From Wikipedia, the free encyclopedia
Jump to: navigation, search
Stephen Hawking
black and white photo of Hawking in a chair, in an office.
Stephen Hawking at NASA, 1980s
Born Stephen William Hawking
(1942-01-08) 8 January 1942 (age 76)
Oxford, England
Residence United Kingdom
Nationality British
Alma mater
Known for
  • Jane Wilde
    (m. 1965–1991, divorced)
  • Elaine Mason
    (m. 1995–2006, divorced)
  • with Jane Wilde - Robert (1967), Lucy (1969), and Timothy (1979)
Scientific career
Doctoral advisor Dennis Sciama
Other academic advisors Robert Berman
Notable students

Stephen William Hawking, CH, CBE, FRS, FRSA (born 8 January 1942) is a British theoretical physicist, cosmologist, and author. Among his significant scientific works have been a collaboration with Roger Penrose on gravitational singularities theorems in the framework of general relativity, and the theoretical prediction that black holes emit radiation, often called Hawking radiation. Hawking was the first to set forth a cosmology explained by a union of the general theory of relativity and quantum mechanics. He is a vocal supporter of the many-worlds interpretation of quantum mechanics.

He is an Honorary Fellow of the Royal Society of Arts, a lifetime member of the Pontifical Academy of Sciences, and a recipient of the Presidential Medal of Freedom, the highest civilian award in the United States. Hawking was the Lucasian Professor of Mathematics at the University of Cambridge between 1979 and 2009.

Hawking has achieved success with works of popular science in which he discusses his own theories and cosmology in general; his A Brief History of Time stayed on the British Sunday Times best-sellers list for a record-breaking 237 weeks. Hawking has a motor neurone disease related to amyotrophic lateral sclerosis (ALS), a condition that has progressed over the years. He is almost entirely paralysed and communicates through a speech generating device. He married twice and has three children.

Early life and education[edit]

Stephen Hawking was born on 8 January 1942 to Frank and Isobel Hawking.[1][2] Despite family financial constraints, both parents had attended Oxford University, where Frank had studied medicine and Isobel Philosophy, Politics and Economics.[2] The two met shortly after the beginning of the Second World War at a medical research institute where Isobel was working as a secretary and Frank as a medical researcher.[2][3] Hawking's parents lived in Highgate but as London was under attack during the Second World War, his mother went to Oxford to give birth in greater safety.[4] He has two younger sisters, Philippa and Mary, and an adopted brother, Edward.[5] Hawking began his schooling at the Byron House School; he later blamed its "progressive methods" for his failure to learn to read while at the school.[6]

In 1950, when his father became head of the division of parasitology at the National Institute for Medical Research, Hawking and his family moved to St Albans, Hertfordshire.[6][7] The eight-year-old Hawking attended St Albans High School for Girls for a few months; at that time, younger boys could attend one of the houses.[8][9] In St Albans, the family were considered highly intelligent and eccentric.[6][10] They lived a frugal existence in a large, cluttered, and poorly maintained house, and travelled in a converted London taxicab.[11][12] The family placed a high value on education, with regular trips to museums, and meals spent with everyone reading in silence.[6] During one of Hawking's father's frequent absences working in Africa,[13] the rest of the family spent four months in Majorca visiting his mother's friend Beryl and her husband, the poet Robert Graves.[8] On their return to England, Hawking attended Radlett School for a year[9] and from September 1952, St Albans School.[14] Hawking's father wanted his son to attend the well-regarded Westminster School, but 13-year-old Hawking was ill on the day of the scholarship examination. His family could not afford the school fees without the financial aid of a scholarship, so Hawking remained at St Albans.[15][16] As a positive consequence, Hawking remained with the close group of friends with whom he enjoyed board games, the manufacture of fireworks, model aeroplanes and boats,[17] and long discussions about Christianity and extrasensory perception.[18] From 1958, and with the help of the mathematics teacher Dikran Tahta, they built a computer from clock parts, an old telephone switchboard and other recycled components.[19][20]

Although at school he was known as "Einstein", Hawking was not initially successful academically.[21] With time, he began to show considerable aptitude for scientific subjects, and inspired by Tahta, decided to study mathematics at university.[22][23][24] Hawking's father advised him to study medicine, concerned that there were few jobs for mathematics graduates,[25] and wanted Hawking to attend University College, Oxford, his own alma mater. As it was not possible to read mathematics there at the time, Hawking decided to study physics and chemistry, and despite his headmaster's advice to wait till the next year, took the scholarship examinations in March 1959.[23][26] After he performed well on the exams and interviews, University College accepted Hawking and offered him a scholarship.[26][27]

University studies[edit]

Hawking went up to Oxford in October 1959 at the age of 17.[28] For the first 18 months he was bored and lonely: he was younger than many other students, and found the academic work "ridiculously easy".[29][30] His physics tutor, Robert Berman, later said, "It was only necessary for him to know that something could be done, and he could do it without looking to see how other people did it."[31] A change occurred during his second and third year when, according to Berman, Hawking made more effort "to be one of the boys". He developed into a popular, lively and witty college member, interested in classical music and science fiction.[28] Part of the transformation resulted from his decision to join the college Boat Club, where he coxed a rowing team.[32][33] The rowing trainer at the time noted that Hawking cultivated a daredevil image, steering his crew on risky courses that led to damaged boats.[34][32]

Hawking has estimated that he studied for only approximately 1000 hours during his three years at Oxford. These unimpressive study habits made sitting his Finals a challenge, and he decided to answer only theoretical physics rather than those requiring factual knowledge. A first-class honours degree was a condition of acceptance for his planned graduate study in cosmology at the University of Cambridge with Fred Hoyle.[35][36] Anxious, he slept poorly the night before the examinations and the final result was on the borderline between first and second class honours, making a viva necessary.[36][37] Hawking was concerned that he was viewed as a lazy and difficult student, so when asked at the oral examination to describe his future plans said, "If you award me a First, I will go to Cambridge. If I receive a Second, I shall stay in Oxford, so I expect you will give me a First."[36][38] He was held in higher regard than he believed: as Berman commented, the examiners "were intelligent enough to realize they were talking to someone far cleverer than most of themselves".[36] After receiving a first-class BA (Hons.) degree, and following a trip to Iran with a friend, he began his graduate work at Trinity Hall, Cambridge in October 1962.[39][40]

Hawking's first year as a doctoral student was a difficult one. He was initially disappointed to find that he had been assigned Dennis William Sciama as a supervisor rather than Hoyle,[41][42] and he found his training in mathematics inadequate for work in general relativity and cosmology.[43] He was also struggling with his health. Hawking had noticed clumsiness during his final year at Oxford, including a fall on some stairs and difficulties when rowing.[44][45] The problems worsened, and his speech became slightly slurred; his family noticed the issues when he returned home for Christmas and medical investigations were begun.[46][47] The diagnosis of motor neurone disease came when Hawking was 21. At the time doctors gave him a life expectancy of two years.[48][49] but Hawking's illness has advanced more slowly than typical cases of ALS.[50][51] After his diagnosis, Hawking fell into a depression; though his doctors advised that he continue with his studies, he felt there was little point.[52] At the same time, however, his relationship with Jane Wilde, friend of his sister, and whom he had met shortly before his diagnosis, continued to develop. The couple were engaged in October 1964.[53][54] Hawking later said that the engagement "gave him something to live for."[55] Despite the disease's progression—Hawking had difficulty walking without support, and his speech was almost unintelligible—he now returned to his work with enthusiasm.[56] Hawking started developing a reputation for brilliance and brashness when he publicly challenged the work of Fred Hoyle and his student Jayant Narlikar at a lecture in June 1964.[57][58] When Hawking began his graduate studies, there was much debate in the physics community about the prevailing theories of the creation of the universe: the Big Bang and the Steady State theories.[59] Inspired by Roger Penrose's theorem of a spacetime singularity in the centre of black holes, Hawking applied the same thinking to the entire universe, and during 1965 wrote up his thesis on this topic.[60] There were other positive developments: Hawking received a research fellowship at Gonville and Caius College, and he and Jane were married on July 14, 1965.[61] He completed his doctorate in March 1966,[62] and his essay entitled "Singularities and the Geometry of Space-Time" shared top honours with one by Penrose to win that year's Adams Prize.[63][62]



The first years of marriage were hectic: Jane lived in London during the week as she completed her degree and they travelled to the United States several times for conferences and physics-related visits. The couple had difficulty finding housing that was within Hawking's walking distance to the Department of Applied Mathematics and Theoretical Physics (DAMTP). Jane began a Ph.D/ program, and a son, Robert, was born in May 1967.[64][65] In his work, and in collaboration with Penrose, Hawking extended the singularity theorem concepts first explored in his Ph.D. thesis. This included not only the existence of singularities but also the theory that the universe might have started as a singularity. Their joint essay was the runner-up in the 1968 Gravity Research Foundation competition.[66][67] In 1970 they published a proof that if the universe obeys the general theory of relativity and fits any of the models of physical cosmology developed by Alexander Friedmann, then it must have begun as a singularity.[68][69][70]

During the late 1960s, Hawking's physical abilities declined once again: he began to use crutches and ceased lecturing regularly.[71] As he slowly lost the ability to write, he developed compensatory visual methods, including seeing equations in terms of geometry.[72][73] The physicist Werner Israel later compared the achievements to Mozart composing an entire symphony in his head.[74][75] Hawking was, however, fiercely independent and unwilling to accept help or make concessions for his disabilities. Jane Hawking later noted that "Some people would call it determination, some obstinacy. I've called it both at one time or another."[76] He required much persuasion to accept the use of a wheelchair at the end of the 1960s.[77] Hawking was a popular and witty colleague, but his illness as well as his reputation for brashness and intelligence distanced him from some.[76] In 1969, Hawking accepted a specially created 'Fellowship for Distinction in Science' to remain at Caius.[78]

A daughter, Lucy, was born in 1970.[79] Soon after Hawking discovered what became known as the second law of black hole dynamics, that the event horizon of a black hole can never get smaller.[80] With James M. Bardeen and Brandon Carter, he proposed the four laws of black hole mechanics, drawing an analogy with thermodynamics.[81] To Hawking's irritation, Jacob Bekenstein, a graduate student of John Wheeler, went further—and ultimately correctly—applying thermodynamic concepts literally.[82][83] In the early 1970s, Hawking's work with Carter, Werner Israel and David C. Robinson strongly supported Wheeler's no-hair theorem that no matter what the original material from which a black hole is created it can be completely described by the properties of mass, electrical charge and rotation.[84][85] His essay titled "Black Holes" won the Gravity Research Foundation Award in January 1971.[86] Hawking's first book The Large Scale Structure of Space-Time written with George Ellis was published in 1973.[87]

Beginning in 1973, Hawking moved into the study of quantum gravity and quantum mechanics.[88][87] His work in this area was spurred by a visit to Moscow and discussions with Yakov Borisovich Zel'dovich and Alexander Starobinsky, whose work showed that according to the uncertainty principle rotating black holes emit particles.[89] To Hawking's annoyance, his much-checked calculations produced findings that contradicted his second law, which claimed black holes could never get smaller,[90] and supported Bekenstein's reasoning about their entropy.[91][89] His results, which Hawking presented from 1974, showed that black holes emit radiation, known today as Hawking radiation, which may continue until they exhaust their energy and evaporate.[92][93][94] Initially, Hawking radiation was controversial. However by the late 1970s and following the publication of further research, the discovery was widely accepted as a significant breakthrough in theoretical physics.[95][96][97] In March 1974, a few weeks after the announcement of Hawking radiation, Hawking was invested as a Fellow of the Royal Society, one of the youngest scientists to be so honoured.[98][99]

Hawking rarely discussed his illness and physical challenges, even—in a precedent set during their courtship—with Jane.[100] Hawking's disabilities meant that the responsibilities of home and family rested firmly on his wife's increasingly overwhelmed shoulders, leaving him more time to think about physics.[101] When in 1974 Hawking was appointed to the Sherman Fairchild Distinguished Scholar visiting professorship at the California Institute of Technology (Caltech), Jane proposed that a graduate or post-doctoral student live with them and help with his care. Hawking accepted, and Bernard Carr travelled to California with them as the first of many students who fulfilled this role.[102][103] The family spent a generally happy and stimulating year in Pasadena.[104] Hawking worked with his friend on the faculty, Kip Thorne,[105] and engaged him in scientific wager about whether the dark star Cygnus X-1 was a black hole. The wager was a surprising "insurance policy" against the proposition that black holes did not exist.[106] Hawking acknowledged that he had lost the bet in 1990, which was the first of several that he was to make with Thorne and others.[107] Hawking has maintained ties to Caltech, spending a month there almost every year since this first visit.[108]


Hawking outside, in his wheelchair, talking to David Gross and Edward Witten
Hawking with string theorists David Gross and Edward Witten at the 2001 Strings Conference, TIFR, India

Hawking returned to Cambridge in 1975 to a new home, a new job—as Reader. Don Page, with whom Hawking had begun a close friendship at CalTech, arrived to work as the live-in graduate student assistant. With Page's help and that of a secretary, Jane's responsibilities were reduced so she could returned to her thesis and her new interest in singing.[109] The mid to late 1970s were a period of growing public interest in black holes and of the physicist who was studying them. Hawking was regularly interviewed for print and television.[110][111] He also received increasing academic recognition of his work.[112] In 1975 he was awarded both the Eddington Medal and the Pius XI Gold Medal, and in 1976 the Dannie Heineman Prize, the Maxwell Prize and the Hughes Medal.[113][114] Hawking was appointed a professor with a chair in gravitational physics in 1977.[115] The following year he received the Albert Einstein Medal and an honorary doctorate from the University of Oxford.[54][112] The Hawking family welcomed a third child, Timothy, in April 1979.[112] That autumn Hawking was appointed the Lucasian Professor of Mathematics at the University of Cambridge, a position he held for 30 years until he retired in 2009.[112][116] Hawking's inaugural lecture as Lucasian Professor of Mathematics was titled: "Is the end in sight for Theoretical Physics" and proposed N=8 Supergravity as the leading theory solve many of the outstanding problems physicists were studying.[117] Hawking's promotion coincided with a health crisis which led to Hawking accepting, albeit reluctantly, some nursing services at home.[118] At the same time he was also making a transition in his approach to physics, becoming more intuitive and speculative rather than insisting on mathematical proofs. "I would rather be right than rigorous" he told Kip Thorne.[119] In 1981 he proposed that information in a black hole is irretrievably lost when a black hole evaporates. This information paradox violates the fundamental tenet of quantum mechanics, and was to lead to years of debate, including "the Black Hole War" with Leonard Susskind and Gerard 't Hooft.[120][121]

In December 1977, Jane had met organist Jonathan Hellyer Jones when singing in a church choir. Hellyer Jones became close to the Hawking family, and by the mid 1980s, he and Jane had developed romantic feelings for each other.[115][122][123] According to Jane, her husband was accepting of the situation, stating "he would not object so long as I continued to love him."[115][124][125] Jane and Hellyer Jones determined not to break up the family and their relationship remained platonic for a long period.[126]

Cosmological inflation—a theory proposing that following the Big Bang the universe initially expanded incredibly rapidly before settling down to a slower expansion—was proposed by Alan Guth and also developed by Andrei Linde.[127] Following a conference in Moscow in October 1981, Hawking and Gary Gibbons organized a three-week Nuffield Workshop in the summer of 1982 on the Very Early Universe at Cambridge University, which focussed mainly on inflation theory.[128][129][130] Hawking also began a new line of quantum theory research into the origin of the universe. In 1981 at a Vatican conference he presented work suggesting that there might be no boundary—or beginning or ending—to the universe.[131][132] He subsequently developed the research in collaboration with Jim Hartle, and in 1983 they published developed a model, known as the Hartle–Hawking state. It proposed that prior to the Planck epoch, the universe had no boundary in space-time; before the Big Bang, time did not exist and the concept of the beginning of the universe is meaningless.[133] The initial singularity of the classical Big Bang models was replaced with a region akin to the North Pole. One cannot travel north of the North Pole, but there is no boundary there—it is simply the point where all north-running lines meet and end.[134][135] Initially the no-boundary proposal predicted a closed universe which had implications about the existence of God. As Hawking explained "If the universe has no boundaries but is self-contained... then God would not have had any freedom to choose how the universe began."[136] But Hawking did not rule out the existence of a Creator, asking in A Brief History of Time "Is the unified theory so compelling that it brings about its own existence?"[137] In his early work, Hawking spoke of God in a metaphorical sense. In A Brief History of Time he wrote: "If we discover a complete theory, it would be the ultimate triumph of human reason—for then we should know the mind of God."[138] In the same book he suggested the existence of God was unnecessary to explain the origin of the universe.[139] Later discussions with Neil Turok led to the realisation that it is also compatible with an open universe.[140] Further work by Hawking in the area of arrows of time led to the 1985 publication of a paper theorising that if the no-boundary proposition were correct, then when the universe stopped expanding and eventually collapsed, time would run backwards.[141] A paper by Don Page and Raymond Laflamme led Hawking to withdraw this concept.[142] Honours continued to be awarded: in 1981 Hawking he was awarded the American Franklin Medal,[143] and in 1982 made a Commander of the Order of the British Empire (CBE).[144][145] Awards do not pay the bills, however, and motivated by the need to finance the children's education and home expenses, in 1982 Hawking determined to write a popular book about the universe that would be accessible to the general public.[146][147] Instead publishing with an academic press, he signed a contract with Bantam Books, a mass market publisher, and received a large advance for his book.[148][149] A first draft of the book, called A Brief History of Time was completed in 1984.[150] During a visit to CERN in Geneva in the summer of 1985, Hawking contracted pneumonia which in his condition was life-threatening; he was so ill that Jane was asked if life support should be terminated. She refused but the consequence was a tracheotomy, which would require round-the-clock nursing care, and remove what remained of his speech.[151][152] The National Health Service would pay for a nursing home but Jane was determined that he would live at home. The cost of the care was funded by an American foundation.[153][154] Nurses were hired for the three shifts required to provide the round-the-clock support he required. One of those employed was Elaine Mason, a vivacious woman who was to become Hawking's second wife.[155]

For his communication, Hawking initially raised his eyebrows to choose letters on a spelling card.[156] But he then received a computer program called the "Equalizer" from Walt Woltosz. In a method he uses to this day, using a switch he selects phrases, words or letters from a bank of about 2500-3000 that are scanned.[157][158] The program was originally run on desktop computer. However Elaine Mason's husband David, a computer engineer, adapted a small computer and attached it to his wheelchair.[159] Released from the need to use somebody to interpret his speech, Hawking commented that "I can communicate better now than before I lost my voice."[160] The voice he uses has an American accent and is no longer produced.[161][162] Despite the availability of other voices, Hawking has retained his original voice, saying that he prefers his current voice and identifies with it.[163] At this point, Hawking activated a switch using his hand and could produce up to 15 words a minute.[164] Lectures were prepared in advance, and sent to the speech synthesiser in short sections as they were delivered.[161]

One of first messages Hawking produced in on his speech generating device was a request for his assistant to help him finish writing A Brief History of Time.[164] Peter Guzzardi, his editor at Bantam, pushed him to explain his ideas clearly in non-technical language, a process that required multiple revisions from an increasingly irritated Hawking.[165] The book was published in April 1988 in the US and in June in the UK, and proved to be extraordinary success, rising quickly to the top of bestseller lists in both countries and remaining there for weeks and months.[166][167][168] The book was translated into multiple languages,[169] and ultimately sold at estimated 9 million copies.[168] Media attention was intense,[169] and Newsweek magazine cover and a television special both described him as "Master of the Universe". Success led to significant financial rewards, but also the challenges of celebrity status.[170] Hawking travelled extensively to promote his work.[169] He had difficulty refusing the invitations and visitors which left limited time for work and his students.[171] Some colleagues were resentful of the attention Hawking received, feeling it was due of his disability.[172][173] He received further academic recognition, including five further honorary degrees,[174] the Gold Medal (1985),[175] the Paul Dirac Medal (1987)[174] and, jointly with Penrose, the prestigious Wolf Prize (1988).[176] In 1989, he was named a Companion of Honour by Queen Elizabeth II.[171]

1990 to 2000[edit]

Hawking's marriage had been strained for many years. Jane felt overwhelmed by the intrusion into their family life of the nurses and assistants that he needed. The impact of his celebrity was challenging for colleagues and family members, and Jane described her role as "simply to tell him that he's not God."[177][178] Hawking's agnostic views of religion also contrasted with her strong Christian faith.[179][178] In the late 1980s Hawking became increasingly close to one of his nurses, Elaine Mason, to the dismay of some colleagues, carers and family members who were disturbed by her protectiveness and strength of personality.[180] and moved in with her in February 1990.[144][181] Following his divorce from Jane in the spring of 1995, he married Mason in September.[182][144] He declared "It's wonderful—I have married the woman I love."[183]

Hawking maintained his public profile, including bringing science to a wider audience. In 1992 a film version of "A Brief History of Time"—directed by Errol Morris and produced by Stephen Spielberg—was premiered. Hawking had wanted the film to be scientific rather than biographical, but was persuaded otherwise. The film, while a critical success, was however not widely released.[184] A popular-level collection of essays, interviews and talk titled Black Holes and Baby Universes and Other Essays was published in 1993[185] and six-part television series Stephen Hawking's Universe and companion book appeared in 1997. This time, as Hawking insisted, the focus was entirely on science.[186][187]. He also made several appearances in popular culture. At the release party for the home video version of the "A Brief History of Time", Leonard Nimoy, who had played Spock on Star Trek, learnt that Hawking was interested in appearing on the show. He made the necessary contact and Hawking appeared as himself on Star Trek: The Next Generation in 1993.[188][189][190] The same year, his synthesiser voice was recorded for the Pink Floyd song "Keep Talking"[191][185], and in 1999 for an appearance on The Simpsons.[192] Hawking also pursued his work in physics: in 1993 he co-edited a book on Euclidean quantum gravity with Gary Gibbons, and published a collected edition of his own articles on black holes and the Big Bang.[193] In 1994 at Cambridge's Newton Institute, Hawking and Penrose delivered a series of six lectures, which were published in 1996 as "The Nature of Space and Time".[194] In 1997, Hawking conceded a public scientific wager made in 1991 with Kip Thorne and John Preskill of Caltech. Hawking had bet that Penrose's proposal of a "cosmic censorship conjecture"—that there could be no "naked singularities" unclothed within a horizon—was correct.[195] After discovering his concession might have been premature, a new, more refined, wager was made. This specified that that such singularities would occur without extra conditions.[196] The same year, Thorne, Hawking and Preskill made another bet, this time about the black hole information paradox.[197] Thorne and Hawking argued that since general relativity made it impossible for black holes to radiate and lose information, the mass-energy and information carried by Hawking Radiation must be "new", and not from inside the black hole event horizon. Since this contradicted the quantum mechanics of microcausality, quantum mechanics would need to be rewritten. Preskill argued the opposite, that since quantum mechanics suggests that the information emitted by a black hole relates to information that fell in at an earlier time, the concept of black holes given by general relativity must be modified in some way.[198] In 1999 he was awarded the Julius Edgar Lilienfeld Prize of the American Physical Society.[199] The same year, Jane Hawking published a memoir, Music to Move the Stars, describing her marriage to Hawking and its breakdown. Its revelations caused a sensation in the media, but as was his usual practice regarding his personal life, Hawking made no public comment except to say that he did not read biographies about himself.[200]

2000 to present[edit]

Hawking sitting in his wheelchair inside
Hawking on 5 May 2006, during the press conference at the Bibliothèque nationale de France to inaugurate the Laboratory of Astronomy and Particles in Paris and the French release of his work God Created the Integers

Following his second marriage, Hawking's family felt excluded and marginalized from his life.[201] Soon after turn of the century, and for a period of about five years, family and staff became increasingly worried that the scientist was being physically abused.[202][201] Police investigations took place were closed as Hawking refused to make a complaint.[203][201][204]

Hawking continued his writings for a popular audience, publishing The Universe in a Nutshell in 2001,[citation needed] and in 2005 A Briefer History of Time which he wrote with Leonard Mlodinow to update his earlier works to make them accessible to a wider audience.[citation needed] Over the years, Hawking maintained his public profile with attention-getting statements. For example in 1994, he claimed that computer viruses were a form of life,[205] and later that alien life exists and that humanity should avoid contact with them.[206][207]

In 2004, Hawking announced that he was conceding the 1997 bet with Preskill because he now believed that black hole horizons should fluctuate and leak information.[197][208] Along with Thomas Hertog at the European Organization for Nuclear Research (CERN), in 2006 Hawking proposed a theory of "top-down cosmology", which says that the universe had no unique initial state and therefore that it is inappropriate to formulate a theory that predicts the universe's current configuration from one particular initial state.[209] Top-down cosmology posits that in some sense, the present "selects" the past from a superposition of many possible histories. In doing so, the theory suggests a possible resolution of the fine-tuning question.[210]

The same year Hawking and Elaine quietly divorced,[211][212] following which Hawking resumed closer relationships with Jane, his children and grandchildren.[212][178] Reflecting this happier period a revised version of Jane's book called Travelling to Infinity, My Life with Stephen was published in 2007.[201] The same year, Hawking and his daughter, Lucy, published George's Secret Key to the Universe, a children's book designed to explain theoretical physics in an accessible fashion and featuring characters similar to those in the Hawking family.[213][214] This first book was followed by sequels in 2009 and 2011.[215]

Hawking's early life and the onset of his illness was the subject of the 2004 BBC Four TV film Hawking in which he was portrayed by Benedict Cumberbatch.[citation needed] In 2008, Hawking was featured in the documentary series Stephen Hawking, Master of the Universe, for Channel 4.[citation needed] Hawking made several appearance in animated form on The Simpsons, [216] and Futurama and in person on the The Big Bang Theory in 2012.[217] [218]

Hawking has expressed his concerns that life on earth is risk due to "a sudden nuclear war, a genetically engineered virus or other dangers we have not yet thought of".[219] He views spaceflight and the colonisation of space as necessary for the future of humanity.[219][220] Motivated by an desire both to increase public interest in spaceflight and a desire to show the potential of people with disabilities, he participated in zero-gravity flight in a "Vomit Comet", courtesy of Zero Gravity Corporation, during which he experienced weightlessness eight times.[221][222][219]

Hawking, without his wheelchair, floating weightless in the air inside a plane
Hawking taking a zero-gravity flight in a "Vomit Comet" in 2007

Hawking's disease-related deterioration continued to decline, and in 2005 he began to control his communication device with movements of his cheek muscles.[223][224][225] with a rate of about one word per minute.[224] With this decline there is a risk of him acquiring locked-in syndrome, so Hawking is collaborating with research brain–computer interface that could translate Hawking's brain patterns into switch activations.[225][226] In 2002, following a UK-wide vote, the BBC included him in their list of the 100 Greatest Britons.[227] In 2003 he won the Michelson-Morley Award of Case Western Reserve University.[144] Hawking was awarded the Copley (2006) Medals from the Royal Society.[144][228] He has also been awarded Spain's Fonseca Prize (2008)[229] In 2009 he received America's highest civilian honour, the Presidential Medal of Freedom.[230]

Barack Obama talking to Stehen Hawking in the White House
U.S. President Barack Obama talks with Stephen Hawking in the Blue Room of the White House before a ceremony presenting him and 15 others the Presidential Medal of Freedom on 12 August 2009.

On 19 December 2007, a statue of Hawking by artist Ian Walters was unveiled at the Centre for Theoretical Cosmology, University of Cambridge.[231] Buildings have been named after him, including the Stephen W. Hawking Science Museum in San Salvador, El Salvador,[232] the Stephen Hawking Building in Cambridge,[233] and the Stephen Hawking Centre at Perimeter Institute in Canada.[234] He presided over the unveiling of the "Chronophage" (time-eating) Corpus Clock at Corpus Christi College Cambridge in September 2008.[235] He received the Russian Fundamental Physics Prize (2012).[236]

As required by university regulations, Hawking retired as Lucasian Professor of Mathematics in 2009. He has continued to work as director of research at the Department of Applied Mathematics and Theoretical Physics, and has no plans to retire.[237]

Hawking has stated that he is "not religious in the normal sense" and he believes that "the universe is governed by the laws of science. The laws may have been decreed by God, but God does not intervene to break the laws."[238] In an interview published in The Guardian, Hawking regarded the concept of Heaven as a myth, believing that there is "no heaven or afterlife" and that such a notion was a "fairy story for people afraid of the dark."[138] At Google's Zeitgeist Conference in 2011, Hawking said that "philosophy is dead." He believes philosophers "have not kept up with modern developments in science" and that scientists "have become the bearers of the torch of discovery in our quest for knowledge." He said that philosophical problems can be answered by science, particularly new scientific theories which "lead us to a new and very different picture of the universe and our place in it".[239] In August 2012 Hawking narrated the Enlightenment segment of the 2012 Summer Paralympics opening ceremony.[240]

Selected academic works[edit]

Popular publications[edit]

Children's fiction[edit]

Hawking and his daughter Lucy on stage at a presentation
Stephen Hawking being presented by his daughter Lucy Hawking at the lecture he gave for NASA's 50th anniversary

Co-written with his daughter Lucy.

Films and series[edit]

See also[edit]


  1. ^ Larsen 2005, pp. xiii, 2.
  2. ^ a b c Ferguson 2011, p. 21.
  3. ^ White & Gribbin 2002, p. 6.
  4. ^ Ferguson 2011, pp. 21–22.
  5. ^ Larsen 2005, pp. 2, 5.
  6. ^ a b c d Ferguson 2011, p. 22.
  7. ^ Larsen 2005, p. xiii.
  8. ^ a b Larsen 2005, p. 3.
  9. ^ a b Ferguson 2011, p. 24.
  10. ^ White & Gribbin 2002, p. 12.
  11. ^ Ferguson 2011, pp. 22–23.
  12. ^ White & Gribbin 2002, pp. 11–12.
  13. ^ White & Gribbin 2002, p. 13.
  14. ^ White & Gribbin 2002, p. 8.
  15. ^ White & Gribbin 2002, pp. 7–8.
  16. ^ Larsen 2005, p. 4.
  17. ^ Ferguson 2011, pp. 25–26.
  18. ^ White & Gribbin 2002, pp. 14–16.
  19. ^ Ferguson 2011, p. 26.
  20. ^ White & Gribbin 2002, pp. 19–20.
  21. ^ Ferguson 2011, p. 25.
  22. ^ White & Gribbin 2002, pp. 17–18.
  23. ^ a b Ferguson 2011, p. 27.
  24. ^ Hoare, Geoffrey; Love, Eric (5 January 2007). "Dick Tahta". London: Guardian News and Media. Retrieved 5 March 2012. 
  25. ^ White & Gribbin 2002, p. 41.
  26. ^ a b White & Gribbin 2002, pp. 42–43.
  27. ^ Ferguson 2011, pp. 27–28.
  28. ^ a b Ferguson 2011, p. 28.
  29. ^ Ferguson 2011, pp. 28–29.
  30. ^ White & Gribbin 2002, pp. 46–47, 51.
  31. ^ Ferguson 2011, p. 29.
  32. ^ a b Ferguson 2011, pp. 30–31.
  33. ^ Hawking 1992, p. 44.
  34. ^ White & Gribbin 2002, p. 50.
  35. ^ White & Gribbin 2002, p. 53.
  36. ^ a b c d Ferguson 2011, p. 31.
  37. ^ White & Gribbin 2002, p. 54.
  38. ^ White & Gribbin 2002, pp. 54–55.
  39. ^ White & Gribbin 2002, p. 56.
  40. ^ Ferguson 2011, pp. 31–32.
  41. ^ Ferguson 2011, p. 33.
  42. ^ White & Gribbin 2002, p. 58.
  43. ^ Ferguson 2011, pp. 33–34.
  44. ^ Ferguson 2011, p. 32.
  45. ^ Donaldson, Gregg J. (May 1999). "The Man Behind the Scientist". Tapping Technology. Archived from the original on 2005-05-11. Retrieved 23 December 2012. 
  46. ^ White & Gribbin 2002, p. 59.
  47. ^ Ferguson 2011, pp. 34–35.
  48. ^ Larsen 2005, pp. 18–19.
  49. ^ White & Gribbin 2002, pp. 59–61.
  50. ^ Mitsumoto & Munsat 2001, p. 36.
  51. ^ Harmon, Katherine (7 January 2012). "How Has Stephen Hawking Lived to 70 with ALS?". Scientific American. Retrieved 15 March 2012. 
  52. ^ White & Gribbin 2002, pp. 61–63.
  53. ^ Ferguson 2011, pp. 37–40.
  54. ^ a b Larsen 2005, p. xiv. Cite error: Invalid <ref> tag; name "FOOTNOTELarsen2005xiv" defined multiple times with different content (see the help page).
  55. ^ Ferguson 2011, p. 40.
  56. ^ White & Gribbin 2002, pp. 69–70.
  57. ^ Ferguson 2011, p. 42.
  58. ^ White & Gribbin 2002, pp. 68–69.
  59. ^ Ferguson 2011, p. 34.
  60. ^ White & Gribbin 2002, pp. 71–72.
  61. ^ Ferguson 2011, pp. 43–44.
  62. ^ a b Ferguson 2011, p. 47.
  63. ^ Larsen 2005, p. xix.
  64. ^ Ferguson 2011, pp. 45–47.
  65. ^ White & Gribbin 2002, pp. 92–98.
  66. ^ White & Gribbin 2002, p. 101.
  67. ^ Ferguson 2011, p. 61,64.
  68. ^ Ferguson 2011, pp. 64–65.
  69. ^ White & Gribbin 2002, pp. 115–16.
  70. ^ Hawking, Stephen; Penrose, Roger (1970). "The Singularities of Gravitational Collapse and Cosmology". Proceedings of the Royal Society A. 314 (1519): 529–548. Bibcode:1970RSPSA.314..529H. doi:10.1098/rspa.1970.0021. 
  71. ^ Ferguson 2011, pp. 48–49.
  72. ^ Ferguson 2011, pp. 76–77.
  73. ^ White & Gribbin 2002, pp. 124–25.
  74. ^ Ridpath, Ian (4 May 1978). "Black hole explorer". New Scientist. Retrieved 9 January 2013. 
  75. ^ White & Gribbin 2002, p. 124.
  76. ^ a b Ferguson 2011, p. 48.
  77. ^ White & Gribbin 2002, p. 117.
  78. ^ Ferguson 2011, p. 49.
  79. ^ Ferguson 2011, p. 65.
  80. ^ Ferguson 2011, pp. 65–67.
  81. ^ Larsen 2005, p. 38.
  82. ^ Ferguson 2011, pp. 67–68.
  83. ^ White & Gribbin 2002, pp. 123–24.
  84. ^ Larsen 2005, p. 33.
  85. ^ R. D. Blandford (30 March 1989). "Astrophysical Black Holes". In S. W. Hawking and W. Israel. Three Hundred Years of Gravitation. Cambridge University Press. p. 278. ISBN 978-0-521-37976-2. 
  86. ^ Larsen 2005, p. 35.
  87. ^ a b Ferguson 2011, p. 68.
  88. ^ Larsen 2005, p. 39.
  89. ^ a b White & Gribbin 2002, p. 146.
  90. ^ Ferguson 2011, p. 70.
  91. ^ Larsen 2005, p. 41.
  92. ^ Hawking, Stephen W. (1974). "Black hole explosions?". Nature. 248 (5443): 30–31. Bibcode:1974Natur.248...30H. doi:10.1038/248030a0. 
  93. ^ Hawking, Stephen W. (1975). "Particle creation by black holes". Communications in Mathematical Physics. 43 (3): 199–220. Bibcode:1975CMaPh..43..199H. doi:10.1007/BF02345020. 
  94. ^ Ferguson 2011, pp. 69–73.
  95. ^ Ferguson 2011, pp. 70–74.
  96. ^ Larsen 2005, pp. 42–43.
  97. ^ White & Gribbin 2002, pp. 150–51.
  98. ^ Larsen 2005, p. 44.
  99. ^ White & Gribbin 2002, p. 133.
  100. ^ Ferguson 2011, pp. 37–39, 77.
  101. ^ Ferguson 2011, p. 78.
  102. ^ Ferguson 2011, pp. 82–83.
  103. ^ Stephen Hawking (1994). Black Holes and Baby Universes and Other Essays. Random House. p. 20. ISBN 978-0-553-37411-7. 
  104. ^ Ferguson 2011, pp. 83–88.
  105. ^ Ferguson 2011, pp. 82, 86.
  106. ^ Ferguson 2011, pp. 86–88.
  107. ^ Ferguson 2011, pp. 150,189, 219.
  108. ^ Ferguson 2011, p. 95.
  109. ^ Ferguson 2011, pp. 89–90.
  110. ^ Ferguson 2011, p. 90.
  111. ^ White & Gribbin 2002, pp. 132–33.
  112. ^ a b c d Ferguson 2011, p. 92.
  113. ^ White & Gribbin 2002, p. 162.
  114. ^ Larsen 2005, pp. xv.
  115. ^ a b c Ferguson 2011, p. 91.
  116. ^ "Hawking gives up academic title". BBC News. 30 September 2009. Retrieved 1 October 2009. 
  117. ^ Ferguson 2011, pp. 93–94.
  118. ^ Ferguson 2011, pp. 92–93.
  119. ^ Ferguson 2011, p. 96.
  120. ^ Ferguson 2011, pp. 96–101.
  121. ^ Leonard Susskind (7 July 2008). The Black Hole War: My Battle with Stephen Hawking to Make the World Safe for Quantum Mechanics. Hachette Digital, Inc. pp. 9,18. ISBN 978-0-316-01640-7. 
  122. ^ Larsen 2005, pp. xiv, 79.
  123. ^ Hawking 2007, pp. 279–80.
  124. ^ a b Larsen 2005, p. 79.
  125. ^ Hawking 2007, p. 285.
  126. ^ Ferguson 2011, pp. 91–92.
  127. ^ Ferguson 2011, pp. 108–11.
  128. ^ Ferguson 2011, pp. 111–14.
  129. ^ See Guth (1997) for a popular description of the workshop, or The Very Early Universe, ISBN 0-521-31677-4 eds Gibbons, Hawking & Siklos for a detailed report.
  130. ^ Hawking, S.W. (1982). "The development of irregularities in a single bubble inflationary universe". Phys.Lett. B115 (4): 295. Bibcode:1982PhLB..115..295H. doi:10.1016/0370-2693(82)90373-2. 
  131. ^ Ferguson 2011, pp. 102–13.
  132. ^ White & Gribbin 2002, p. 180.
  133. ^ Hartle, J.; Hawking, S. (1983). "Wave function of the Universe". Physical Review D. 28 (12): 2960. Bibcode:1983PhRvD..28.2960H. doi:10.1103/PhysRevD.28.2960. 
  134. ^ Baird 2007, p. 234.
  135. ^ White & Gribbin 2002, pp. 180–83.
  136. ^ Ferguson 2011, p. 129.
  137. ^ Ferguson 2011, p. 130.
  138. ^ a b Sample, Ian (15 May 2011). "Stephen Hawking: 'There is no heaven; it's a fairy story'". The Guardian. Retrieved 17 May 2011. 
  139. ^ Burgess, Anthony (29 December 1991). "Towards a Theory of Everything". The Observer. p. 42. Though A Brief History of Time brings in God as a useful metaphor, Hawking is an atheist 
  140. ^ Yulsman 2003, pp. 174–176.
  141. ^ Ferguson 2011, pp. 180–182.
  142. ^ Ferguson 2011, p. 182.
  143. ^ White & Gribbin 2002, p. 274.
  144. ^ a b c d e Larsen 2005, pp. x–xix.
  145. ^ Ferguson 2011, p. 114.
  146. ^ Ferguson 2011, pp. 134–35.
  147. ^ White & Gribbin 2002, pp. 205, 220–21.
  148. ^ Ferguson 2011, p. 134.
  149. ^ White & Gribbin 2002, pp. 220–27.
  150. ^ Ferguson 2011, p. 135.
  151. ^ Ferguson 2011, pp. 132–36.
  152. ^ White & Gribbin 2002, pp. 232–36.
  153. ^ Ferguson 2011, pp. 136–37.
  154. ^ White & Gribbin 2002, pp. 235–36.
  155. ^ Ferguson 2011, p. 139.
  156. ^ Ferguson 2011, p. 136.
  157. ^ Ferguson 2011, pp. 137–38.
  158. ^ White & Gribbin 2002, pp. 236–37.
  159. ^ Ferguson 2011, p. 140.
  160. ^ Ferguson 2011, pp. 140–41.
  161. ^ a b Ferguson 2011, p. 138.
  162. ^ Greenemeier, Larry (10 August 2009). "Getting Back the Gift of Gab: Next-Gen Handheld Computers Allow the Mute to Converse". Scientific American. Retrieved 11 September 2012. 
  163. ^ "Stephen Hawking says pope told him not to study beginning of universe". USA Today. 15 June 2006. Retrieved 12 December 2012. 
  164. ^ a b Ferguson 2011, p. 137.
  165. ^ Ferguson 2011, pp. 140–42.
  166. ^ Ferguson 2011, p. 143.
  167. ^ White & Gribbin 2002, pp. 243–45.
  168. ^ a b Radford, Tim (31 July 2009). "How God propelled Stephen Hawking into the bestsellers lists". The Guardian. Retrieved 5 March 2012. 
  169. ^ a b c Ferguson 2011, pp. 143–44.
  170. ^ Ferguson 2011, pp. 145–46.
  171. ^ a b Ferguson 2011, p. 149.
  172. ^ Ferguson 2011, pp. 147–48.
  173. ^ White & Gribbin 2002, pp. 230–31.
  174. ^ a b Ferguson 2011, p. 146.
  175. ^ Larsen 2005, p. xvi.
  176. ^ White & Gribbin 2002, p. 279.
  177. ^ Ferguson 2011, pp. 164–65.
  178. ^ a b c Highfield, Roger (3 January 2012). "Stephen Hawking: driven by a cosmic force of will". The Daily Telegraph. London: The Daily Telegraph. ISSN 0307-1235. OCLC 49632006. Retrieved 7 December 2012. 
  179. ^ Ferguson 2011, pp. 80–81.
  180. ^ Ferguson 2011, p. 145.
  181. ^ Hawking 2007, p. 470.
  182. ^ Ferguson 2011, pp. 186–87.
  183. ^ Ferguson 2011, p. 187.
  184. ^ Ferguson 2011, pp. 168–70.
  185. ^ a b Ferguson 2011, p. 178.
  186. ^ Ferguson 2011, p. 189.
  187. ^ Larsen 2005, p. 97.
  188. ^ Ferguson 2011, pp. 177–78.
  189. ^ Larsen 2005, pp. 93–94.
  190. ^ Okuda & Okuda 1999, p. 380.
  191. ^ Larsen 2005, pp. xiii, 94.
  192. ^ Ferguson 2011, p. 192.
  193. ^ Ferguson 2011, p. 180.
  194. ^ Ferguson 2011, p. 188.
  195. ^ Ferguson 2011, pp. 189–90.
  196. ^ Ferguson 2011, p. 190.
  197. ^ a b Hawking, S.W. (2005). "Information loss in black holes". Physical Review D. 72 (8). arXiv:hep-th/0507171Freely accessible. Bibcode:2005PhRvD..72h4013H. doi:10.1103/PhysRevD.72.084013. 
  198. ^ Preskill, John. "John Preskill's comments about Stephen Hawking's concession". Retrieved 29 February 2012. 
  199. ^ "Julius Edgar Lilienfeld Prize". American Physical Society. Retrieved 29 August 2008. 
  200. ^ Ferguson 2011, pp. 187, 192.
  201. ^ a b c d "Welcome back to the family, Stephen". The Times. 6 May 2007. Archived from the original on 3 December 2008. Retrieved 6 May 2007. 
  202. ^ Ferguson 2011, pp. 197, 225.
  203. ^ Harrison, David (25 January 2004). "Police plan to ask Stephen Hawking about abuse claims". The Daily Telegraph. London: TMG. ISSN 0307-1235. OCLC 49632006. Retrieved 3 February 2013. 
  204. ^ Adams, Tim (4 April 2004). "Tim Adams talks to Jane Hawking about her ex husband Stephen". The Observer. London: GMG. ISSN 0261-3077. OCLC 60623878. 
  205. ^ Ferguson 2011, pp. 178–79.
  206. ^ Hickman, Leo (25 April 2010). "Stephen Hawking takes a hard line on aliens". The Guardian. Retrieved 24 February 2012. 
  207. ^ "Stephen Hawking warns over making contact with aliens". BBC News. 25 April 2010. Retrieved 24 May 2010. 
  208. ^ Ferguson 2011, pp. 219–20.
  209. ^ Highfield, Roger (26 June 2008). "Stephen Hawking's explosive new theory". The Telegraph. Retrieved 9 April 2012. 
  210. ^ Hawking, S.W.; Hertog, T. (2006). "Populating the landscape: A top-down approach". Physical Review D. 73 (12). arXiv:hep-th/0602091Freely accessible. Bibcode:2006PhRvD..73l3527H. doi:10.1103/PhysRevD.73.123527. 
  211. ^ Sapsted, David (20 October 2006). "Hawking and second wife agree to divorce". The Daily Telegraph. Retrieved 18 March 2007. 
  212. ^ a b Ferguson 2011, p. 225.
  213. ^ "Man must conquer other planets to survive, says Hawking". Daily Mail. 13 June 2006. Retrieved 16 February 2012. 
  214. ^ Ferguson 2011, pp. 230–231.
  215. ^ a b c d e f g h i j "Books". Stephen Hawking Official Website. Retrieved 28 February 2012. 
  216. ^ Cheng, Maria (5 January 2012). "Stephen Hawking to turn 70, defying disease". Retrieved 3 March 2012. 
  217. ^ "Professor Stephen Hawking films Big Bang Theory cameo". BBC News. 12 March 2012. Retrieved 12 March 2012. 
  218. ^ Highfield, Roger (3 January 2012). "Stephen Hawking: driven by a cosmic force of will - Telegraph". The Daily Telegraph. London: TMG. ISSN 0307-1235. OCLC 49632006. Retrieved 7 December 2012. 
  219. ^ a b c Overbye, Dennis (1 March 2007). "Stephen Hawking Plans Prelude to the Ride of His Life". The New York Times. New York: NYTC. ISSN 0362-4331. Retrieved 9 February 2013. 
  220. ^ Highfield, Roger (16 October 2001). "Colonies in space may be only hope, says Hawking". The Daily Telegraph. London. Retrieved 5 August 2007. 
  221. ^ "Hawking takes zero-gravity flight". BBC News. 27 April 2007. Retrieved 17 June 2012. 
  222. ^ "Physicist Hawking experiences zero gravity". CNN. 26 April 2007. Archived from the original on 4 May 2007. Retrieved 4 May 2007. 
  223. ^ Ferguson 2011, p. 224.
  224. ^ a b de Lange, Catherine (30 December 2011). "The man who saves Stephen Hawking's voice". New Scientist. Retrieved 18 June 2012. 
  225. ^ a b Boyle, Alan (25 June 2012). "How researchers hacked into Stephen Hawking's brain". NBC News. Retrieved 29 September 2012. 
  226. ^ "Start-up attempts to convert Prof Hawking's brainwaves into speech". BBC. 7 July 2012. Retrieved 29 September 2012. 
  227. ^ "100 great Britons – A complete list". Daily Mail. 21 August 2002. Retrieved 2 August 2012. 
  228. ^ "Oldest, space-travelled, science prize awarded to Hawking". The Royal Society. 24 August 2006. Retrieved 29 August 2008. 
  229. ^ "Fonseca Prize 2008". University of Santiago de Compostela. Retrieved 7 August 2009. 
  230. ^ MacAskill, Ewen (13 August 2009). "Obama presents presidential medal of freedom to 16 recipients". Guardian News and Media. Retrieved 5 March 2012. 
  231. ^ "Vice-Chancellor unveils Hawking statue". University of Cambridge. 21 December 2007. Retrieved 19 May 2008. 
  232. ^ Komar, Oliver; Buechner, Linda (October 2000). "The Stephen W. Hawking Science Museum in San Salvador Central America Honours the Fortitude of a Great Living Scientist". Journal of College Science Teaching. XXX (2). Archived from the original on 30 July 2009. Retrieved 28 September 2008. 
  233. ^ "The Stephen Hawking Building". BBC News. 18 April 2007. Retrieved 24 February 2012. 
  234. ^ "Grand Opening of the Stephen Hawking Centre at Perimeter Institute". Perimeter Institute. Retrieved 6 June 2012. 
  235. ^ "Time to unveil Corpus Clock". 22 September 2008. Archived from the original on 26 September 2008. Retrieved 22 May 2009. 
  236. ^ "Fundamental Physics Prize - News". Fundamental Physics Prize. Retrieved 11 December 2012. 
  237. ^ "Professor Stephen Hawking to stay at Cambridge University beyond 2012". The Daily Telegraph. London: TMG. 26 March 2010. ISSN 0307-1235. OCLC 49632006. Retrieved 9 February 2013. 
  238. ^ Stewart, Phil (31 October 2008). "Pope sees physicist Hawking at evolution gathering". Reuters. Retrieved 22 May 2009. 
  239. ^ Warman, Matt (17 May 2011). "Stephen Hawking tells Google 'philosophy is dead'". The Telegraph. Retrieved 17 June 2012. 
  240. ^ "Paralympics: Games opening promises 'journey of discovery'". BBC. 29 August 2012. Retrieved 29 August 2012. 
  241. ^ "Black Holes and Baby Universes". Kirkus Reviews. 20 March 2010. Retrieved 18 June 2012. 
  242. ^ "A Brief History of Time: Synopsis". Errol Morris. Retrieved 18 June 2012. 
  243. ^ "Stephen Hawking's Universe". PBS. Retrieved 26 June 2012. 
  244. ^ "The Hawking Paradox". BBC. Retrieved 9 February 2012. 
  245. ^ Richmond, Ray (3 August 2007). ""Masters of Science Fiction" too artistic for ABC". Reuters. Retrieved 7 December 2012. 
  246. ^ "Master of the Universe". Channel 4. Retrieved 4 March 2012. 
  247. ^ "Into the Universe with Stephen Hawking". Discovery Channel. Retrieved 25 April 2010. 
  248. ^ "Brave New World with Stephen Hawking". Channel 4. Retrieved 18 June 2012. 
  249. ^ "Stephen Hawking's Grand Design". Discovery Channel. Retrieved 25 October 2012. 


External links[edit]