Gabriel Lippmann | Biography

Gabriel Lippmann had a distinguished career as an inventor, theoretician and academic. At the Faculty of Sciences, a laboratory in Paris, France, he became professor of mathematical physics in 1883, a professor of experimental physics in 1886, and, later, director of the laboratory. He stayed active in this position, overseeing the laboratory's incorporation into the Sorbonne, until he died at sea on July 13, 1921. A member of the French Academy of Sciences and the Bureau des Longitudes, he was elected in 1908 as a Foreign Member of the Royal Society of London. Even before he had finished his doctorate in 1875, he embarked on a lifetime of publishing papers and the creation of measuring instruments to accompany research and observation in physics, astronomy, and seismology. Lippmann is most often remembered, however, for developing an early process of color photography . It was for this achievement that he received the 1908 Nobel Prize for physics.

Born in Hollerich, Luxemburg, on August 16, 1845, to French parents, Gabriel Jonas Lippmann began his education at home. When he was 13, his family settled in Paris, where he entered the Lycée Napoléon. After 10 years he attended the (cole Normale. During this time, he assisted with the publication of the Annales de Chimie et de Physique by summarizing German articles. In this manner he learned of recent discoveries in electricity. In 1873 he traveled, as part of a scientific mission, to Germany, where, at Heidelberg, he worked in physicist Gustav Kirchhoff's laboratory. There, Wilhelm Kühne, a professor of physiology, showed him an experiment in which a drop of mercury, covered with diluted sulfuric acid, contracted when touched with a piece of iron wire--only to recover its original shape when the wire was removed. Lippmann theorized that the wire had somehow changed the tiny electrical current between the acid and the mercury, causing it to ball up. He obtained permission to systemically confirm his supposition with experiments in Kirchhoff's laboratory.

Creates the Capillary Electrometer and Pursues Its Theoretical Implications

Lippmann's investigations resulted in an 1873 publication that theoretically described the mercury phenomenon that Kühne had shown him as well as the device he developed from it, the capillary electrometer. This instrument, which came into wide use before the advent of solid-state electronics, could measure electrical currents as small as 1/1,000 of a volt. Its elegant design consisted of a narrow tube (or capillary), pitched at a slight horizontal angle, containing mercury covered with diluted acid. Any change in the electric charge between the two liquids caused a ripple at their interface to move up the tube. As a result of Lippmann's work on the capillary electrometer, the Sorbonne awarded him a doctorate in 1875.

In 1876 Lippmann published a paper showing that it was possible to reverse the electromagnetic phenomenon he had investigated in 1873. Returning to the experiment of mercury covered with acid, he demonstrated that altering the shape of the mercury by mechanical means, somehow squeezing it together, had an impact on the electrical field between the mercury and the acid. To demonstrate definitively the reversibility of the two processes, Lippmann devised an engine based on the principles of his capillary electrometer. This engine turned when electrified and produced electricity when turned mechanically. Lippmann built upon the earlier work of French engineer N(colas-L(onard-Sadi Carnot. In 1824 Carnot demonstrated, with a reversible heat engine, the thermodynamic principle that there exists an inverse (or opposing) and measurable relationship between heat and force. Following this reasoning, Lippmann established a more general theorem that he published in 1881. It states that given any phenomenon, the reverse phenomenon also exists and that one can calculate its degree of change.

Advances Observational Methods in Astronomy and Seismology

Lippmann made important innovations in observation for physics, such as introducing high-speed photographs to record the behavior of pendulums. Not content to confine his efforts to one field, he also modernized observational instruments in astronomy and seismology. His most notable upgrade was a device called the coelostat. Using a mirror attached to a machine that reproduced the axis and rotation of Earth, the coelostat ensured that whole regions of the sky, rather than a single star, could be photographed without registering any motion. By increasing the area to be recorded, it improved on an earlier device, the siderostat. Lippmann created another instrument related to the coelostat, called the uranograph. This device produced a photographic map of the sky with its longitudes automatically imprinted on it. Lippmann also devised a method for measuring longitudinal differences between observatories through radio and photography. In his contributions to the field of seismology, Lippmann proposed using telegraphic signals for the early detection of earthquakes as well as for measuring how quickly they traveled. In addition, he suggested a seismograph that would record seismic waves while taking into account Earth's acceleration.

Wins 1908 Nobel Prize in Physics for Color Photography

The achievement that won Lippmann his widest recognition, and the 1908 Nobel Prize in physics, was his perfection of a photographic process with relatively permanent color. As early as the beginning of the nineteenth century, it was widely known that moist silver chloride could reproduce the colors of the spectrum. In 1848, Edmond Becquerel managed to reproduce colored objects on a silver plate covered with a layer of silver chloride. Unfortunately, Becquerel had no way of fixing the colors, which faded rapidly. In 1890, Otto Weiner confirmed, through an experiment, that Becquerel's phenomenon was the result of "interference" light waves trapped at different levels in the layer of silver chloride.

In 1891 Lippmann published a method where a transparent plate with a layer of silver nitrate, gelatin, and potassium bromide in emulsion was placed, emulsion-side-down, in a holder with mercury in it. During exposure, which in the initial experiments lasted 15 minutes, light waves became fixed in the emulsion after repeatedly bouncing off the mercury, faithfully reproducing the colors in nature. After the plate was developed, the colors, seen in reflected light, were permanent. Although it presented a significant leap forward at the time, Lippmann's method proved impractical. There was no way to create copies and the exposure time, although later reduced to a minute, was still too long to suit the needs of mass production.

Lippmann married Mademoiselle Cherbuliez in 1888, their union producing no children. There is little public information regarding his personal life. What he is known for is his body of work, which is considered ingenious and progressive. Rather than the antiquated photographic process for which he received the Nobel Prize, however, many scientists believe Lippmann's real contributions to science lay in his work with the capillary electrometer and his theoretical papers.