The physicist and author of A Brief History of Time died peacefully at his home in Cambridge early on Wednesday afternoon (NZT).
His children Lucy, Robert and Tim said in a statement, "We are deeply saddened that our beloved father passed away today".
Doctors predicted he would only live a few years, but he instead thrived, focusing on his work that included seeking to bridge the gap between Albert Einstein's General Theory of Relativity that describes the motion of large objects and the Theory of Quantum Mechanics dealing with subatomic particles. His courage and persistance with his brilliance and humour inspired people across the world. "He once said, aIt would not be much of a universe if it wasn't home to the people you love.' We will miss him for ever", the statement added.
Published for the first time in 1988, the title made the Guinness Book of Records after it stayed on the Sunday Times bestsellers list for an unprecedented 237 weeks.
When his speech started to slur, he was diagnosed with amyotrophic lateral sclerosis - a form of motor neurone disease - aged just 21, in 1963.
Another user wrote: "Even though I can't understand Hawking Dada's books. he is the one who knows the secret of this world".
He said: "Perhaps one day we will be able to use gravitational waves to look back into the heart of the Big Bang".
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Hawking was born in Oxford, England, on what turned out to be an auspicious date: January 8, 1942 - the 300th anniversary of the death of astronomer and physicist Galileo Galilei.
Hawking's seminal contributions continued through the 1980s.
In May last year, Hawking warned that humans should leave earth within 100 years if we wanted to survive. Hawking shocked the physics world when he calculated that this surface should slowly emit radiation (soon to become known as Hawking radiation).
At Cambridge, he held the position of Lucasian Professor of Mathematics - the prestigious post held from 1669 to 1702 by Sir Isaac Newton, widely considered one of the greatest scientists in modern history.
Hawking also moved into popular culture, with cameos in "Star Trek: The Next Generation" and "The Simpsons", while his voice appeared in Pink Floyd songs.
It's also believed that the scientist was a rash driver.
His early life was chronicled in the 2014 film "The Theory of Everything", with Eddie Redmayne winning the best actor Academy Award for his portrayal of the scientist.
American astrophysisist Neil deGrasse Tyson wrote: "His passing has left an intellectual vacuum in his wake. If we find the answers to these questions, we really shall know the mind of God". "Think of it as a kind of vacuum energy permeating the fabric of spacetime that defies measure".