George Gabriel Stokes (1819–1903) was an Irish-born physicist and mathematician who spent over half a century at Cambridge — he held Newton's old chair, the Lucasian Professorship, for 54 years. He was a triple threat: a superb theorist, a careful experimenter, and the man who figured out why the sky-blue glow of a fluorescent mineral appears when you shine ultraviolet light on it.

What the subject kept

The theorem that turns a swirl around the edge of a surface into the curl flowing through it is Stokes' theorem, the grand generalisation that contains the divergence theorem as a special case:

His name is also stamped all over fluid mechanics — the Navier–Stokes equations describe how every river, jet stream and coffee-swirl moves, and Stokes' law tells you how fast a tiny sphere sinks through honey. He even coined the word fluorescence.