Duke.

Louis grew up in relative solitude, read a lot, and was interested in history, especially political history. From early childhood, he was distinguished by a good memory and could accurately read an excerpt from a theatrical production or name a complete list of ministers of the Third Republic. He was predicted to have a great future in the public sphere.

Young Louis de Broglie studied at home under the guidance of private priest teachers. After the death of the head of the family in 1906, the elder brother Maurice, who became the new Duke de Broglie, took care of the education of the younger one, sending him to the prestigious Lyceum Jeanson de Sailly. Here Louis, who inherited the title of Prince of the Holy Roman Empire, received his bachelor's degrees in philosophy and mathematics.

He studied well in subjects such as French, history, physics, philosophy, showed average results in mathematics, chemistry and geography, and was weak in drawing and foreign languages. At the age of eighteen, Louis de Broglie entered the University of Paris, where he initially studied history and law, but soon became disillusioned with these disciplines and the methods of teaching them. At the same time, he was not attracted to the military or diplomatic career that was common in his family.

After serving in the army during the First World War, he worked in the laboratory of his brother, Maurice de Broglie, where he studied high-frequency radiation. The result of this work was his doctoral dissertation, “Research in the Field of Quantum Theory,” which Broglie defended in 1924. In it, he put forward the idea of ​​the wave properties of matter, suggesting that material particles should also have wave properties associated with their mass and energy.

Experimental confirmation of this idea was obtained in 1927 in experiments on electron diffraction in crystals, and later it received practical application in the development of magnetic lenses for an electron microscope. Broglie's concept of wave-particle duality was used by E. Schrödinger when creating wave mechanics.

The scientist was awarded the 1929 Nobel Prize in Physics for his discovery of the wave nature of the electron. From 1928 to 1962, Louis Broglie was a professor at the University of Paris. In 1933 he became a member of the French Academy of Sciences, and in 1942 he became one of its permanent secretaries. He worked a lot on educational issues and organized a center for the study of modern theoretical physics at the Henri Poincaré Institute. He is the author of popular publications on physics. For his popular science works, UNESCO awarded him the first Kalinga Prize. In 1973, the Louis de Broglie Foundation was founded to support research into fundamental problems in physics.