## Cauchy’s stressful science

Stories from Physics for 11-14 14-16

Hooke’s law was generalised to three-dimensional materials by Augustin-Louis Cauchy. However, the stress of physics was not the only strain Cauchy experienced.

Cauchy’s parents were royalists and his family were forced to flee Paris after the French Revolution. Food was scarce in the post-revolutionary turmoil and, for a time, the Cauchys had to live on a limited supply of hard crackers and rice. Cauchy inherited his parents’ beliefs: he was a staunch royalist and Catholic, and he was argumentative and belligerent, becoming unpopular amongst his colleagues.

Though he was a prolific publisher, Cauchy’s approach to working was so chaotic he sometimes published the same work twice. He overwhelmed the Paris Academy with long publications, forcing the introduction of a rule that remains in force today: that papers cannot exceed four pages. Undeterred, he founded his own journal and even published his ideas in local newspapers.

After the 1830 revolution, Cauchy was again forced to flee Paris, travelling first to Switzerland, then to Italy. He settled in Prague, becoming the science tutor of a young French duke. Cauchy was a poor teacher and his student mocked him – when Cauchy revealed he had worked on the repair of the Paris drainage system, the duke gleefully told those he met that Cauchy’s career had begun in the sewers.

When Cauchy was able to return to Paris, his stubbornness meant he refused to swear an oath of allegiance to the new regime. He found a post at the Bureau of Longitude, but because of his refusal to swear the oath, he wasn’t paid and was banned from submitting papers. Cauchy’s stubbornness was temporarily rewarded when, 10 years after his return to Paris, King Louis-Phillipe fled for England and the oath was abolished. Within four years, it was reintroduced by the new Emperor of France for all state functionaries, but Cauchy was exempted. He died a few years later having made significant contributions to elasticity, wave theory and several branches of mathematics.

### References

**Cauchy’s stressful science**

J. S. Rao, *History of Rotating Machinery Dynamics,* Dordrecht, Springer Science+Business Media, 2011, p. 45

I. James, *Remarkable Mathematicians: From Euler to Von Neumann*, Cambridge, Cambridge University Press, 2002, pp. 82-90