Gerard K. O'Neill

Gerard K. O'Neill was an American physicist and space activist.

Born on the 6 February 1927, Brooklyn, New York City, New York, United States

Died on the 27 April 1992, Redwood City, California, United States.

He was involved with high-energy particle physics and its application to navigation and space colonization, and professor of physics at Princeton University. His book "The High Frontier" won the Phi Beta Kappa award as the best science book of 1977 and popularized his way of looking at near-earth space "not as a void, but as a culture medium, rich in matter and energy." O'Neill argued that colonization of space is the obvious solution to such problems as overpopulation and fossil fuel depletion. He designed one of the early particle accelerators. It was O'Neill who suggested that the right place to build the first non-terrestrial habitat was a point about equidistant from the Earth and the Moon known as Lagrange 5, or L5.

His 1976 book The High Frontier: Human Colonies in Space presented the idea for very large self sustaining Space habitats now called O'Neill cylinders.