Integration in time (and space) of the equations of mass, momentum and energy conservation plays a growing role in QbD. An early contributor to this field was Lewis Fry Richardson, whose 1922 book, Weather Prediction by Numerical Process, laid the basis for modern weather prediction techniques. Richardson also occupied himself with understanding turbulence and like Corrsin, was briefly moved to write a verse about his ideas. Corrsin was inspired by Shakespeare; Richardson by Jonathan Swift and Augustus de Morgan to write about the cascade of energy from large to small scales:
Big whorls have little whorls,
Which feed on their velocity;
And little whorls have lesser whorls,
And so on to viscosity
(in the molecular sense).Many subsequent students of turbulence and mixing built on Richardson's work, and the Richardson Number is named in his honour. He also analyzed wars using mathematics and had early ideas about fractals while studying the lengths of shared borders between countries. Recipients of the Lewis Fry Richardson Medal have included Benoit Mandelbrot.
De Morgan had written:
Great fleas have little fleas upon their backs to bite 'em,
And little fleas have lesser fleas, and so ad infinitum.
And the great fleas themselves, in turn, have greater fleas to go on;
While these again have greater still, and greater still, and so on.
Swift originally wrote (in 1733):
So, naturalists observe, a flea
Hath smaller fleas that on him prey;
And these have smaller still to bite 'em;
And so proceed ad infinitum.
Thus every poet, in his kind,
Is bit by him that comes behind.