After receiving a doctorate in physics in Germany in 1906, Geiger traveled to England, where he assisted chemist Ernest Rutherford. In 1908, they designed an instrument to detect and count alpha particles, positively charged ionizing particles produced by radioactive decay. He then returned to Germany, directing radiation research at several universities. Two decades later, Geiger developed the sensitive, portable radiation counter that now bears his name. Geiger was a member of what “club”? Discuss
Source: The Free Dictionary