Mathematics in nature : modeling patterns in the natural world The confluence of nature and mathematical modeling Estimation : the power of arithmetic in solving Fermi problems Shape size and similarity : the problem of scale Meteorological optics I : shadows crepuscular rays and related optical phenomena Meteorological optics II : a calculus I approach to rainbows halos and glories Clouds sand dunes and hurricanes (Linear) waves of all kinds Stability Bores and nonlinear waves The Fibonacci sequence and the golden ratio Bees honeycombs bubbles and mud cracks River meanders branching patterns and trees Bird flight How did the leopard get its spots