My Life in Science, my Teachers, Pupils and Friends

Leonid Brekhovskikh

Shirshov Oceanology Institute, Russian Academy of Science, Nakhimov pr.36, 117851 Moscow, Russia
BERLIN, GERMANY 17 MARCH 1999
Summary: Why and how did I become an acoustition? Sixty years of creativity in the golden times of Russian Science, including oceanography and ocean acoustics. Contacts with which outstanding persons did influence my world outlook? What could I pass to my pupils? What does the "iron mode of life" mean? Child dreams. Have they become a reality? What is the short and long-term future of Russian science from my point of view?
I was born in 1917 and was staying upto thirteen years in a small remote village in the northern part of Russia. There were six brothers and one sister in our family. In 1930 I moved to the Urals to stay together with my elder brother. There I finished eight classes of the secondary school, and two years left to complete the full school course. However, after having summer training I entered the physical department of the Perm University ( in the Urals). I took a great interest in theoretical physics. Quantum mechanics was developed rapidly in those years. Two young scientists, Peter Stepanov and Olga Bazilevskaya, were my first genuine outstanding teachers. They devoted themselves entirely to science. Students were caught up in their devotion. Having graduated the university in 1939, I went to Moscow and handed in an application to post-graduate course of the well-known Lebedev Physical Institute of the USSR Academy of Science. The competition was . The selection committee consisted of such outstanding scientists as Sergei Vavilov ( the Director), Igor Tamm, Michael Leontovich and others. Two marks were put for entrance examinations on physics - one for knowledge, another one for quick wits. I passed the exams and my hard but fascinating postgraduate life started. In a post-graduate student hostel I found myself in a one and the same room together with Alexander Prokhorov - the future Nobel Prize winner. He became my best friend for the whole life. Our life was hard as a research grant was too little. We were helped by the Spartan type code of life that we called as " the iron mode of life". Effect of this code told not only on the post-graduate years, but on many years later.

My Ph.D. thesis was devoted to scattering of X-rays in crystals, taking into account their thermal oscillations. It was defended in 1941 at the beginning of the war with fascist Germany in Kazan. ( The Physical institute was evacuated in Kazan - farther away from the

front line). After defence of my Ph.D thesis such subjects as theoretical physics and quantum mechanics were of no importance. We had to work for the defence of our country. A famous acoustician, academician in the future. Prof. N.N.Andreev invited me to work in his group which was developing means against the new weapon - bottom acoustical mines. These mines exploded under the ship, initiated by his noise. Thus I became an acoustician and Prof.N.N.Andreev became dear to me a supervisor. Our work was started in Kazan and then continued and successfully finished in zones, close to military operations, at the Black sea and the Caspian sea. One of the problems that our group dealt with was the sound propagation in a shallow sea. I started to work on this problem and later generalized it on the broad class of layered media, including the also electromagnetic waves propagation. As a result of this work I defended thesis for a Doctor's degree again in Moscow in the Physical Institute. I was lucky to be a participant (in theoretical interpretation) of the discovery of the underwater sound channel (USC). The experiments were fulfilled in the Japan sea (1946) and the results were analyzed in Moscow. A little bit earlier the USC was discovered by two American scientists (Prof.Ewing and Prof.Worzel) in the Atlantic. However this work was published in the not very familiar for us journal and therefore we knew nothing about it. In general, the USC was discovered thrice. Firstly, it was predicted by the German scientist Dr.V.H.Lichte in 1919. His work, published in Physikalische Zeitschrift (1919, v. 17), remained unnoticed.

In 1956 the 2nd International Acoustical Congress was held in Boston ( USA). It was my second visit abroad. Prof.R.Bolt was the president of the congress. It was our first meeting. There I got aquainted with other outstanding scientists - C.Harris, I.Tolstoy, U.Ingard.

Under the leadership of Prof.N.Andreev the acoustical laboratory enlarged fast. At the end of 1953 the independent Acoustical institute of the USSR Academy of Sciences was established on its basis. I was appointed to be a director of this institute by the Academy of Science leaders. To study acoustics of the ocean we equiped with perfect by that time instrumentations two ocean ships, named after two famous Russian scientists "Sergei Vavilov" and "Petr Lebedev". Dr. I.E.Mikal'tzev was the central figure who was equipping these ships.

At the end of 1960 these research ships started their first cmise in the Atlantic ocean. Enormous material on the sound propagation in various ocean conditions, its scattering at the rough surface of the ocean, its bottom, biological objects, ambient noise in the ocean et.c. was collected during the following 15 years. Material was summarized and analized in the collective monograph "Ocean acoustics", marked with State prize award of the USSR in 1976.

Though management of the institute and intensive investigations took me a lot of time, I was eager to summarize and systematize my own theoretical researches. As a result was the monograph "Waves in Layered Media" published in 1957 in Russian edition and in 1960 in

English edited by Prof. Robert Bayer (the Brown University. USA). The book appeared to be popular and was translated also into Chinese. Inspite of its more than 40-year age references on this book are found rather often even now. On its basis my pupil O.Godin and I published the renewed and broadened version titled "Acoustics of Layered Media". In English it was published by Springer Verlag in two volumes in 1990-1992. The second edition of this book is going to be issued soon also by Springer Verlag.

I am pleased to remember the work on the book titled "Fundamentals of Ocean Acoustics" together with my other pupil of the elder generation Prof. Yu.P.Lysanov. Besides Rusian, two English editions by "Springer" are popular.

In 1956 I spent a month and a half in China in a group of 25 well-known scientists from the Soviet Union. We had to work out the plan for development of science in China for the following 12 years. This work was fulfilled successfully. The head of the Chinese government, seeing us off, told us that they would fulfill this plan in 3 years. In China we travelled a lot and got aquainted with many people. One of them was Guan-Din Hua. He was my assistant in China and then my post-graduate student in Moscow. Later he became a world-wide known scientist.

In 1958 I was lucky to spend also a month and a half in Geneva along with academician I.E.Tamm. We together with the scientists from other countries developed methods of detection of nuclear explosions in atmosphere, in water and in Earth crust. There I got aquainted with a famous scientist and a nice person Prof.Hans Bete (USA).

Speaking of my contacts with well-known persons, I should say about my close aquaintance with Audrey Sakharov. Being a yong man, in 1943 he was working in the Acoustical laboratory as well as me. His theme was sound scattering by air bubbles in water. When I was defending thesis for a Doctor's degree in 1947 he was sitting side by side with my wife in the conference hall and was troubled by the fact that he wasn't allowed to defend his work until he would pass the exam on the Marxist phylosophy which he didn't understand well.

In 1953 I was elected a Correspondent Member and in 1968 a Full Member (academician) of the USSR Academy of Sciences. At the beginning of 1969 I was elected the head of the devision of oceanology, physics of atmosphere and geography of the Academy of Sciences. I was the head of this devision for 23 years. It may seem strange to most of the western people as a person in the west couldn't occupy an administrative post for more than 10 years. It happened in the Soviet Union as it was common that the leaders of the communist party occupied their leading posts till their death. That is why they were not in a hurry to change the administrative leaders in science also. During 23 years there were some troubled moments in my life, connected with the directives of the communist party. Once I was summoned to M.Keldysh, President of the USSR Academy of Sciences, and was told that an

extra unit to elect an academician in my devision was alloted but for a definite person. It couldn't be used for anybody else. However academicians in my devision elected another scientist but not that one who was alloted. They elected Prof. M Budyko, who was more popular as a scientist. Party official circles were against him and M.Keldysh had to do his best to ruin his nomination. After that I fell into disgrace with academician M.Keldysh for some years.

The new position broadened my interest to the Ocean not only in the field of acoustics. I had the luck to be the chief scientist of the big expedition to the North Atlantic, when we measured curresnts at various depth simultaneously in 17 points separated from one another at maximum distance 200 km during half a year. This experiment resulted in the discovery of the so-called mesoscale eddyes. My report at the Joint Oceanographic Assembly in 1970 in Tokyo caused a sensation to some extent. After some years these results were confirmed by the analogous experiment fulfilled by the American scientists. The joined experiment was fulfilled later and it was found out that about 90% of the kinetic energy of the ocean waters is contained in these eddyes. It was a very important stage in the ocean dynamic study.

To continue scientific work I passed to the Shirshov Oceanology Institute, where I organized the department of ocean acoustics which included 3 laboratories. I was supported to this by the President of the USSR Academy of Sciences A.P.Alexandrov and the director of the Institute Prof.A.Monin. I was the head of this department in general and the head of the laboratory of sound waves propagation inside this department.

My international connections became wider. For many years Iwas the member of the Scientific Committee on Ocean Researches. We were also in close connections with the Woods Hole Oceanographic Institution and with the Scrirrs Institution in California. I was in friendly terms with Prof Walter Munk and Dr. Bill Nierenberg. Prof.W.Munk took a great interest in ocean acoustical tomography and we were drawn into it also. To carry out such experiments we needed research ships equiped with modem instrumentation. Such ships "Academician Vavilov" and "Academician loffe" we built in Finland. Prof. Yu.Zhitkovsky was the central figure in building the ships. They were very expensive and cost together with instrumentation for about $ 90 million. There was a lot talked and written about disadvantages of the Soviet regime. However it provided money for science development generously. Several decades, beginning from the fifties could be called as the "gold time" of soviet science, including ocean science as well.

At present science in Russia is in extremely poor conditions. Budget for 1999 of the so large country as Russia is comparable with that of so small country as Denmark. One could easily emagine what part of this budget would be used for science. Nevertheless, I hope that in some 10-20 years Russia will overcome this deep economical and financial crisis and will obtain normal economy and worthy science.

Beginning from 1953 up to now I taught students. Firstly I gave lectures on wave propagation at the Moscow State University and since 1975 I have been the head of chair of acoustics in the Moscow Physical Technical Institute. I left capable students to work in the laboratory and then they became well-known scientists themselves. Among them are Dr. O.Godin, Dr.A.Voronovich, Dr.V.Goncharov, Dr.V.Kurtepov, Dr.Yu.Chepurin and others. Dr.D.Mikhin is my talented pupil of the young generation. He is some kind of my grand pupil. I would like to mention my pupils or rather friends from the Acoustical Institute -Prof.Yu.Lysanov, Prof.I.Andreeva, Dr.F.Kryazhev and others.

I am grateful to the international scientific community for high appreciation of my work that is resulted in awarding me with the Rayleigh gold medal in 1976 by the Great Britain Acoustical Institute, Karpinsky Prize by A.Toepfer Foundation in 1986 and with Walter Munk medal by Oceanographic society in 1997. The report of Prof.W.Munk, an outstanding scientist from whom I learnt a lot, you have already listened to. I should say a few words about Dr. Alfred Toepfer. He died, when only few months left for his centinary. He lived in Hamburg and had business in sea transportation. He supported through his foundation a lot of scientific and cultural projects. In Russia he established the Karpinsky prize award for outstanding achievements of Russian scientists. The prize was named after A.P.Karpinsky, because he was the first President of the Academy of Sciences after the revolution 1917.

Have the dreams of my childhood and youth become true? In my childhood I had a dream to become a traveller and in my youth I dreamed to become a scientist in theoretcal physics. I was lucky as both my dreams became a reality.

I am immensely greatful to the American Acoustical Society and the European Acoustics Association for organizing this session. I have an opportunity to meet here many of my old friends from many countries. A lot of compliments were said to me at this session, and I refer it not only to myself but to all my pupils and close colleagues, the joint work with them was the main treasure of my life.