Aleksandr Lyapunov, Russian mathematician and physicist (died 1918)

Aleksandr Mikhailovich Lyapunov was a Russian mathematician, mechanician and physicist. He was the son of the astronomer Mikhail Lyapunov and the brother of the pianist and composer Sergei Lyapunov.

June 6 is the 157th day of the year in the Gregorian calendar; 208 days remain until the end of the year.