Robert A. Millikan

Robert Andrews Milliken was born in Morrison, Illinois (USA) on March 22, 1868, is the second son of Pastor Shiras, Franklin Milliken and Pastor Mary Jane Andrews. He was living a rural life as a child, and he went to Maquoketa High School (Iowa State). After working for a while as a court reporter, he entered Oberlin University (Ohio) in 1886. In his undergraduate course, his favorite subjects were Greek and mathematics, but after graduating in 1891, he spent two years as a faculty member in basic physics.

Robert Millikan grew up in the American countryside and is the son of pastor Sivere Millikan. He studied at Oberlin University. After graduation, he taught elementary school physics. After becoming a teacher of all grade, he became a professor at the University of Chicago. Milikan has made many progress in his career, but so far his greatest discovery was the control of the electronics. Milikan identified an electronic unit charge (Millikan Nobel Prize) discovered by Thomson. You can calculate the mass of electrons and positively charged atoms using the unit charge of electrons. He found an electronic unit charge using his own oil drop experiment. In the oil droplet experiment, Millikin dropped oil droplets a certain distance in the air and measured the time required for oil droplets to fall. Then he turned on the electric field and measured the time it takes for oil droplets to rise the same distance.

In 1909, American physicist Robert A. Milican revealed more information about electrons through his "oil drop" experiment. Milikan creates small oil droplets that can be formed using friction or X-rays. Although these droplets initially fall due to gravity, their downward progression can be slowed down or even reversed by the lower electric field in the device. Millikan can determine the charge of a single droplet by adjusting the field strength and performing careful measurements and appropriate calculations (Figure 2).

Since the late nineteenth century scientists knew that electrons had a negative charge. The value of this charge was first measured by American physicist Robert Milliken between 1909 and 1910. In the Millipel oil drop experiment, he hung a small oil droplet in a room containing oil mist. By measuring the drop velocity of oil droplets, he can determine their weight. Oil droplets with electric charges can be decelerated or stopped by applying electric power (for example, obtained by friction when traveling through air). Millikan was able to determine the charge on each droplet by comparing the applied force to the change in motion. After he measured a lot of drops, he learned that the cost of all drops is a simple multiple of the number. This basic charge unit is the charge on the electron and the different charges on the oil droplet correspond to those with 2, 3, 4, ... additional electrons.