Astronomy Bio...Bruno Rossi

Jay Bitterman

BRUNO ROSSI WAS BORN in Venice on April13, 1905. He was the eldest son of Rino Rossi and Lina Minerbi. His father was a successful electrical engineer who started working on the electrification of Venice. He studied physics at the University of Padua and in 1927 he received his doctorate from the University of Bologna. In 1929 he delved into the mysterious field of cosmic ray physics by devising the first instrument to record the simultaneous occurrence of three or more electrical pulses. It was known as Rossi coincidence circuit and was a fundamental electronic device for studying high-energy nuclear physics and a basic building block of modern computers.

In 1931 he discovered that although cosmic-ray particles were rapidly losing energy, they could pass through massive thicknesses (up to a meter of lead) of matter. In addition he found that individual cosmic rays that collided with atoms, quite often, created a large number of secondary particles that were called showers. These findings added to the evidence that these astonishing energies were associated with cosmic rays. The penetrating particles were positively related to the HohenstrahIung that Victor Hess discovered during his 1911-12 manned balloon flights. Hess had verified the existence of a "radiation from above" that came from outer space and generated ionization throughout the atmosphere. Rossi's interest in the bombardment from space eventually led him into space research when the technical means for putting instruments outside the Earth's atmosphere became available.

His academic career began at the University of Florence where he was the chairman of the physics department in Padua from 1932 to 1938 until the Fascist regime dismissed him. In 1940 he joined the faculty of Cornell University after spending brief periods of time in Copenhagen; Manchester, England; and Chicago. In 1943 he joined the staff of the Los Alamos Laboratory in New Mexico, where the atomic bomb was developed and left in 1946 to accept a professorship at Massachusetts Institute of Technology,

In 1958 he focused attention on the direct measurements of ionized interplanetary gas using space probes. In 1961 he and his associates constructed a detector that was put on the Explorer X satellite. It discovered the magnetopause, the space boundary beyond which Earth's magnetic field loses its dominance. In 1963 he also started an exploratory search for cosmic x-rays that resulted in the discovery of the strong Scorpio X-ray source. It was the first known source to be observed outside the solar system. This discovery launched the introduction of X-ray astronomy that serves as a principal tool for astrophysics research. In 1966 he received the rank of Institute Professor that was reserved for scholars of special distinction.

Dr. Rossi had memberships in many scientific societies, including the National Academy of Sciences and American Academy of Arts and Sciences. Among his honors he received the United States Medal of Science, the Gold Medal of the Italian Physical Society, the Elliot Cresson Gold Medal and the Wolf Prize in Physics.

On Sunday, November 21, 1993 Dr Bruno Rossi, at the age of 88, died at his home in Cambridge, Massachusetts due to cardiac arrest. His wife Nora Lombroso Rossi; two daughters, Florence Moloney of Sunnyvale, Calif. and Linda Rossi of Manhattan; a son Frank of Boston, and two grandchildren survive him.