Joseph John Thomson citations

Joseph John Thomson, né le 18 décembre 1856 et mort le 30 août 1940, est un physicien anglais.

Il a découvert l'électron ainsi que les isotopes et a inventé la spectrométrie de masse ; il a analysé la propagation d'ondes guidées.

Il a reçu le prix Nobel de physique de 1906 pour « ses recherches théoriques et expérimentales sur la conductivité électrique dans les gaz ». Ces recherches ont fourni les preuves de l'existence de l'électron. Wikipedia  

✵ 18. décembre 1856 – 30. août 1940
Joseph John Thomson photo
Joseph John Thomson: 9   citations 0   J'aime

Joseph John Thomson Citations

“Cet exemple illustre les différences dans les effets qui peuvent résulter de la recherche en science pure ou appliquée. La recherche en science appliquée aurait sans aucun doute conduit à l'amélioration et au développement des anciennes méthodes; la recherche en science pure nous a donné une méthode entièrement nouvelle et beaucoup plus puissante. En fait, la recherche en science appliquée conduit à des réformes, la recherche en science pure conduit à des révolutions et les révolutions, qu'elles soient politiques ou industrielles, sont des choses très rentables si l'on est du côté des gagnants.”

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.
en
Citation rapportée

Joseph John Thomson: Citations en anglais

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

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!”

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.”

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

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

Auteurs similaires

Albert Einstein photo
Albert Einstein 67
physicien allemand
Richard Feynman photo
Richard Feynman 5
physicien américain
Marie Curie photo
Marie Curie 3
physicienne et chimiste française d'origine polonaise
Gilbert Keith Chesterton photo
Gilbert Keith Chesterton 43
écrivain, journaliste, poète, illustrateur, apologiste cath…
Haruki Murakami photo
Haruki Murakami 21
écrivain japonais
George Orwell photo
George Orwell 27
écrivain britannique
Bertrand Russell photo
Bertrand Russell 20
mathématicien, logicien, philosophe, épistémologue, homme p…
John Lennon photo
John Lennon 10
auteur-compositeur-interprète britannique
Quentin Crisp photo
Quentin Crisp 30
acteur et modèle
Frithjof Schuon photo
Frithjof Schuon 173
métaphysicien, théologien et philosophe suisse