![]() ![]() Millikan went on to win the 1923 Nobel Prize for Physics, in part for this work, and Fletcher kept the agreement a secret until his death. Professor Millikan took sole credit, in return for Harvey Fletcher claiming full authorship on a related result for his dissertation. Millikan and his then graduate student Harvey Fletcher used the oil-drop experiment to measure the charge of the electron (as well as the electron mass, and Avogadro's number, since their relation to the electron charge was known). Therefore, if one of these two values were to be discovered, the other could easily be calculated. However, the actual charge and mass values were unknown. Thomson had already discovered the charge-to-mass ratio of the electron. Starting in 1908, while a professor at the University of Chicago, Millikan worked on an oil-drop experiment in which he measured the charge on a single electron. Millikan receives a check for over $40,000 for winning the Nobel Prize He also served on the board of trustees for Science Service, now known as Society for Science & the Public, from 1921 to 1953. Millikan proved that this radiation is indeed of extraterrestrial origin, and he named it " cosmic rays." As chairman of the Executive Council of Caltech (the school's governing body at the time) from 1921 until his retirement in 1945, Millikan helped to turn the school into one of the leading research institutions in the United States. There he undertook a major study of the radiation that the physicist Victor Hess had detected coming from outer space. In 1921 Millikan left the University of Chicago to become director of the Norman Bridge Laboratory of Physics at the California Institute of Technology (Caltech) in Pasadena, California. He used this same research to obtain an accurate value of Planck’s constant. In 1914 Millikan took up with similar skill the experimental verification of the equation introduced by Albert Einstein in 1905 to describe the photoelectric effect. He obtained more precise results in 1910 with his famous oil-drop experiment in which he replaced water (which tended to evaporate too quickly) with oil. The results suggested that the charge on the droplets is a multiple of the elementary electric charge, but the experiment was not accurate enough to be convincing. He began by measuring the course of charged water droplets in an electric field. ![]() In 1909 Millikan began a series of experiments to determine the electric charge carried by a single electron. In 1896 he became an assistant at the University of Chicago, where he became a full professor in 1910. Millikan graduated from Oberlin College in 1891 and obtained his doctorate at Columbia University in 1895. Robert Andrews Millikan (Ma– December 19, 1953) was an American experimental physicist honored with the Nobel Prize for Physics in 1923 for the measurement of the elementary electric charge and for his work on the photoelectric effect.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |