Donald Flanders (Manhattan Project mathematician)

https://ahf.nuclearmuseum.org/ahf/profile/donald-moll-flanders/

Donald Flanders was an American mathematician who worked on the Manhattan Project at Los Alamos. Flanders was a group leader in the Theoretical Division headed by Hans Bethe. The T-5 group, which often employed the wives of Los Alamos scientists and workers, was given computations needed by other groups and used Marchant computers for their work. Physicist Roy Glauber, also a member of the Theoretical Division, remembered that Flanders was also very musical and served as the director of the singing groups at Los Alamos.

III. ELECTROMECHANICAL CALCULATORS

Frankel and Nelson, Figs. 2 and 3, had set up a “hand-computing activity to support development of

   NUCLEAR TECHNOLOGY · VOLUME 207 · SUPPLEMENT 1 · 2021

Fig. 2. Stanley P. Frankel.

the electromagnetic isotope separator and early critical- mass calculations” at Lawrence’s Berkeley laboratory.3,9 Frankel and Nelson arrived at Los Alamos in early 1943 to continue the critical mass work for the gun bombs. They were tasked to order electromechanical desk calcu- lators for Los Alamos’s “initial theoretical work.”9 To balance cost and capability, they chose a mix of high- speed, ten-digit Marchants and Fridens and economical, but slow, eight-digit Monroes.9
Some of these calculators were distributed to scientists who had the “most computing work,”9 such as critical mass calculations.

Others were used to set up the central comput- ing pool, Group T-5, in the summer of 1943, which was led by

Donald (Moll) Flanders

9,17 (Fig. 4) a mathematics pro- fessor at New York University.

12 The original human com- puters were the wives of the technical staff, who were eventually replaced by Women’s Army Corps (WAC) staff.18 Mary Frankel (Fig. 5) set up the problems for the human computers to calculate.18 An example could be linear interpolation of a table, c = (a + b)/2. Frankel would set up a calculating sheet with a row telling where to get “a” and a space for its value, a row to get “b,” a row that says do
Fig. 3. Eldred C. Nelson.

NUCLEAR TECHNOLOGY · VOLUME 207 · SUPPLEMENT 1 · 2021
Fig. 4. Donald “Moll” Flanders.
LOS ALAMOS COMPUTING FACILITY DURING THE MANHATTAN PROJECT · ARCHER S193