Goldstein scientist biography book summary

He was an early investigator of discharge tubes, the discoverer of anode rays or canal rays, later identified as positive ions in the gas phase including the hydrogen ion. He studied at Breslau and later, under Helmholtz , in Berlin. Goldstein worked at the Berlin Observatory from to but spent most of his career at the Potsdam Observatory, where he became head of the astrophysical section in Later, in , Johann Wilhelm Hittorf studied discharge tubes with energy rays extending from a negative electrode , the cathode.

These rays produced a fluorescence when they hit a tube's glass walls, and when interrupted by a solid object they cast a shadow. In the s, Goldstein undertook his own investigations of discharge tubes and named the light emissions studied by others Kathodenstrahlen , or cathode rays. He found that cathode rays were emitted perpendicularly from a metal surface, and carried energy.

Eugen goldstein atomic theory

He attempted to measure their velocity by the Doppler shift of spectral lines in the glow emitted by Crookes tubes. In , he discovered that tubes with a perforated cathode also emit a glow at the cathode end. Goldstein concluded that in addition to the already-known cathode rays, later recognized as electrons moving from the negatively charged cathode toward the positively charged anode , there is another ray that travels in the opposite direction.

Because these latter rays passed through the holes, or channels, in the cathode, Goldstein called them Kanalstrahlen , or canal rays.