Here's a look at the life of the world renowned theoretical physicist, cosmologist, astronomer and mathematician, Stephen Hawking.
Personal: Birth date: January 8, 1942
Birthplace: Oxford, England (grew up in and around London)
Birth name: Stephen William Hawking
Father: Frank Hawking, a doctor and research biologist
Mother: E. Isobel Hawking
Marriages: Elaine Mason (1995-2006, divorce); Jane Wilde (1965-1991, divorce)
Children: with Jane Wilde: Timothy, Lucy and Robert
Education: Oxford University, B.A., 1962; Cambridge University, Ph.D., 1966
Other Facts: Stephen Hawking's birthday (January 8, 1942) is the 300th anniversary of the death of astronomer and physicist Galileo Galilei.
He is the 17th Lucasian Professor of Mathematics, an academic chair at Cambridge University. From 1669 to 1702, the position was held by Sir Isaac Newton.
Has guest-starred, as himself, on "The Big Bang Theory," "Star Trek: The Next Generation" and "The Simpsons."
Lou Gehrig's Disease (Amyotrophic Lateral Sclerosis or ALS), is usually fatal after three years. Hawking has survived it for 50 years.
The disease has left him paralyzed and completely dependent on others and/or technology for everything: bathing, dressing, eating, mobility and speech. He's able to move only a few fingers on one hand.
His speech synthesizer has an American accent.
Timeline: 1963 - Is diagnosed with the motor neuron disease, amyotrophic lateral sclerosis (ALS).
1966 - Completes doctoral work in theoretical physics, submitting a thesis on black holes.
1970 - Combines the theory of relativity with quantum theory and finds that black holes emit radiation.
1979 - Becomes the 17th Lucasian professor of mathematics at Cambridge University.
1982 - Awarded CBE - Commander of the Order of the British Empire.
1985 - Hospitalized with pneumonia Hawking requires an emergency tracheotomy, causing permanent damage to his larynx and vocal cords. A keyboard operated electronic speech synthesizer is refined and adapted to his wheelchair by David Mason, an engineer married to Elaine Mason, one of Hawking's nurses (and future wife).
1988 - His book, "A Brief History of Time: From the Big Bang to Black Holes," is published.
2004 - Reverses the 1966 theory that black holes swallow everything in their path forever and declares that black holes will never support space travel to other universes.
April 26, 2007 - Becomes the first quadriplegic to experience zero gravity, aboard a Zero Gravity Corporation flight.
October 2007 - "George's Secret Key to the Universe," the first in a series of children's books to help explain the universe, written with daughter Lucy is published.
November 30, 2008 - Is appointed by the Perimeter Institute for Theoretical Physics in Waterloo, Ontario to be its first Distinguished Research Chair.
May 19, 2009 - "George's Cosmic Treasure Hunt," the second in the series of children's books written with daughter Lucy, is published.
July 30, 2009 - Is awarded the 2009 Presidential Medal of Freedom by President Barack Obama.
September 30, 2009 - Steps down as Lucasian Professor of Mathematics at Cambridge University after 30 years. Hawking will continue to work at the university.
2009-present - Director of Research at the Institute for Theoretical Cosmology at the Department of Applied Mathematics and Theoretical Physics at Cambridge University.
September 7, 2010 - "The Grand Design," written with Leonard Mlodinow, is published.
August 28, 2012 - "George and the Big Bang," the third installment in a series of children's books written with daughter Lucy, is published.
December 2012 - Wins the Fundamental Physics Prize and is awarded $3 million for his theory on black holes emitting energy.
September 10, 2013 - Hawking publishes "My Brief History," a biography that looks at his life and the development of his intellect.
June 5, 2014 - "George and the Unbreakable Code" the fourth installment in a series of children's books written with daughter Lucy, is published.