This World Wide Web page written by
Oberlin College Physics Department;
last updated 4 February 2011.
A lot has been said and written about Richard Feynman: biographies, movies, plays, web sites, etc. It's easy to find out about him. This is not true of Feynman's graduate student Al Hibbs. (Hibbs earned his Ph.D. from CalTech under Feynman's guidance in 1955. Dissertation: "The growth of water waves due to the action of the wind".) The best biography seems to be the one at this NASA site.
Hibbs discussed Quantum Mechanics and Path Integrals (among other things) with Groucho Marx on the television program You Bet Your Life. (Season 1, episode 3, airing 30 December 1952.)
It is widely reported (including on the inside back cover of Quantum Mechanics and Path Integrals: Emended Edition) that Al Hibbs was slated to become an astronaut on the Apollo 25 moon mission. A more complete version of this story appears in a correction published by the Los Angeles Times on 12 March 2003:
"An obituary of Albert R. Hibbs, Jet Propulsion Laboratory systems designer and spokesman for unmanned spacecraft missions, in the Feb. 27 California section, said he qualified to become an astronaut on Apollo 25, only to see the Apollo moon-landing program canceled. In fact, the exact Apollo mission he was qualified for is unclear; the program was canceled after Apollo 17, with only three more flights officially listed by NASA. Hibbs did pass physical and psychological testing as required of all candidates for the spaceflight program."
More information on cancelled Apollo missions up to Apollo 20 is given by NASA and by Wikipedia.