Hippolyte Fizeau
Encyclopedia
Armand Hippolyte Louis Fizeau (September 23, 1819 – September 18, 1896) was a French
physicist
.
. His earliest work was concerned with improvements in photographic processes. Following suggestions by François Arago
, Léon Foucault
and Fizeau collaborated in a series of investigations on the interference of light and heat. In 1848, he predicted the redshift
ing of electromagnetic waves.
In 1849 he published the first results obtained by his method for determining the speed of light
(see Fizeau-Foucault apparatus
). Fizeau in 1864 made the first suggestion that the "length of a light wave be used as a length standard".
He was involved in the discovery of the Doppler effect
.
In 1853 he described the use of the capacitor
(then called the condenser) as a means to increase the efficiency of the induction coil
. Subsequently he studied the thermal expansion
of solid
s, and applied the phenomenon of interference of light to the measurement of the dilatations of crystal
s. He became a member of the Académie des Sciences in 1860 and of the Bureau des Longitudes
in 1878. He died at Venteuil
on September 18, 1896.
His name is one of the 72 names inscribed on the Eiffel Tower.
French people
The French are a nation that share a common French culture and speak the French language as a mother tongue. Historically, the French population are descended from peoples of Celtic, Latin and Germanic origin, and are today a mixture of several ethnic groups...
physicist
Physicist
A physicist is a scientist who studies or practices physics. Physicists study a wide range of physical phenomena in many branches of physics spanning all length scales: from sub-atomic particles of which all ordinary matter is made to the behavior of the material Universe as a whole...
.
Biography
Fizeau was born in ParisParis
Paris is the capital and largest city in France, situated on the river Seine, in northern France, at the heart of the Île-de-France region...
. His earliest work was concerned with improvements in photographic processes. Following suggestions by François Arago
François Arago
François Jean Dominique Arago , known simply as François Arago , was a French mathematician, physicist, astronomer and politician.-Early life and work:...
, Léon Foucault
Léon Foucault
Jean Bernard Léon Foucault was a French physicist best known for the invention of the Foucault pendulum, a device demonstrating the effect of the Earth's rotation...
and Fizeau collaborated in a series of investigations on the interference of light and heat. In 1848, he predicted the redshift
Redshift
In physics , redshift happens when light seen coming from an object is proportionally increased in wavelength, or shifted to the red end of the spectrum...
ing of electromagnetic waves.
In 1849 he published the first results obtained by his method for determining the speed of light
Speed of light
The speed of light in vacuum, usually denoted by c, is a physical constant important in many areas of physics. Its value is 299,792,458 metres per second, a figure that is exact since the length of the metre is defined from this constant and the international standard for time...
(see Fizeau-Foucault apparatus
Fizeau-Foucault apparatus
The Fizeau–Foucault apparatus was designed by the French physicists Hippolyte Fizeau and Léon Foucault for measuring the speed of light. The apparatus involves light reflecting off a rotating mirror, toward a stationary mirror some 20 miles away...
). Fizeau in 1864 made the first suggestion that the "length of a light wave be used as a length standard".
He was involved in the discovery of the Doppler effect
Doppler effect
The Doppler effect , named after Austrian physicist Christian Doppler who proposed it in 1842 in Prague, is the change in frequency of a wave for an observer moving relative to the source of the wave. It is commonly heard when a vehicle sounding a siren or horn approaches, passes, and recedes from...
.
In 1853 he described the use of the capacitor
Capacitor
A capacitor is a passive two-terminal electrical component used to store energy in an electric field. The forms of practical capacitors vary widely, but all contain at least two electrical conductors separated by a dielectric ; for example, one common construction consists of metal foils separated...
(then called the condenser) as a means to increase the efficiency of the induction coil
Induction coil
An induction coil or "spark coil" is a type of disruptive discharge coil. It is a type of electrical transformer used to produce high-voltage pulses from a low-voltage direct current supply...
. Subsequently he studied the thermal expansion
Thermal expansion
Thermal expansion is the tendency of matter to change in volume in response to a change in temperature.When a substance is heated, its particles begin moving more and thus usually maintain a greater average separation. Materials which contract with increasing temperature are rare; this effect is...
of solid
Solid
Solid is one of the three classical states of matter . It is characterized by structural rigidity and resistance to changes of shape or volume. Unlike a liquid, a solid object does not flow to take on the shape of its container, nor does it expand to fill the entire volume available to it like a...
s, and applied the phenomenon of interference of light to the measurement of the dilatations of crystal
Crystal
A crystal or crystalline solid is a solid material whose constituent atoms, molecules, or ions are arranged in an orderly repeating pattern extending in all three spatial dimensions. The scientific study of crystals and crystal formation is known as crystallography...
s. He became a member of the Académie des Sciences in 1860 and of the Bureau des Longitudes
Bureau des Longitudes
The Bureau des Longitudes is a French scientific institution, founded by decree of 25 June 1795 and charged with the improvement of nautical navigation, standardisation of time-keeping, geodesy and astronomical observation. During the 19th century, it was responsible for synchronizing clocks...
in 1878. He died at Venteuil
Venteuil
Venteuil ) is a commune in the Marne department in north-eastern France....
on September 18, 1896.
His name is one of the 72 names inscribed on the Eiffel Tower.
See also
- Fizeau-Foucault apparatusFizeau-Foucault apparatusThe Fizeau–Foucault apparatus was designed by the French physicists Hippolyte Fizeau and Léon Foucault for measuring the speed of light. The apparatus involves light reflecting off a rotating mirror, toward a stationary mirror some 20 miles away...
- Fizeau experimentFizeau experimentThe Fizeau experiment was carried out by Hippolyte Fizeau in 1851 to measure the relative speeds of light in moving water. Albert Einstein later pointed out the importance of the experiment for special relativity...
- Fizeau interferometerFizeau interferometerA Fizeau interferometer is similar to a Fabry–Pérot interferometer in that they both consist of two reflecting surfaces. In a Fizeau interferometer, however, the two surfaces are usually much less than totally reflecting , so that secondary reflections don't contribute greatly to the fringe...
- Léon FoucaultLéon FoucaultJean Bernard Léon Foucault was a French physicist best known for the invention of the Foucault pendulum, a device demonstrating the effect of the Earth's rotation...