John von Neumann : biography
The Fuchs–von Neumann work was passed on, by Fuchs, to the USSR as part of his nuclear espionage, but it was not used in the Soviets’ own, independent development of the Teller–Ulam design. The historian Jeremy Bernstein has pointed out that ironically, "John von Neumann and Klaus Fuchs, produced a brilliant invention in 1946 that could have changed the whole course of the development of the hydrogen bomb, but was not fully understood until after the bomb had been successfully made."
The ICBM Committee
In 1955, von Neumann became a commissioner of the United States Atomic Energy Program. Shortly before his death, when he was already quite ill, von Neumann headed the US government’s top secret von Neumann Intercontinental ballistic missile (ICBM) committee. Its purpose was to decide on the feasibility of building an ICBM large enough to carry a thermonuclear weapon. Von Neumann had long argued that while the technical obstacles were sizeable, they could be overcome in time. The SM-65 Atlas passed its first fully functional test in 1959, two years after his death.
Mutually assured destruction
John von Neumann is credited with the equilibrium strategy of mutually assured destruction, providing the deliberately humorous acronym, MAD. (Other humorous acronyms coined by von Neumann include his computer, the Mathematical Analyzer, Numerical Integrator, and Computer – or MANIAC).
Von Neumann was a founding figure in computer science.Goldstine, pp. 167–178. Von Neumann’s hydrogen bomb work was played out in the realm of computing, where he and Stanislaw Ulam developed simulations on von Neumann’s digital computers for the hydrodynamic computations. During this time he contributed to the development of the Monte Carlo method, which allowed solutions to complicated problems to be approximated using random numbers. He was also involved in the design of the later IAS machine.
Because using lists of "truly" random numbers was extremely slow, von Neumann developed a form of making pseudorandom numbers, using the middle-square method. Though this method has been criticized as crude, von Neumann was aware of this: he justified it as being faster than any other method at his disposal, and also noted that when it went awry it did so obviously, unlike methods which could be subtly incorrect.
While consulting for the Moore School of Electrical Engineering at the University of Pennsylvania on the EDVAC project, von Neumann wrote an incomplete First Draft of a Report on the EDVAC. The paper, whose public distribution nullified patent claims, described a computer architecture in which the data and the program are both stored in the computer’s memory in the same address space.The name for the architecture is discussed in , part of the online , in Robert Slater’s computer history book, Portraits in Silicon (MIT Press, 1989), and in Nancy Stern’s book From ENIAC to UNIVAC (Digital Press,1981).
John von Neumann also consulted for the ENIAC project, when ENIAC was being modified to contain a stored program. Since the modified ENIAC was fully functional by 1948 and the EDVAC wasn’t delivered to Ballistics Research Laboratory until 1949, one could argue that ENIAC was the first computer to use a stored program. John von Neumann also designed the instruction set for the modified ENIAC, and he should be given credit for this. The stored program version of ENIAC ran 6 times slower, but it was still entirely I/O bound, and programs could be developed and debugged in days rather than weeks, which is one of the advantages of having stored programs.
This architecture is to this day the basis of modern computer design, unlike the earliest computers that were ‘programmed’ by altering the electronic circuitry. Although the single-memory, stored program architecture is commonly called von Neumann architecture as a result of von Neumann’s paper, the architecture’s description was based on the work of J. Presper Eckert and John William Mauchly, inventors of the ENIAC at the University of Pennsylvania.