Millikan

[ mil-i-kuhn ]

noun

1. Robert Andrews, 1868–1953, U.S. physicist: Nobel Prize 1923.

Millikan

/ ˈmɪlɪkən /

noun

1. MillikanRobert Andrews18681953MUSSCIENCE: physicist Robert Andrews. 1868–1953, US physicist. He measured the charge of an electron (1910), verified Einstein's equation for the photoelectric effect (1916), and studied cosmic rays; Nobel prize for physics 1923

Millikan

/ mĭl′ĭ-kən /

1. American physicist who measured the electron charge and experimentally verified Einstein's equation describing the photoelectric effect. For this work he received the 1923 Nobel Prize for physics. Milllikan also proved the existence of (and coined the term for) cosmic rays.

Biography

Robert Millikan calculated the charge of an electron with his famous oil-drop experiment in 1910, which took advantage of the fact that droplets of oil can carry an electric charge on their surfaces. He took a closed transparent chamber with two parallel horizontal metal plates, one passing through the middle of the chamber and one on the bottom. The upper plate had a small hole in it, and the plates were connected by an electric current, giving them a charge. Millikan sprayed tiny droplets of oil into the chamber's upper half; these floated downward, with some falling through the hole in the upper plate. Their mass could be calculated by measuring how fast they fell. Millikan then ionized the air in the lower half by beaming x-rays at it, which stripped electrons from the air molecules; the electrons attached themselves to the droplets, giving them a negative charge. By changing the voltage between the two plates, which changed the electric differential between them, he could modulate the rate of the droplets' fall. If the voltage equaled the known gravitational force acting on a droplet, the droplet remained stationary. This voltage, together with the droplet's mass, he then used to calculate the droplet's charge. Millikan found through many experiments that the charge was always a whole-number multiple of a particular quantity, which he deduced was the charge of a single electron (1.602 × 10 ⁻¹⁹ coulombs). For this discovery, he was awarded the Nobel Prize for physics in 1923.

Example Sentences

That’s when the officer, who Long Beach school officials said in a statement was “conducting safe passage for students” leaving the Millikan campus, happened upon the scene.

From The Daily Beast

Rodriguez is not currently a student at Millikan, authorities said.

From The Daily Beast

Millikan's charge carriers were minute oil drops, which were given elementary charges by means of ionizing rays from radium.

From Project Gutenberg

From cowpunching he had graduated into the tough little body of territorial rangers at the head of which was "Hurry Up" Millikan.

From Project Gutenberg

He had been thinking of how he must report almost immediately to HurryUp Millikan, of the rangers.

From Project Gutenberg

It is a condenser and adapter of the cosmic force that you call the Millikan rays.

From Project Gutenberg

Howard and his guest drove to Millikan's Draw, for the wound of the latter was still too new to stand so long a horseback ride.

From Project Gutenberg