J. J. Thomson - WikipediaIn , Thomson showed that cathode rays were composed of previously unknown negatively charged particles now called electrons , which he calculated must have bodies much smaller than atoms and a very large charge-to-mass ratio. His experiments to determine the nature of positively charged particles, with Francis William Aston , were the first use of mass spectrometry and led to the development of the mass spectrograph. Thomson was awarded the Nobel Prize in Physics for his work on the conduction of electricity in gases. His mother, Emma Swindells, came from a local textile family. His father, Joseph James Thomson, ran an antiquarian bookshop founded by a great-grandfather. He had a brother, Frederick Vernon Thomson, who was two years younger than he was.
The Mystery of Matter: “INTO THE ATOM” (Documentary)
J. J. Thomson
He went on to elaborate this view. Hacking worried that the simple manipulation of the first quotation, the changing of the charge on an oil drop or on a superconducting niobium sphere, which involves only the charge of the electron, was insufficient grounds for belief in electrons. His second illustration, which he believed more convincing because it involved several properties of the electron, was that of Peggy II, a source of polarized electrons built at the Stanford Linear Accelerator Center in the late s. Peggy II provided polarized electrons for an experiment that scattered electrons off deuterium to investigate the weak neutral current. Although I agree with Hacking that manipulability can often provide us with grounds for belief in a theoretical entity, [ 1 ] his illustration comes far too late. It is conjectural because, despite having good reasons for belief in the existence of an entity or in the truth of a scientific law, we might be wrong. Both Hacking, as noted above, and Cartwright emphasize the manipulability of an entity as a criterion for belief in its existence.
Electricity and matter. by: Thomson, J. J. (Joseph John), Sir, Publication date: Topics: Electricity, Matter, Radio-activity.
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