Physics Guy@physicsguyIn 1938, Bibha Chowdhuri left light-sensitive plates coated with samarium sulphate out for months to catch cosmic particles, with some kept in a Calcutta refrigerator and others at Sandakphu.
Two of the Sandakphu plates showed about 30 starburst patterns, traces of atomic nuclei breaking apart. Later work with DM Bose used the shapes of these tracks to tell particles apart, a method Cecil Powell later used in his Nobel-winning mesotron research.
Their 1941 papers suggested some of the particles were lighter and probably mesotrons, now known as muons.
