In Folha, Viana comments on the career of mathematician Steve Smale.

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

As I write this column, researchers from around the world are gathering at the University of Berkeley, California , to celebrate the 95th birthday and extraordinary career of mathematician Steve Smale, whose scientific contributions span from topology, dynamical systems, and mathematical economics to linguistics, complexity theory, and bioinformatics.

Six and a half decades ago, in the early 1960s, Smale was in Rio de Janeiro for the first of many visits to the then newly created Institute of Pure and Applied Mathematics (IMPA). During that visit, he proved the Poincaré conjecture for spheres of dimension 5 or greater, a feat that earned him the Fields Medal.

Furthermore, motivated by a letter he received from his colleague Norman Levinson in February of that year, he discovered the "Smale horseshoe," a mathematical model that explains the persistently complex behavior of the solutions to certain differential equations and which sparked a revolution in the field of dynamical systems.

This period of his career also attracted a degree of controversy that advances in mathematics rarely achieve. The controversy began in 1966, when Smale went to Moscow to participate in the International Congress of Mathematicians and receive the Fields Medal.

The United States was embroiled in the controversy surrounding the Vietnam War, and Smale played an active role in the protests, even being summoned to testify before the House Un-American Activities Committee. In Moscow, he held a press conference with Soviet, Vietnamese, and American journalists on the steps of the university, where he criticized both the Vietnam War and the Soviet invasion of Hungary in 1956.

Finally, a black car arrived with Soviet officials who took him on a long ride to an unknown destination. According to Smale, he was treated with great respect and, finally, was taken back to the university, without understanding what had happened. But the shock of the forced ride wasn't the worst part.

The criticisms of the war, delivered in the capital of the enemy Soviet Union, were poorly received in the United States. The trip had been paid for with his grant, and the university, claiming that there was a misuse of public funds, which could only be used for strictly research activities, suspended the payment.

In the letter requesting that the payment be reinstated, Smale explained that mathematicians do research all the time, in the most diverse circumstances (which is true!), and gave an example that went viral: "My most famous works were done on the beaches of Rio de Janeiro."

The argument did not convince President Nixon's scientific advisor: "This jovial spirit makes mathematicians seriously believe that the taxpayer should accept that mathematical creation on the beaches of Rio de Janeiro be financed with public funds."

Read the full article on the Folha de São Paulo website.

Read also: Computer Vision Thematic Session is a highlight at CBM