RIP Edward Lorenz
Edward Lorenz, meteorologist and founder of chaos theory,
passed away today at the age of 90. He discovered the chaotic properties of nonlinear systems as a result of an unexpected result while running numerical weather simulations in 1961, and changed the way we think about complex systems.
For those of you with a mathematical background, I recommend taking a look at his 1963 paper "
Deterministic Nonperiodic Flow," in which he proves one of the most basic results of chaotic dynamics (that nonperiodic flows are unstable against small perturbations), applies it to a simple problem in fluid dynamics, demonstrates vividly and in pictures the way that the system becomes unpredictable, and reflects on its significance for weather prediction. It seems a fitting way to mark his passing, and the paper is
great; very straightforward
1 and well-written, and full of the best pictures that 1963-era computing could produce.
1 By comparison to most technical papers in mathematics, that is, and especially to most papers on differential equations. I realize that this is not the best definition of "straightforward."