1. Quotes
  2. Authors
  3. J. J. Thomson

J. J. Thomson Quotes

Sir Joseph John Thomson was a British physicist and Nobel Laureate in Physics, credited with the discovery of the electron, the first subatomic particle to be discovered.

In 1897, Thomson showed that cathode rays were composed of previously unknown negatively charged particles , which he calculated must have bodies much smaller than atoms and a very large charge-to-mass ratio. Thomson is also credited with finding the first evidence for isotopes of a stable element in 1913, as part of his exploration into the composition of canal rays . 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 1906 Nobel Prize in Physics for his work on the conduction of electricity in gases. Wikipedia  

✵ 18. December 1856 – 30. August 1940
J. J. Thomson photo
J. J. Thomson: 8   quotes 15   likes

Famous J. J. Thomson Quotes

“The difficulties which would have to be overcome to make several of the preceding experiments conclusive are so great as to be almost insurmountable.”

J. J. Thomson

Warning about the non-conclusiveness for the experimental foundation of electrostatic theory, in a footnote of the third edition of: [James Clerk Maxwell, A Treatise on Electricity and Magnetism, Vol.1, 3rd Edition, Oxford University Press, 1891, 37]
Quotes eat me

“The electron: may it never be of any use to anybody!”

J. J. Thomson

A popular toast or slogan at J. J. Thomson's Cavendish Laboratory in the first years of the 1900s, as quoted in Proceedings of the Royal Institution of Great Britain, Volume 35 (1951), p. 251.
Attributed

“I can see no escape from the conclusion that they are charges of negative electricity carried by particles of matter.”

J. J. Thomson

"Cathode rays" http://web.lemoyne.edu/~GIUNTA/thomson1897.html Philosophical Magazine, 44, 293 (1897).
Quotes eat me
Context: As the cathode rays carry a charge of negative electricity, are deflected by an electrostatic force as if they were negatively electrified, and are acted on by a magnetic force in just the way in which this force would act on a negatively electrified body moving along the path of these rays, I can see no escape from the conclusion that they are charges of negative electricity carried by particles of matter.

“We see from Lenard's table that a cathode ray can travel through air at atmospheric pressure a distance of about half a centimetre before the brightness of the phosphorescence falls to about half its original value. Now the mean free path of the molecules of air at this pressure is about 10-5 cm., and if a molecule of air were projected it would lose half its momentum in a space comparable with the mean free path. Even if we suppose that it is not the same molecule that is carried, the effect of the obliquity of the collisions would reduce the momentum to half in a short multiple of that path. Thus, from Lenard's experiments on the absorption of the rays outside the tube, it follows on the hypothesis that the cathode rays are charged particles moving with high velocities, that the size of the carriers must be small compared with the dimensions of ordinary atoms or molecules. The assumption of a state of matter more finely subdivided than the atom of an element is a somewhat startling one; but a hypothesis that would involve somewhat similar consequences—viz. that the so-called elements are compounds of some primordial element—has been put forward from time to time by various chemists.”

J. J. Thomson

Royal Institution Lecture (April 30, 1897) as quoted by Edmund Taylor Whittaker, A History of the Theories of Aether and Electricity from the Age of Descartes to the Close of the Nineteenth Century http://books.google.com/books?id=CGJDAAAAIAAJ (1910).
Quotes eat me

“I have described at some length the application of Positive Rays to chemical analysis; one of the main reasons for writing this book was the hope that it might induce others, and especially chemists, to try this method of analysis. I feel sure that there are many problems in chemistry, which could be solved with far greater ease by this than any other method. The method is surprisingly sensitive — more so than even that of spectrum analysis, requires an infinitesimal amount of material, and does not require this to be specially purified; the technique is not difficult if appliances for producing high vacua are available.”

J. J. Thomson

Rays of Positive Electricity (1913).
Quotes eat me

“This example illustrates the differences in the effects which may be produced by research in pure or applied science. A research on the lines of applied science would doubtless have led to improvement and development of the older methods—the research in pure science has given us an entirely new and much more powerful method. In fact, research in applied science leads to reforms, research in pure science leads to revolutions, and revolutions, whether political or industrial, are exceedingly profitable things if you are on the winning side.”

J. J. Thomson

Cited from Lord Rayleigh, The Life of Sir J. J. Thomson (1943), p. 199.
Attributed

“If, in the very intense electric field in the neighbourhood of the cathode, the molecules of the gas are dissociated and are split up, not into the ordinary chemical atoms, but into these primordial atoms, which we shall for brevity call corpuscles; and if these corpuscles are charged with electricity and projected from the cathode by the electric field, they would behave exactly like the cathode rays.”

J. J. Thomson

"Cathode rays" http://web.lemoyne.edu/~GIUNTA/thomson1897.html Philosophical Magazine, 44, 293 (1897).
Quotes eat me

“As the cathode rays carry a charge of negative electricity, are deflected by an electrostatic force as if they were negatively electrified, and are acted on by a magnetic force in just the way in which this force would act on a negatively electrified body moving along the path of these rays, I can see no escape from the conclusion that they are charges of negative electricity carried by particles of matter.”

J. J. Thomson

"Cathode rays" http://web.lemoyne.edu/~GIUNTA/thomson1897.html Philosophical Magazine, 44, 293 (1897).

Similar authors

Peter Higgs photo
Peter Higgs 8
British physicist
Niels Bohr photo
Niels Bohr 37
Danish physicist
Clinton Davisson photo
Clinton Davisson 1
physicist
Samuel C. C. Ting photo
Samuel C. C. Ting 1
physicist
Frits Zernike photo
Frits Zernike 1
Dutch physicist
Richard Feynman photo
Richard Feynman 181
American theoretical physicist
Max Planck photo
Max Planck 30
German theoretical physicist
Ernst Ruska photo
Ernst Ruska 2
German physicist
Arno Allan Penzias photo
Arno Allan Penzias 6
American physicist
Stephen Hawking photo
Stephen Hawking 122
British theoretical physicist, cosmologist, and author