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Robert Millikan. About Him…. born on March 22, 1868 in Morrison, IL went to Oberlin College in 1886-1891 1893 obtained masters in physics, was appointed Fellow in physics at Columbia University & got Ph. D in 1895 professor at University of Chicago from 1910-1921
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About Him… • born on March 22, 1868 in Morrison, IL • went to Oberlin College in 1886-1891 • 1893 obtained masters in physics, was appointed Fellow in physics at Columbia University & got Ph. D in 1895 • professor at University of Chicago from 1910-1921 • vice president of the American Association for the Advancement of Science, and American member of the committee on intellectual cooperation of the league of nations, and American representative at the international congress of physics • winner of the com stock prize of the national academy of sciences, Edison Medal of the American institute of electrical engineer, Hughes medal the Rovel society of great Britain, and noble prize for physics.
Not so nice??? • charged with racism & sexism • exploited grad. students • manipulation of researched data • had a fit because reseachers questioned the accuracy of his value for aire viscosity & treatment of data • Controversy on if he was really the true experimentalist in the oil-drop experiment
Oil-drop Experiment • Created to find electric charge of an electron • Used 2 metal electrodes(+,-) with 5,000 volts going through them • Used precision for electric and gravitational force • Found charge of electric field and calculate the charge of the oil • High powered beam of radiation hit the oil drops and would peel off the electrons • Electrons peeled off slowed down the speed of the falling oil • Adjusting the current of radiation the oil drops could stop in fall • Repeating this they could calculate the single charge of an electron • 1.602x10-19 coulomb • The electrons would stick to the oil droplets like flour stuck to dough
His Discoveries... • found single charge of electron • found mass of electron using Thomson's discovery • proved quantity was a constant for all electrons demonstrations • Put end to all opposition to the atomic & kinetic theories of matter • Made first direct photoelectric determinations of Planck’s constant H • Discovered law of motion of a particle falling towards the earth after entering the earth’s atmosphere
Photoelectric Effect • People previously thought light could not push energy around because it is energy, not matter. • Einstein contradicted this in 1905 essays in a theory • Millikan confirmed Einstein's theory. • Discovered light can bounce off of certain materials and cause particles to be removed from material.
How he affected science • oil drop experiment was first successful attempt to measure the effect of an subatomic particle • Scientists could now study one drop of water (or oil) at a time instead of an entire cloud
Robert Millikan By: Jill Young Kim Rasmussen Nick Galo Lauren Schaller Farah Kader & Ashley Demarco