Robert Millikan. By: Brigitte Jacoby and Steph Wall. Robert Millikan's Background. He was born on March 22, 1868 in Illinois He died on December 19, 1953 Robert Millikan had 5 other brothers and sisters He went to Oberlin College in Ohio, as did both of his parents
By: Brigitte Jacoby and Steph Wall
He was born on March 22, 1868 in Illinois
He died on December 19, 1953
Robert Millikan had 5 other brothers and sisters
He went to Oberlin College in Ohio, as did both of his parents
He was asked to teach a basic physics course for a semester at Oberlin College
Robert became interested in physics when preparing for this task
He was the only physics graduate of his class
Millikan married Greta Irvin Blanchard in 1902 and they had three sons
He retired in 1946 and his autobiography was published in 1950
Robert was fascinated by electricity and found the charge of the electron
He helped create anti-submarine devices during WWI as Vice Chairman of the National Research Council
Millikan, in 1921, became part of the California Institute of Technology
He was involved in studies of radiation that Victor Hess had detected impacting Earth from outer space (now called cosmic rays)
Millikan proved that the electron was a fundamental particle with a fundamental charge in his famous oil-drop experiment
In 1913, he published his value for the charge, which remained the accepted value for decades
The determination forvalue of the electron, and the ingenuity of his oil-dropexperiment, earned Millikan international recognition and the 1923 Nobel Prize in physics.
He published 6 physics textbooks and served as president in the American Physical Society
Millikan was also VP of the American Association for the Advancement of Science
H.A. Wilson first developed the standard technique for measuring charge
This process used water, not oil
Water droplets would be given an electric charge and the rate at which they fell would be measured
An electric field attracted the charged droplets upward and opposed the force of gravity
By determining the strength of the electric field and the mass of the water droplets, he could calculate the charge on the droplets and on the electrons.
Millikan tried Wilson's technique but found that the rapid evaporation of the water droplets made measuring difficult and the results unpredictable
Using an atomizer Millikan thinly sprayed oil droplets above two parallel plates (an atomizer is a device that turns a stream of liquid into a spray)
The droplets were falling through a small hole in the upper plate to the space between them
The droplets could be seen at one side through a short focal distance telescope
To make these droplets more visible Robert lit them up from one side
The view was intersected by two very small, horizontal lines.
Droplets of oil could electrify themselves by owing to friction when they were atomized
The oil droplets could also get a charge from an X-ray to complete a potential electric field
By doing this, he discovered how the charge of the droplets affected the way they fell
In the end, after many trials of his experiments, Robert Millikan discovered the charge of the electron was negative
"Robert A. Millikan." Notable Scientists from 1900 to the Present. Ed. Brigham Narins. Detroit: Gale Group, 2008. Gale Science In Context. Web. 7 Oct. 2011.
"Robert Andrews Millikan." Science and Its Times. Ed. Neil Schlager and Josh Lauer. Vol. 6. Detroit: Gale, 2000. Gale Science In Context. Web. 7 Oct. 2011.
Millikan's experiment. (n.d.). Retrieved October 10, 2011, from ThinkQuest website: http://library.thinkquest.org/19662/low/eng/exp-millikan.html
American Physical Society to commemorate University of Chicago as historic physics site in honor of Nobel laureate Robert Millikan. (2006, November 28). Retrieved October 14, 2011, from http://www-news.uchicago.edu/releases/ 06/061128.millikan.shtml