Stephen Hawking, the British physicist and author of A Brief History of Time, has passed away at the age of 76.
"He was a great scientist and an extraordinary man whose work and legacy will live on for many years", said his children in a statement.
He published several best-selling works of popular science, including his 1988 book "A Brief History of Time", which set out to explain cosmology, the study of the universe, to readers with little or no prior understanding of complex scientific theories.
Hawking's scholarly pursuits dealt with time - whether it has a beginning and end, what happens in a black hole and whether time warps are possible.
Though he was given only two years to live after his diagnosis, he lived more than 50 years.
For years, Hawking's fought with ALS, also known as Lou Gehrig's disease, after being diagnosed more than a half-century ago.
FILE PHOTO: Stephen Hawking arrives at the United Kingdom premiere of the film "The Theory of Everything" which is based around his life, at a cinema in central London, Britain, December 9, 2014. Hawking reportedly met actor Eddie Redmayne, as part of Redmayne's preparation for taking on the role of Hawking.
He was confined to a wheelchair by the time he was 30, and in 1986, aged 44, his voice was removed to save his life after an attack of pneumonia.More news: GOP lawmakers criticize Murphy's tax hike plan
Lucy Hawking said her father had an exasperating "inability to accept that there is anything he can not do".
Hawking was diagnosed with motor neurone disease in 1963 at the age of 21.
Hawking's cause of death has not yet been released.
He made cameo television appearances in "The Simpsons" and "Star Trek" and counted among his fans U2 guitarist The Edge, who attended a January 2002 celebration of Hawking's 60th birthday.
Born on January 8, 1942 - 300 years to the day after the death of the father of modern science, Galileo Galilei - he believed science was his destiny.
Hawking gained a Ph.D.in cosmology at Cambridge University and studied as a fellow at Gonville and Caius College.
Hawking remained active at Cambridge as a Dennis Stantion Avery and Sally Tsui Wong-Avery Director of Research as the Department of Applied Mathematics and Theoretical Physics.
Hawking first married Jane Wilde in 1965 and had three children.