Lev Landau (years of life - 1908-1968) - the great Soviet physicist, a native of Baku. He owns a lot of interesting research and discoveries. Can you answer the question, why did Lev Landau receive the Nobel Prize? In this article, we will talk about his achievements and the main facts of the biography.
Origin of Lev Landau
You can talk for a long time about such a scientist as Lev Landau. Years of life, occupation and achievements of this physicist - all this will surely interest readers. Let's start from the very beginning - with the origin of the future scientist.
He was born in the family of Lyubov and David Landau. His father was a well-known petroleum engineer. He worked in the oil fields. As for her mother, she was a doctor by profession. It is known that this woman carried out physiological research. Apparently, Lev Landau came from an intelligent family. His older sister, by the way, became a chemical engineer.
Years of study
Lev Davidovich went to high school, which he brilliantly graduated at the age of 13. His parents felt that their son was still veryyoung for higher education. Therefore, they decided to send him to the Baku Economic College for one year. Then, in 1922, he was admitted to Baku University. Here Lev Landau studied chemistry and physics. Two years later, Lev Davidovich transferred to Leningrad University, to the Faculty of Physics.
First research papers, graduate school
At the age of nineteen, Landau had already become the author of four scientific papers that were published. In one of these works, the so-called density matrix was used for the first time. This term is widely used today. It describes quantum energy states. Landau graduated from the university in 1927. Then he entered graduate school, choosing the Leningrad Institute of Physics and Technology. In this educational institution, he worked on quantum electrodynamics and the magnetic theory of the electron.
Business trip
In the period from 1929 to 1931, Lev Landau was on a scientific mission. Years of life, occupation and achievements of this scientist are associated with close cooperation with foreign colleagues. So, during a business trip, he visited Switzerland, Germany, the Netherlands, England and Denmark. During these years, he met and became acquainted with the founders of quantum mechanics, which was then just emerging. Among the scientists Landau met were Wolfgang Pauli, Werner Heisenberg and Niels Bohr. To the latter, Lev Davidovich retained friendly feelings for the rest of his life. This scientist had a particularly strong influence on Landau.
Lev Davidovich, being behindboundary, carried out important studies of free electrons (their magnetic properties). In addition, together with Peierls, he also conducted research on relativistic quantum mechanics. Thanks to these works, Lev Landau, whose occupation interested foreign colleagues, began to be considered one of the leading theoretical physicists. The scientist learned how to handle highly complex theoretical systems. It should be noted that later this skill was very useful to him when Landau began to conduct research on low-temperature physics.
Moving to Kharkiv
Lev Davidovich returned to Leningrad in 1931. However, he soon decided to move to Kharkov, which at that time was the capital of Ukraine. Here the scientist worked at the Ukrainian Institute of Physics and Technology, was the head of its theoretical department. At the same time, Lev Davidovich was the head of the departments of theoretical physics at Kharkov University and the Kharkov Engineering and Mechanical Institute. In 1934, the Academy of Sciences of the USSR awarded him the degree of Doctor of Physical and Mathematical Sciences. For this, Landau did not even need to defend a dissertation. The title of professor was awarded the following year to such a scientist as Lev Landau.
His occupation covered more and more new areas of science. Landau in Kharkov published works on such topics as sound dispersion, the origin of stellar energy, light scattering, energy transfer that occurs during collisions, superconductivity, the magnetic properties of various materials, etc. Thanks to this, he became known as a theoretician with unusually versatile scientificinterests.
A distinctive feature of Landau's work
Later, when plasma physics appeared, Landau's work on particles interacting electrically proved to be very useful. Borrowing some concepts from thermodynamics, the scientist expressed a number of innovative ideas regarding low-temperature systems. It must be said that all Landau's works are characterized by one important feature - the virtuoso use of the mathematical apparatus in the search for solutions to complex problems. Lev Landau made a significant contribution to quantum theory, as well as to the study of the interaction and nature of elementary particles.
Lev Landau School
The range of his research is truly wide. They cover almost all major areas of theoretical physics. Thanks to such a breadth of his interests, the scientist attracted many talented young scientists and gifted students to Kharkov. Among them was Evgeny Mikhailovich Lifshits, who became Lev Davidovich's collaborator and his closest friend. The school that grew up around Lev Landau turned Kharkov into one of the leading centers of theoretical physics in the USSR.
The scientist was convinced that a theoretical physicist should be thoroughly versed in all areas of this science. To this end, Lev Davidovich developed a very strict training program. He called this program "the theoretical minimum". Applicants who wanted to participate in the workshop he led had to meet very high standards. Suffice it to say that for 30 years, despite the manywishing, only 40 people passed the exams on the "theorimum". However, those who succeeded, Lev Davidovich generously devoted his attention and time. In addition, they were given complete freedom of choice when choosing a research topic.
Creating a theoretical physics course
Landau Lev Davidovich maintained friendly relations with his staff and students. They affectionately called the scientist Dau. To help them in 1935, Lev Davidovich created a detailed course in theoretical physics. It was published by Landau jointly with E. M. Lifshitz and was a series of textbooks. Their content was updated and revised by the authors over the next 20 years. These books have gained immense popularity. They have been translated into many languages of the world. Currently, these textbooks are rightfully considered classics. In 1962, Landau and Lifshitz received the Lenin Prize for the creation of this course.
Working with Kapitsa
Lev Davidovich in 1937 responded to the invitation of Peter Kapitza (his photo is presented below) and became the head of the department of theoretical physics at the Moscow Institute of Physical Problems, newly created at that time. However, the next year the scientist was arrested. The false accusation was that he was spying for Germany. Only thanks to the intervention of Kapitsa, who personally applied to the Kremlin, Lev Landau was released.
When Landau moved from Kharkov to Moscow, Kapitsa was just experimenting with liquid helium. If the temperature falls below 4.2 K (absolutetemperature is measured in degrees Kelvin and is measured from -273, 18 ° C, that is, from absolute zero), gaseous helium becomes a liquid. In this state, it is called helium-1. If you lower the temperature to 2.17 K, it goes into a liquid called helium-2. It has some very interesting properties. Helium-2 is able to flow through the smallest holes with ease. It seems as if he has no viscosity at all. The substance rises up the wall of the vessel, as if gravity does not act on it. In addition, its thermal conductivity exceeds the thermal conductivity of copper hundreds of times. Kapitsa decided to call helium-2 a superfluid liquid. However, upon inspection, it turned out that its viscosity is not zero.
Scientists have suggested that such unusual behavior is due to effects that belong not to classical physics, but to quantum theory. These effects appear only at low temperatures. Usually they make themselves felt in solids, since under these conditions most substances freeze. Helium is an exception. This substance remains liquid down to absolute zero unless it is subjected to high pressure. Laszlo Tissa suggested in 1938 that liquid helium is actually a mixture of two forms: helium-2 (superfluid liquid) and helium-1 (normal liquid). When the temperature drops to almost absolute zero, the former becomes the dominant component. This hypothesis explains the appearance of different viscosities under different conditions.
How Landau explained the phenomenon of superfluidity
Lev Landau, short biographywhich describes only his main achievements, was able to explain the phenomenon of superfluidity, using a completely new mathematical apparatus. Other scientists relied on quantum mechanics, which they used to analyze the behavior of individual atoms. Landau, on the other hand, considered the quantum states of a liquid practically in the same way as if it were a solid body. He hypothesized that there are two components of excitation, or movement. The first of these are phonons, which describe the normal rectilinear propagation of sound waves at low energy and momentum. The second is rotons, which describe rotational motion. The latter is a more complex manifestation of excitations that occurs at higher values of energy and momentum. The scientist noted that the observed phenomena can be explained by the contributions of rotons and phonons and their interaction.
Landau argued that liquid helium can be considered as a "normal" component, which is immersed in a superfluid "background". How can one explain the fact that liquid helium flows out through a narrow gap? The scientist noted that only the superfluid component flows in this case. And the rotons and phonons collide with the walls holding them.
The meaning of Landau's theory
Landau's theory, as well as its further improvements, played a very important role in science. They not only explained the observed phenomena, but also predicted some others. One example is the propagation of two waves that have different properties and are called the first and second sound. The first sound isordinary sound waves, while the second is a temperature wave. Thanks to the theory created by Landau, scientists were able to make significant progress in understanding the nature of superconductivity.
World War II and post-war years
Lev Davidovich during the Second World War was engaged in the study of explosions and combustion. In particular, he was interested in shock waves. After May 1945 and until 1962, the scientist worked on various tasks. In particular, he investigated the rare isotope of helium, which has an atomic mass of 3 (usually its mass is 4). Lev Davidovich predicted the existence of a new type of wave propagation for this isotope. "Zero sound" - that's what Lev Davidovich Landau called it. His biography is marked, in addition, by participation in the creation of the atomic bomb in the USSR.
Car accident, Nobel Prize and the last years of life
At the age of 53, he was in a car accident, as a result of which he was seriously injured. Many doctors from the USSR, France, Canada, Czechoslovakia fought for the life of a scientist. He was unconscious for 6 weeks. For three months after the car accident, Lev Landau did not even recognize his relatives. The Nobel Prize was awarded to him in 1962. However, due to he alth reasons, he was unable to travel to Stockholm to receive it. In the photo below you can see L. Landau with his wife in the hospital.
The award was presented to a scientist in Moscow. After that, Lev Davidovich lived for another 6 years, but he never returned to research.smog. Lev Landau died in Moscow as a result of complications from his injuries.
Landau family
In 1937, the scientist married Concordia Drobantseva, a process engineer in the food industry. This woman was from Kharkov. The years of her life are 1908-1984. A son was born in the family, who later became an experimental physicist and worked at the Institute of Physical Problems. The photo below shows L. Landau with his son.
That's all there is to say about a scientist like Lev Landau. His biography, of course, includes only the basic facts. The theories he created are quite complex for the unprepared reader. Therefore, the article only briefly talks about what Lev Landau became famous for. The biography and achievements of this scientist are still of great interest all over the world.
