The greatest equations ever

A Physics World reader survey was initiated at the first quarter of 2004 to determine the greatest equations. Respondents proposed some 50 different equations ranging from obvious classics to overlooked candidates, personal favorites and equations invented by the respondents themselves. Generally, the responses suggested that there is no single criterion for greatness, and that a truly great equation ranks high in each of the given criteria. However, most votes were given to Euler's equation and to Maxwell's equations, which describe how an electromagnetic field varies in space and time.