A Real Cloud Computer

Attempts to calculate the weather numerically have a long history. The first effort along these lines took place not in some cutting-edge university or government lab but on what the lone man doing it described as "a heap of hay in a cold rest billet." Lewis Fry Richardson, serving as an ambulance driver during World War I and working with little more than a table of logarithms, made a heroic effort to calculate weather changes across central Europe from first principles way back in 1917. The day he chose to simulate had no particular significance-other than that a crude set of weather-balloon measurements was available to use as a starting point for his many hand calculations. It's no surprise that the results didn't at all match reality. Three decades (and one world war) later, mathematician John von Neumann, a computer pioneer, returned to the problem of calculating the weather, this time with electronic assistance, although the limitations of the late-1940s computer he was using very much restricted his attempt to simulate nature. The phenomenal advances in computing power since von Neumann's time have, however, improved the accuracy of numerical weather forecasting and allowed it to become a routine part of daily life. Will it rain this afternoon? Ask the weatherman, who in turn will consult a computer calculation.