Man of the Day: Yakov Zeldovich

Yakov Zeldovich, physicist, academician of the Academy of Sciences of the USSR, was born on March 8, 1914.

Private bussiness

Yakov Borisovich Zeldovich (1914 - 1987) was born in Minsk. His father, Boris Naumovich Zeldovich, was a lawyer, and his mother, Anna Petrovna Zeldovich (Kiveliovich), was a translator. In 1924, the family moved to Leningrad, where Yakov entered the third grade of high school, graduating in 1930. After that, he got a job as a laboratory assistant at the Institute of Mechanical Processing of Mineral Resources (“Mekhanobr”).

In May 1931, Yakov Zeldovich became a laboratory assistant at the Institute of Chemical Physics of the USSR Academy of Sciences (ICP). In the 1930s, Zeldovich, who formally had only a secondary education, was actively engaged in self-training in the field of physics. In 1932-1934 he studied at the correspondence department of the Faculty of Physics and Mathematics of Leningrad State University (LSU), but did not complete his studies. Later he attended lectures at the Faculty of Physics and Mechanics of the Polytechnic Institute.

In 1934, Zeldovich became a graduate student at the Institute of Chemical Physics and two years later successfully defended his candidate’s thesis, and three years later, his doctorate. In 1937, he created and headed the department of high-temperature kinetics of reactions in explosive processes at the ICP, and then also the laboratory of combustion physics. At the end of August 1941, he and the institute were evacuated to Kazan. In 1943, together with the laboratory, he was transferred to Moscow. From 1946 to 1948 he headed the theoretical department of the Institute of Chemical Physics of the USSR Academy of Sciences.

Back in 1939–1940, Zeldovich, together with Yuli Khariton , published three articles on the fission of uranium nuclei and the chain reaction. In one of them, scientists wrote: “The kinetics of the development of chain decay is decisive for judging certain ways of practical, energetic or explosive use of uranium decay.” Zeldovich began preparing for such use in the mid-40s, when he was part of a group of scientists working on the Soviet atomic project. In 1947, a group of physicists from the Institute of Chemical Physics of the USSR Academy of Sciences, led by Zeldovich, was sent to KB-11 (Arzamas-16), where the first Soviet atomic bomb was created. Subsequently, Yakov Zeldovich also participated in the creation of the Soviet hydrogen bomb. For his work on the atomic project, Zeldovich received the title of Hero of Socialist Labor three times (1949, 1954, 1956).

Zeldovich worked in Arzamas-16 until 1963. In 1946 he was elected a corresponding member, and in 1958 - an academician of the USSR Academy of Sciences.

From 1965 to 1983, Zeldovich headed a department at the Institute of Applied Mathematics of the USSR Academy of Sciences. Also in 1965, he became a professor at the Faculty of Physics of Lomonosov Moscow State University, and in 1984-1987 - head of the department of relativistic astrophysics at Moscow State University.

Since 1983, he headed a department of the Institute of Physical Problems of the USSR Academy of Sciences, and was a consultant to the directorate of the Institute of Space Research of the USSR Academy of Sciences. Since 1977 - head of the Scientific Council on Combustion of the USSR Academy of Sciences.

Yakov Zeldovich died in Moscow on December 2, 1987.

What is he famous for?

Numerous discoveries of Yakov Zeldovich are associated with the theory of combustion, ignition and flame propagation, theories of ignition by a heated surface, thermal propagation of laminar flames in gases, limits of flame propagation, combustion of condensed substances. He described the propagation of shock and detonation waves and the gas dynamics of the explosion. Independently of each other, Ya. B. Zeldovich in the USSR, John von Neumann in the USA and Werner Döring in Germany created a model of detonation propagation, later called the Zeldovich – Neumann – Döring (ZND) model. They found that when detonation propagates, the substance first heats up as the shock wave front passes, and chemical reactions begin in the substance after some time equal to the auto-ignition delay. During chemical reactions, heat is released, which leads to additional expansion of the products and an increase in the speed of their movement. Thus, the zone of chemical reactions acts as a kind of piston, pushing the leading shock wave and ensuring its stability. From these topics, Zeldovich moved on to studying the conditions of stationary fission of uranium in power plants and its explosive fission.

What you need to know

Yakov Zeldovich

Since the 1960s, Yakov Zeldovich has worked a lot in the field of astrophysics and cosmology, where he achieved no less results than his previous works. His research covered a number of problems: the theory of the formation of black holes and neutron stars, the release of energy and the emission of X-rays when matter falls into black holes; development of the theory of the evolution of the “hot” Universe, the properties of the cosmic microwave background radiation, the theory of galaxy formation and the large-scale structure of the Universe, the inflationary theory of the early Universe. Together with I. D. Novikov, he wrote the monographs “The Theory of Gravity and the Evolution of Stars” and “The Structure and Evolution of the Universe.” Together with Rashid Sunyaev , Zeldovich created the theory of scattering of relict radiation by electrons ( Sunyaev-Zeldovich effect ). In 1964, Yakov Zeldovich and independently the American physicist Edwin Salpeter hypothesized that the source of energy for quasars is accretion disks around massive black holes.

Direct speech

From the memoirs of Andrei Sakharov : “The discovery of uranium fission changed the scientific fate of Zeldovich, like the fate of many scientists, for years to come - in a broader sense, it changed the fate of all of us. His pioneering research together with Yu.B. Khariton on the theory of explosive and controlled nuclear fission chain reactions were also the last works published in the open literature before the curtain of secrecy fell in this area. They had a huge impact on everyone who worked in this field. From the very beginning of Soviet work on the atomic (later thermonuclear) problem, Zeldovich was at the epicenter of events. His role here was absolutely exceptional. <…> Zeldovich extremely disapproved of my social activities, which irritated and even frightened him. He once said: “People like Hawking are truly dedicated to science. Nothing can distract them." I couldn’t understand why he couldn’t come to my aid, which, given our friendship, I considered myself entitled to ask for. I knew that all this tormented Zeldovich. It also hurt me. Today, these events of past years seem to be nothing more than foam, carried away by the stream of life. Unfortunately, after my return from Gorky, I met Zeldovich only once or twice, and then only in public, so it was hardly possible to talk to him like a human being. This is another lesson - don’t put off until tomorrow what you can do today.”

From the memoirs of Vladislav Mokhov : “The relationship between Yakov Borisovich and A.D. was interesting. Sakharov. Both knew how to think very quickly, but in all other respects they were completely different people, pronounced sanguine and choleric, “lark” and “night owl”; Yakov Borisovich, a lover of harsh, often obscene expressions, and the reserved, intelligent Andrei Dmitrievich.”

From the memoirs of Semyon Gershtein : “After some time, YaB, having inquired about my classes, said: “Since you give lessons, I want to ask you to study with my girls.” I began to refuse, saying that they did not need it at all, they were already excellent students, excellent students, and would only be embarrassed that they had a tutor (in those days they were ashamed of this). However, YaB found the following objection: “Experimental skills are not taught at school. Buy instruments and let them do experiments.” I could only agree (I had some experience: in a rural school I tried to create a kind of physical practice so that each student could complete several laboratory works). In textbook stores we were able to purchase some pretty good equipment—an optical bench, lenses, galvanometers, etc. A small Wilson chamber was also found. And so Olya, Marina and I began to set up various experiments and solve problems related to them. Sometimes experiments ended in embarrassment for me - a couple of times I burned out sensitive electrical appliances. YaB was making fun of me; I often took part in the experiments myself, and I, along with my students, listened with interest to his comments on the use of the phenomena under consideration in various technical devices. I was surprised by YaB's experimental skills and his ability to “work with his hands.” “I started as an experimenter,” he told me, “and before that I worked as a laboratory assistant” (I didn’t know then that YaB did not have an official higher education). I don’t know whether my lessons benefited the students (invented, as I understood, to help me), but they taught me a lot and helped me hold out until May 1955, when Landau managed to carry out his plan and take me to graduate school in Physics Problems.”

From the memoirs of Vladimir Zakharov : “For the first time I saw Yakov Borisovich “in person” in the winter of 1961–62. in Akademgorodok. The winter there is long, and it is difficult to remember a more precise time. Roald Sagdeev defended his doctoral dissertation, and YaB, a full academician for three years, was his official opponent. The defense as such was completely erased from my memory, but I remembered the banquet very well thanks to YaB. He walked out into the middle of the hall, a short, strong, middle-aged man wearing round glasses, cheerful and energetic. And he made the following toast:

— There were two thieves, young and old. They staged a competition: they had to climb a tree and rob a crow's nest without the crow sitting on the eggs noticing anything. The young thief climbed up as he was - in a jacket and boots. The crow noticed him and started screaming. The old thief said: “Oh! Look at it the right way!” He took off his boots, took off his jacket, climbed a tree, stole eggs. I went down - no jacket, no boots, no young thief. So, let’s drink to the young generation of scientists!”

10 facts about Yakov Zeldovich

• Yakov Zeldovich came to the Institute of Chemical Physics for the first time in a group of excursionists. The questions he asked demonstrated knowledge of thermodynamics, molecular physics and chemistry at least at a third-year university level. Surprised employees invited the excursionist to come work for them.
• According to legend, the Institute of Mechanical Processing of Mineral Resources agreed to the transfer of laboratory assistant Zeldovich to the Institute of Chemical Physics in exchange for a vacuum pump.
• Formally, Yakov Zeldovich never received a higher education.
• During the war, Zeldovich's work on describing combustion processes was used to create projectiles for the Katyusha rocket launcher, and later to develop solid fuel rockets.
• The sense of humor that distinguished Yakov Zeldovich gave rise to many stories that enriched scientific folklore. For example, during a discussion with T. Lysenko, who argued that if the tails of mice are cut off for many generations in a row, tailless mice should begin to be born, Zeldovich objected: “For many millennia, hundreds of generations in a row, Jewish boys have been circumcised. Until now, not a single case has been recorded of a Jewish boy being born already circumcised.”
• In one of the conversations, Yakov Zeldovich made an interesting remark about Gogol’s “The Inspector General”: “I figured,” he said, “that the city fathers should be veterans of the Patriotic War of 1812 by age. And having risked their lives for their Motherland, they now do not think it shameful to take a piece of cloth from a merchant, for whom, in essence, they risked their lives. Khlestakov, due to his youth, did not participate in the war and, taking for granted the fruits of victory, cannot understand things that are elementary for the ruling class of veterans.”
• In 1955, Zeldovich signed the “Letter of the Three Hundred,” which contained criticism of T. Lysenko.
• In addition to scientific monographs, Yakov Zeldovich wrote several textbooks, including “Higher Mathematics for Beginners” (1960) and “Higher Mathematics for Beginning Physicists and Technicians” (1982).
• Zeldovich's son Boris Yakovlevich also became a famous scientist, a specialist in nonlinear optics, and a corresponding member of the Russian Academy of Sciences.
• Zeldovich received two personalized awards from the Academy of Sciences. In 1977, he was awarded the Igor Kurchatov gold medal “for predicting the properties of ultracold neutrons and their detection and study,” and in 2002 he received the Alexander Friedman Prize for a series of works: “The effect of a decrease in the brightness of cosmic microwave background radiation in the direction of galaxy clusters.” Since 2015, the Russian Academy of Sciences has been awarding the gold medal named after Ya. B. Zeldovich for outstanding work in the field of physics and astrophysics.

Materials about Yakov Zeldovich

Article about Yakov Zeldovich in Russian Wikipedia

Kiperman S. Familiar and unfamiliar Zeldovich

Yakov Borisovich Zeldovich (memoirs, letters, documents)