Edge of Chaos — Charles-Eugene Delaunay
Charles-Eugene Delaunay, mining engineer and astronomer, sought the calm order of an academic life, but instead his was a life and career at the edge of chaos. Delaunay suffered a tragi-comic career in the shadow of Urbain le Verrier. Both attained recognition for wielding mathematics to uncover the secrets of the solar system. However, le Verrier’s calculation of the position of a new planet, Neptune, earned far more public acclaim than Delaunay’s monumental work to calculate the precise orbit of the Moon. Le Verrier resented the competition, just the same, and attacked Delaunay’s work, without justification. The untimely death of Delaunay’s wife sent his work into a tailspin. When Delaunay finally received his due and succeeded le Verrier as director of the Paris Observatory, it was 1870, the year of the disastrous Franco-Prussian War, which ended with Paris under siege. Delaunay was called on to defend the Observatory from being ransacked during the bloody finale of the Paris Commune. The following year, Delaunay, who had a life-long aversion to water, drowned in a boating accident while vacationing at the seashore.
Delaunay’s work marked the beginning of the end to the idea, championed by Simon Laplace, that nature behaves predictably, as if drive by a clockwork mechanism. Beginning with Isaac Newton, generations of scientists had tried their hand at predicting the moon’s motion in its orbit. Each attempt seemed only to succeed in revealing yet another subtle factor that caused the moon to deviate from the path prescribed for it by Newton’s theory. Delaunay’s equations took everything into account, but his calculations required 900 pages to fully describe. In the end, Delaunay’s work proved to be of more interest to other theorists than to those with a practical need. In fact, as others were to discover later, Delaunay had succeeded in mapping the limits of predictability. In 1890, a member of a new generation of scientists, Henri Poincaré, showed that the laws of celestial mechanics can sometimes lead to unpredictable, chaotic changes in the motion of orbiting bodies.
Charles-Eugene Delaunay is one of the 72 scientists and engineers named on the Eiffel Tower.
