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The physicist César Lattes, who is honored today (July 11) in a Google Doodle, is famous across Latin America for his discovery of the pion — a subatomic particle produced by shockwaves from exploding stars.
The Google Doodle released today (July 11) is a tribute to César Lattes, a pioneering Brazilian physicist who would have celebrated his 100th birthday today. Born to Italian immigrants in 1924 in Curitiba, Brazil, Lattes is widely credited with the discovery of the subatomic particle known as the pion, or pi meson — which is produced in the shockwaves from star explosions and rains down on Earth in the form of cosmic rays.
“Happy birthday César Lattes, thank you for paving the way for experimental physics in Latin America and around the world!” Google representatives wrote in a blog post honoring Lattes.
Lattes’ induction to advanced experimental physics began in 1934 at the recently founded University of São Paulo, where he was the only student enrolled in a course run by the then-famous Italian experimental physicist Giuseppe Occhialini. Occhialini taught Lattes to develop photographic film exposed to radiation.
In 1944 Occhialini went to the University of Bristol to work with the English physicist Cecil Frank Powell on the development of nuclear emulsion plates that could detect traces of highly energetic particles. Consisting of photosensitive silver salt suspended inside gelatin, the plates, upon development, clearly showed the tracks of charged particles that had passed through them.
After obtaining one of the plates sent by Occhialini, Lattes realized that it was missing a key ingredient: boron.
“Lattes correctly suspected that adding boron to photographic plates would give him a clearer image of particles breaking down,” according to the Google blog post. “It worked so well, he could see each proton.” […]
msamba 