In his final years, Richard Feynman's curiosity took him to some surprising places. We hear from his companions on the trips he took — and one he wasn’t able to. (Part three of a three-part series.)

• SOURCES: 
  • Alan Alda, actor and screenwriter.
  • Barbara Berg, friend of Richard Feynman.
  • Helen Czerski, physicist and oceanographer at University College London.
  • Michelle Feynman, photographer and daughter of Richard Feynman.
  • Cheryl Haley, friend of Richard Feynman.
  • Debby Harlow, friend of Richard Feynman.
  • Ralph Leighton, biographer and film producer.
  • Charles Mann, science journalist and author.
  • John Preskill, professor of theoretical physics at the California Institute of Technology.
  • Lisa Randall, professor of theoretical particle physics and cosmology at Harvard University.
  • Christopher Sykes, documentary filmmaker.
  • Stephen Wolfram, founder and C.E.O. of Wolfram Research; creator of Mathematica, Wolfram|Alpha, and the Wolfram Language.

• RESOURCES: 
  • I Love My Wife..., directed by Ian Tierney (2020).
  • Quantum Man: Richard Feynman's Life in Science, by Lawrence M. Krauss (2011).
  • Perfectly Reasonable Deviations From the Beaten Track: Selected Letters of Richard P. Feynman, edited by Michelle Feynman (2005).
  • The Pleasure of Finding Things Out, by Richard Feynman (1999).
  • The Demon-Haunted World: Science as a Candle in the Dark, by Carl Sagan and Ann Druyan (1995).
  • Genius: The Life and Science of Richard Feynman, by James Gleick (1992).
  • The Quest for Tannu Tuva, by Christopher Sykes (1988)
  • “What Do You Care What Other People Think?” by Richard Feynman and Ralph Leighton (1988).
  • The Second Creation: Makers of the Revolution in Twentieth-century Physics, by Robert Crease and Charles Mann (1986).
  • Surely You're Joking, Mr. Feynman!, by Richard Feynman and Ralph Leighton (1985).
  • Fun to Imagine, BBC docuseries (1983).

• EXTRAS: 
  • “The Curious, Brilliant, Vanishing Mr. Feynman,” series by Freakonomics Radio (2024).