Abstract
THE Royal Swedish Academy of Sciences, Stockholm, has awarded the Nobel prize for physics for 1923 to Dr. R. A. Millikan, director of the Norman Bridge Laboratory of Physics at the California Institute of Technology, Pasadena, and the Nobel prize for chemistry for 1923 to Prof. F. Pregl, professor of applied medical chemistry in the medical faculty of theKarl Franzens University, Graz, Austria. Dr. Millikan is best known for his work on the determination of the absolute value of the charge of the electron. Before his experiments various measures had been made of this, by condensing a cloud on free electrons in a gas and observing how the cloud behaved. Millikan found that it was possible to watch the single drops, and thus discovered many inaccuracies to which the earlier work was subject, and this enabled him to modify it into a method of precision. In his final arrangement, a small drop of oil or mercury was watched in a microscope as it slowly fell under gravity or, acquiring a charge, rose in an electric field. In this way he could observe directly the atomic nature, of electricity; for if the speed of the drop ever changed it would always change by a discrete amount In the course of these experiments he worked out the problem of the motion of a sphere in a viscous fluid, and found under what conditions Stokes's law is verified; more recently he has made his work throw light on the nature of the collision of a gas molecule with a solid or liquid surface. It is a fairly safe prediction that it will be long before methods are devised which will give more accurate values than Millikan's for the electronic charge and the associated constants. Only second in importance is his very accurate determination of the quantum by means of the photoelectric effect. His work not only completely verified the Einstein theory, but also showed that the “limiting potential” of that theory is identical with the ordinary contact potential. Since then Dr. Millikan has added a great deal to our knowledge of the spectrum in the region of very short waves.
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Current Topics and Events. Nature 112, 767–769 (1923). https://doi.org/10.1038/112767a0
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DOI: https://doi.org/10.1038/112767a0