Supercomputers complement scientific theory and observation by modeling and analyzing anything that is too large (planets), too small (drug molecules), or too expensive or dangerous (crash tests for cars) to test in the laboratory. Determining where and when earthquakes will strike; exploring which nanomaterials will convert sunlight into energy; and understanding how fast brain tumors grow — these important and complex societal problems require powerful computers like Stampede, which provides a peak performance of nearly 10 petaflops (PF), or nearly 10 quadrillion math operations per second.