Biography
Robert Andrews Millikan (1868-1953) was an American experimental physicist known for his precise measurements of fundamental physical constants, which earned him the Nobel Prize in Physics in 1923. Born in Morrison, Illinois, Millikan attended Maquoketa Community High School, went to Oberlin College for his undergraduate studies, and furthered his education at Columbia University and the University of Chicago, specializing in experimental physics.
His most renowned scientific contribution was the oil drop experiment, conducted between 1909 and 1913. This work provided the first accurate measurement of the elementary electric charge, proving that electric charge exists in discrete units and determining the charge of the electron. The experiment involved suspending tiny oil droplets between electrically charged plates and observing their movement to calculate the charge on individual electrons.
Besides his work on electron charge, Millikan also significantly advanced the study of cosmic rays and photoelectric effects. He researched cosmic radiation, confirming and expanding on Victor Hess's work, and demonstrated the extraterrestrial origin of these high-energy particles. His studies on the photoelectric effect provided vital experimental proof of Einstein's theoretical predictions, supporting the quantum theory of light.
During his career, Millikan held academic positions at the University of Chicago and later led the California Institute of Technology, transforming it into a renowned center for scientific research. He was married to Greta Millikan and spent his later years in San Marino, California, where he passed away in 1953. He received many honors and awards, such as the Edison Medal, Hughes Medal, and Faraday Lectureship Prize, recognizing his contributions to physics on an international scale.
Before Fame
Growing up in rural Illinois, Millikan's early life gave him a practical approach to scientific investigation. In the late 19th century, he saw the quick technological progress of the industrial age, which sparked his interest in understanding electricity and matter. He went from a small-town high school to some of America's top universities, where he was influenced by the new field of experimental physics. While studying at Columbia University and the University of Chicago in the 1890s, Millikan worked with leading physicists who stressed the importance of precise measurement and careful experimental design, principles that would shape his major research later on.
Key Achievements
- Determined the elementary electric charge through the famous oil drop experiment (1909-1913)
- Won the Nobel Prize in Physics in 1923 for measuring electron charge and photoelectric effect work
- Provided experimental verification of Einstein's photoelectric effect equation
- Advanced understanding of cosmic rays and confirmed their extraterrestrial origin
- Transformed California Institute of Technology into a leading scientific research institution
Did You Know?
- 01.Millikan's oil drop experiment required him to observe individual droplets for hours at a time through a microscope, demanding extraordinary patience and steady hands
- 02.He initially used water droplets for his charge measurement experiments, but switched to oil because water evaporated too quickly
- 03.Millikan served as a lieutenant colonel in World War I, working on military applications of physics including meteorology and ballistics
- 04.He coined the term 'cosmic rays' for the high-energy particles from space that he studied extensively in the 1920s and 1930s
- 05.His elementary charge measurement was so precise that it remained the accepted value for over 50 years
Family & Personal Life
Awards & Honors
| Award | Year | Details |
|---|---|---|
| Nobel Prize in Physics | 1923 | for his work on the elementary charge of electricity and on the photoelectric effect |
| Edison Medal | 1922 | — |
| Faraday Lectureship Prize | 1924 | — |
| ASME Medal | 1926 | — |
| Oersted Medal | 1940 | — |
| Hughes Medal | 1923 | — |
| Matteucci Medal | 1925 | — |
| Franklin Medal | 1937 | — |
| Comstock Prize in Physics | 1913 | — |
| Fellow of the American Academy of Arts and Sciences | — | — |
| Honorary Fellow of the Royal Society Te Apārangi | 1944 | — |
| doctor honoris causa from the University of Paris | 1939 | — |