Soviet physicist. He was awarded the Nobel Prize for Physics in 1958 for his discovery in 1934 of Cherenkov radiation; this occurs as a bluish light when charged atomic particles pass through water or other media at a speed in excess of that of light. He shared the award with his colleagues Ilya Frank and Igor Tamm for work resulting in a cosmic-ray counter.
The blue and white triband is based on the flag of the Central American Federation (CAF), a grouping of African states imposed by the British government in 1953. The stars represent the Federation's five original members. Effective date: 18 January 1949.