Today’s Google Doodle celebrates the birthday of Brazilian physicist and teacher César Lattes, renowned for his groundbreaking discovery of the ‘pion’ or ‘pi meson.’ This subatomic particle, with a mass 270 times greater than an electron, significantly advanced our understanding of nuclear forces. The animated doodle pays tribute to Lattes, born on this day in 1924, recognizing his pivotal contribution to the field of physics.
The story of Lattes’ discovery dates back to a time when a researcher brought two photographic plates to a mountaintop to capture more cosmic rays. Lattes, with his innovative approach, modified one of the plates, leading to the revelation of tracks from a previously unseen particle – the pion. These pions, smaller than atoms, are formed when space matter collides with Earth’s atmosphere. Lattes’ ingenious technique, which involved adding boron to photographic plates, provided a clearer image of particles breaking down, allowing him to observe each proton.
Lattes’ research didn’t stop at uncovering the existence of pi mesons; he also discovered that some mesons are heavier than others. This groundbreaking work earned his research team the prestigious Nobel Prize in Physics. Following this triumph, Lattes became a physics professor at the University of São Paulo and later at the State University of Campinas.
Google Doodle highlights Lattes’ commitment to scientific advancement by mentioning his efforts in securing more government funding for science. This initiative led to the establishment of the CBPF – the Brazilian Centre for Research in Physics, where Lattes served as the scientific director. He dedicated himself to mentoring countless students pursuing their graduate theses in nuclear emulsion (particle detection) and geochronology (rock dating) across Brazil, the United States, and Italy.
Lattes’ contributions to nuclear forces and particle physics earned him numerous accolades, including the Einstein Award from the Brazilian Academy of Sciences and an Order of Merit from Brazil and Italy. In recognition of his profound impact, dozens of schools, roads, and town squares bear his name.
Lattes’ journey began at the University of São Paulo, where he graduated in 1943 as the sole physics major in his class. In his early twenties, he delved into the study of cosmic rays, high-energy particles originating from space. His passion for physics and dedication to research have left an enduring legacy on the scientific community, cementing his place as a true pioneer in the field.