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.