Lippmann, Gabriel

▪ French physicist

born Aug. 16, 1845, Hollerich, Luxembourg

died July 13, 1921, at sea, en route from Canada to France

 French physicist who received the Nobel Prize for Physics in 1908 for producing the first colour photographic plate. He was known for the innovations that resulted from his search for a direct colour-sensitive medium in photography.

      Though born of French parents in Luxembourg, Lippmann grew up in Paris and was a bright but unruly student. Despite the fact that he never received his teacher's certificate, he was appointed professor of mathematical physics at the Sorbonne in 1883. He later was appointed head of the Sorbonne's Laboratories of Physical Research (1886).

      Lippmann's scientific talents were varied, but he was best known for his contributions in the fields of optics and electricity. He did early, important studies of piezoelectricity (precursors of Pierre Curie's work) and of induction in resistanceless, or superconductive, circuits (precursors of Heike Kammerlingh-Onnes' validations). He also invented the coleostat, an instrument that allowed for long-exposure photographs of the sky by compensating for the Earth's motion during the exposure.

      In 1891 Lippmann revealed a revolutionary colour-photography process, later called the Lippmann process, that utilized the natural colours of light wavelengths instead of using dyes and pigments. He placed a reflecting coat of mercury behind the emulsion of a panchromatic plate. The mercury reflected light rays back through the emulsion to interfere with the incident rays, forming a latent image that varied in depth according to each ray's colour. The development process then reproduced this image, and the result, when viewed, was brilliantly accurate. This direct method of colour photography was slow and tedious because of necessarily long exposure times, and no copies of the original could be made. It never achieved popularity, therefore, but it was an important step in the development of colour photography.

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