As Chairman of the Executive Council ofCaltech (the school's governing body at the time) from 1921 to 1945, Millikan helped to turn the school into one of the leading research institutions in the United States.[4][5] He also served on the board of trustees for Science Service, now known asSociety for Science & the Public, from 1921 to 1953.[citation needed]
At the close of my sophomore year [...] my Greek professor [...] asked me to teach the course in elementary physics in the preparatory department during the next year. To my reply that I did not know any physics at all, his answer was, "Anyone who can do well in my Greek can teach physics." "All right," said I, "you will have to take the consequences, but I will try and see what I can do with it." I at once purchased an Avery'sElements of Physics, and spent the greater part of my summer vacation of 1889 at home – trying to master the subject. [...] I doubt if I have ever taught better in my life than in my first course in physics in 1889. I was so intensely interested in keeping my knowledge ahead of that of the class that they may have caught some of my own interest and enthusiasm.[11]
Millikan's enthusiasm for education continued throughout his career, and he was the coauthor of a popular and influential series of introductory textbooks,[12] which were ahead of their time in many ways. Compared to other books of the time, they treated the subject more in the way in which it was thought about by physicists. They also included many homework problems that asked conceptual questions, rather than simply requiring the student to plug numbers into a formula.
In 1895, Millikan travelled to Germany and spent a year at the universities ofBerlin andGöttingen. The following year, he returned to the United States to become an assistant at theUniversity of Chicago. He was appointed Professor of Physics in 1910.[5]
In 1917, solar astronomerGeorge Ellery Hale convinced Millikan to begin spending several months each year at Throop College of Technology, a small academic institution inPasadena, California, that Hale wished to transform into a major center for scientific research and education. In 1920, Throop College was renamed theCalifornia Institute of Technology (Caltech), and the following year Millikan left the University of Chicago to become Chairman of the Executive Council of Caltech, a position he held until his retirement in 1945.
Millikan's original oil-drop apparatus, circa 1909–1910Millikan receives a check for over $40,000 for winning the Nobel Prize.
In 1909, Millikan worked on an experiment in which he measured thecharge of a singleelectron.J. J. Thomson had already discovered thecharge-to-mass ratio of the electron. However, the actual charge and mass values were unknown. Therefore, if one of these two values were to be discovered, the other could easily be calculated. Millikan and his then graduate student,Harvey Fletcher, used theoil drop experiment to measure the charge of the electron (as well as the electron mass, andAvogadro constant, since their relation to the electron charge was known).[17]
Millikan took sole credit in return for Fletcher claiming full authorship on a related result for his dissertation.[18] Millikan went on to win the 1923Nobel Prize in Physics, in part for this work, and Fletcher kept the agreement a secret until his death.[19] After a publication on his first results in 1910,[20] contradictory observations byFelix Ehrenhaft started a controversy between the two physicists.[21] After improving his setup, Millikan published his seminal study in 1913.[22]
Theelementary charge is one of the fundamentalphysical constants, and accurate knowledge of its value is of great importance. His experiment measured the force on tiny charged droplets of oil suspended against gravity between two metal electrodes. Knowing the electric field, the charge on the droplet could be determined. Repeating the experiment for many droplets, Millikan showed that the results could be explained asinteger multiples of a common value (1.592 × 10−19coulomb), which is the charge of a single electron. That this is somewhat lower than themodern value of 1.602 176 53(14) x 10−19coulomb is probably due to Millikan's use of an inaccurate value for theviscosity ofair.[23][24]
Although at the time of Millikan's oil drop experiment, it was becoming clear that there exist such things assubatomic particles, not everyone was convinced. Experimenting withcathode rays in 1897, J. J. Thomson had discovered negatively charged "corpuscles", as he called them, with a charge-to-mass ratio 1840 times that of ahydrogen ion. Similar results had been found byGeorge FitzGerald andWalter Kaufmann. Most of what was then known about electricity and magnetism could be explained on the basis that charge is a continuous variable. This in much the same way that many of the properties of light can be explained by treating it as a continuous wave rather than as a stream ofphotons.
The beauty of the oil drop experiment is that as well as allowing quite accurate determination of the fundamental unit of charge, Millikan's apparatus also provided a 'hands on' demonstration that charge is actually quantized. General Electric Company'sCharles Steinmetz, who had previously thought that charge is a continuous variable, became convinced otherwise after working with Millikan's apparatus.
There is some controversy over selectivity in Millikan's use of results from his second experiment measuring the electron charge. This issue has been discussed byAllan Franklin,[25] a former high-energy experimentalist and current philosopher of science at theUniversity of Colorado. Franklin contends that Millikan's exclusions of data do not affect the final value of the charge obtained, but that Millikan's substantial "cosmetic surgery" reduced the statistical error. This enabled Millikan to give the charge of the electron to better than one-half of one percent. In fact, if Millikan had included all of the data he discarded, the error would have been less than 2%. While this would still have resulted in Millikan's having measured the charge ofe− better than anyone else at the time, the slightly larger uncertainty might have allowed more disagreement with his results within the physics community, which Millikan likely tried to avoid.David Goodstein argues that Millikan's statement, that all drops observed over a 60 day period were used in the paper, was clarified in a subsequent sentence that specified all "drops upon which complete series of observations were made". Goodstein attests that this is indeed the case and notes that five pages of tables separate the two sentences.[26]
Millikan and Albert Einstein at the California Institute of Technology, 1932
WhenAlbert Einstein published his 1905 paper on the particle theory of light, Millikan was convinced that it had to be wrong, because of the vast body of evidence that had already shown that light was awave. He undertook a decade-long experimental program to test Einstein's theory, which required building what he described as "a machine shopin vacuo" in order to prepare the very clean metal surface of the photoelectrode. His results, published in 1914, confirmed Einstein's predictions in every detail,[27] but Millikan was not convinced of Einstein's interpretation, and as late as 1916 he wrote, "Einstein's photoelectric equation... cannot in my judgment be looked upon at present as resting upon any sort of a satisfactory theoretical foundation," even though "it actually represents very accurately the behavior" of thephotoelectric effect. In his 1950 autobiography, however, he declared that his work "scarcely permits of any other interpretation than that which Einstein had originally suggested, namely that of the semi-corpuscular or photon theory of light itself.[28]
Although Millikan's work formed some of the basis for modernparticle physics, he was conservative in his opinions about 20th century developments in physics, as in the case of the photon theory. Another example is that his textbook, as late as the 1927 version, unambiguously states the existence of theether, and mentions Einstein's theory of relativity only in a noncommittal note at the end of the caption under Einstein's portrait, stating as the last in a list of accomplishments that he was "author of thespecial theory of relativity in 1905 and of thegeneral theory of relativity in 1914, both of which have had great success in explaining otherwise unexplained phenomena and in predicting new ones."
Millikan is also credited with measuring the value of thePlanck constant by using photoelectric emission graphs of various metals.[29]
At Caltech, most of Millikan's scientific research focused on the study ofcosmic rays (a term he coined). In the 1930s, he entered into a debate withArthur Compton over whether cosmic rays were composed of high-energy photons (Millikan's view) orcharged particles (Compton's view). Millikan thought his cosmic ray photons were the "birth cries" of new atoms continually being created to counteractentropy and prevent theheat death of the universe. Compton was eventually proven right by the observation that cosmic rays are deflected by theEarth's magnetic field (hence must be charged particles).
In the aftermath of the1933 Long Beach earthquake, Millikan chaired the Joint Technical Committee on Earthquake Protection. They authored a report proposing means to minimize life and property loss in future earthquakes by advocating stricter building codes.[33]
At this moment, August 22, 1938, the principles of representative ballot government, such as are represented by the governments of the Anglo-Saxon, French, and Scandinavian countries, are in deadly conflict with the principles of despotism, which up to two centuries ago had controlled the destiny of man throughout practically the whole of recorded history. If the rational, scientific, progressive principles win out in this struggle there is a possibility of a warless, golden age ahead for mankind. If the reactionary principles of despotism triumph now and in the future, the future history of mankind will repeat the sad story of war and oppression as in the past.
A more controversial belief of his waseugenics – he was one of the initial trustees of theHuman Betterment Foundation and praisedSan Marino, California for being "the westernmost outpost of Nordic civilization ... [with] a population which is twice as Anglo-Saxon as that existing in New York, Chicago, or any of the great cities of this country."[44] In 1936, Millikan advised the president ofDuke University in the then-racial segregated southern United States against recruiting a female physicist and argued that it would be better to hire young men.[45]
During the mid to late 20th century, several colleges named buildings, physical features, awards, and professorships after Millikan. In 1958,Pomona College named a science building Millikan Laboratory in honor of Millikan. After reviewing Millikan's association with the eugenics movement, the college administration voted in October 2020 to rename the building as the Ms. Mary Estella Seaver and Mr. Carlton Seaver Laboratory.[48]
On theCaltech campus, several physical features, rooms, awards, and a professorship were named in honor of Millikan, including the Millikan Library, which was completed in 1966. In January 2021, on account of Millikan's affiliation with theHuman Betterment Foundation, the Caltech Board of Trustees authorized removal of Millikan's name (and the names of five other historical figures affiliated with the Foundation), from campus buildings.[49] The Robert A. Millikan Library has been renamed Caltech Hall.[50] In November 2021, the Robert A. Millikan Professorship was renamed the JudgeShirley Hufstedler Professorship.[51]
This removal was opposed by mathematicianThomas C. Hales, who argued that "Millikan's beliefs fell within acceptable scientific norms of his day".[52] He further criticized the Committee on Naming and Recognition (CNR) report for "failing to meet the minimal standards of accuracy and scholarship that are expected of official documents issued by one of the world's great scientific institutions", saying that it should be retracted, and called for Caltech to "restore Robert Andrews Millikan to a place of honor."[52]
Possible name removal from secondary schools during the 21st century
In November 2020, Millikan Middle School (formerly Millikan Junior High School) in the suburban Los Angeles neighborhood ofSherman Oaks started the process of renaming their school.[53] In February 2022, the Board of Education for the Los Angeles Unified School District voted unanimously to rename the school in honor of musicianLouis Armstrong.[54]
In August 2020, theLong Beach Unified School District established a committee that would examine the need for renaming of theirRobert A. Millikan High School.[55][56] An October 2023 attempt to get the school board to restart the stalled renaming process failed.[57] As of August 2024[update], Long Beach remains the only city that still has an educational institution named in honor of Millikan.
In the spring of 2021, theAmerican Association of Physics Teachers voted unanimously to remove Millikan's name from theRobert A. Millikan award, which honors "notable and intellectually creative contributions to the teaching of physics."[58] A few months later, AAPT announced that the award would be renamed in honor of University of Washington professor of physicsLillian C. McDermott who died the previous year.[59]
"If Kevin Harding's equation and Aston's curve are even roughly correct, as I'm sure they are, for Dr. Cameron and I have computed with their aid the maximum energy evolved in radioactive change and found it to check well with observation, then this supposition of an energy evolution through the disintegration of the common elements is from the one point of view a childish Utopian dream, and from the other a foolish bugaboo."[60]
"No more earnest seekers after truth, no intellectuals of more penetrating vision can be found anywhere at any time than these, and yet every one of them has been a devout and professed follower of religion."[61]
Millikan, R A (1950).The Autobiography of Robert Millikan
Millikan, Robert Andrews (1917).The Electron: Its Isolation and Measurements and the Determination of Some of its Properties. The University of Chicago Press.
Nobel Lectures, "Robert A. Millikan – Nobel Biography". Elsevier Publishing Company, Amsterdam.
Segerstråle, U (1995) Good to the last drop? Millikan stories as "canned" pedagogy,Science and Engineering Ethics vol 1, pp197–214
Kargon, Robert H (1977). "The Conservative Mode: Robert A. Millikan and the Twentieth-Century Revolution in Physics".Isis.68 (4):509–526.doi:10.1086/351871.JSTOR230006.S2CID170329412.
Kargon, Robert H (1982).The rise of Robert Millikan: portrait of a life in American science. Ithaca: Cornell University Press.
Nobel Prize controversies – Millikan is widely believed to have been denied the 1920 prize for physics owing to Felix Ehrenhaft's claims to have measured charges smaller than Millikan's elementary charge. Ehrenhaft's claims were ultimately dismissed and Millikan was awarded the prize in 1923.
^Millikan, Robert Andrews (1980) [reprint of original 1950 edition].The autobiography of Robert A. Millikan. Prentice-Hall. p. 14.
^The books, coauthored withHenry Gordon Gale, wereA First Course in Physics (1906),Practical Physics (1920),Elements of Physics (1927), andNew Elementary Physics (1936).
^"Dr. Millikan of Caltech Dies at 85: Famous Physicist Known as Leader in Many Fields".Los Angeles Times. December 20, 1953. p. 1.ProQuest166559215.Dr. Robert Andrews Millikan, the active founder of the California Institute of Technology and dean of the world's physicists, died in a Pasadena convalescent yesterday shortly after noon. He was 85.
^"Robert A. Millikan, Nobel Prize Physicist".Washington Post. December 20, 1953. p. M14.ProQuest152605614.Dr. Robert A. Millikan, dean of the American physicists and Nobel Prize winning authority, died today at a rest home. He was 85.
^"Dr. Millikan, Nobel Prize Physicist, Dies: Scientist, 85, Known for Isolating Electron".Chicago Daily Tribune. December 20, 1953. p. A11.ProQuest178583066.Dr. Robert Andrews Millikan, 85, world famous physicist and authority on cosmic rays, died in a rest home today. He was confined to his bed for months with infirmities of age.
^"Solemn Tribute Paid to Dr. Robert Millikan: Friends and Admirers File Past Bier; Immortalization Services Set Today".Los Angeles Times. December 23, 1953. p. 4.ProQuest166552921.
^Goodstein, David (2000)."In defense of Robert Andrews Millikan"(PDF).Engineering and Science. Pasadena, California: California Institute of Technology. Archived fromthe original(PDF) on June 25, 2010. RetrievedAugust 30, 2018.
Robert Millikan standing on right during historic gathering of the Guggenheim Board Fund for Aeronautics 1928. Orville Wright seated second from right, Charles Lindbergh standing third from right
