Sir J.J. ThomsonBorn 18 Dec 1856; died 30 Aug 1940 at age 83. Joseph John Thomson was an English physicist who helped revolutionize the knowledge of atomic structure by his discovery of the electron (1897). He received the Nobel Prize for Physics in 1906 and was knighted in 1908. Thomson experimented with currents of electricity inside empty glass tubes, investigating a long-standing puzzle known as “cathode rays.” His experiments prompted him to make a bold proposal: these mysterious rays are streams of particles much smaller than atoms. He called these particles “corpuscles,” and suggested that they might make up all of the matter in atoms. It was startling to imagine particles inside the atom at a time when most people thought that the atom was indivisible, the most fundamental unit of matter. |
