Gabriel Lippmann

Jonas Ferdinand Gabriel Lippmann (16 August 1845 - 13 July 1921) was a Franco-Luxembourgish physicist and inventor. He won the Nobel Prize in Physics for his work on colour photography.
Early life and education
Gabriel Lippmann was born in Bonnevoie, Luxembourg (Luxembourgish: Bouneweg), on 16 August 1845. At that time, Bonnevoie was part of the commune of Hollerich. Bonnevoie is now a district of Luxembourg City.) His father, Isaie was a French Jew. He managed the family glove-making business. In 1848, the family moved to Paris. At first, Lippmann was tutored by his mother, Miriam Rose (Levy). He later studied at the Lycee Napoleon (now Lycee Henri-IV). In school, Lippmann did not do well at paying attention. He did have a special interest in mathematics. In 1868, he was admitted to the Ecole normale superieure in Paris, In 1872, the French government sent him to Heidelberg University. He was able to specialize in electricity Lippmann receiving a doctorate with "summa cum laude" distinction in 1874. Lippmann then returned to Paris in 1875. he continued to study until 1878. He then became professor of physics at the Sorbonne.
Career
Lippmann made important contributions to different areas of physics.
The capillary electrometer
One of Lippmann's early discoveries was the relationship between electrical and capillary phenomena. This let him create a sensitive capillary electrometer. It became known as the Lippmann electrometer. This device was used in the first ECG machine.
Piezoelectricity
In 1881, Lippmann predicted the converse piezoelectric effect.
Colour photography
Lippmann is remembered as the inventor of a way to reproducing colours by photography. It is based on the interference phenomenon. This work earned him the Nobel Prize in Physics for 1908.
In 1886, Lippmann's interest turned to a method of creating the colours of the solar spectrum on a photographic plate. On 2 February 1891, he told the Academy of Sciences: "I have succeeded in obtaining the image of the spectrum with its colours on a photographic plate whereby the image remains fixed and can remain in daylight without deterioration." By April 1892, he said that he had succeeded in creating colour images of a stained glass window, a group of flags, a bowl of oranges topped by a red poppy and a colourful parrot.
The interference phenomenon in optics is a result of the wave propagation of light. When light of a given wavelength is reflected at itself by a mirror, standing waves are created. This is similar to the ripples that are caused when a stone is dropped into water. A standing waves is created when the waves are reflected back at themselves by a surface such as the wall of a pool. In the case of normal incoherent light, the standing waves can only be seen in an extremely small area of space next to the reflecting surface.
Lippmann projected an image onto a special photographic plate. The plate was able to record details smaller than the wavelengths of visible light. The light passed through a glass sheet into a very thin and almost transparent photographic emulsion. The emulsion containing extremely small silver halide grains. A temporary mirror of liquid mercury reflected the light back through the emulsion/ This created standing waves. The nodes almost no effect but their antinodes created an image. After development, the result was distinct parallel layers made up of submicroscopic metallic silver grains. These layers were a permanent record of the standing waves. In each part of the image, the spacing of the layers corresponded to the half-wavelengths of the light photographed.
Light was shone on the finished plate at a nearly perpendicular angle. Daylight or another source of white light was used. At each point on the plate, light of the same wavelength as the light which had created the layers was reflected back toward the viewer. Light of other wavelengths passed through the emulsion. The wavelengths (colours) of the light which had formed the original image created a full-colour image.
In practice, the Lippmann process was not easy to use. Higher resolution needed smaller grains. Smaller grains were less affected by light so they needed to be exposed to the light for a longer amount of time. With a lens with a large opening and a very brightly sunlit subject, a camera exposure of less than one minute were rare. Exposures measured in minutes were normal. Pure colours photographed well, but the colors of real-world objects could be a problem to photograph. The process could not make colour prints on paper. It was not possible to make a good copy of a Lippmann colour photograph by rephotographing it. The requirements needed to see the colours to best effect meant the photographs could not be used for casual use.
The coelostat
Lippmann also invented the coelostat. It is a tool used in astronem that compensated for the rotation of the Earth. This lets people photograph areas of the sky without apparent movement.
Personal life
Lippmann married the daughter of the writer Victor Cherbuliez in 1888. He died on 13 July 1921 aboard the steamer France after leaving Canada.