Editing Harvard Mark I (section)

==Contribution to the Manhattan Project==
In 1928 [[Leslie Comrie|L.J. Comrie]] was the first to turn IBM "punched-card equipment to scientific use: computation of astronomical tables by the method of finite differences, as envisioned by Babbage 100 years earlier for his Difference Engine".<ref>{{cite web|url=http://www.columbia.edu/cu/computinghistory/comrie.html|title= Columbia University Computing History: L.J. Comrie|access-date=15 December 2013}}</ref> Very soon after, IBM  started to modify its tabulators to facilitate this kind of computation.  One of these tabulators, built in 1931, was The Columbia Difference Tabulator.<ref>{{cite web|url=http://www.columbia.edu/cu/computinghistory/packard.html|title=The Columbia Difference Tabulator – 1931|access-date=15 December 2013}}</ref>

[[John von Neumann]] had a team at Los Alamos that used "modified IBM punched-card machines"<ref name=better>{{harvp|Cohen|2000|p=166}}</ref> to determine the effects of the implosion. In March 1944, he proposed to run certain problems regarding implosion on the Mark I, and he arrived at Harvard together with two mathematicians to write a simulation program to study the implosion of the first [[atomic bomb]].{{sfnp|Cohen|2000|p=164}}

<blockquote>The Los Alamos group completed its work in a much shorter time than the Cambridge group.  However, the punched-card machine operation computed values to six decimal places, whereas the Mark I computed values to eighteen decimal places. Additionally, Mark I integrated the partial differential equation at a much smaller interval size [or smaller mesh] and so...achieved far greater precision.<ref name=better /></blockquote>

"Von Neumann joined the [[Manhattan Project]] in 1943, working on the immense number of calculations needed to build the atomic bomb. He showed that the implosion design, which would later be used in the [[Trinity (nuclear test)|Trinity]] and [[Fat Man]] bombs, was likely faster and more efficient than the gun design."<ref>{{cite web|url=https://www.atomicheritage.org/profile/john-von-neumann |title=Atomic Heritage Foundation: John von Neumann|access-date=12 May 2019}}</ref>