29/03/2023

Folha: How reliable are the scientists' images?

Imagem falsa do matemático francês Adrien-Marie Legendre (1752 – 1833) / Reprodução Wikipédia

Reproduction of Marcelo Viana's column in Folha de S. Paulo.

Ten years ago, I was explaining to Anita, my daughter, who the characters depicted in the stained-glass window of a museum were when she—then three years old—proudly exclaimed: "I studied that one at my school; he came out of the bathtub!" She was referring to the famous scene—it's unknown by whom—of the Greek mathematician and scientist Archimedes jumping out of the bath and shouting "Eureka!"

In fact, the representation in the stained glass window referred to the philosopher Plato, but the child wasn't wrong. We have no idea what either of them looked like, since there are no images made by anyone who knew them in person. Anita only identified a generic image of a "classical Greek thinker" (which, incidentally, made her doting father very proud).

It is even more surprising that there are no reliable images of scientists much closer to us in time. And the case of the French mathematician Adrien-Marie Legendre (1752–1833) is particularly strange.

Legendre is one of the four great Ls with which France graced the world in the 18th and 19th centuries, along with Lagrange , Laplace, and Leverrier. He did fundamental work in number theory, analysis, celestial mechanics, and various applications of mathematics. Several concepts bear his name: Legendre transform, Legendre symbol, Legendre relation, among others.

In my courses, I frequently discuss the Legendre differential equation . And Legendre polynomials are used extensively in numerical calculus, in addition to playing a crucial role in solving the quantum mechanical equations for the hydrogen atom (Bohr-Sommerfeld model).

For these contributions, Legendre is one of 72 scientists whose names are inscribed on the Eiffel Tower as a tribute. Furthermore, in 1811 he was knighted by Emperor Napoleon Bonaparte, one of history's rulers who most prioritized merit and science (with a particular fondness for mathematics).

Despite his enormous scientific prestige, very little is known about Legendre's life. In particular, we have no reliable image of him. This is probably exactly what he wanted: in his eulogy, Siméon-Denis Poisson stated that "our esteemed colleague frequently expressed the wish that when we speak of him we do so only in relation to his scientific works, which are, in fact, his whole life."

To read the full text, visit the newspaper's website.