An outstanding scientist, Professor Iosif Z. Fisher, an authority in the field of theoretical physics, was born on the 24 of February 1919 in Minsk. There he graduated from the school and entered the Byelorussian State University
I. Z. Fisher was not a favorite of fortune. During the thirties his parents were subjected to repressions. His father was shot and his mother died after being dismissed of eight years' imprisonment.
He graduated from the university in 1941, when the war with Germany broke out in the Soviet Union. Because of his weak eyesight, Fisher was not drafted and began the pedagogical work, but very soon he joined the army as a volunteer, and fought till the end of war in the rank of sergeant in an artillery division. This ``odd'' sergeant had Dirac's book Principles of Quantum Mechanics among the most necessary things in his backpack. He was decorated with orders and medals for his front service.
When the war was over, I. Z. Fisher came back to his native town and to the university. There he became a graduate student, then Assistant Professor, and then Professor.
At the very beginning of his scientific carrier, Professor Fisher was interested in cosmology, general theory of relativity, elementary particles and gravity. Further on, his scientific interests concentrated on a broad circle of different theoretical problems of condensed matter, i.e. simple liquids, solutions, electrolytes, critical phenomena and some other problems.
Professor Fisher was one of the first to apply the method of correlation functions to the studies of equilibrium properties of simple liquids. These studies combined with a review of some other works are expounded in his book Statistical Theory of Liquids, published in 1961, and later translated into English and published in the USA. This book, without doubt, played an important role in the development of concepts of the nature of liquid matter.
Professor Fisher's scientific and pedagogical activities became especially fruitful when in 1963 he moved to the Mechnikov's State University in Odessa. There he headed the chair of theoretical physics. Modern courses of lectures of theoretical physics are delivered for the undergraduates, and a systematic seminar is organized for graduate students and researchers. There Professor Fisher's scientific and pedagogical talent manifested itself especially brightly. A wide circle of students and colleagues was formed around him. The work Fisher and Komarov appeared, in which correlation functions technique which had earlier been used for the theory of neutron scattering, was applied to the theory of Raleigh light scattering in dense gases and liquids. This work stimulated a number of theoretical and experimental studies.
A series of works by I. Z. Fisher and L. S. Reut is dedicated to the theory of of some processes taking place in liquid helium, e.g. an adsorption of atomic impurities in quantum vortices in liquid helium, motion of thermalized ions in liquid helium in external fields, surface excitation in liquid 4He over the mobility of positive ions in solutions 3He-4He. The theory of the influence of finite lifetime of excitation on thermodynamic properties of helium had been developed.
Professor Fisher has been developing some aspects of always modern theory of critical phenomena for a long time. He developed the theory of diffusion flow in binary solutions in the vicinity of critical points as well as the modern picture of the two-phase nature of diffusion processes near critical point. Both phenomena have been experimentally confirmed. Professor Fisher considered the important problem of the nature of light intensity distribution as the function of frequency in the far wing of scattered spectrum.
This is not the complete description of the interests and achievements of professor Fisher, but this is sufficient to appreciate his contribution to the development of science.
In the peak of his scientific and pedagogical carrier, Professor Fisher underwent a new severe ordeal: in 1977 he suffered from a stroke, which disabled him for a long time. Unbelievably great efforts were made by his wife Lina Reut, his students, colleagues and friends to help him in this tragic period of his life.
A. I. Burshtein, H. Ratajczak, I. Fabelinskii