![]() ![]() Once he had this apparatus further experiments with electric and magnetic fields could reveal a great deal more about the particles. ![]() ![]() This enabled Thompson to refute the claim by Hertz that electric fields didn't cause deflection (maybe Hertz's glassblower wasn't as good). The critical experiments done by Thompson relied on having an excellent glassblower who was able to construct an apparatus where electrodes inside the discharge tube which could be charged with an electric field (while retaining a very high vacuum). Hertz, though, claimed electric fields would not deflect them (he was wrong). Later, scientists such as Crookes observed that the rays could be deflected by magnetic fields (though he thought they were just negatively charged gas particles). Initially the rays were seen to travel in straight lines. So the idea that some sort of ray was emitted by the cathode in the tube was developed. They were first observed as experiments in gas discharge tubes started to exploit better and better vacuums (the early experiments observed the varying forms of discharge in low pressure gases cathode rays only become significant when there is very little gas left in the tubes).Īt very high vacuums, people observed that the glass at the end of the tubes would glow even though the contents of the tubes did not (as there were too few gas particles left to cause a discharge). Scholarly yet accessible to those with basic physics knowledge, this book should be of interest to historians of science, professional scientists and engineers, teachers and students of physics, and general readers interested in the development of modern physics.Thompson was able to measure the ratio of their mass to their speedĬathode "rays" had been known for some time before Thomson. The author also focuses on the controversies over N-rays, Becquerel's positive electron, and the famous Ehrenhaft-Millikan dispute over subelectrons. It explores the events leading to Millikan's unambiguous isolation of the electron and the simultaneous circumstances surrounding the birth of Ernest Rutherford's nuclear atom and the discovery of radioactivity in 1896. It also provides an overview of the history of modern physics up to the advent of the old quantum theory around 1920.Ĭonsolidating scholarly material while incorporating new material discovered by the well-respected author, the book covers the continental and English race for the source of the cathode rays, culminating in Thomson's corpuscle in 1897. The book traces the evolution of the concept of electrical charge, from the earliest glow discharge studies to the final cathode ray and oil drop experiments of J.J. Thomson's Electron presents the compelling story of the discovery of the electron and its role as the first subatomic particle in nature. ![]() Flash of the Cathode Rays: A History of J.J. The electron is fundamental to almost all aspects of modern life, controlling the behavior of atoms and how they bind together to form gases, liquids, and solids. ![]()
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