Benoit B. Mandelbrot

Conceived and developed the fractal geometry of nature and used it in a number of physical sciences (e.g., turbulence, physical clusters, galaxies, geomorphology) and social sciences (e.g. linguistics, economics, finance). Main contributions to mathematics include the theory of multifractal measures and functions, the Mandlebrot Set (the conjecture that led to defining it remains unresolved after 20 years), the 4/3 conjecture on the Brownian boundary (recently proved). Contributed to high and popular art and culture; pioneered in teaching of mathematics to non-mathematicians.