John von Neumann
Not all little geniuses turn out to be accomplished adults, but John von Neumann is a shining example of a mathematics prodigy who went on to make major contributions to both computers and atomic weaponry.
Born in Hungary in 1903, von Neumann stood out at a young age for his insane memory and voracious appetite for learning. The story goes that by age 6, he would amuse his parents' friends and neighbors by memorizing complete pages from the phone book and dividing eight-digit numbers in his head. He also liked to tell jokes in classical Greek [source: Britannica].
Eager to escape the mounting antisemitism of 1930s Europe, von Neumann took a position at Princeton University's Institute for Advanced Study, where some dude named Albert Einstein was also a professor. In 1943, von Neumann was recruited for the Manhattan Project, where he designed some of the most important elements of the first atomic bombs and even helped choose Hiroshima and Nagasaki as the first targets [source: Atomic Heritage Foundation].
But von Neumann wasn't done yet. In 1945, he achieved a major breakthrough in early computing by describing something called the "stored program technique," essentially solving the problem of having to build new hardware for every application [source: Center for Computing History]. He was also instrumental in building the first electronic general purpose computer, the Electronic Numerical Integrator And Computer (ENIAC) in 1946 at the University of Pennsylvania.
Lastly, von Neumann is also considered the father of game theory, a mathematical approach to economics that went on to influence the study of a range of fields, including evolutionary biology. We told you this guy was a big deal.