On NPR Weekend Edition today, Keith Devlin (more from Devlin here) was on. He’s written a new book, The Millennium Problems, in which he describes seven unsolved mathematical problems chosen by the the Clay Mathematics Institute of Cambridge, Massachusetts. CMI is offering a prize of one million dollars for each solved problem. The seven problems are: Birch and Swinnerton-Dyer Conjecture, Hodge Conjecture, Navier-Stokes Equations, P vs NP, Poincare Conjecture, Riemann Hypothesis, Yang-Mills Theory, and Rules etc. Good luck!