By: Tiana Perez
Robert A. Millikan
Robert A. Millikan was an educator, a physicist, and a scientist. He was born on March 22nd in 1868 in Morrison Illinois. He is the second son of Silas Franklin Millikan and Mary Jane Andrews. He attended Maquoketa High School in Iowa. In 1886 he entered Oberlin College in Ohio after working as a court reporter. During his undergraduate course his favorite subjects were Greek and Mathematics. After his graduation he was an elementary physics teacher for two years. During that time period he developed his interest in that subject.
Robert Millikan is most famous for his Oil-Drop Experiment where he discovered the charge of an electron. He also determined there was a smallest unit charge. Millikan put a charge on a tiny drop of oil and measured how strong the applied electric field had to be in order to stop the drop from falling. Since he could find the mass of the one drop and could calculate the force of gravity on the drop, he could determine the electric charge that the drop must have. After varying the charge on different drops, he determined that the charge was always a multiple of -1.6 x 10 -19 C, the charge of an electron.That meant that it was electrons carrying that charge.
Millikan Oil Drop Experiment Animation