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Who Was Stephen Hawking?

Stephen Hawking was an English theoretical physicist whose work on black holes changed how scientists understand the universe, and whose book A Brief History of Time made him one of the most famous scientists who ever lived. Born in Oxford in 1942 and diagnosed in his early twenties with a degenerative disease that gradually took away his ability to move and to speak, he went on to hold the Lucasian professorship of mathematics at Cambridge, a chair once held by Isaac Newton, and to produce the prediction that black holes emit radiation, now known as Hawking radiation. He wrote best-selling books, appeared in popular culture, and became a public voice on the future of humanity, warning about artificial intelligence, about contact with alien life and about the need to explore space. He died in Cambridge in 2018, aged 76. This article explains his science in plain language, his life, and why his ideas still matter.

Last updated: 13 November 2026

1. Oxford childhood and Cambridge

Stephen William Hawking was born on 8 January 1942 in Oxford, England, where his parents had moved from London to escape the bombing of the Second World War. His father was a research biologist and his mother had studied philosophy, politics and economics at Oxford, and the household was academic and unconventional. As a boy he was fascinated by how things worked, taking apart clocks and radios, and he was a keen, if not outstanding, schoolboy. He studied physics at University College, Oxford, graduating with a bachelor's degree in 1962, and then moved to Trinity Hall, Cambridge, to study for a doctorate in cosmology, the science of the origin and structure of the universe.

At Cambridge he worked on the physics of the beginning of the universe, a subject that was then in the middle of a revolution. The discovery of the cosmic microwave background, the faint radiation left over from the Big Bang, had shown that the universe had a beginning, and the question was what the laws of physics could say about it. Hawking's doctoral thesis, completed in 1966, was on the properties of expanding universes, and it already showed the style that would define his career: the use of mathematics to ask questions about the universe that seemed, at first, unanswerable. He was elected a research fellow at Gonville and Caius College at Cambridge, and he stayed at Cambridge for the rest of his life.

His early work was done with Roger Penrose, a mathematician at Oxford, and it produced the singularity theorems, which showed that the universe must have begun in a singularity, a point of infinite density, and that black holes must contain singularities too. The theorems were a major achievement, and they established Hawking, in his twenties, as one of the leading cosmologists in the world. The work was abstract and mathematical, but it had a concrete implication: the universe had a beginning, and the laws of physics as then understood broke down at that beginning. That implication would occupy him for the rest of his career.

2. The diagnosis that changed everything

In the early 1960s, while he was a student at Oxford and then at Cambridge, Hawking began to notice that he was becoming clumsy, dropping things and falling over. In 1963, at the age of 21, he was diagnosed with amyotrophic lateral sclerosis, a degenerative disease of the nerve cells that control movement, and he was told that he had only a few years to live. The diagnosis, and the prognosis, were devastating, and he has written that he fell into a depression, wondering whether there was any point in continuing his work. He met Jane Wilde, a student of languages, at a New Year's party, and they married in 1965. He has said that the engagement gave him a reason to live, and that the prospect of marriage made him determined to continue.

The disease progressed slowly, much more slowly than doctors had expected, and Hawking continued to work for more than fifty years after the diagnosis. By the late 1960s he was using a wheelchair, and by the 1980s he had lost the ability to speak clearly. In 1985, after an illness, he had a tracheotomy, an operation that removed his ability to speak altogether, and he began to communicate through a computerised speech synthesiser, operated at first by a hand switch and later by a sensor that detected movements of his cheek. The computer voice, with its American accent, became one of the most recognisable sounds in the world, and Hawking, who was offered a more natural-sounding voice, chose to keep it because it had become his identity.

It is important to write about Hawking's disability with respect, and to avoid the sentimental language that often surrounded him. He was not defined by his disease, and he disliked being treated as an inspiration simply for continuing to work. He used a wheelchair, and he communicated through a synthesiser, and those facts are part of his life, but they are not the explanation of his science. His science was the product of his mind, and his mind was unaffected by the disease. The long survival after a diagnosis of a few years was unusual, and doctors have never fully explained it, but it allowed him to do the work that made him famous. The biography on this site gives the verified facts; the point here is that the disability was a condition of his life, not its meaning.

3. Black holes and Hawking radiation

Hawking's most famous scientific prediction was made in 1974, and it is known as Hawking radiation. A black hole is a region of space where gravity is so strong that nothing, not even light, can escape from it. Before Hawking, physicists believed that black holes were, in effect, black: they absorbed everything and emitted nothing, and nothing could be known about what happened inside them. Hawking showed, by combining the theory of general relativity, which describes gravity, with quantum theory, which describes the behaviour of particles at the smallest scales, that black holes should in fact emit subatomic particles, slowly losing energy and mass until they eventually evaporate. The prediction was startling, because it suggested that black holes were not entirely black, and that they had a temperature.

The idea can be explained, in simplified form, like this. Quantum theory says that empty space is never truly empty: pairs of particles and antiparticles are constantly appearing and disappearing. Near the edge of a black hole, the event horizon, one member of such a pair can fall into the black hole while the other escapes, carrying energy away. To an observer far away, the black hole appears to be emitting radiation. The effect is tiny for large black holes, and it has never been directly observed, because the radiation from a black hole of the size formed by a collapsed star would be far too faint to detect. But the prediction has been accepted by most physicists, because it follows from the combination of two well-tested theories, and it has become one of the most important ideas in modern physics.

Hawking radiation mattered for a second reason: it connected black holes to the laws of thermodynamics, the laws that govern heat and energy. Before Hawking, black holes seemed to violate those laws, because they appeared to destroy information. Hawking's work showed that black holes had a temperature and an entropy, a measure of disorder, and that they obeyed the laws of thermodynamics after all. The discovery opened a new field, the study of the quantum properties of black holes, and it led to the black hole information paradox, the question of what happens to information that falls into a black hole. Hawking argued for many years that information was destroyed; in 2004 he conceded that it was not, a change of mind that was widely reported and that showed his willingness to admit when he was wrong.

4. The singularity theorems and the no-boundary proposal

Hawking's work with Penrose in the 1960s, the singularity theorems, showed that the universe must have begun in a singularity and that the collapse of a star must end in one. The theorems were mathematical, but they had a philosophical implication that Hawking returned to again and again: if the universe began in a singularity, then the laws of physics as we know them could not describe the beginning, because they break down at a singularity. That raised the question of whether the universe needed a creator, or whether it could explain itself, and Hawking's later work was an attempt to answer it.

In 1983, with the physicist James Hartle, he proposed the no-boundary proposal, an idea about the beginning of the universe that removed the need for a singularity. The proposal suggested that the universe had no boundary in time, in the sense that time itself behaved like space in the very early universe, and that the universe could have come into being without a single moment of creation. The idea is difficult to explain without mathematics, and it remains a proposal rather than a proven theory, but it showed Hawking's ambition: to find a description of the universe that was complete and self-contained, needing no outside cause. He returned to the idea in his later books, and it remains one of his most discussed contributions.

Hawking also worked on the idea of mini black holes, tiny black holes that he suggested in 1971 might have formed in the moments after the Big Bang, each containing as much as a billion tons of mass but occupying only the space of a proton. Such objects, if they existed, would be governed by both relativity and quantum mechanics, and their discovery would confirm his theories. None has ever been found, and the idea remains speculative, but it shows the range of his thinking: from the largest structures in the universe to the smallest, and from the beginning of time to its end.

5. A Brief History of Time and the public scientist

In 1988 Hawking published A Brief History of Time: From the Big Bang to Black Holes, a book that explained cosmology to a general audience and became one of the best-selling science books of all time. The book was written while he was already unable to speak, and it was composed using his speech synthesiser, a sentence at a time. It stayed on the bestseller lists for years, and it made him a celebrity, a scientist whose face was recognised around the world. He followed it with The Universe in a Nutshell in 2001, A Briefer History of Time in 2005, and The Grand Design in 2010, written with Leonard Mlodinow, which argued that the universe could have created itself from nothing, a claim that drew both praise and criticism.

The fame brought Hawking into popular culture in a way that few scientists have experienced. He appeared as himself in television programmes, he was the subject of documentaries and films, and his voice became a cultural reference. The film The Theory of Everything, released in 2014, told the story of his early life and his relationship with Jane, and it won an Academy Award for the actor who played him. Hawking himself was ambivalent about the celebrity, and he sometimes complained that he was more famous for his wheelchair than for his science. But he also used the fame, speaking publicly about science, about disability and about the future of humanity, and becoming, in the eyes of many, the public face of physics.

His honours were numerous. He was elected a fellow of the Royal Society in 1974, one of its youngest fellows, and he became professor of gravitational physics at Cambridge in 1977. In 1979 he was appointed to the Lucasian professorship of mathematics, the chair once held by Isaac Newton, and he held it until 2009. He was made a Commander of the Order of the British Empire in 1982 and a Companion of Honour in 1989, and he received the Copley Medal from the Royal Society in 2006 and the Presidential Medal of Freedom from the United States in 2009. He was never awarded a Nobel Prize, because his most famous prediction, Hawking radiation, has never been observed, and the prize is not given for unconfirmed predictions. The absence of a Nobel Prize is often noted, and it is a reminder that fame and scientific recognition are not the same thing.

6. Views on artificial intelligence, aliens and the future

In his later years Hawking became known for his warnings about the future, and it is important to present them as his views, not as established facts. He warned that artificial intelligence could become a threat to humanity, saying in a 2014 interview that the development of full artificial intelligence could spell the end of the human race, because machines might redesign themselves and outpace human control. He was not opposed to AI research, and he supported its use in science and medicine, but he argued that its development needed to be guided and that humanity should think carefully about the risks. Others in the field disagreed, arguing that the dangers were exaggerated and that the benefits were immediate. The debate continues, and Hawking's warnings are part of it.

He held similar views about contact with alien life. He argued that if alien civilisations existed, humanity should be cautious about trying to contact them, because a more advanced civilisation might not treat humans well, and he pointed to the history of encounters between civilisations on Earth as a warning. He also supported the search for alien life, and he was involved in projects to listen for signals from space. The two positions sit together: curiosity about whether life exists elsewhere, and caution about what contact might mean. His views were his own, and they were not shared by all scientists, some of whom argued that the risks were speculative and that the search for life was worthwhile in itself.

He was also a strong supporter of space exploration, arguing that humanity needed to become a multi-planet species in order to survive, and that the exploration of space was the best insurance against disaster on Earth. He supported private spaceflight and he spoke, in his final years, about the need to colonise other planets within a century. These were not scientific predictions but expressions of his belief that humanity's future lay beyond Earth, and they were widely reported. Whether they were realistic is a matter of debate, but they showed a scientist who thought on the largest possible scale, about the fate of the species rather than the fate of a single theory.

7. Family, honours and legacy

Hawking's personal life was as eventful as his scientific one. He married Jane Wilde in 1965, and the couple had three children: Robert, Lucy and Timothy. The marriage ended in divorce in 1995, and Hawking then married Elaine Mason, one of his nurses, in the same year; that marriage ended in divorce in 2006. Jane wrote a memoir about their life together, which became the basis for the film The Theory of Everything, and the film's portrayal of their relationship was widely discussed. Hawking's children have spoken about growing up with a father whose fame and whose disability shaped their lives, and Lucy Hawking has written children's books about science with her father. The family story is part of the public record, and it shows a man whose private life was as complicated as anyone's.

Hawking died on 14 March 2018 in Cambridge, at the age of 76, more than fifty years after he had been told he had only a few years to live. His funeral was held at Great St Mary's Church in Cambridge, and his ashes were interred in Westminster Abbey in June 2018, near the graves of Isaac Newton and Charles Darwin. The date of his death, 14 March, is also the birthday of Albert Einstein and the day known as Pi Day, a coincidence that was widely noted. The tributes that followed came from scientists, from politicians and from the public, and they recognised not only his science but his determination to live a full life in the face of a disease that had taken almost everything from him except his mind.

His legacy is twofold. In science, Hawking radiation and the singularity theorems remain central to the study of black holes and the beginning of the universe, and the questions he raised about information and about the nature of time are still being worked on. In public life, he showed that a scientist could speak to the world, and that a person with a severe disability could live a life of extraordinary achievement. The biography on this site gives the verified facts of his life; the judgement of his science will be made by physicists, and the judgement of his public role will be made by history. What is already clear is that he changed how the world thinks about black holes, and that he changed how the world thinks about what a scientist can be.

Frequently asked questions

When was Stephen Hawking born and when did he die?

Stephen Hawking was born on 8 January 1942 in Oxford and died on 14 March 2018 in Cambridge, at the age of 76. (Source: Encyclopaedia Britannica.)

What is Hawking radiation?

Hawking radiation is the prediction, made by Hawking in 1974, that black holes emit subatomic particles and slowly lose energy until they evaporate. It follows from combining relativity with quantum theory, and it has never been directly observed. (Source: Encyclopaedia Britannica.)

What disease did Stephen Hawking have?

Hawking was diagnosed in 1963, at the age of 21, with amyotrophic lateral sclerosis, a degenerative disease of the nerve cells that control movement. He used a wheelchair from the late 1960s and communicated through a speech synthesiser after 1985. (Source: Encyclopaedia Britannica.)

What is A Brief History of Time?

A Brief History of Time, published in 1988, is Hawking's best-selling book explaining cosmology to a general audience. It stayed on the bestseller lists for years and made him one of the most famous scientists in the world. (Source: Encyclopaedia Britannica.)

Did Stephen Hawking win a Nobel Prize?

No. Hawking never received a Nobel Prize, because his most famous prediction, Hawking radiation, has never been observed, and the prize is not given for unconfirmed predictions. (Source: Encyclopaedia Britannica.)

What did Stephen Hawking warn about artificial intelligence?

Hawking warned that fully developed artificial intelligence could threaten humanity if machines redesigned themselves beyond human control. This was his own view, and other experts in the field disagreed, arguing the dangers were exaggerated. (Source: Wikipedia.)