Stephen Hawking's second ex-wife today said his death aged 76 would have been a 'relief' for her former husband.

The scientist, who inspired millions around the world, passed away at home in Cambridge this morning more than 50 years after he was given just two years to live.

His second wife Elaine, his former nurse who he married in 1995 but divorced in 2006, has also said he proposed to her twice after they split up following allegations she had attacked him.

Speaking from her home in Chipping Camden, Gloucestershire today she said: 'His death was a relief for him, I believe.

'He was the love of my life and I very reluctantly had to let go of him. He proposed to me twice after our divorce because he couldn't quite cope with it.

'I know his first wife likes to put me down, but we had 22 years together which was wonderful. For us our marriage was loving. People didn't like it and they tore us apart'.

Professor Hawking's death has sparked an outpouring of grief across the world.

His children visited his home today and in a statement Lucy, Robert and Tim said: 'We are deeply saddened that our beloved father passed away today. He was a great scientist and an extraordinary man whose work and legacy will live on for many years.

'He once said, 'It would not be much of a universe if it wasn't home to the people you love.' We will miss him forever'.

The world's most celebrated scientist was last seen in public in Mayfair just before Christmas

Stephen Hawking's daughter, Lucy and youngest son, Tim, visited their father's house today

The scientist married former nurse Elaine Mason in 1995 and they divorced in 2006

His family say he passed away peacefully at his home in Cambridge (pictured today)

Professor Stephen Hawking (pictured in 2015 with his first wife Jane and daughter Lucy) died more than 50 years after being diagnosed with motor neurone disease

They also said their father's 'courage, persistence, brilliance and humour inspired people across the world'.

He passed away peacefully in Cambridge this morning after a long battle with motor neurone disease, his family has revealed.

Today the last pictures of Professor Hawking emerged and showed him out enjoying dinner in Mayfair with friends just before Christmas and his children visited his home today.

His former personal assistant has said the academic may have died following complications caused by a chest infection, which he suffers from every year.

Professor Hawking was diagnosed with motor neurone disease in 1963 when he was 21 and he defied medical experts who said he would be dead within two years.

Lucy, 47 and Tim, 38, were seen leaving Hawking's house in the centre of Cambridge, near to where he worked at Gonville and Caius College, at lunchtime today.

The pair, who have made regular visits to their dad over the years, were spotted leaving the home in a taxi.

Lucy, who wore a long grey coat, significantly helped care for her father as his motor neurone disease saw his condition deteriorate.

A journalist and novelist, she has a son William and co-wrote a series of children's books with her father, with the first one titled George's Secret Key to the Universe, published in 2007.

Hawking's eldest son, Robert, who lives in America, was not seen at the house.

In the following 55 years he became the world's most famous scientist since Albert Einstein for his work exploring the mysteries of space, time and black holes despite being wheelchair-bound and only able to communicate using a computer and his famous voice synthesizer.

Fellow physicist Lawrence Krauss tweeted: '‏A star just went out in the cosmos. Stephen Hawking fought and tamed the cosmos bravely for 76 years and taught us all something important about what it truly means to celebrate about being human. I will miss him'.

University of Cambridge vice-chancellor Professor Stephen Toope said today: 'His exceptional contributions to scientific knowledge and the popularisation of science and mathematics have left an indelible legacy. His character was an inspiration to millions'.

His most famous book 'A Brief History of Time' became an international bestseller with more than 10million copies sold - although the physicist joked himself that many who owned it never finished it and more struggled to understand its complexity.

The Cambridge-based scientist, who married twice, embraced popular culture appearing in The Simpsons, The Big Bang Theory, Star Trek, Futurama and Little Britain.

He said he embraced popular culture because he wanted to make science more mainstream and encourage the world to 'look up at the stars and not down at your feet'.

In a recent poll he was voted the 25th greatest Briton of all time and was immortalised in the 2014 Oscar-winning biopic The Theory of Everything, where he was played by Eddie Redmayne.

The actor said today: 'We have lost a truly beautiful mind, an astonishing scientist and the funniest man I have ever had the pleasure to meet. My love and thoughts are with his extraordinary family.'

The world's most celebrated scientist Professor Stephen Hawking has died at the age of 76

Flags across the city where he worked are flying at half mast today as it mourns for its most famous academic

A tearful woman leaves upset after signing a book of condolence for Stephen Hawking at Gonville and Caius College in Cambridge today

Theresa May led tributes to a 'brilliant mind' whose 'courage and humour was an inspiration'

Benedict Cumberbatch, who also played Prof Hawking on screen, said in a statement to the Press Association: 'I was so sad to hear that Stephen has died. I send my heartfelt love and condolences to all his family and colleagues.

'I feel so lucky to have known such a truly great man who's profundity was found both in his work and the communication of that work. Both in person and in books.

'He virtually created the publishing genre of popular science. A heroic feat to bring the wondrous complexities of the universe to all outside of specialists in this field.

'But truly courageous when considering it was achieved by a man who lived a life trapped in his body from the age of 21 when he was diagnosed with motor neurone disease.

'His support of the sciences, art, education and the NHS and charities such as the MND foundation will also live on as will his wickedly funny sense of humour.

'I will miss our margaritas but will raise one to the stars to celebrate your life and the light of understanding you shone so brightly on them for the rest of us. You were and are a true inspiration for me and for millions around the world. Thank you.'

Prime Minister Theresa May said Dr Hawking was 'a brilliant and extraordinary mind – one of the great scientists of his generation' whose 'courage, humour and determination to get the most from life was an inspiration'.

Professor Stephen Hawking's former personal assistant Judith Croasdell, 69, believes he died of a chest infection, something he suffers from annually around this time of year.

Remember to look up at the stars and not down at your feet. Try to make sense of what you see and wonder about what makes the universe exist. Be curious. And however difficult life may seem, there is always something you can do and succeed at. It matters that you don't just give up - Dr Stephen Hawking

Judith said: 'I believe he died of a chest infection, that is my guess. He had one every year and that would always bring him down but I think it got him this time.

'I didn't know that he was ill but it was seasonal, every year he would get worse and every year he would get this chest infection and you would think he would never survive.

'Its an awful shock, but he is gone.

'I would say he was the longest living man with motor neurone disease (MND) and after suffering from it for so long, it just crept up on him.

'To be honest I am just trying to take it in, I feel quite upset. I am devastated but not totally surprised because he was a miracle really.'

Hawking's most famous works included a mathematical model for Albert Einstein's General Theory of Relativity and the nature of the universe such as The Big Bang and Black Holes.

He wrote or co-wrote 15 books all in the face of severe health problems.

Paying tribute to him Astronomer Royal Professor Lord Martin Rees, who is emeritus professor of cosmology and astrophysics at the University of Cambridge, said: 'Tragedy struck Stephen Hawking when he was only 22. He was diagnosed with a deadly disease, and his expectations dropped to zero.

'He himself said that everything that happened since then was a bonus. And what a triumph his life has been.

'His name will live in the annals of science; millions have had their cosmic horizons widened by his best-selling books; and even more, around the world, have been inspired by a unique example of achievement against all the odds - a manifestation of amazing will-power and determination.'

Professor Hawking was last seen in public on December 13 in central London accompanied by a team of nurses

Dr Hawking was immortalised in the Oscar-winning biopic The Theory of Everything, where he was played by Eddie Redmayne and his many awards included the 2009 Presidential Medal of Freedom by Obama

Dr Hawking agreed to appear in The Simpsons and many other hit shows saying he wanted to make science more mainstream

Professor Brian Cox told BBC Radio 4's Today programme: 'I think he is one of the greats. There are many good theoretical physicists who make a big contribution, but there aren't that many greats.

Outpouring of grief after death of Stephen Hawking Social media went into meltdown today after the death of Stephen Hawking. His death emerged at around 3am today and has sparked thousands of tweets every minute from people paying tribute to the great scientist. Physicist James Hartle, whose work with Prof Hawking led to the Hartle-Hawking model of the universe's origins, said his colleague had 'inspired a lot of people'. Prof Hartle told BBC Radio 4's Today: 'What was unique about him was that he had a marvellous ability to see through all the clutter in physics and to see what the essential points are and that, of course, was a great thing for going forward.' He added: 'My memory of him would be on several fronts: first our work together, as a scientist, and second as a human being whose whole story is of triumph over adversity and who inspired a lot of people, including me.' Advertisement

'And by that I mean that I think there are physicists in a thousand years time, they will still be talking about Hawking radiation, they will be using his fundamental results on black holes.

'Actually, the last time I saw him at his 75th birthday party, he was talking about the new gravitational wave experiment where we've seen the collisions of black holes, and speculating that those results might be able to prove some of his theorems once and for all.

'Plus his contributions to the physics of the very early universe, so there are at least three and possibly more areas where his work will be remembered as long as there are cosmologists and that's the best you can hope for as a scientist.'

British astronaut Tim Peake said Prof Hawking 'inspired generations to look beyond our own blue planet and expand our understanding of the universe'.

'His personality and genius will be sorely missed. My thoughts are with his family,' he wrote on Twitter.

Inventor of the World Wide Web, Sir Tim Berners-Lee, tweeted: 'We have lost a colossal mind and a wonderful spirit. Rest in peace, Stephen Hawking.'

Nasa remembered Prof Hawking as a 'renowned physicist and ambassador of science'.

'His theories unlocked a universe of possibilities that we & the world are exploring. May you keep flying like superman in microgravity, as you said to astronauts on @Space-Station in 2014,' the organisation tweeted.

Indian Prime Minister Narendra Modi said Prof Hawking had 'made the world a better place' and that his death was 'anguishing'.

Pop superstar Katy Perry said 'there's a big black hole in my heart' following Prof Hawking's death.

Jonathan Ross lamented that humankind was significantly down on intelligence points following Prof Hawking's death.

'RIP Stephen Hawking. The world just dropped a lot of IQ points. And, he was a fun person. Very sad news,' the presenter tweeted.

Astrophysicist Neil deGrasse Tyson was one of the first to pay tribute to Professor Stephen Hawking following his death aged 76.

Sharing a photo of himself and Prof Hawking on Twitter, he said: 'His passing has left an intellectual vacuum in his wake. But it's not empty. Think of it as a kind of vacuum energy permeating the fabric of spacetime that defies measure. Stephen Hawking, RIP 1942-2018.'

Stephen Hawking as a baby with his father Dr Frank Hawking shortly after his birth in 1942

Stephen Hawking (left) is pictured as a child with his sisters Mary and Phillipa

Stephen Hawking with his Aunt Muriel on VE day in 1945 and aged 12 in the garden of his St Albans home in 1954

Stephen Hawking posing for a photo in his garden in St Albans, aged 12, with his bicycle in the snow

Stephen Hawking, who died this morning, aged 76, pictured coxing the rowing team in 1961, during his university days at Oxford

Stephen Hawking at his Oxford graduation after being awarded his degree in 1962

The flag at 14th century Gonville & Caius college was flying at half mast today as scores of students, academics and visitors queued up to sign a book of condolence in the foyer of the college chapel.

Isabelle Picard, 20, of Bromley, south London, who studies physics at Clare College, wrote: 'You inspired me to pursue physics and I thank you so much for that. Your bravery in the face of your illness is so inspirational and will always continue to inspire me. Thank you again.'

Isabelle added as she walked away 'He was an inspiration to so many people. He showed such bravery in the face of his own physical problems.'

Maddy Ducharme, 21, of Huntington Beach, California, who studies history at Pembroke College, Cambridge, wrote: 'You've inspired so many of us in Cambridge and all over the world. Thank you for your research, determination, optimism and wisdom. We are forever indebted to you.'

Maddy said after signing the book: 'His work was a testament to human determination and the ability to do anything, despite the odds. Everyone can be inspired by what he achieved. He was just a really wise and amazing person.'

Valentin Hübner, 20, of Vienna, Austria, who is studying maths at Pembroke College, wrote: 'I hope your biggest wonders lie ahead.'

He added: 'I saw Prof Hawking around Cambridge a couple of times. I signed the book because he was such an inspiring figure. He showed what humanity can achieve, despite being severely impaired.'

James Smith, 31, of Cambridge who is a researcher at the Department of War Studies at King's College, London, added: 'I signed the book to show my respects. He encouraged people to get involved in academia and research and set their sights high.'

Semi-retired counsellor Morven Baker, 66, of Wilmington, North Carolina, who is visiting Cambridge, said: 'He was a great man and I am honoured to be hear breathing the same air as he did.'

Jane and Stephen in the mis-1960s, shortly after his diagnosis with motor neurone disease and being given two years to live

Professor Stephen Hawking and his first wife Jane are pictured with children Robert, Lucy and Tim

Jane and Stephen divorced in 1991 in an acrimonious split that caused major tensions with his family

Professor Stephen Hawking was the Lucasian Professor of Mathematics at Cambridge University (pictured in 2000)

Hawking is shown at a press conference to announce Breakthrough Starshot, a new space exploration initiative, at One World Observatory on April 12, 2016 in New York City

Dr Hawking was born on January 8, 1942 in Oxford, England.

His family had moved to Oxford from north London to escape the threat of World War II rockets.

When he was 8, they moved St. Albans, a town about 20 miles north of the capital, where he would attend St Albans School and later University College, Oxford where his father attended.

His prodigious talent and unorthodox study methods meant he used few books and made no notes but could still solve problems like no other students.

He wanted to study mathematics but the subject was not available at the college so he chose physics instead.

In 1962, he went to the University of Cambridge's Department of Applied Mathematics and Theoretical Physics to conduct research in cosmology.

In 1965, he received his PhD with his thesis 'Properties of Expanding Universes' and would soon publish his first academic book 'The Large Scale Structure of Space-Time'.

At the age of 21, Hawking was diagnosed with amyotrophic lateral sclerosis (ALS), a nerve system disease that weakens muscles and impacts physical function.

But he continued his scientific work, appeared on television and married for a second time.

As one of Isaac Newton's successors as Lucasian Professor of Mathematics at Cambridge University, Hawking was involved in the search for the great goal of physics — a 'unified theory.'

Such a theory would resolve the contradictions between Einstein's General Theory of Relativity, which describes the laws of gravity that govern the motion of large objects like planets, and the Theory of Quantum Mechanics, which deals with the world of subatomic particles.

(L-R) British actress Felicity Jones, ex-wife of Stephen Hawking, Jane Wilde Hawking, British physicist Stephen Hawking, and British actor Eddie Redmayne arrive for the UK premiere of 'The Theory of Everything' in Leicester Square in London

Astrophysicist Hawking floats on a zero-gravity jet in April 2007. The modified jet carrying Hawking, physicians and nurses, and dozens of others first flew up to 24,000 feet over the Atlantic Ocean off Florida

Professor Hawking was even asked to use his mathematical genius to help England win the World Cup and perfect their penalties

FROM THE BIG BANG TO BLACK HOLES: HOW STEPHEN HAWKING HELPED EXPLAIN THE UNIVERSE'S BIGGEST MYSTERIES Stephen Hawking probed the very limits of human understanding both in the vastness of space and in the bizarre sub-molecular world of quantum theory. As well as numerous best-selling books, Hawking also published several important scientific papers during an illustrious research career. Through his groundbreaking theories, the legendary physicist examined the origins of the universe and helped explain the behaviour of black holes. Stephen Hawking, who sought to explain some of the most complicated questions of life while working under the shadow of a likely premature death, has died at 76 1970 Space-time in black holes One of Hawking's first key ideas was how space and time react within the brutal confines of black holes. Black holes are regions of space with a gravitational field so intense that no matter or radiation can escape. The objects are so powerful they bend time and space in bizarre ways, and in 1970 Hawking showed how black holes alter 'space-time'. 'Space-time' is a theory used by physicists to describe the fusion of 3D space and time into a four-dimensional continuum. Up until the '70s physicists had known Einstein's theory allowed for 'singularities' - points where space-time appeared to be infinitely curved. But it was unclear whether or not these singularities actually existed. Birkbeck College physicist Sir Roger Penrose showed that singularities do exist as they can form in black holes. Alongside Sir Penrose, Hawking applied the same idea to the universe in its entirety in 1970. They showed that Einstein's theory predicted a singularity in our distant past: The Big Bang. 1971-72 Black hole mechanics Black holes are regions of space with a gravitational field so intense that no matter or radiation can escape. Their field is so intense that they form their own set of physical laws unlike anything else in the universe. Hawking devised the second law of black holes, which states that the total surface area of a black hole will never get smaller. In separate work, Hawking sparked the 'no hair' theorem of black holes. This states that black holes can be characterised by three numbers – their mass, charge and angular momentum. The 'hair' in Hawking's idea is other information that disappears when it falls into the black hole. 1974-75 How black holes vanish Hawking showed that black holes emit heat and eventually vanish in an extremely slow process. While a black hole with the mass of the sun would take longer than the age of our universe to evaporate, smaller ones disappear faster. Near the end of their lives they release heat at a dramatic rate, with an average-sized black hole releasing the energy of a million hydrogen bombs in just a tenth of a second. Hawking's drew on 'quantum theory' for the finding - the branch of physics concerned with how the universe works at the subatomic level. Through his groundbreaking theories, the legendary physicist helped explain the behaviour of black holes (artist's impression) and examined the origins of the universe 1982 How galaxies arise Many physicists believe the universe inflated rapidly shortly after the Big Bang. Hawking was one of the first to show how galaxies may have formed during this explosion of time and space. He found that quantum fluctuations - tiny variations in the distribution of matter - grew into the galaxies that dot the cosmos today. This is because strong gravitational forces made matter clump together. Hawking's theory is supported by recent observations of the faint afterglow of the Big Bang, which spotted the sort of variations Hawking worked with. 1983 How the universe began Hawking is best known for his attempts to combine two key theories of physics: Quantum theory and Einstein's general relativity. While quantum theory covers how tiny subatomic particles stitch together the fabric of our universe, general relativity deals with larger objects. It describes how galaxies, stars, black holes, planets and more interact with one another via gravitational forces. Much of Hawking;s work focussed on combining quantum theory and general relativity with Einstein's theory of gravity. He suggested that this new theory, known as quantum gravity, could fill in many of the gaps of our current understanding of physics and the universe. In 1983 the physicist partnered with Chicago University's Professor Jim Hartle to propose a 'wave function of the universe'. Known as the Hartle-Hawking state, this notion is meant to figure out how the universe began through quantum mechanics. In theory, this could be used to understand the properties of the universe around us. 1988 A brief history of time Hawking's bestselling book A Brief History of Time has sold more than ten million copies since it was published in 1988. The book, which described the structure, origin, development and eventual fate of the universe, was a surprise success for the relatively unknown physicist, staying in the Sunday Times bestseller list for 237 weeks. Hawking wrote the book for readers with no knowledge of any scientific theories. The physicist joked himself that many who owned the book struggled to understand its complexity and never finished it. The book ultimately propelled Hawking to stardom, with the physicist publishing or co-publishing 15 books in total and writing or starring in multiple scientific documentaries, television shows, films and more. What happened before the Big Bang? At the time of the Big Bang 13.8 billion years ago, all matter in the universe erupted from a singularity to create the cosmos. But scientists are unsure what happened before then. In a recent TV interview, Hawking said 'nothing was around before the Big Bang'. Instead, time and space existed in a 'bent state' that was distorted along another dimension. The physicist believes the Big Bang was the formation of what we now regard as time because the event broke down the laws of physics. This means that anything that preceded it cannot be applied to our understanding of time and existence. By Harry Pettit, science and technology reporter Advertisement

For Hawking, the search was almost a religious quest — he said finding a 'theory of everything' would allow mankind to 'know the mind of God.'

He wrote in 'A Brief History of Time' that 'a complete, consistent unified theory is only the first step: our goal is a complete understanding of the events around us, and of our own existence.'

In later years, though, he suggested a unified theory might not exist.

He followed up in the book in 2001 with the more accessible sequel, 'The Universe in a Nutshell,' updating readers on concepts like super gravity, naked singularities and the possibility of an 11-dimensional universe.

Hawking said belief in a God who intervenes in the universe 'to make sure the good guys win or get rewarded in the next life' was wishful thinking.

'But one can't help asking the question: Why does the universe exist?' he said in 1991. 'I don't know an operational way to give the question or the answer, if there is one, a meaning. But it bothers me.'

The combination of his best-selling book and his almost total disability — for a while he could use a few fingers, later he could only tighten the muscles on his face — made him one of science's most recognizable faces.

U.S. President Barack Obama (R) presents the Medal of Freedom to physicist Hawking during a ceremony in the East Room of the White House August 12, 2009 in Washington, DC

In this file photo taken on May 14, 2008, South Africa former President Nelson Mandela (R) meets with British scientist Professor Hawking (L) in Johannesburg

The Queen meets Stephen Hawking during a reception for Leonard Cheshire Disability charity at St James's Palace in London in 2014

Pope Francis meets the eminent physicist at the Vatican on November 28, 2016

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.

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. The film focused still more attention on Hawking's remarkable achievements.

Some colleagues credited that celebrity with generating new enthusiasm for science.

His achievements and his longevity helped prove to many that even the most severe disabilities need not stop patients from living.

Richard Green, of the Motor Neurone Disease Association said Hawking met the classic definition of the disease, as 'the perfect mind trapped in an imperfect body.' He said Hawking had been an inspiration to people with the disease for many years.

Although it could take him minutes to compose answers to even simple questions Hawking said the disability did not impair his work.

It certainly did little to dampen his ambition to physically experience space himself: Hawking savored small bursts of weightlessness in 2007 when he was flown aboard a jet that made repeated dives to simulate zero-gravity.

Hawking had hoped to leave Earth's atmosphere altogether someday, a trip he often recommended to the rest of the planet's inhabitants.

'In the long run the human race should not have all its eggs in one basket, or on one planet,' Hawking said in 2008. 'I just hope we can avoid dropping the basket until then.'

Hawking first earned prominence for his theoretical work on black holes. Disproving the belief that black holes are so dense that nothing could escape their gravitational pull, he showed that black holes leak a tiny bit of light and other types of radiation, now known as 'Hawking radiation.'

'It came as a complete surprise,' said Gary Horowitz, a theoretical physicist at the University of California, Santa Barbara. 'It really was quite revolutionary.'

Horowitz said the find helped move scientists one step closer to cracking the unified theory.

Hawking's other major scientific contribution was to cosmology, the study of the universe's origin and evolution. Working with Jim Hartle of the University of California, Santa Barbara, Hawking proposed in 1983 that space and time might have no beginning and no end.

'Asking what happens before the Big Bang is like asking for a point one mile north of the North Pole,' he said.

Hawking addressing The Cambridge Union on November 21, 2017, in one of his final public appearances

'Life would be tragic, if it wasn't so funny': The wit and wisdom of Professor Stephen Hawking who said he owed his longevity 'to his work AND his sense of humour'

Dr Stephen Hawking's science will leave a lasting legacy but his words of wisdom and sense of humour will also be long remembered after his death aged 76 today.

Actor Eddie Redmayne, who played the physicist in the biopic The Theory Of Everything, has led tributes describing him as a 'beautiful mind' and 'the funniest man' he has ever met.

Dr Hawking was left unable to speak because of motor neurone disease but his words spread across the world using his famous voice synthesizer and through his writing.

He spoke plainly on understanding space, the meaning of life and his own battles with adversity, telling others his life showed: 'However difficult life may seem, there is always something you can do'.

And he was always willing to poke fun at himself and said famously: 'Life would be tragic, if it wasn't so funny'.

Here are some of the scientist's most memorable quotes:

Dr Stephen Hawking's words of wisdom and sense of humour will also be long remembered after his death aged 76 today

On the reason why the universe exists: 'If we find the answer to that, it would be the ultimate triumph of human reason - for then we would know the mind of God' - A Brief History Of Time, published 1988.

On being diagnosed with motor neurone disease: 'My expectations were reduced to zero when I was 21. Everything since then has been a bonus' - Interview in The New York Times, December 2004.

On black holes: 'Einstein was wrong when he said, 'God does not play dice'. Consideration of black holes suggests, not only that God does play dice, but that he sometimes confuses us by throwing them where they can't be seen' - The Nature Of Space And Time, published 1996.

On God: 'It is not necessary to invoke God to light the blue touch paper and set the universe going' - The Grand Design, published 2010.

On commercial success: 'I want my books sold on airport bookstalls' - Interview in The New York Times, December 2004.

On fame: 'The downside of my celebrity is that I cannot go anywhere in the world without being recognised. It is not enough for me to wear dark sunglasses and a wig. The wheelchair gives me away' - Interview on Israeli TV, December 2006.

On an imperfect world: 'Without imperfection, you or I would not exist' - In Into The Universe With Stephen Hawking, The Discovery Channel, 2010.

On euthanasia: 'The victim should have the right to end his life, if he wants. But I think it would be a great mistake. However bad life may seem, there is always something you can do, and succeed at. While there's life, there is hope' - Quoted in People's Daily Online, June 2006.

On intellectual showboating: 'People who boast about their IQ are losers' - Interview in The New York Times, December 2004.

On the possibility of contact between humans and aliens: 'I think it would be a disaster. The extraterrestrials would probably be far in advance of us. The history of advanced races meeting more primitive people on this planet is not very happy, and they were the same species. I think we should keep our heads low' - In Naked Science: Alien Contact, The National Geographic Channel, 2004.

On the importance of having a sense of humour: 'Life would be tragic if it weren't funny' - Interview in The New York Times, December 2004.

On death: 'I have lived with the prospect of an early death for the last 49 years. I'm not afraid of death, but I'm in no hurry to die. I have so much I want to do first' - Interview in The Guardian, May 2011.'

'Medical miracle' Stephen Hawking defied the odds for 55 years Stephen Hawking was one of the world's most acclaimed cosmologists, a medical miracle, and probably the galaxy's most unlikely superstar celebrity. After being diagnosed with a rare form of motor neurone disease in 1964 at the age of 22, he was given just a few years to live. Yet against all odds Professor Hawking celebrated his 70th birthday nearly half a century later as one of the most brilliant and famous scientists of the modern age. Despite being wheelchair-bound, almost completely paralysed and unable to speak except through his trademark voice synthesiser, he wrote a plethora of scientific papers that earned him comparisons with Albert Einstein and Sir Isaac Newton. At the same time he embraced popular culture with enthusiasm and humour, appearing in TV cartoon The Simpsons, starring in Star Trek and providing the voice-over for a British Telecom commercial that was later sampled on rock band Pink Floyd's The Division Bell album. His rise to fame and relationship with his first wife, Jane, was dramatised in a 2014 film, The Theory Of Everything, in which Eddie Redmayne put in an Oscar-winning performance as the physicist battling with a devastating illness. He was best known for his work on black holes, the mysterious infinitely dense regions of compressed matter where the normal laws of physics break down, which dominated the whole of his academic life. Hawking is pictured with his children Robert, Lucy & Tim and his first wife Jane Prof Hawking's crowning achievement was his prediction in the 1970s that black holes can emit energy, despite the classical view that nothing - not even light - can escape their gravity. Hawking Radiation, based on mathematical concepts arising from quantum mechanics, the branch of science that deals with the weird world of sub-atomic particles, eventually causes black holes to 'evaporate' and vanish, according to the theory. Had the existence of Hawking Radiation been proved by astronomers or physicists, it would almost certainly have earned Prof Hawking a Nobel Prize. As it turned out, the greatest scientific accolade eluded him until the time of this death. Born in Oxford on January 8 1942 - 300 years after the death of astronomer Galileo Galilei - Prof Hawking grew up in St Albans. He had a difficult time at the local public school and was persecuted as a 'swot' who was more interested in jazz, classical music and debating than sport and pop. Although not top of the class, he was good at maths and 'chaotically enthusiastic in chemistry'. As an undergraduate at Oxford, the young Hawking was so good at physics that he got through with little effort. He later calculated that his work there 'amounted to an average of just an hour a day' and commented: 'I'm not proud of this lack of work, I'm just describing my attitude at the time, which I shared with most of my fellow students. 'You were supposed to be brilliant without effort, or to accept your limitations and get a fourth-class degree.' Hawking got a first and went to Cambridge to begin work on his PhD, but already he was beginning to experience early symptoms of his illness. During his last year at Oxford he became clumsy, and twice fell over for no apparent reason. Shortly after his 21st birthday he went for tests, and at 22 he was diagnosed with motor neurone disease. The news came as an enormous shock that for a time plunged the budding academic into deep despair. But he was rescued by an old friend, Jane Wilde, who went on to become his first wife, giving him a family with three children. After a painful period coming to terms with his condition, Prof Hawking threw himself into his work. At one Royal Society meeting, the still-unknown Hawking interrupted a lecture by renowned astrophysicist Sir Fred Hoyle, then at the pinnacle of his career, to inform him that he had made a mistake. An irritated Sir Fred asked how Hawking presumed to know that his calculations were wrong. Hawking replied: 'Because I've worked them out in my head.' Eddie Redmayne won a Best Actor Oscar for his portrayal of Hawking in 2014 In the 1980s, Prof Hawking and Professor Jim Hartle, from the University of California at Santa Barbara, proposed a model of the universe which had no boundaries in space or time. The concept was described in his best-selling popular science book A Brief History Of Time, published in 1988, which sold 25 million copies worldwide. As well as razor sharp intellect, Prof Hawking also possessed an almost child-like sense of fun, which helped to endear him to members of the public. He booked a seat on Sir Richard Branson's Virgin Galactic sub-orbital space plane and rehearsed for the trip by floating inside a steep-diving Nasa aircraft - dubbed the 'vomit comet' - used to simulate weightlessness. On one wall of his office at Cambridge University was a clock depicting Homer Simpson, whose theory of a 'doughnut-shaped universe' he threatened to steal in an episode of the cartoon show. He is said to have glared at the clock whenever a visitor was late. From 1979 to 2009 he was Lucasian Professor of Mathematics at the university - a post once held by Sir Isaac Newton. He went on to become director of research in the university's Department of Applied Mathematics and Theoretical Physics. Upheaval in his personal life also hit the headlines, and in February 1990 he left Jane, his wife of 25 years, to set up home with one of his nurses, Elaine Mason. The couple married in September 1995 but divorced in 2006. Throughout his career Prof Hawking was showered with honorary degrees, medals, awards and prizes, and in 1982 he was made a CBE. But he also ruffled a few feathers within the scientific establishment with far-fetched statements about the existence of extraterrestrials, time travel, and the creation of humans through genetic engineering. He has also predicted the end of humanity, due to global warming, a new killer virus, or the impact of a large comet. In 2015 he teamed up with billionaire Yuri Milner who has launched a series of projects aimed at finding evidence of alien life. Hawking and his new bride Elaine Mason pose for pictures after the blessing of their wedding at St. Barnabus Church September 16, 1995 The decade-long Breakthrough Listen initiative aims to step up the Search for Extraterrestrial Intelligence (Seti) by listening out for alien signals with more sensitivity than ever before. The even bolder Starshot Initiative, announced in 2016, envisages sending tiny light-propelled robot space craft on a 20-year voyage to the Alpha Centauri star system. Meanwhile Prof Hawking's 'serious' work continued, focusing on the thorny question of what happens to all the information that disappears into a black hole. One of the fundamental tenets of physics is that information data can never be completely erased from the universe. A paper co-authored by Prof Hawking and published online in Physical Review Letters in June 2016 suggests that even after a black hole has evaporated, the information it consumed during its life remains in a fuzzy 'halo' - but not necessarily in the proper order. Prof Hawking outlined his theories about black holes in a series of Reith Lectures broadcast on BBC Radio 4 in January and February 2016. Press Association Advertisement

In 2004, he announced that he had revised his previous view that objects sucked into black holes simply disappeared, perhaps to enter an alternate universe. Instead, he said he believed objects could be spit out of black holes in a mangled form.

That new theory capped his three-decade struggle to explain a paradox in scientific thinking: How can objects really 'disappear' inside a black hole and leave no trace, as he long believed, when subatomic theory says matter can be transformed but never fully destroyed?

Hawking was born Jan. 8, 1942, in Oxford, and grew up in London and St. Albans, northwest of the capital. In 1959, he entered Oxford University and then went on to graduate work at Cambridge.

Signs of illness appeared in his first year of graduate school, and he was diagnosed with ALS, also known as Lou Gehrig's disease after the New York Yankee star who died of it. The disease usually kills within three to five years.

According to John Boslough, author of 'Stephen Hawking's Universe,' Hawking became deeply depressed. But as it became apparent that he was not going to die soon, his spirits recovered and he bore down on his work.

Brian Dickie, director of research at the Motor Neurone Disease Association, said only 5 percent of those diagnosed with ALS survive for 10 years or longer. Hawking, he added, 'really is at the extreme end of the scale when it comes to survival.'

Hawking married Jane Wilde in 1965 and they had three children, Robert, Lucy and Timothy.

Jane cared for Hawking for 20 years, until a grant from the United States paid for the 24-hour care he required.

He was inducted into the Royal Society in 1974 and received the Albert Einstein Award in 1978. In 1989, Queen Elizabeth II made him a Companion of Honor, one of the highest distinctions she can bestow.

He whizzed about Cambridge at surprising speed — usually with nurses or teaching assistants in his wake — traveled and lectured widely, and appeared to enjoy his fame.

He then retired from his chair as Lucasian Professor in 2009 and took up a research position with the Perimeter Institute for Theoretical Physics in Waterloo, Ontario.

Hawking divorced Jane in 1991, an acrimonious split that strained his relationship with their children.

Writing in her autobiographical 'Music to Move the Stars,' she said the strain of caring for Hawking for nearly three decades had left her feeling like 'a brittle, empty shell.'

Hawking married his one-time nurse Elaine Mason four years later, but the relationship was dogged by rumours of abuse.

Police investigated in 2004 after newspapers reported that he'd been beaten, suffering injuries including a broken wrist, gashes to the face and a cut lip, and was left stranded in his garden on the hottest day of the year.

Hawking called the charges 'completely false.' Police found no evidence of any abuse. Hawking and Mason separated in 2006.

Lucy Hawking said her father had an exasperating 'inability to accept that there is anything he cannot do.'

'I accept that there are some things I can't do,' he told The Associated Press in 1997. 'But they are mostly things I don't particularly want to do anyway.'

Then, grinning widely, he added, 'I seem to manage to do anything that I really want.'

'May you keep flying like superman in microgravity': The world of science and celebrity unite in grief as NASA, Katy Perry and Piers Morgan lead tributes to Stephen Hawking The world today paid tribute to physicist Stephen Hawking, who died today at the age of 76. The famed British theoretical physicist passed away peacefully at his home in Cambridge this morning after a long battle with motor neurone disease, his family has revealed. And the celebrity and scientific world, including NASA, Katy Perry, and Piers Morgan, took to Twitter to pay their respects to the father of three. Posting a video, NASA tweeted: 'Remembering Stephen Hawking, a renowned physicist and ambassador of science. His theories unlocked a universe of possibilities that we & the world are exploring. 'May you keep flying like superman in microgravity, as you said to astronauts on @Space_Station in 2014.' British TV presenter Jonathan Ross tweeted: 'RIP Stephen Hawking. The world just dropped a lot of IQ points. And, he was a fun person. Very sad news.' Good Morning Britain host Piers Morgan wrote: 'RIP Professor Stephen Hawking, 76. The world's most brilliant man, and someone who never stopped wondering 'Why?' What a life. What a genius.' American pop star Katy Perry said: 'there's a big black hole in my heart hours before Pi day. Rest In Peace... See you in the next'. Comedian David Walliams posted a picture of himself with Hawking on TV show Little Britain, with the caption: 'Goodbye #StephenHawking. Thank you for being - amongst everything else - a great laugh.' While fellow science educator, American astrophysicist Neil deGrasse Tyson, tweeted his own tribute: 'His passing has left an intellectual vacuum in his wake. But it's not empty. Think of it as a kind of vacuum energy permeating the fabric of spacetime that defies measure. Stephen Hawking, RIP 1942-2018.' Simpsons executive producer Matt Selman shared a screen shot of an animated Hawking talking with Homer at a bar with the caption: 'Farewell to Stephen Hawking, the most intelligent guest star in the brief history of The Simpsons'. He will be remembered: The late theoretical physicist received an outpouring of love and kind wishes from celebrities around the world Maria Shriver wrote: 'A new star is in the heavens tonight. Rest in peace, Stephen Hawking. Your advice and wisdom live on.' Kaley Cuoco, who got to work with Professor Hawking when he appeared on a 2012 episode of TV series The Big Bang Theory, Titled The Hawking Excitation, shared an image of herself and her cast members with the celebrated scientist on set. She wrote alongside the image on Instagram: 'It was truly such an honor getting to work with the incredible Stephen Hawking.. He made us laugh and we made him laugh. 'His life and career workings have been many a subject matter on [The Big Bang Theory] and we are all better for it. You will be missed but the world is grateful for the knowledge and courage you leave in your path. Thank you for being an inspiration to everyone'. Actress Zoe Saldana wrote on Twitter: 'Farewell to a brilliant mind. Thank you for being so generous with your knowledge in the brief time you were with us.' Kumail Nanjiani paid tribute, writing: 'RIP Stephen Hawking. Genuinely very sad to hear that. If you haven't, read A Brief History of Time. It'll make the world feel more amazing and beautiful and strange. It'll also make you feel smart and stupid all at once.' Actress Mira Sorvino shared how much the physicist influenced her thinking early in life: 'I am very saddened to hear of Stephen Hawking's passing. His book was an enormous influence on me in college and meeting and getting to talk with him was one of the great thrills of my life. You are shining in the heavens you so loved now!' In a statement Professor Hawking's children, Lucy, Robert and Tim said: 'We are deeply saddened that our beloved father passed away today. 'He was a great scientist and an extraordinary man whose work and legacy will live on for many years.' The family praised Hawking's 'courage and persistence' that inspired people across the world. 'He once said, 'It would not be much of a universe if it wasn't home to the people you love.' We will miss him forever.' Advertisement

'The most intelligent guest star in the brief history of The Simpsons': How Stephen Hawking won over legions of new fans with guest roles in hits including The Big Bang Theory, Futurama and Star Trek

Stephen Hawking may have become a household name for his work in theoretical physics, but the scientist appeared on some of the largest shows on television.

Hawking, who passed away in the early hours of Wednesday at 76, was not one to shy away from doing the occasional acting gig and always gave the green-light for making jokes at his expense.

'Farewell to Stephen Hawking, the most intelligent guest star in the brief history of The Simpsons,' said the iconic show's executive producer Matt Selman.

Stephen Hawking, who passed away on Tuesday at age 76, was not one to shy away from doing the occasional acting gig. The theoretical physicists was often the butt of his own jokes which highlighted his life with ALS and his computerized voice (Appearing on the Simpsons)

'Farewell to Stephen Hawking, the most intelligent guest star in the brief history of The Simpsons,' said the iconic show's executive producer Matt Selman

Hawking played a guest role as himself on the Simpsons for several episodes from 1999 until 2010.

One particular episode - 'They Saved Lisa's Brain - featured the renowned author traveling to Springfield, Illinois, to inform the masses that their idea of utopia would fail.

The minor Hollywood celebrity would also do a couple of appearances on the adult-animated show Futurama.

He appeared on the wacky show's second season as himself but would find most of his body gone when he appeared in a later episode with just his head.

Time with Futurama: He appeared on the wacky show's second season as himself but would find most of his body gone when he appeared in a later episode with just his head

Hawking acting credit spans almost three decades, as evident in an appearance he had on Star Trek: The Next Generation in 1993

During the season six finale, Lt. Commander Data can be seen playing poker with 'hologram' versions of Hawking, Albert Einstein, and Isaac Newton

Norman Cook took to Instagram to share how working with Hawking was an 'honor'

Hawking was written into an episode of Family Guy, but that character was voiced by Seth McFarlane

During his time on that particular show, Hawking was a part of Vice Presidential Action Rangers - led by Al Gore - and worked to maintain the space-time continuum.

Hawking acting credit spans almost three decades, as evident in an appearance he had on Star Trek: The Next Generation in 1993.

During the season six finale, Lt. Commander Data can be seen playing poker with 'hologram' versions of Hawking, Albert Einstein, and Isaac Newton.

The physicist was an avid Trekkie, even going so far as to have Spock himself - Leonard Nimoy - offer some remarks about Hawking at a screening for 'A Brief History of Time.'

But Hawking spent the majority of his screen time on the ever so loved nerd show 'Big Bang Theory.'

Appearing in seven episodes, Hawking is a favorite of the main characters, but especially Sheldon.

Sheldon is even lucky when Hawking appears on Skype to wish him a happy birthday for the series 200th episode.

Hawking spent the majority of his screen time on the ever so loved nerd show 'Big Bang Theory'

He appeared on seven episodes, including the 200th one where he sang happy birthday to Sheldon via Skype

The scientist also had a movie about his life come out in 2014 called 'The Theory of Everything.' The film was nominated for Best Picture and Eddie Redmayne played Hawking, won a Best Actor Oscar for his performance

Hawking was written into an episode of Family Guy, but that character was voiced by Seth McFarlane. He also is referenced throughout several other shows like Doctor Who, Malcolm in the Middle, Dexter's Laboratory, and Seinfeld.

The scientist also had a movie about his life come out in 2014 called 'The Theory of Everything.' The film was nominated for Best Picture and Eddie Redmayne played Hawking, winning a Best Actor Oscar for his performance.

Hawking would make other television appearances such as: Last Week Tonight with John Oliver, Late Night with Conan O'Brien, The Culture Show, Alien Planet and more.

From a cheeky schoolboy posing next to his sisters, to 'floating in space': The extraordinary life in pictures of Stephen Hawking

Stephen Hawking was one of the world's most acclaimed cosmologists, a medical miracle, and probably the galaxy's most unlikely superstar celebrity.

After being diagnosed with a rare form of motor neurone disease in 1964 at the age of 22, he was given just a few years to live.

Yet against all odds Professor Hawking celebrated his 70th birthday nearly half a century later as one of the most brilliant and famous scientists of the modern age.

He died today at his home in Cambridge, aged, 76, and tributes have flooded in from all over the world.

Here, MailOnline looks at his life in pictures....

Stephen Hawking (left) pictured as a young boy, with his baby sister Mary. Professor Hawking died today, aged 76

Stephen Hawking fishing when he was a young boy (left) and in the garden before school, aged, 12 (right)

British cosmologist Stephen Hawking on October 10, 1979 in Princeton, New Jersey, USA

Graduate assistant Colin P. Williams talks with physicist Stephen Hawking at Harvard University in Cambridge, MA on Apr. 12, 1984 (left) and Mr Hawking with his first wife, Jane, receiving an honorary degree from Cambridge University in 1989 (right)

Stephen Hawking pictured in 1988 on Master of the Universe - a documentary television series produced by Channel 4

Stephen Hawking and his first wife, Jane, at Cambridge University in 1989, where the professor was awarded an honorary degree

The Queen Mother with Professor Stephen Hawking during her visit to Queen's College, University of Cambridge, 10 June 1992

Professor Stephen Hawking and Nobel Prize winner Dorothy Hodgkin, with their portraits unveiled at the National Portrait Gallery in London in 1992

Professor Stephen Hawking pictured on his wedding day after marrying for the second time to former nurse Elaine

A kiss for scientist and theorist Stephen Hawking from his new bride Elaine Mason after their civil wedding September 15, 1995

Professor Stephen Hawking, pictured at a Waterstone Lecture at the Royal Albert Hall in London in 1995

Professor Stephen Hawking and his second wife, Elaine, at a photocall at Cambridge University on his 60th birthday in 2002

Stephen and Elaine Hawking at the Premiere of Lemony Snicket's A Series of Unfortunate Events at the Empire in Leicester Square, London, in 2004

Astrophysicist Stephen Hawking is assisted off the tarmac at the Kennedy Space Center by his caregiver, Monica Guy, as he is applauded by members of the flight crew after completing a zero-gravity flight, Thursday, April 26, 2007, in Cape Canaveral, Florida

Professor Stephen Hawking, in 2007, in front of a bust of himself, which was unveiled in Cambridge University's Centre for Theoretical Cosmology

Professor Stephen Hawking at The Royal Society in London during a press conference previewing the Starmus science and arts festival

Former South African President Nelson Mandela meets with British scientist Professor Stephen Hawking in Johannesburg in 2008

Professor Stephen Hawking delivers a speech entitled 'Why We Should Go Into Space' at the The George Washington University in Washington DC in April 2008

Professor Stephen Hawking during the unveiling of The Corpus Clock, a new installation at Corpus Christi College at Cambridge University in September 2008

The world's most famous scientist Prof Stephen Hawking at the opening of Cambridge University's new Centre for Mathematical Sciences where his work is based

U.S. President Barack Obama presents the Medal of Freedom to physicist Stephen Hawking during a ceremony in the East Room of the White House on August 12, 2009

Professor Stephen Hawking in 2010 watching the first preview of his show for the Discovery Channel, Stephen Hawking's Universe

Cast member actress Jane Fonda (who portrays a Musicologist with ALS) (L) and Physicist Stephen Hawking (R) pose backstage after a preview performance of '33 Variations' at Center Theatre Group's Ahmanson Theatre on February 1, 2011 in Los Angeles

Professor Stephen Hawking at the Premier of the biopic of his life, 'Hawking', which is premiering at a Gala performance at Emmanuel College in Cambridge in September 2013

Professor Stephen Hawking speaks to media at a press conference in 2014, at the Savoy Hotel, to launch the formula of how England can win the football World Cup

Professor Stephen Hawking and Benedict Cumberbatch Motor Neurone Disease Association reception and dinner, in Buckingham Palace, London, in March 2015

Eddie Redmayne (who played Hawking in The Theory of Everything) and Professor Stephen Hawking at the after-party dinner for the EE British Academy Film Awards at Grosvenor House Hotel in London

Stephen Hawking attends the Pride Of Britain awards at the Grosvenor House Hotel on October 31, 2016 in London

Pope Francis greets physicist Stephen Hawking during an audience with participants at a plenary session of the Pontifical Academy of Sciences, at the Vatican in 2016

Professor Stephen Hawking onstage during the New Space Exploration Initiative 'Breakthrough Starshot' Announcement at One World Observatory on April 12, 2016 in New York City

British scientist Stephen Hawking addresses the media while a picture of the cosmos is shown on a video screen during a press conference on top of One World Trade Center in New York, April 12, 2016

Professor Stephen Hawking, in July 2017, talking about his life and work during a public symposium to celebrate his 75th birthday at Lady Mitchell Hall in Cambridge

Stephen Hawking's final warning to humanity: Legendary physicist believed we must leave Earth in the next 200 years or face EXTINCTION Humans must leave Earth in the next 200 years if we want to survive. That was the stark warning issued by Professor Stephen Hawking in the months before his death today at the age of 76. The legendary physicists believed that life on Earth could be wiped out by a disaster such as an asteroid strike, AI or an alien invasion. He also warned over-population, human aggression and climate change could cause humanity to self-destruct. He believed, if our species had any hope of survival, future generations would need to forge a new life in space. CLIMATE CHANGE Hawking said that Earth (stock image) will one day look like the 460°C (860°F) planet Venus if we don't cut greenhouse gas emissions One of Hawking's main fears for the planet was global warming. 'Our physical resources are being drained, at an alarming rate. We have given our planet the disastrous gift of climate change,' Hawking warned in July. 'Rising temperatures, reduction of the polar ice caps, deforestation, and decimation of animal species. We can be an ignorant, unthinking lot.' Hawking said that Earth will one day look like the 460°C (860°F) planet Venus if we don't cut greenhouse gas emissions. 'Next time you meet a climate change denier, tell them to take a trip to Venus. I will pay the fare,' Hawking quipped. The physicist also believed President Donald Trump's decision to withdraw from the Paris Climate Agreement has doomed our planet. He warned Trump's decision would caused avoidable damage to our 'beautiful planet' for generations to come. 'We are close to the tipping point where global warming becomes irreversible,' the celebrated scientist told BBC last year. ASTEROID STRIKES If global warming doesn't wipe us out, Hawking believed Earth would be destroyed by an asteroid strike (stock image) If global warming doesn't wipe us out, Hawking believed Earth would be destroyed by an asteroid strike. 'This is not science fiction. It is guaranteed by the laws of physics and probability,' he said. 'To stay risks being annihilated. 'Spreading out into space will completely change the future of humanity. It may also determine whether we have any future at all.' Hawking was working with Russian billionaire Yuri Milner's Breakthrough Starshot project to send a fleet of tiny 'nanocraft' carrying light sails on a four light-year journey to Alpha Centauri, the nearest star system to Earth. 'If we succeed we will send a probe to Alpha Centauri within the lifetime of some of you alive today,' he said. Astronomers estimate that there is a reasonable chance of an Earth-like planet existing in the 'habitable zones' of Alpha Centauri's three-star system. 'It is clear we are entering a new space age. We are standing at the threshold of a new era', said Hawking. 'Human colonisation and other planets is no longer science fiction, it can be science fact.' Hawking believed that In the long run the human race should not have all its eggs in one basket, or on one planet. 'I just hope we can avoid dropping the basket until then', he said. AI VERSUS HUMANS Hawking even went so far as to say that AI may replace humans altogether, although he didn't specify a timeline for his predictions (stock image) Hawking claimed that AI will soon reach a level where it will be a 'new form of life that will outperform humans.' He even went so far as to say that AI may replace humans altogether, although he didn't specify a timeline for his predictions. The chilling comments during a recent interview with Wired. He said: 'The genie is out of the bottle. I fear that AI may replace humans altogether. 'If people design computer viruses, someone will design AI that improves and replicates itself. 'This will be a new form of life that outperforms humans.' He also he said the AI apocalypse was impending and 'some form of government' would be needed to control the technology. During the interview, Hawking also urged more people to take an interest in science, claiming that there would be 'serious consequences' if this didn't happen. AGGRESSION Hawking has previously warned aggression is humanity's biggest failing and could 'destroy it all'. The remark was made back in 2015 in response to a question about what human shortcomings he would change. Talking to an audience in the Science Museum, the renowned scientist said 'The human failing I would most like to correct is aggression'. 'It may have had survival advantage in caveman days, to get more food, territory or a partner with whom to reproduce, but now it threatens to destroy us all', writes the Independent. He said he feared evolution has 'inbuilt' it into the human genome, commenting that there was no sign of conflict lessening. What's more, he said the development of militarised technology and weapons of mass destruction could make this instinct even more dangerous. He said empathy was the best of human emotions and meant we could be brought together in a loving state. ALIENS Humans must leave Earth within 200 years if we want to survive. That was the stark warning issued by Professor Stephen Hawking in the months before he death today at the age of 76 Hawking also warned that if we ever did find aliens they would probably wipe us out. 'As I grow older I am more convinced than ever that we are not alone,' he said in a video posted online called Stephen Hawking's Favourite Places. The clip showed him visiting different locations across the cosmos, writes the Independent. One of the places he visits is Gliese 832c, a planet that people speculate could be home to alien life. 'One day we might receive a signal from a planet like Gliese 832c, but we should be wary of answering back. 'Meeting an advanced civilization could be like Native Americans encountering Columbus. That didn't turn out so well', he said. Hawking became increasing convinced there was other life out there as he got older and he led a new project called the Breakthrough Listen project to find out. He said that any alien civilisation would be 'vastly more powerful and may not see us as any more valuable than we see bacteria.' OVERPOPULATION The renowned scientist also warned that a man-made catastrophe could spell the end for our species. 'For me, the really concerning aspect of this is that now, more than at any time in our history, our species needs to work together,' Hawking said in a Guardian opinion piece in 2016. 'We face awesome environmental challenges: climate change, food production, overpopulation, the decimation of other species, epidemic disease, acidification of the oceans. 'Together, they are a reminder that we are at the most dangerous moment in the development of humanity', he said. In November 2016, Hawking was more conservative in his estimates. He warned that humans could not survive another 1,000 years on 'fragile' Earth. At a talk in Cambridge, Hawking gave a one-hour whirlwind history of man's understanding of the origin of the universe from primordial creation myths to the most cutting edge predictions made by 'M-theory'. He said: 'Perhaps one day we will be able to use gravitational waves to look back into the heart of the Big Bang. 'Most recent advances in cosmology have been achieved from space where there are uninterrupted views of our Universe but we must also continue to go into space for the future of humanity. 'I don't think we will survive another 1,000 years without escaping our fragile planet.' Hawking, who has said he wanted to go into space on Virgin boss Richard Branson's Ride Virgin Atlantic spaceship, continued: 'I therefore want to encourage public interest in space, and I have been getting my training in early.' Hawking added: 'It has been a glorious time to be alive and doing research in theoretical physics. 'Our picture of the universe has changed a great deal in the last 50 years and I am happy if I have made a small contribution. 'The fact that we humans who are ourselves mere collections of fundamental particles of nature have been able to come so close to understanding the laws that are governing us and our universe is a great achievement.' Hawking has previously described his views on the future of space travel, in the afterword of the book, 'How to Make a Spaceship.' He said: 'I believe that life on Earth is at an ever-increasing risk of being wiped out by a disaster, such as a sudden nuclear war, a genetically engineered virus, or other dangers,' he said. 'I think the human race has no future if it doesn't go to space.' Making a poignant plea to his young audience of students from the University of Oxford, where he himself did his undergraduate degree, he said: 'Remember to look up to the stars and not down at your feet. 'Try to make sense of what you see and wonder about what makes the universe exist. 'Be curious and however life may seem there's always something you can do and succeed at - it matters that you don't just give up.' Advertisement

'There is no heaven or afterlife, that is a fairy story': How Stephen Hawking confronted the dark realities of his own death

Professor Stephen Hawking passed away today at the age of 76, after battling motor neuron disease for 55 years.

He lived with the prospect of an early death for decades - and it made him confront its dark realities head on.

The physicist famously said 'there is no heaven or afterlife', describing the belief that we live on after death as a 'fairy story'.

He believed that living your best life was more important than hoping for a heaven.

One of the most brilliant minds of all-time, and the leading scholar on the topic of black holes, Professor Stephen Hawking (pictured) believed that life after death was a myth

Professor Hawking attended the University of Cambridge and became ill with the degenerative condition in 1963.

With an initial diagnosis of two years left to live, Hawking defied all odds.

'I have lived with the prospect of an early death for the last 49 years,' Professor Hawking told The Guardian in 2011.

WHAT IS MOTOR NEURONE DISEASE? Motor neurone disease is a rare condition that mainly affects people in their 60s and 70s, but it can affect adults of all ages. It's caused by a problem with cells in the brain and nerves called motor neurones. These cells gradually stop working over time. It's not known why this happens. Having a close relative with motor neurone disease, or a related condition called frontotemporal dementia, can sometimes mean you're more likely to get it. But it doesn't run in families in most cases. Early symptoms can include weakness in your ankle or leg, like finding it hard to walk upstairs; slurred speech, finding it hard to swallow, a weak grip, and gradual weight loss If you have these sympthoms, you should see a GP. They will consider other possible conditions and can refer you to a specialist called a neurologist if necessary. If a close relative has motor neurone disease or frontotemporal dementia and you're worried you may be at risk of it – they may refer you to a genetic counsellor to talk about your risk and any tests you can have Source: NHS UK Advertisement

'I'm not afraid of death, but I'm in no hurry to die. I have so much I want to do first.'

With such a philosophical approach to life and possessing one of the most analytical minds the world has ever seen, Professor Hawking was inspirational in his strength.

Although the man inspired millions through his books, lectures, theories and the recent biopic about his life, Professor Hawking did not believe in life after death.

In the same 2011 interview, he said: 'I regard the brain as a computer which will stop working when its components fail.

'There is no heaven or afterlife for broken down computers; that is a fairy story for people afraid of the dark.'

For many, the comfort of an after life is something which offers reassurance approaching death.

In the case of Professor Hawking, he believed that living your best life was more important than hoping for a heaven.

'We should seek the greatest value of our action,' he said, when asked how we should live.

Professor Hawking founded many theories which gave birth to the modern field of quantum physics.

Arguably the person who understood the foundation of the universe better than anyone, it offered a unique perspective to him.

'Science predicts that many different kinds of universe will be spontaneously created out of nothing. It is a matter of chance which we are in,' he said.

Hawking was a long-time critic of the idea of a deity and religions.

He believed that it was natural for people to believe in an all-powerful God before science offered an explanation.

In his opinion, science offered a clearer and more thorough explanation than faith.

Some religious advocates took the words that Hawking used to end his famous book A Brief History Of Time, as his belief in a God.

The final sentence read: 'It would be the ultimate triumph of human reason – for then we should know the mind of God'.

In his later publication, The Grand Design, he clarified that this comment was meant metaphorically, not literally.

He believed that it wasn't necessary for a creator to have begun the universe.

Before he became ill, Professor Stephen Hawking attended and worked at the University of Cambridge (pictured). After graduating and achieving academic distinction, he was based in Cambridge as an academic for the rest of his life where he developed his theories

This then, put him in direct contradiction with the people who had made use of that quote.

'What I meant by 'we would know the mind of God' is, we would know everything that God would know, if there were a God. Which there isn't. I'm an atheist,' he told El Mundo.

'When people ask me if a god created the universe, I tell them that the question itself makes no sense.

'Time didn't exist before the Big Bang, so there is no time for God to make the universe in.

'It's like asking directions to the edge of the earth; The Earth is a sphere; it doesn't have an edge; so looking for it is a futile exercise.'

Professor Hawking captured the public's imagination as a trapped mind exploring the boundaries of scientific knowledge.

While he allowed for the potential identification of God with the laws of nature, he thoroughly rejected the idea of 'a human-like being' with whom one could have a personal relationship.

Speaking to El Mundo, he added: 'We are each free to believe what we want, and it's my view that the simplest explanation is; there is no god.

'No one created our universe, and no one directs our fate. This leads me to a profound realisation; There is probably no heaven, and no afterlife either.

'We have this one life to appreciate the grand design of the universe, and for that I am extremely grateful.'

In an interview with Reuters in 2007, Hawking said 'I believe the universe is governed by the laws of science', and that 'the laws may have been decreed by God, but God does not intervene to break the laws.'

Speaking in 2010, a few months before the publication of The Great Design, he told ABC News' Diane Sawyer: 'When you look at the vast size of the universe and how insignificant an accidental human life is in it, that seems most impossible.

'There is a fundamental difference between religion, which is based on authority, [and] science, which is based on observation and reason,' he added. 'Science will win because it works.'

Distancing himself further from the idea of a universal creator in The Grand Design itself, he added: 'Spontaneous creation is the reason there is something rather than nothing, why the universe exists, why we exist.

'It is not necessary to invoke God to light the blue touch paper and set the universe going.

Hawking presented his ideas on the origin of the universe at various scientific conferences organised at the Vatican over the years, as a member of the Pontifical Academy of Sciences.

He met with Pope John Paul II, Pope Benedict XVI and Pope Francis on a number of occasions.

In 2006, the physicist recalled Pope John Paul II discouraging scientists from studying the creation of the universe as that was God's work.

He joked about the pontiff ignoring he had presented a paper at the conference precisely on that topic.

'I didn't fancy the thought of being handed over to the Inquisition like Galileo,' Hawking quipped.

That didn't stop him from discussing his no-boundary proposal on the creation of the universe at the Vatican, a decade later.

'Asking what came before the Big Bang is meaningless because there is no notion of time available to refer to,' he said at the Pontifical Academy of Sciences in 2016.