Last thursday Benoit Mandelbrot died in Cambridge, Mass. Mandelbrot was a hugely important figure in mathematics: he refined the concept and study of fractals--an object that looks the same the closer you zoom in on it. The discovery of fractals showed the world that mathematics could be applied to realms previously off-limits to rigorous inquiry. Just as calculus unlocked the mysteries of change, fractal geometry revealed the inner structure of nature's jagged contours. A nice obituary is here.
In honor of Mandelbrot, I'm re-posting this spectacular documentary about fractal geometry done by Nova. It includes many great clips of Mandelbrot and of the crazy computer-generated imagery we've all seen but never really understood.