Yakov Borisovich Zel'dovich (8 March 1914 – 2 December 1987) was a prolific Soviet physicist born in Belarus. He played an important role in the development of Soviet nuclear and thermonuclear weapons, and made important contributions to the fields of adsorption and catalysis, shock waves, nuclear physics, particle physics, astrophysics, physical cosmology, and general relativity.
1.) Yakov Borisovich Zel'dovich (2004). R.A. Sunyaev. ed. Zeldovich: Reminiscences. CRC Press. p. 69. ISBN 9780415287906. "I think that you know me well enough: I am an absolute atheist, and all days of the week are completely the same to me."
2.) Andrei Sakharov: Facets of a Life. Atlantica Séguier Frontières. 1991. p. 599. ISBN 9782863320969. "Speaking about religion, Yakov Borisovich could say unambiguously, "I'm an absolute atheist"."