quarta-feira, 4 de agosto de 2010


Cesare Mansueto Giulio Lattes (born 11 July 1924, Curitiba, Paraná, Brazil, died 8 March 2005, Campinas, São Paulo), also known as Cesar (or César) Lattes, was a Brazilian experimental physicist, co-discoverer of the... pion, a composite subatomic particle made of a quark and an antiquark. From 1947 to 1948, Lattes launched on his main research line by studying cosmic rays. He visited a weather station on top of the 5,200-meter high Chacaltaya mountain in Bolivia, using photographic plates to register the rays. Traveling to England with his teacher Occhialini, Lattes went to work at the H.H. Wills Laboratory of the University of Bristol, directed by Cecil Powell. There, he improving on the nuclear emulsion used by Powell, by adding more boron to it. In 1947, he made his great experimental discovery with Powell: the pion (or pi meson). Lattes then proceeded to write a paper for Nature without bothering to ask for Powell's consent. In the same year, he was responsible for calculating the new particle's mass. A year later, working with Eugene Gardner at UC Berkeley, Lattes was able to detect the artificial production of pions in the lab's cyclotron, by bombarding carbon atoms with alpha particles. He was 24 years old. Lattes, in the period of the Second World War, started researches that contributed to the advance of the science relating to the atomic structure. The discovery of the ‘meson pi’ (an ephemeral particle, with mass between the electron’s and the proton’s) was essential for the studies about radiation. To perform his researches, Lattes, with notorious enterprising spirit, created the Chaclataya laboratory, in Bolivia. Jointly with other researchers, he obtained important advances as the artificial reproduction of the pions. Working with the Japanese scientists, he made discoveries such as the “Fireballs” phenomenon, name given to the clouds of mesons within the atoms. Despite being a critic of Einstein, his researches were critical for the development of the ‘Relativity Theory’, for they were precursor of the conception of the ‘quarks’. Thus, they present foundations of the theories about the creation and expansion of the universe. Wiki and http://lattes.cnpq.br/english/conteudo/cesare.htm
The Nobel Prize in Physics 1950 was awarded to Cecil Powell