Robert Andrew MillikanIn 1909 Robert Andrew Millikan set up an apparatus to measure the chargeof an electron within an accuracy range of 3%. In 1913 he came out with avalue of the electrical charge that would serve the world of science for ageneration. Young Millikan had a childhood like most others: he had no idea what hisprofession would be. Once he recalled trying to jump from a rowboat to a dock,falling in the water, and almost drowning. Here he had his first account withphysics – Newtons Third Law of Motion: “For every action there is an equal andopposite reaction”. Even in High School Physics courses Millikan was not sospirited, which may have had a little to do with his teachers habit of spendingthe summers using a divining rod to find water.
After Millikan graduated fromMaquoketa High he was accepted into Oberlin College. Robert actually began hisphysics career when he taught an elementary course at the request of his Greekprofessor during his sophomore year. He then transferred to Columbia Universityfrom which he graduated in 1893 as the only student graduate in physics. Afterthis accomplishment Millikan travelled to Germany to study with such professorsPlanck and others.
When this period was on his resume Millikan was offered aposition in the Physics department at the University of Chicago and Millikantook it. After teaching for a period Millikan decided that physics could onlybe taught properly through the practice of experimentation and getting yourhands in it just as many other things are. Thus, he began writing bettertextbooks for the University of Chicago, “In fact he spent the morning of hiswedding day reading proofs of his textbooks” (http://physics. uwstout. edu/sotw/millikan.
html )During his 12 hours of teaching each day Millikan spent half of his timedoing research. In 1909 he constructed his first oil drop apparatus todetermine the charge of an electron. Millikan discovered that the chargedepended on the frequency of incident light. In the beginning of hisexperimentation Millikan was using a drop of water.
Using a water drop onlygave Millikan forty five seconds in which to measure the charge, due to thevolatility of the water. Millikan then switched to using a drop of oil becauseof its low volatility and as a result was allowed four and one half hours tomeasure the charge. In 1909 Millikan figured he was within 2% of being accurate. In 1910Millikan actually announced numerical value for this fundamental atomic constant,4. 891×10-10 esu.
After Millikan announced this number he was elected ViceChairman and Director of Research for the National Research Council in 1917. Millikan realized there were inaccuracies when then photocurrent near the cutoffpoint was too low to measure. Noticing that the current was highest when themetal was fresh Millikan fashioned his targets into thick cylinders and riggedup an electro-magnetically controlled knife to shave off the ends of the blocks. Millikan went on to the Physics Laboratory at California Institute ofTechnology, where he obtained his Doctorate and stayed on doing research onCosmic Rays until he retired in 1945.
It was while he was at Cal Tech in 1923that he won the Nobel Prize in Physics. Millikan was the first Cal TechDoctorate to achieve a Nobel Prize.
