Celebrating César Lattes

On this day in 1924, Lattes was born in Curitiba, Brazil.

Lattes studied at the University of S�o Paulo and graduated in 1943 as the only physics major in his class. In his early twenties, he started studying cosmic rays, or high-energy particles from space. Lattes correctly suspected that adding boron to photographic plates would give him a clearer image of particles breaking down. It worked so well, he could see each proton.

To reach more cosmic rays, a researcher brought two photographic plates to the top of a mountain. The plate that Lattes modified showed tracks from a particle that had never been observed before — the pion! Pions, or pi mesons, are smaller than an atom, and form when space matter crashes into Earth’s atmosphere. Not only did he uncover their existence, but he also found that some mesons are heavier than others. This work won his research team a Nobel Prize in Physics.

Shortly after, Lattes became a physics professor at the University of São Paulo and later at the State University of Campinas. He campaigned for more government funding for science which led to the formation of the CBPF, a physics research institute where Lattes was the scientific director. He mentored many students working on their graduate theses in nuclear emulsion (particle detection) and geochronology (rock dating) across Brazil, the United States, and Italy.

Lattes received many awards for his advancements in nuclear forces and particle physics, including the Einstein Award from the Brazillian Academy of Sciences and an Order of Merit from Brazil and Italy. Dozens of schools, roads, and town squares are named in his honor.

Happy birthday César Lattes, thank you for paving the way for experimental physics in Latin America and around the world!