ABSTRACT
In 1930, cosmic ray physics was still a fresh new field that had been ushered in at the turn of century. In 1901, C. T. R. Wilson, Hans Geitel, and Julius Elster independently discovered in the atmosphere the presence of penetrating radiation
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Yoshio Nishina: Father of Modern Physics in
FIGURE 5.1 Victor F. Hess, the pioneer of cosmic ray research. (Courtesy of AIP Emilio Segrè Visual Archives.)
whose source was unknown. Some suggested an extraterrestrial source. By 1910, the balloon experiment was initiated to determine whether the intensity of the radiation depend on the altitude.
