Question: The Zel'dovich number is a dimensionless number named after a scientist that died in what year?
Sentence (from "Yakov Borisovich Zel'dovich"): Yakov Borisovich Zel'dovich {'1': ", '2': ", '3': 'ForMemRS', '4': "} (Belarusian: Якаў Барысавіч Зяльдовіч , Russian: Я́ков Бори́сович Зельдо́вич ; 8 March 1914 – 2 December 1987), also known as YaB, was a Russian physicist of Belarusian Jewish ethnicity, who is known for his prolific contributions in cosmology and the physics of thermonuclear and hydrodynamical phenomena.
Relevant evidence: Yes