When the movie based on your life is called A Beautiful Mind you can bet you have more than ample grey matter between the ears. The word ‘genius’ is thrown around pretty often these days but, when used to describe mathematician John Nash, it is certainly not out of place.

Nash and his wife were killed in a tragic taxi crash on Sunday, the aftermath of which has brought many of his brilliant achievements back into the public spotlight. Awarded the Nobel Prize in 1994, he was heralded by many he worked with as the greatest mind they had ever come across.

He was perhaps most famous for the Nash equilibrium, a concept that falls under the study of game theory. We’re probably going to struggle to keep up here but let’s give it a bash. This from Mashable:

…game theory provided a way to analyze “situations in which two or more individuals make decisions that will influence one another’s welfare.”

Because of John Nash, game theory now has wide-ranging applications to everything from business, law and finance to agriculture, war and, most important for Nash, economics.

…he took game theory from “a collection of toy cases in mathematics to a generalizable theory applicable to virtually anything.”

Nash was so gifted that Princeton awarded him a Ph.D. in 1950 when he was just 21. We”ll leave the last word to Robber Dijkgraaf, director of the Institute for Advanced Study at the university:

John Nash was a mathematician who just picked his own mountains, and produced results that nobody expected, that actually many people thought were impossible. And, in that sense, he opened up entirely new worlds. It could have been in economics. It could have been in very abstract mathematics and geometry. He really kind of touched so many different fields.

[source:mashable]