Edward Lorenz, the father of chaos theory, died of cancer today, April 16, at the age of 90. Lorenz was the first to formalize the idea that tiny variations in initial conditions could set similar, deterministic systems on vastly different courses. A vivid example of this principle was the "butterfly effect": the idea that the flap of a butterfly's wings in Brazil could set off a tornado in Texas.

In this obituary, a colleague at MIT summed Lorenz up thusly: "By showing that certain deterministic systems have formal predictability limits, Ed...fomented what some have called the third scientific revolution of the 20th century, following on the heels of relativity and quantum physics. ...He was also a perfect gentleman." Both admirable accomplishments.

Once in his grave, Lorenz will, of course, turn over in it every time Jeff Goldblum explains chaos theory in Jurassic Park.

Photo of the "Lorenz attractor"