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Land, Edwin Herbert

light crystals polarized honorary

(1909–91) US inventor: invented Polaroid® and a fast photographic process.

To obtain polarized light (ie light in which the electromagnetic vibrations are all in one plane) the early method was the use of a prism. Later it was realized that passing light through some organic crystals gave polarized light (ie the crystals are dichroic) but the crystals could not be grown to large size. While Land was a Harvard student, he realized that very small crystals would serve the purpose if they were all aligned together and not randomly orientated; and he found a way of doing this, with the aligned crystals (of quinine iodosulphate) embedded in a clear plastic sheet of any required size. The result was given the trade name Polaroid®, and it is widely used in scientific instruments requiring polarized light and in sunglasses, where it is useful because reflected sunlight is partly polarized. Land abandoned his degree course to develop his inventions; the best-known is an ingenious camera in which a multi-layered film is used with developing chemicals included, which are released to process the film in seconds and give an acceptable colour print. He never graduated in the usual sense but Harvard awarded him an honorary doctorate in 1957 to add to his exceptionally large collection of honorary degrees.

Landau, Lev Davidovitch [next] [back] Land, Edwin - Overview, Personal Life, Career Details, Chronology: Edwin Land, Social and Economic Impact

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