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Sir Joseph John Thomson (18 December 1856 – 30 August 1940) was an English physicist who received the Nobel Prize in Physics in 1906 for his discovery of the electron, the first subatomic particle to be found.
He believed the rays to consist of streams of particles of ordinary molecular magnitude. It remained for Sir J. J. Thomson to expound on the subatomic nature of cathode rays (consisting of streams of negative electrons [27]). Nevertheless, Crookes's experimental work in this field was the foundation of discoveries which eventually changed the ...
Crookes X-ray tube from around 1910 Another Crookes x-ray tube. The device attached to the neck of the tube (right) is an "osmotic softener". When the voltage applied to a Crookes tube is high enough, around 5,000 volts or greater, [16] it can accelerate the electrons to a high enough velocity to create X-rays when they hit the anode or the glass wall of the tube.
Atoms were thought to be the smallest possible division of matter until 1899 when J. J. Thomson discovered the electron through his work on cathode rays. [37]: 86 [5]: 364 A Crookes tube is a sealed glass container in which two electrodes are separated by a vacuum.
The electron was discovered between 1879 and 1897 in works of William Crookes, Arthur Schuster, J. J. Thomson, and other physicists; its charge was carefully measured by Robert Andrews Millikan and Harvey Fletcher in their oil drop experiment of 1909.
Crookes insisted it was a particle, while Hertz maintained it was a wave. The debate was resolved when an electric field was used to deflect the rays by J. J. Thomson. This was evidence that the beams were composed of particles because scientists knew it was impossible to deflect electromagnetic waves with an electric field.
A 1933 portrait of E. T. Whittaker by Arthur Trevor Haddon. The book was originally written in the period immediately following the publication of Einstein's Annus Mirabilis papers and several years following the early work of Max Planck; it was a transitional period for physics, where special relativity and old quantum theory were gaining traction.
The cathode ray tube by which J. J. Thomson demonstrated that cathode rays could be deflected by a magnetic field. The Thomson Medal and Prize is an award which has been made, originally only biennially in even-numbered years, since 2008 by the British Institute of Physics for "distinguished research in atomic (including quantum optics) or molecular physics".