Victor Ambartsumian

Born: September 18, 1908, Tbilisi, Georgia

Died: August 12, 1996, Byurakan, Armenia

Victor Ambartsumian was a SovietArmenian scientist, and one of the founders of theoretical astrophysics. He worked in the field of physics of stars and nebulae, stellar astronomy, dynamics of stellar systems andcosmogony of stars and galaxies, and contributed to mathematical physics.

Ambartsumian founded the Byurakan Observatory in 1946. He was the second and longest-serving president of the Armenian Academy of Sciences (1947–93) and also served as the president of the International Astronomical Union from 1961 to 1964 and was twice elected the President of the International Council of Scientific Unions (1966–72).

During the years of the World War II, Ambartsumian created a new theory of light diffusion in turbid media, based on invariance principle invention of his own. Using that mathematical tool Ambartsumian resolved a number of nonlinear problems of the light diffusion. The invariance principle formulated by Ambartsumian and various modifications of this principle presently are being widely used to solve extremely complicated problems in astrophysics, mathematical and theoretical physics, electronics, geophysics, atmospheric physics, and other areas of science.

Ambartzumian’s works contributed to the development of Tomography. In particular He was the first to give numerical inversion of the Radon transform. This involved the 3D velocity distribution of stars in the Galaxy.

Named after him- Minor planet 1905 Ambartsumian