The Vanishing Mr. Feynman

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. Chri