Physicist who became the second American to win the Nobel Prize for Physics in 1923 for his work measuring the charge of the electron. He coined the term "cosmic rays" to describe radiation of extraterrestrial origins.
During WWI he worked on military applications of aeronautics and meteorology.
His well-known oil-drop experiment involved letting small drops of oil fall in a test chamber, and then suspending them in mid-air via a magnetic field.
He was born in Morrison, Illinois, and went to high school in Maquoketa, Iowa. His father was a Congregational minister and his mother was a former dean at a small college.
Enrico Fermi, another atomic scientists, won the Nobel Prize for his own contributions several years after Millikan.