César Lattes

From Wikipedia, the free encyclopedia

Cesare Mansueto Giulio Lattes (b. July 11, 1924, Curitiba, Paraná, Brazil, d. March 8, 2005, Campinas, São Paulo) was a Brazilian experimental physicist, co-discoverer of the pi meson or pion, one of the nuclear particles.

Lattes was born to a family of Italian Jewish immigrants in Curitiba, Southern Brazil. He did his first studies in that town and in São Paulo, and his university studies at the University of São Paulo, graduating in 1943, in Mathematics and Physics. He was part of an initial group of brilliant young Brazilian physicists who worked under European teachers such as Gleb Wataghin (1899-1986) and Giuseppe Occhialini (1907-1993). Lattes was considered the most brilliant of those and was noted at a very young age as a bold researcher. His colleagues, who also became important Brazilian scientists, were Oscar Sala, Mário Schenberg, Roberto Salmeron, Marcelo Damy de Souza Santos and Jayme Tiomno. At the age of 23, he was one of the founders of the Brazilian Center of Physical Research (Centro Brasileiro de Pesquisas Físicas) in Rio de Janeiro.

From 1947 to 1948, Lattes launched on his main research line, by studying cosmic rays, which were discovered in 1932 by American physicist Carl David Anderson. He set up a laboratory on top of the 5,000-meter high Andes mountains 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 Frank Powell (1903-1969). After improving on the nuclear emulsion used by Powell, by asking Kodak Co. to add more boron to it, in 1947, he made with them his great experimental discovery, that of a new atomic particle, the pi meson (or pion), which disintegrates into a new kind of particle, the mu meson. Brash young Lattes then proceeded to write a paper for Nature magazine without bothering to ask for Powell's consent. In the same year, he was responsible for calculating the new particle's mass, a painstaking job. A year later, working with Eugene Gardner (1913-1950) at the University of California, Berkeley, Lattes was able to detect the artificial production of pion particles in the lab's cyclotron, by bombarding carbon atoms with alpha particles. He was 24 years old.

In 1949, Lattes returned as a professor and researcher with the Federal University of Rio de Janeiro and the Brazilian Center for Physical Research. After another brief stay in the USA (from 1955 to 1957), he returned to Brazil and accepted a position at his alma mater, the Department of Physics of the University of São Paulo.

In 1967, Lattes accepted a position of full professor with the new "Gleb Wataghin" Institute of Physics at the State University of Campinas, named after his former professor, which he helped to found. He became also the chairman of the Department of Cosmic Rays, Chronology, High Energies and Leptons. In 1969, he and his group discovered the mass of the so-called fire balls, a phenomenon induced by naturally occurring high-energy collisions, and which was detected by means of special lead-chamber nuclear emulsion plates invented by him, and placed at the Chacaltaya peak of the Bolivian Andes.

Lattes retired in 1986, when he received the titles of doctor honoris causa and professor emeritus of that university. After retirement he continued to live in a house in the suburban area very near to the University's campus. He died of a heart attack on March 8, 2005.

Lattes is one of the most distinguished and honored Brazilian physicists, and his work was fundamental for the development of atomic physics. He was also a great scientific leader of Brazilian Physics and was one of the main personalities behind the creation of the important Brazilian National Research Council (Conselho Nacional de Desenvolvimento Científico e Tecnológico). He figures as one of the few Brazilians in Isaac Asimov's Biographical Encyclopedia of Science and Technology, as well as in the Encyclopædia Britannica. Although he was the main researcher and the first author of the historical Nature article describing the meson pi, Cecil Powell alone was awarded the Nobel Prize for Physics in 1950 for "his development of the photographic method of studying nuclear processes and his discoveries regarding mesons made with this method". The reason for this apparent neglect is that the Nobel Committee policy until 1960 was to give the award to the research group head, only. After his death UNICAMP decided to give his name to the central library.

[edit] Quote

"Science should be universal, without a doubt. However, one should not believe unconditionally in this."

[edit] Bibliography

• Lattes, C. M. G., Muirhead, H., Occhialini, G. P. S. & Powell, C. F. Processes involving charged mesons. Nature, 159, 694 - 697, (1947).
• Lattes, C. M. G.; Occhialini, G. P. S.; Powell, C. F. A determination of the ratio of the masses of pi-meson and mu-meson by the method of grain-counting. Proceedings of the Physical Society, v.61, p.173-183, 1948.
• Gardner, E.; Lattes, C. M. G. Production of mesons by the 184-inch Berkeley cyclotron. Science, v.107, p.270-271, 1948.
• Lattes, C. M. G.; Orsini, C. Q.; Pacca, I. G.; Cruz, M. T.; Okuno, E.; Fujimoto, Y.; Yokoi, K. Observation of extremely high energy nuclear events with emulsion chamber exposed on Mt. Chacaltaya. Il Nuovo Cimento, v.XXVIII, n.3, p.2160-, 1963.

[edit] External links

• C.M.G. Lattes. Encyclopædia Britannica.
• Special Dedication to Cesar Lattes. UNICAMP Archive System, March 2005.
• To Cesar What Belongs to Lattes. State University of Campinas (in Portuguese).
• Cesar Lattes, a Brief Biography. Brazilian Center of Physical Research (In Portuguese)
• Photos of César Lattes at Chacaltaya, Bolivia.