Everything about L On Foucault totally explained
Jean Bernard Léon Foucault (
18 September 1819 –
11 February 1868) was a
French physicist best known for the invention of the
Foucault pendulum, a device demonstrating the effect of the Earth's rotation. He also made an early measurement of the
speed of light, discovered
eddy currents, and although he didn't invent it, is credited with naming the
gyroscope. The
Foucault crater on the
Moon is named after him.
Early years
Foucault was the son of a publisher at
Paris, where he was born on
September 18,
1819. After an education received chiefly at home, he studied medicine, which, however, he speedily abandoned for physical science due to a fear of blood. He first directed his attention to the improvement of
L. J. M. Daguerre's photographic processes. For three years he was experimental assistant to
Alfred Donné (
1801–
1878) in his course of lectures on microscopic
anatomy.
With
A. H. L. Fizeau he carried on a series of investigations on the intensity of the
light of the
sun, as compared with that of
carbon in the
arc lamp, and of
lime in the flame of the
oxyhydrogen blowpipe; on the interference of
infrared radiation, and of light rays differing greatly in lengths of path; and on the chromatic
polarization of light.
Middle years
His demonstration in
1851 of the diurnal motion of the Earth by the rotation of the plane of oscillation of a freely suspended, long and heavy pendulum in
the Panthéon in
Paris, caused a sensation in both the learned and popular worlds, for it was the first dynamical proof of the Earth's rotation. In the following year he invented (and named) the
gyroscope as a conceptually simpler experimental proof. In
1855 he received the
Copley Medal of the
Royal Society for his 'very remarkable experimental researches'. Earlier in the same year he was made
physicien (physicist) at the imperial observatory at Paris.
In September of 1855 he discovered that the
force required for the rotation of a
copper disc becomes greater when it's made to rotate with its rim between the poles of a
magnet, the disc at the same time becoming heated by the
eddy current or "Foucault currents" induced in the metal.
In
1857, Foucault invented the polarizer which bears his name, and in the succeeding year devised a method of testing the mirror of a reflecting telescope to determine its shape. The so-called "
Foucault Test" allows the worker to tell if the mirror is perfectly spherical, or if it deviates from a sphere. Prior to Foucault's invention, testing reflecting telescope mirrors was a "hit or miss" proposition. With
Charles Wheatstone’s revolving mirror he in
1862 determined the speed of light to be 298,000
km/
s (about 185,000
mi./s) —10,000 km/s less than that obtained by previous experimenters and only 0.6% off the currently accepted value.
Later years
In that year, he was made a member of the
Bureau des Longitudes and an officer of the
Légion d'Honneur. In
1864 he was made a member of the
Royal Society of London, and the next year a member of the mechanical section of the Institute. In
1865 his papers on a modification of
Watt's governor appeared, upon which he'd for some time been experimenting with a view to making its period of revolution constant, and on a new apparatus for regulating the electric light; and in the year (Compt. Rend. lxiii.) he showed how, by the deposition of a transparently thin film of
silver on the outer side of the object glass of a telescope, the sun could be viewed without injuring the eye. His chief scientific papers are to be found in the
Comptes Rendus,
1847—
1869.
Death and afterwards
Foucault died of what was probably a rapidly-developing case of
multiple sclerosis on
February 11,
1868 in Paris and was buried in the
Cimetière de Montmartre.
Further Information
Get more info on 'L On Foucault'.
|
External Link Exchanges
Do you know how hard it is to get a link from a large encyclopaedia? Well we're different and will prove it. To get a link from us just add the following HTML to your site on a relevant page:
<a href="http://l__on_foucault.totallyexplained.com">Léon Foucault Totally Explained</a>
Then simply click through this link from your web page. Our crawlers will verify your link, extract the title of your web page and instantly add a link back to it. If you like you can remove the words Totally Explained and embed the link in article text.
As long as your link remains in place, we'll keep our link to you right here. Please play fair - our crawlers are watching. Your site must be closely related to this one's topic. Any kind of spamming, dubious practises or removing the link will result in your link from us being dropped and, potentially, your whole site being banned. |
