Were Albert Einstein and John von Neumann alive at the same time?
Yes. Albert Einstein and John von Neumann were alive at the same time for 51 years, from 1903 to 1955.
Albert Einstein was 24 when John von Neumann was born.
John von Neumann was 51 when Albert Einstein died, aged 76.
John von Neumann
Hungarian and American mathematician and physicist
Born 28 December 1903 · died 8 February 1957, aged 53