Genius_ The Life and Science of Richard Feynman - James Gleick [276]
168 THE DANGEROUS PRACTICALITIES: Hawkins et al. 1983, 13.
168 FEYNMAN SPENT A LONG TIME TήINKING: F-H, 12–13.
168 BRANCHING-PROCESSES THEORY: Ulam 1976, 153; Harris 1963; David Hawkins, “The Spirit of Play,” in Cooper 1989.
169 HE ARRIVED AT A PRACTICAL METHOD: Bethe, interview. 169 BEGAN TO LOVE HANS BETHE: F-W, 409–10.
169 HE HAD INVITED ONE OF HIS MIT FRATERNITY FRIENDS: Feynman to Daniel Robbins, 24 June 1942, PERS.
169 HE WOULD BE PARTLY OUT OF THE RUSH: Feynman to Lucille Feynman, 24 June 1943, PERS.
169 WHEN HE WAS INVITED TO MEET A STRANGER: Welton 1983, 7.
170 DO YOU KNOW WHAT WE’RE DOING HERE?: Ibid.
170 IT STINKS: Davis 1968, 215.
170 AS WELTON LISTENED: Welton, interview.
170 HE WAS AMUSED AND IMPRESSED: Welton 1983, 8–9; Welton, interview.
171 WELTON BECAME THE FOURTH PHYSICIST: Along with Frederick Reines, Julius Ashkin, and Richard Ehrlich.
171 DEFINITELY UNGENTLE HUMOR: Welton 1983, 9.
171 ALL RIGHT, PENCILS: F-H, 42–43.
172 BY DEFINITION, AT CRITICAL MASS: Hawkins et al. 1983, 77.
172 FOR A SPHERICAL BOMB: Welton 1983, 11; Welton, interview.
173 BETHE HAD TOLD THEM: Bethe, interview; F-H, 23.
173 WHEN THE LOS ALAMOS METALLURGISTS: Hawkins et al. 1983, 139.
173 IT PUSHED THE THEORISTS PAST THE LIMITS: Welton 1983, 13.
173 FEYNMAN SOLVED THAT PROBLEM: Feynman and Welton 1947, a book-length report, draws together the chief findings of Feynman and his group on critical-mass calculations and neutron scattering. Feynman’s own contribution to the version of the problem in which neutrons are assumed to have a single characteristic velocity—a practical simplification of methods developed by others— appears in Feynman 1946b.
173 THE EXPERIENCE OF ACTUAL COMPUTATION: F-H, 23–24.
173 AS HE DROVE THE MEN: Welton 1983, 14.
173 THAT SEEMED AN IMPOSSIBLE LEAP: Ashkin, Ehrlich, and Feynman 1944. Welton recalled wryly (1983, 14): “Only a short period of reflection was … required before Feynman announced that we were going to take the accumulated computational results from T-2. put them through the meat grinder, season them with some further insights (yet to be produced) and extrude this mixture as a handy interpolation-extrapolation formula.”
174 UNFORTUNATELY CANNOT BE EXPECTED: Feynman 19466, 3.
174 UNFORTUNATELY THE FIGURES CONTAINED: Ashkin, Ehrlich, and Feynman 1944, 4.
174 THESE METHODS ARE NOT EXACT: Feynman and Welton 1947, 6. 174 AN INTERESTING THEOREM WAS FOUND: Feynman 1946b, 3.
174 IN ALL CASES OF INTEREST: Feynman and Welton 1947, 6.
175 BETHE’S DEPUTY, WEISSKOPF: Weisskopf, oral-history interview, 31, AIP.
176 HE TOLD THEM HE COULD SPOT: F-H, 18.
176 WELL, FOUR HOURS AND TWENTY MINUTES AGO: Nicholas Metropolis, interview, Los Alamos, N.M.
176 YOU KNOW HOW IT IS WITH DAYLIGHT SAVING TIME: Morrison 1988, 42.
177 YOU WANT TO KNOW EXACTLY?: Feynman 1975, 109.
177 THAT’S 1.35: F-H, 41.
178 ALL RIGHT. IT’S PI TO THE FOURTH: Ibid., 39.
178 THEN PAUL OLUM SPOKE UP: Olum, interview; F-L for SYJ, 176.
178 SIMILARLY, WORKING WITH BETHE: Bethe, interview.
179 THEY WERE RARELY USED: Metropolis and Nelson 1982, 348–49.
180 LET’S LEARN ABOUT THESE DAMNED THINGS: Metropolis, interview.
180 THEY SPENT HOURS TAKING APART: Bethe, interview; Metropolis 1990, 237; Metropolis and Nelson 1982, 349.
180 ESCALATION OF THE COMPUTATION EFFORT: Metropolis and Nelson 1982, 350.
181 SO MUCH MORE POWERFUL WERE THEY: Weisskopf 1991, 134.
181 EVEN BEFORE THE IBM MACHINES ARRIVED: F-W, 362–63; Brode 1960; Feynman 1975, 125.
182 HE LEFT FEYNMAN WITH TWO ENDURING MEMORIES: Feynman 1975, 129.
182 FEYNMAN THOUGHT AT FIRST: F-H, 55–56: “We discovered a very annoying thing that we didn’t understand…. When we set up the differential equation, we solved it numerically and the numbers seemed to come out irregularly. Then we would check and it would be the same thing…. The points would sort of wiggle around irregularly, and [von Neumann] explained that that was correct, that was all right, that was very interesting…. And there was nothing we could do about