Ylem was a term used by the physicist who was a developer of the theory credited to whom?
George Gamow: George Gamow (March 4 [O.S. February 20] 1904 August 19, 1968), born Georgiy Antonovich Gamov (Russian: Гео́ргий Анто́нович Га́мов ; ] ), was a theoretical physicist and cosmologist. George Gamow:  He was an early advocate and developer of Lemaître's Big Bang theory.
i don't know