Richard Feynman (1918–1988) American theoretical physicist
statement at hearing by Rogers Commission, 11 February 1986, Report of the PRESIDENTIAL COMMISSION on the Space Shuttle Challenger Accident, volume 4, p. 680 http://history.nasa.gov/rogersrep/v4part4.htm#4; also quoted in Genius: The Life and Science of Richard Feynman (1992) by James Gleick, p. 423