Gabriel Lippmann

French physicist Gabriel Lippmann (1845–1921) is the inventor of an early process that yielded the first permanent color photograph. Though his system was too unwieldy to be used commercially at the time, Lippmann was awarded the 1908 Nobel Prize in physics for his achievement. "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," noted a World of Physics essay on his career.

Born on August 16, 1845, Lippmann was a native of Hollerich, Luxemburg, where his French parents were living at the time. His early education came at home, but when he was 13 years old the family moved to Paris, France, and he enrolled at the Lycée Napoléon. He later studied at Paris's École Normale, where he proved a brilliant student. He eventually found work with theAnnales de Chimie et de Physique, summarizing German scientific articles for French publication. He was fascinated by the reports coming in about discoveries in electricity from France's neighbor to the east. In 1873, he took part in a scientific mission to Heidelberg, Germany, and took a post there in the laboratory of physicist Gustav Kirchhoff.

Patented Several Inventions

Lippmann found another mentor in Heidelberg in Wilhelm Kühne, a professor of physiology. Kühne demonstrated to Lippmann an experiment using a drop of mercury, which had been covered with diluted sulfuric acid. The mercury behaved oddly when touched with a piece of iron wire, balling up but then recovering its original shape when the wire was taken away. Lippmann devised a theory for this phenomenon, surmising that the wire had altered an electrical current between the acid and the mercury, which caused it to contract. He was granted permission to conduct experiments in Kirchhoff's laboratory on this, and his ideas were published in 1873.

From those experiments Lippmann went on to devise his first invention of significance, an early voltometer called the capillary electrometer. Its narrow tube, or "capillary," was placed at a horizontal angle, and held mercury covered with diluted acid. The change in the electric charge between the two liquids caused a shudder at the point where they met, and moved up the tube. This capillary electrometer was the first highly sensitive voltometer, able to measure electrical currents as small as 1/1,000 of a volt, and was widely used in the era before solid–state electronics.

Thanks in part to this invention, Lippmann was granted his doctorate by the Sorbonne, the University of Paris, in 1875. A year later, he published another paper that showed how it was possible to reverse the electromagnetic phenomenon. This could be done, he demonstrated, by altering the shape of the mercury by mechanical means; if it was squeezed together, it impacted the electrical field between the mercury and the acid. In order to demonstrate this phenomenon, he devised an engine that worked on the same principles of the capillary electrometer. The engine would turn when electrified and produced electricity when turned mechanically. "Lippmann built upon the earlier work of French engineer Nicolas–Léonard–Sadi Carnot," explained the World of Physics contributor. "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."

Enjoyed Long and Esteemed Career

In 1883, Lippmann became a professor of mathematical physics at Paris's Faculty of Sciences laboratory. He was named professor of experimental physics there three years later, and eventually served as laboratory director and oversaw its administrative incorporation into the Sorbonne. His other contributions to physics were many: he devised a method of taking high–speed photographic images to record the behavior of pendulums, and also worked on several instruments that came into use in the sciences of astronomy and seismology. One of these was the coelostat, the successor to siderostat. This particular device was a mirror attached to a machine, which reproduced the axis and rotation of the Earth. This enabled scientists to photograph large regions of the sky, not just a single star, without any motion of the Earth interfering with the picture. Lippmann's offshoot of his coelostat was the uranograph, which made a photographic map of the sky with longitudes automatically imprinted on it. He also found ways to measure longitudinal differences between observatories through radio and photography. In seismology, he found a way to use telegraphic signals to allow for the early detection of earthquakes and how fast they traveled.

Despite this impressive list of achievements in science, it was for the first permanent color photographic process that Lippmann would be awarded the 1908 Nobel Prize in physics. Back in the early 1800s, scientists discovered that moist silver chloride could reproduce the colors of the spectrum. In 1848, Edmond Becquerel became the first to reproduce colored objects on a silver plate covered with a layer of silver chloride, but the colors faded on the plate over time. In 1890, Otto Weiner confirmed that Becquerel's achievement came from "interference" light waves that had been trapped at different levels in the layer of silver chloride, which was related to the phenomenon of seeing rainbow colors in soap bubbles, or in an oil patch on a road.

A year later, in 1891, Lippmann published findings that described a new method for color photography, using a transparent plate with a layer of silver nitrate, gelatin, and potassium bromide in an emulsion. The plate was then placed, emulsion–side–down, in a holder in a camera. "When the incoming light struck the light reflected from the mercury, stationary light patterns were produced that left their impression in the emulsion," explained the World of Invention. "This impression reproduced the natural colors of" what had been photographed by the camera. Though the colors reproduced were permanent, Lippmann's was an impractical method. It was not possible to make multiple copies, for example, and the lengthy exposure time—from three hours but eventually reduced to just a minute—still made it unfeasible for mass production.

Little is known about Lippmann's life outside of the laboratory. He married a woman named Cherbuliez in 1888, but they had no children. Author of two books, Cours de thermodynamique in 1886 and Cours d'acoustique et d'optique in 1888, he was a member of the French Academy of Sciences, the Bureau des Longitudes, and a foreign member of the Royal Society of London. He died at sea on July 13, 1921, aboard the liner La France, on the return journey from a French scientific mission to Canada.

Books

World of Invention, 2nd edition Gale Group, 1999.

World of Physics, 2 volumes Gale Group, 2001.

Periodicals

Times (London, England), July 15, 1921.

Lippmann, Gabriel Jonas

(b. Hollerich, Luxembourg, 16 August 1845;d. at sea 12 July 1921),

physics, instrumental astronomy.

Lippmann’s parents were French and settled in Paris while he was still a boy. There he attended first the Lycée Napoléon and later the École Normale Supérieure. In the early stages of his career he collaborated with Bertin in the publication of Annales de chimie et de physique by abstracting German papers. This work led him to develop an interest in contemporary research in electricity. While on a scientific mission to Germany he was shown by Wilhelm Kühne, professor of physiology at Heidelberg, an experiment in which a drop of mercury, covered by dilute sulfuric acid, contracts on being touched with an iron wire and regains its original shape when the wire is removed. Lippmann realized that there was a connection between electrical polarization and surface tension and obtained permission to conduct a systematic investigation of this phenomenon in Kirchhoff’s laboratory.

These experiments resulted in the development of the capillary electrometer, a device sensitive to changes in potential of the order of 1/1,000 of a volt. The instrument consists essentially of a capillary tube, which is inclined at a few degrees from the horizontal, containing an interface between mercury and dilute acid. If the potential difference between the two liquids is varied, the effective surface tension at the meniscus is altered and, as a result, the meniscus moves along the capillary tube. Although the device could be calibrated, it was more usually employed in potentiometer and bridge measurements as a null instrument. It possessed the advantage, significant at the time, of being independent of magnetic and electric fields. Lippmann’s researches on electrocapillarity received recognition in the form of a doctorate awarded by the Sorbonne in 1875. In a paper published in 1876, Lippmann investigated the application of thermodynamic principles to electrical systems.

In 1883 Lippmann was appointed professor of mathematical physics at the Faculty of Sciences in Paris. In 1886 he succeeded Jules Jamin as professor of experimental physics and later became director of the research laboratory, which was subsequently transferred to the Sorbonne. He retained this position until his death.

Lippmann made numerous contributions to instrumental design, particularly in connection with astronomy and seismology. His most notable contribution was the invention of the coelostat. In this instrument the light from a portion of the sky is reflected by a mirror which rotates around an axis parallel to its plane once every forty-eight sidereal hours.This axis is arranged parallel to the axis of the earth. The light from the mirror enters a telescope fixed to the earth. The arrangement ensures that a region of the sky, and not merely one particular star, may be photographed without apparent movement. In this respect it represented an improvement on the siderostat. Lippmann later put forward a suggestion for the accurate adjustment of a telescope directed at its zenith by reflecting light from a pool of mercury.

Lippmann also devised a number of improvements on observational technique by the introduction of photographic or electrical methods of measurement. These include a method for the measurement of the difference in longitude between two observatories by means of radio waves and photography and an improvement on the method of coincidences for measuring the difference between the periods of two pendulums. The pendulum measurements involve the use of a high-speed flash photograph to determine the change in phase over a short interval of time. Lippmann later investigated the problem of maintaining a pendulum in continuous oscillation. He showed that the period will be unaffected if the maintaining impulse is applied at the instant the pendulum swings through the point of zero displacement. The necessary impulse could, he suggested, be obtained by alternately charging and discharging a capacitor through coils mounted on either side of the pendulum. This arrangement ensures that the impulse is of short duration and is independent of wear on the pendulum contacts.

Lippmann’s contributions to seismology include a suggestion for the use of telegraph signals to give early warning of earth tremors and for the measurement of their velocity of propagation. He also proposed a new form of seismograph intended to give directly the acceleration of the earth’s movement.

In 1908 Lippmann was awarded the Nobel Prize in Physics “for his method, based on the interference phenomenon, for reproducing colours photographically.” In the same year he was elected a fellow of the Royal Society of London. In Lippmann’s color process the sensitive emulsion, which is relatively thick, is backed by a reflecting surface of mercury. As a result the incident light is reflected back toward the source, and the incident and reflected beams combine to produce stationary waves. After development the film is found to contain reflecting planes of silver separated by distances of half a wavelength. When the film is viewed by reflected light, the color corresponding to the original beam is strongly reinforced by reflection by from successive planes.

BIBLIOGRAPHY

I. Original Works. Lippmann’s writings are “Relation entre les phénomènes électriques et capillaries,” in Comptes rendus … de l’Académie des sciences,76 (1873), 1407; “Sur une propriété d’une surface d’eau électrisée,” ibid.,81 (1875), 280—see also ibid.,85 (1877), 142; “Extension du principe de Carnot à la théorie des phénomènes électriques,” ibid.,82 (1876), 1425; “Photographies colorées due specture, sur albumine et sur gélatine bichromatées,” ibid.,115 (1894), 92; “Sur la théorie de la photographic des couleurs simples et composées par la méthode interférentielle,” ibid.,118 (1894), 92;” Sur un coelostat,” ibid., 120 (1895), 1015; “Sur l’entertien du mouvement du pendule sans perturbations,” ibid., 122 (1896), 104; “Méthodes pour comparer, à l’aide de l’étincelle électrique, les durées d’oscillation de deux pendules réglés sensiblement à la même période,” ibid., 124 (1897), 125; “Sur l’emploi d’un fil télégraphique pour l’inscription des tremblements de terre et la measure de leur vitesse de propagation,” ibid., 136 (1903), 203; “Appareil pour enregistrer l’accélération absolue des mouvements séismiques,” ibid.,148 (1909), 138; “Sur une méthode photographique direct pour la détermination des différences des longitudes,” ibid., 158 (1914), 909; and “Méthode pour le réglage d’une lunette en eollimation,” ibid., 88.

II. Secondary Literature. Obituary notices are in Annales de physique,16 (1921), 156; and Proceedings of the Royal Society, ser. A, 101 (1922). See also H. H. Turner, “Some Notes on the Use and Adjustment of the Coelostat,” in Monthly Notices of the Royal Astronomical Society,56 (1896), 408.

I. B. Hopley

LIPPMANN, GABRIEL

LIPPMANN, GABRIEL (1845–1921), French physicist and Nobel Prize winner. Though born in Luxembourg, Lippmann spent most of his life in Paris. His association with the Annalesde chimie et de physique, for which he prepared summaries of the articles written in German, enabled him to keep abreast of innovations in electricity. After working in Heidelberg and under the brilliant H.L.F. von Helmholtz in Berlin, Lippmann was appointed professor of probability and mathematical physics at the Sorbonne (1883–86). From 1886 he was professor of experimental science and director of the Sorbonne's research laboratories, a position which he held until his death. Lippmann was responsible for much basic work in classical physics. His early research at Heidelberg was concerned with the effects of electrical charges on surface tension leading to the development of the "capillary-electrometer." In 1879 he presented before the Académie des Sciences, to which he was elected seven years later, his work dealing with the effective mass of a charged body, in which he claimed that the moment of inertia in a charged body was higher than that of an un-charged body. This conclusion is of fundamental importance in the study of the electron. He also devised various scientific instruments: in astronomy his outstanding contributions were the development of the coelostat, an instrument for obtaining a stationary image of the sky, and the uranograph, an instrument for obtaining a map of the sky with lines of longitude at equal time-intervals. He achieved fame in 1891 through his production of color photographs based on the phenomenon of interference, although the three-color system proposed by J.C. Maxwell was preferred. Lippmann was nevertheless awarded the Nobel Prize for physics for the results of this research. His most important works were his Cours de thermodynamique (1886) and Cours d'acoustique et d'optique (1888). Lippmann was elected president of the Académie des Sciences in 1912.

bibliography:

E. Lebon, Savants du jour: Gabriel Lippmann (1911), incl. bibl.; T. Levitan, Laureates: Jewish Winners of the Nobel Prize (1960), 56–58; N.H. de V. Heathcote, Nobel Prize Winners in Physics, 1901–50 (1953), 65–69.

[Ariel Cohen]