Today’s Google Doodle is celebrating what would have been the 100th birthday of César Lattes, a Brazilian experimental physicist and teacher who discovered the pion, changing the course of nuclear physics.
Google said in its tribute: “Happy birthday César Lattes, thank you for paving the way for experimental physics in Latin America and around the world!”
“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.”
Who is César Lattes?
Growing up with his family of Italian immigrants in Curitiba, Paraná, Brazil, Lattes began to study physics and mathematics, eventually taking his studies to the University of São Paulo, from which he graduated in 1943.
At the age of 25, he founded the Brazilian Centre for Physical Research along with many colleagues who would go on to become important names in physics.
Lattes, was considered the most talented of his cohort along with Oscar Sala, Mário Schenberg, Roberto Salmeron, Marcelo Damy de Souza Santos and Jayme Tiomno worked under European teachers such as Gleb Wataghin and Giuseppe Occhialini.
From 1946 to 1948, Lattes launched his main research into cosmic rays, travelling to England to take his work to the University of Bristol, building on research of nuclear emulsion.
In 1969, his research group discovered “fireballs” which he discovered at the peak of the Andes, by producing high-energy collisions, in a special lead chamber, using nuclear emission plates he had invented.
Lattes later died at 80 years old from a heart attack in the suburbs near his São Paulo campus, in 2005.
What is the pion?
In April 1947, Lattes visited a weather station on top of the 5,200-metre high mountain in Bolivia, bringing two photographic plates to obtain more cosmic rays than were available at a lower altitude.
It was then that Lattes discovered a particle that had never been observed before — the pion also called pi mesons. Pions are smaller than an atom made of a quark and an antiquark, and form when space matter crashes into Earth’s atmosphere. At this point he was just 24 years old.
Later, Lattes deduced that some pions are in fact heavier than others, which ultimately won him a Nobel Prize for Physics in 1950.
Shortly after his discovery Lattes returned to Brazil to teach at University of São Paulo and later at the State University of Campinas, mentoring the next generation of Brazilian physicists.