At the end of this century the world is experiencing dramatic political changes and the SEG is adjusting quickly to them. Not only has SEG gone to Moscow this year, it also honors once more an eminent scientist in that part of the globe which for almost half a century was isolated from the remaining world. The SEG could not have chosen a more distinguished candidate than the Czechoslovakian geophysicist Vlastislav (Slava) Cerveny. Congratulations! According to the Honors and Awards Committee, Slava receives recognition for his "numerous contributions to exploration geophysics and the impact his work has on seismic simulation and imaging technology."
     Slava never actually looked upon himself as an exploration geophysicist. In fact, he would probably deny any knowledge about seismic exploration. All his concern is with the investigation of wave propagation in complex media. What luck for exploration geophysicists! Nowhere is the earth more heterogeneous than in sedimentary basins that hide oil and gas resources. Nowhere can his well written papers and excellent books evoke more interest than in this field. Due to the universality of his work he finds, however, as many admirers in the earthquake- or deep-seismic sounding seismology as in exploration seismics.
     Slava has a life-long love affair with the ray method. This is now one of the main tools in forward and inverse seismic modeling and seismic imaging.
     Who would only two years ago have thought that a 3-D seismic Kirchhoff-type prestack migration involving extensive traveltime computations would become practically feasible? Massively parallel computers have made it possible and Slava's widespread research on the ray method over three decades has largely contributed to this breakthrough.
     Slava was graduated in 1956 in physics from the Charles University in Prague. His talent was recognized early in the Institute of Geophysics of the Charles University, where he gained his PhD in 1961 and where he is now a full professor. His sustained contributions to wave theory led to many invitations. Often away from his family, he spent between three months and two years in places like Moscow, Halifax, Toronto, Cambridge, Paris, Karlsruhe, Stanford, Frankfurt, Kiel, Berkeley and Salvador-Bahia. He also went to China as a UNESCO expert. His MSc and PhD students are in the order of several tens. They remember Slava as a modest, uncomplicated, gifted and clear-minded scientist, who showed tremendous flexibility to adjust to any new working environment and scientific problem.
     Slava is one of the principal developers of the asymptotic ray method (ART) and its various extensions. His book, with Ravi Ravindra, on head waves is the first milestone in his extraordinary scientific career. In the late '60s, when many of us still considered the earth one-dimensional, Slava already concentrated on wave propagation in layered inhomogeneous media. During that time, when research with anisotropic media was considered by many nothing more than a mental exercise, he already published a fundamental paper on the subject. Much of his impressive work is found in the book Ray Method in Seismology.
     Modern ray theory cannot be conceived without such important concepts as dynamic ray tracing, paraxial ray approximation, Fresnel zones, and so forth, which he formulated jointly with Russian and Czechoslovakian colleagues. We are now looking forward to his new book, Seismic Ray Method, on which he is currently working.
     Slava is as fluent in Russian as in English. This made it easy for him to become a "geophysical ambassador," bringing together experts from the east and west a long time before the Iron Curtain fell. His famous workshops in Liblice, which he started in 1978, have been an ideal forum for this.
     Those who know Slava personally are impressed by his vitality and hardworking, well organized lifestyle. While many of us would suffer from too much self-discipline, Slava could not work without it. He needs a tight self-imposed daily working schedule and impresses others through his good sense of humor and his positive outlook on life.

     Peter Hubral and Ivan Psencik