Robert Andrews Millikan
Robert Andrews Millikan ( born March 22, 1868 in Morrison, Illinois, USA, † December 19, 1953 in San Marino in Pasadena, California, USA ) was an American physicist.
Millikan was awarded the 1923 Nobel Prize in Physics for his famous oil drop experiments ( Millikan experiment ), with whom he identified the elementary charge of an electron, as well as for his contribution to the study of the photoelectric effect.
Biography
Robert Andrews Millikan was born in 1868 as the son of a clergyman. After working briefly as a court stenographer, he began in 1886 at Oberlin College ( Ohio) to study. At first, he studied mathematics and Greek, after he completed a multi-week physics course and worked for his final exams as a physics teacher. In 1895 he received his doctorate from Columbia University with a dissertation on the polarization of light emanating from incandescent solid and liquid surfaces. He then went on the advice of his doctor father for a year to Germany, where he deepened his knowledge at the universities of Berlin and Göttingen in future Nobel laureates Max Planck and Walther Nernst. In 1896 he returned to the U.S., where he became an assistant to Albert Michelson and 1910 Professor of Physics at the University of Chicago. Here he examined the radioactivity of uranium and the electrical discharges in gases.
In 1902 he married Greta Blanchard. With her he had three sons Clark, Glenn and Max, who also respected academics were later.
1909 Millikan began a research program to determine the electrical charge of electrons. At first he used for his experiments, the then usual droplet method, later, the oil droplet method, which was more suitable for the determination of the elementary charge, because the oil droplets proved compared to the water droplets as more stable. In these measurements, he was able to determine the smallest unit of electric charge, which was described by Millikan with "e". In 1910 he published his first work on 38 charge measurements on single droplets, which aroused great interest, but also criticism. To rebut these objections, three years later published a second work for the experimental determination of the elementary electric charge e, the results, however, were again questioned ( see below). In 1913, he became the first winner of the Comstock Prize in Physics.
During the First World War Millikan was active in the planning and organization of the National Research Council.
In his 1918 published book " The electron" Millikan claimed that his measurements more precise than those of the competition were, since the values interspersed with very little. This work became the basis of his later fame and award the Nobel Prize in 1923.
From 1921 he was chairman ( chief administrator ) on the Board of the California Institute of Technology ( to 1946 ) and Director of the Norman Bridge Laboratory of Physics, Pasadena ( California). Here began extensive work on cosmic rays, which were continued by Millikan's pupil Carl David Anderson with great success under his leadership. In 1922 he was awarded the American Institute of Electrical Engineers ( AIEE ), the Edison Medal.
Until he went into retirement in 1946, he took on various positions at other universities. He wrote numerous books in which he dealt among other things with religion and science, as well as several textbooks.
Criticism of Millikan's performance
1978 noted historian of science Gerald Holton, that Millikan had fined the results of his experiments to determine the elementary charge of the electron. He had not, as emphasized in his work of 1913, 28 consecutive measurements published, but under all measurement data selected those that met his expectations, while the others were not mentioned. He could by this procedure the allegations of his fiercest critic, the Austrian physicist Felix Ehrenhaft, who carried out similar measurements, but very strongly scattering values received refute. All attempts Ehrenhaft to repeat the actions taken by Millikan precise measurements were unsuccessful, which led to the Honorable turned away from this area of research.
In addition, the Israeli historian of science Alexander Kohn argued in the 1980s that Millikan's groundbreaking idea of using the oil droplets in its measurements, in reality by a student named Harvey Fletcher came, who is not mentioned as co-author in the 1913 published work Millikan and therefore also in the award of the Nobel Prize was not considered. However, Millikan made sure that Fletcher was a PhD with him. Moreover, it was customary that only high-level scientists honors were bestowed, while their employees usually remained unmentioned.
Although this approach Millikan leaves a certain connotation, but you have to hold that he was undoubtedly one of the greatest physicists of the first half of the 20th century. His work on the photoelectric effect, which have been expressly recognized by the Nobel Committee as worthy of an award, according to sources, are entirely his own performance.