Stephen Hawking
| Stephen Hawking | |
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 Stephen Hawking at NASA, 1980s |
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| Born | Stephen William Hawking 8 January 1942 Oxford, England |
| Residence | United Kingdom |
| Nationality | British |
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| Doctoral advisor | Dennis Sciama |
| Other academic advisors | Robert Berman |
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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. Subsequently, he became research director at the university's Centre for Theoretical Cosmology.
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, a condition that has progressed over the years. He is now almost entirely paralysed and communicates through a speech generating device. He married twice and has three children.
Early life and education
Stephen Hawking was born on 8 January 1942 to Frank Hawking, a research biologist, and Isobel Hawking.[1] He has two younger sisters, Philippa and Mary, and an adopted brother, Edward.[2] Hawking's parents were living in North London, but moved to Oxford shortly before his birth, while London was under attack during the Second World War.[3]In 1950, when his father became head of the division of parasitology at the National Institute for Medical Research,[1] Hawking and his family moved to St Albans, Hertfordshire.[3] Hawking attended St Albans High School for Girls from 1950 to 1953; at that time, boys could attend the girls' school until the age of 10.[2] From the age of 11, he attended St Albans School, where he was an average, but not exceptional student.[3] He maintains his connection with the school, giving his name to one of the four houses and to an extracurricular science lecture series.[4]
Hawking has named his secondary school mathematics teacher Dikran Tahta as an inspiration,[5] and originally wanted to study the subject at university. However, Hawking's father wanted him to apply to University College, Oxford, which his father had attended. As University College did not have a mathematics fellow at that time, they did not accept applications from students who wished to study that discipline. Therefore, Hawking applied to study natural sciences with an emphasis in physics. University College accepted Hawking, and he gained a scholarship.[3] While at Oxford, he coxed a rowing team, which helped ease his immense boredom at the university.[6] 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. ... his mind was completely different from all of his contemporaries".[3]
Hawking's unimpressive study habits resulted in a final examination score on the borderline between first and second class honours, making an oral examination necessary.[3] Berman commented: "the examiners then were intelligent enough to realize they were talking to someone far more clever than most of themselves".[3] After receiving his B.A. degree at Oxford in 1962, he left for graduate work at Trinity Hall, Cambridge.[3]
Career
1962–75
Hawking started developing symptoms of amyotrophic lateral sclerosis upon his arrival at Cambridge. He did not distinguish himself in his first two years at the institution. With the help of his doctoral tutor, Dennis William Sciama, he returned to working on his PhD after the disease had stabilised[7] and graduated with his doctorate in 1966,[1] before starting a four-year research fellowship at Cambridge.[7]When Hawking began his graduate studies in the 1960s, there was much debate in the physics community about the opposing theories of the creation of the universe: big bang, and steady state.[7] Hawking and his Cambridge friend and colleague, Roger Penrose, showed in 1970 that if the universe obeys general relativity and fits any of the Friedmann models, then it must have begun as a singularity.[8] This work showed that, far from being mathematical curiosities which appear only in exceptional circumstances, singularities are a fairly common feature of general relativity.[9] For their essay on this subject, Hawking and Penrose were jointly awarded the Adams prize in 1966.[10] This essay served as the basis for a textbook, The Large Scale Structure of Space-Time, that Hawking published with George Ellis in 1973.[11]
In 1969, Hawking accepted a specially created 'Fellowship for Distinction in Science' to remain at Cambridge.[12] In the early 1970s, Hawking's work with Brandon Carter, Werner Israel and D. Robinson strongly supported John Wheeler's no-hair theorem – that any black hole can be fully described by the three properties of mass, angular momentum, and electric charge.[13] With Bardeen and Carter, he proposed the four laws of black hole mechanics, drawing an analogy with thermodynamics.[14] In 1974, he calculated that black holes should emit radiation, known today as Hawking radiation, until they exhaust their energy and evaporate.[8]
Hawking was elected one of the youngest Fellows of the Royal Society in 1974,[15] and in the same year he accepted the Sherman Fairchild Distinguished Scholar visiting professorship at the California Institute of Technology (Caltech) to work with his friend on the faculty, Kip Thorne.[16] He continues to maintain ties to Caltech, having spent a month each year there since 1992.[17]
1975–present
In collaboration with Jim Hartle, Hawking developed a model in which the universe had no boundary in space-time, replacing the initial singularity of the classical Big Bang models 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.[19] While initially the no-boundary proposal predicted a closed universe, discussions with Neil Turok led to the realisation that it is also compatible with an open universe.[20] Later work by Hawking appeared to show that, if this no-boundary proposition were correct, then when the universe stopped expanding and eventually collapsed, time would run backwards (Hawking famously used the example of broken teacups reassembling).[21] However, work by Don Page, a former student of Hawking, led to Hawking withdrawing this concept.[21]
Along with Thomas Hertog at 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.[22] 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.[23]
Thorne–Hawking–Preskill bet
Main article: Thorne–Hawking–Preskill bet
In 1997, Hawking made a public scientific wager with Kip Thorne and John Preskill of Caltech concerning the black hole information paradox.[24]
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 must not originate 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.[25] The winner of the bet was to receive an encyclopedia of the loser's choice, from which information may be accessed.[24]In 2004, Hawking announced that he was conceding the bet because he now believed that black hole horizons should fluctuate and leak information, and gave Preskill a copy of Total Baseball. Comparing the useless information obtainable from a black hole to "burning an encyclopedia", Hawking commented, "I gave John an encyclopedia of baseball, but maybe I should just have given him the ashes".[24]
Recognition
Major awards and honours
- 1975 Eddington Medal[1]
- 1976 Hughes Medal of the Royal Society[1]
- 1979 Albert Einstein Medal[1]
- 1981 Franklin Medal[31]
- 1982 Commander of the Order of the British Empire[1]
- 1985 Gold Medal of the Royal Astronomical Society[1]
- 1986 Member of the Pontifical Academy of Sciences[1]
- 1988 Wolf Prize in Physics[1]
- 1989 Companion of Honour[1]
- 1999 Julius Edgar Lilienfeld Prize of the American Physical Society[32]
- 2003 Michelson Morley Award of Case Western Reserve University[1]
- 2006 Copley Medal of the Royal Society[33]
- 2008 Fonseca Prize of the University of Santiago de Compostela[34]
- 2009 Presidential Medal of Freedom, the highest civilian honour in the United States[35]
Personal life
According to Hawking, when he was diagnosed with ALS during an early stage of his graduate work, he did not see much point in obtaining a doctorate, since he expected to die soon after. Hawking later said that the real turning point was his 1965 marriage to Jane Wilde, a language student.[3] Jane cared for him until 1990 when the couple separated.[1] They had three children: Robert, Lucy, and Timothy.[1] Hawking married his personal care assistant, Elaine Mason, in 1995;[1] the couple divorced In October 2006[36] amid claims by former nurses that she had abused him.[37] In 1999, Jane Hawking published a memoir, Music to Move the Stars, detailing the marriage and its breakdown; in 2010 she published a revised version, Travelling to Infinity, My Life with Stephen.[38]Illness
Symptoms of the disorder first appeared while he was enrolled at the University of Cambridge, when he lost his balance and fell down a flight of stairs, hitting his head.[6] The diagnosis of motor neurone disease came when Hawking was 21, just after he had met Jane Wilde, who was to become his first wife; doctors said they did not expect him to survive for long.[41] From 1974 he could not feed himself or get out of bed, and so graduate students helped, receiving free accommodation in return.[42] His speech became slurred so that he could be understood only by people who knew him well.[42] During a visit to CERN in Geneva in 1985, Hawking contracted pneumonia, which in his condition was life-threatening as it further restricted his already limited respiratory capacity. He had an emergency tracheotomy, losing what remained of his ability to speak.[43] A speech generating device was built in Cambridge, using software from an American company, that enabled Hawking to operate a computer keyboard with small movements of his body, and then have a speech synthesiser speak what he typed.[44]
The particular speech synthesiser hardware he uses, DECtalk, which has an American English accent, is no longer being produced.[45] Asked why he has still kept the same voice after so many years, Hawking stated that he has not heard a voice he likes better and that he identifies with it even though the synthesiser is both large and fragile by current standards.[citation needed] For lectures and media appearances, Hawking appears to speak fluently through his synthesiser,[citation needed] but when he prepares answers, his system produces words at a rate of about one per minute.[46] Hawking's setup uses a predictive text entry system, which requires only the first few characters to auto-complete the word, but as he can only use his cheek for data entry, constructing complete sentences takes time.[46][not in citation given][47] Intel is working on a facial recognition system that will help speed up the writing.[48] Given the deterioration of Hawking's facial nerves continues and there is a risk of him acquiring locked-in syndrome, Hawking is collaborating with neuroscientists on a brain–computer interface that could translate Hawking's thoughts into words.[47][48]
He describes himself as lucky, as the slow progression of his disease has allowed him time to make influential discoveries and has not hindered him from having, in his own words, "a very attractive family".[44]
Space and spaceflight
In 2007, Hawking took a zero-gravity flight in a "Vomit Comet", courtesy of Zero Gravity Corporation, during which he experienced weightlessness eight times.[52] He became the first quadriplegic to float in zero gravity. Before the flight Hawking said:
Many people have asked me why I am taking this flight. I am doing it for many reasons. First of all, I believe that life on Earth is at an ever-increasing risk of being wiped out by a disaster such as sudden nuclear war, a genetically engineered virus, or other dangers. I think the human race has no future if it doesn't go into space. I therefore want to encourage public interest in space.[53]
Religious and philosophical views
In his early work, Hawking spoke of God in a metaphorical sense, such as in A Brief History of Time: "If we discover a complete theory, it would be the ultimate triumph of human reason – for then we should know the mind of God."[54] In the same book he suggested the existence of God was unnecessary to explain the origin of the universe.[55]His ex-wife, Jane, has described him as an atheist.[56] 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."[57] In an interview published in The Guardian newspaper, 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."[54][58]
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".[59]
Popular publications
Hawking's first popular science book, A Brief History of Time, was published on 1 April 1988. It stayed on the British Sunday Times best-sellers list for a record-breaking 237 weeks.[60] A Brief History of Time was followed by The Universe in a Nutshell (2001). A collection of essays titled Black Holes and Baby Universes (1993) was also popular. His book, A Briefer History of Time (2005), co-written by Leonard Mlodinow, updated his earlier works to make them accessible to a wider audience. In 2007 Hawking and his daughter, Lucy Hawking, published George's Secret Key to the Universe, a children's book focusing on science that Lucy Hawking described as "a bit like Harry Potter but without the magic."[61]exploreworld12.blogspot.com
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