Stephen Hawking

2007 Schools Wikipedia Selection. Related subjects: Astronomers and physicists

Stephen Hawking

Professor Stephen William Hawking
Born	8 January 1942 Oxford, UK
Residence	UK
Nationality	British
Field	Physicist
Institution	University of Cambridge
Alma Mater	University of Oxford University of Cambridge
Doctoral Advisor	Dennis Sciama
Doctoral Students	Bruce Allen Fay Dowker Malcolm Perry Bernard J. Carr Gary Gibbons
Known for	Black holes Theoretical cosmology Quantum gravity
Notable Prizes	Copley Medal (2006)
Religion	Does not believe in a personal God

Stephen William Hawking, CH, CBE, FRS (born 8 January 1942) is a theoretical physicist. Hawking is the Lucasian Professor of Mathematics at the University of Cambridge, and a Fellow of Gonville and Caius College, Cambridge. He is known for his significant contributions to the field of quantum physics, particularly his theories regarding theoretical cosmology, quantum gravity, black holes, and his popular works in which he discusses his own theories and cosmology in general. These include the runaway popular science bestseller A Brief History of Time, which stayed on the London Sunday Times bestseller list for a record-breaking 237 weeks.

Despite enduring severe disability and, of late, being rendered quadriplegic by motor neuron disease (specifically, amyotrophic lateral sclerosis, or, " Lou Gehrig's disease"), he has had a successful career for many years, and has achieved status as an academic celebrity. He is considered by most as one of the greatest scientists of the modern age.

Biography

Stephen Hawking was born on January 8, 1942, to Frank Hawking, a research biologist, and Isobel Hawking. He had two younger sisters, Philippa and Mary, and an adopted brother, Edward.

Though Hawking's parents had their home in North London, they relocated to Oxford while Isobel was pregnant with Stephen, desiring a safer location for the birth of their first child (London was under attack at the time by the German air force). After Hawking was born, the family moved back to London, where his father headed the division of parasitology at the National Institute for Medical Research.

In 1950, Hawking and his family moved to St Albans in Hertfordshire where, from the age of 11, he attended St Albans School, where he was a good but not exceptional student. He maintains his connection with the school, giving his name to one of the four houses and to an extra-curricular science lecture series. He has visited to deliver one of the lectures and has also granted a lengthy interview to pupils working on the school magazine, The Albanian. He was always interested in science, but decided that medicine and biology were "too inexact, too descriptive". He enrolled at University College, Oxford with the intent of studying mathematics, but after his first year changed his concentration to physics. His physics tutor, Robert Berman, later said in the New York Times Magazine, "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. ... He didn't have very many books, and he didn't take notes. Of course, his mind was completely different from all of his contemporaries." He was popular with his fellow students, but his unimpressive study habits gave him a final examination score on the borderline between first and second class honours, making an oral examination necessary. Berman said of the oral examination, "And of course the examiners then were intelligent enough to realize they were talking to someone far cleverer than most of themselves."

After receiving his B.A. degree at Oxford in 1962, he stayed to study astronomy, deciding to leave when he found that studying sunspots, which was all the observatory was equipped for, didn't appeal to him and that he was more interested in theory than in observation. He left Oxford for Trinity Hall, Cambridge, where he engaged in the study of theoretical astronomy and cosmology.

Almost as soon as he arrived at Cambridge, he was struck by the motor neuron disease which would cost him the loss of almost all neuromuscular control. During his first two years at Cambridge, he did not distinguish himself, but, after the disease had stabilized and with the help of his doctoral tutor, Dennis William Sciama, he returned to working on his Ph.D. Hawking later said that the real turning point was his 1965 marriage to Jane Wilde, a language student.

Hawking was elected as one of the youngest Fellows of the Royal Society in 1974, was created a Commander of the Order of the British Empire in 1982, and became a Companion of Honour in 1989. Prof. Hawking is a member of the Board of Sponsors of The Bulletin of the Atomic Scientists .

Research fields

Hawking's principal fields of research are theoretical cosmology and quantum gravity.

In the late 1960s, he and his Cambridge friend and colleague, Roger Penrose, applied a new, complex mathematical model they had created from Albert Einstein's general theory of relativity. This led, in 1971, to Hawking proving the first of many singularity theorems; such theorems provide a set of sufficient conditions for the existence of a singularity in space-time. This work showed that, far from being mathematical curiosities which appear only in special cases, singularities are a fairly generic feature of general relativity.

Hawking also suggested that, after the Big Bang, primordial or mini black holes were formed. With Bardeen and Carter, he proposed the four Laws of black hole mechanics, drawing an analogy with thermodynamics. In 1974, he calculated that black holes should thermally create and emit subatomic particles, known as Hawking radiation, until they exhaust their energy and evaporate.

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; while one cannot travel North of the North pole, there is no boundary there. While originally the no-boundary proposal predicted a closed Universe, discussions with Neil Turok led to the realization that the no-boundary proposal is consistent with a Universe which is not closed also.

Illness

Hawking is severely disabled by amyotrophic lateral sclerosis, or ALS (a type of motor neuron disease commonly known in the United States as Lou Gehrig's disease).

When he was young, he enjoyed riding horses and playing with the other children. At Oxford, he coxed a rowing team, which, he stated, helped relieve his immense boredom at university. Symptoms of the disorder first appeared while he was enrolled at Cambridge. He lost balance and fell downstairs, hitting his head. Worried of losing his genius, he took the Mensa International test, to verify that his intellectual abilities were intact. Diagnosis came when Hawking was 21, shortly before his first marriage, and doctors said he would not survive more than two or three years. He battled the odds and has survived much longer than most sufferers of ALS , although he has become increasingly disabled by the gradual progress of the disease.

He gradually lost the use of his arms, legs, and voice, and is now almost completely paralyzed. The computer system attached to his wheelchair is operated by Hawking via an infra-red 'blink switch' clipped onto his glasses. By scrunching his right cheek up, he is able to talk, compose speeches, research papers, browse the World Wide Web and write e-mail. The system also uses radio transmission to provide control over doors in his home and office.

During a visit to the research centre CERN in Geneva in 1985, Hawking contracted pneumonia, which in his condition was life-threatening. It resulted in acute difficulty of breathing, which could only be overcome through a tracheostomy by which Stephen Hawking lost his natural speech ability. He has since used an electronic voice synthesizer to communicate. The voice synthesizer, which has an American accent, is of a model that is no longer produced. Asked why he has still kept it after so many years, Hawking mentioned that he has not heard a voice he likes better and because he identifies with it. Hawking is said to be looking for a replacement since, other than being obsolete, the synthesizer, a DECtalk DTC01 is now considered large and fragile but as of present, finding a software alternative has been difficult. During a lecture in Hong Kong in June 2006, he joked that if he got a new one with a French accent, his wife would divorce him.

When Hawking (then using a wheelchair and unable to dress himself) and his wife were first living together, they received no outside assistance other than from physics students who helped in exchange for extra attention with their work. As his condition worsened, Hawking needed a team of nurses to provide round-the-clock care. He also needed a wheelchair for mobility.

Despite his disease, he describes himself as "lucky" — not only has the slow progress of his disease provided time to make influential discoveries, it has also afforded time to have, in his own words, "a very attractive family" . When Jane was asked why she decided to marry a man with a 3-year life expectancy, she responded: "These were the days of atomic gloom and doom, so we all had rather a short life expectancy."

Hawking's first wife cared for him until 1991 when the couple separated under the pressures of fame, his increasing disability, and an affair Hawking began with one of his nurses, Elaine Mason. He and Elaine Mason were married in 1995. (Elaine Mason's first husband, David Mason, had designed the first version of Hawking's talking computer.) In October 2006, the Hawkings filed for divorce . A 2004 Vanity Fair article by Judy Bachrach indicated allegations of violence toward Hawking by his second wife, though a police investigation into the matter that same year was inconclusive.

In 1999, Jane Hawking published a memoir, Music to Move the Stars, detailing her own long-term relationship with a family friend whom she later married. Hawking's daughter Lucy Hawking is a novelist. Their son Robert Hawking emigrated to the United States, married, and has one child, George Edward Hawking.

Distinction

Hawking's belief that the average person should have access to his work led him to write a series of popular science books in addition to his academic work. The first of these, A Brief History of Time, was published on April 1, 1988 by Hawking, his family and friends, and some leading physicists. It became a documentary in 1991. It surprisingly became a best-seller and was followed by The Universe in a Nutshell (2001).

Both books have remained highly popular all over the world. A collection of essays titled Black Holes and Baby Universes (1993) was also popular. He has now written a new book, A Briefer History of Time (2005) that aims to update his earlier works and make them accessible to a wider audience. He has recently announced that he plans to write a children's book focusing on science that has been described to be "like Harry Potter, but without the magic."

Hawking is also known for his wit; he is famous for his oft-made statement, "When I hear of Schrödinger's cat, I reach for my pistol." This was a deliberately ironic paraphrase of the phrase "Whenever I hear the word culture... I release the safety-catch of my Browning", from the play Schlageter (Act 1, Scene 1) by German playwright and Nazi Poet Laureate, Hanns Johst.

His wit has both entertained the non-specialist public and helped them to understand complex questions. Asked in October 2005 on the British daytime chat show Richard & Judy, to explain his assertion that the question "What came before the Big Bang?" was meaningless, he compared it to asking "What lies north of the north pole?"

Hawking is an active supporter of various causes. He appeared on a political broadcast for the United Kingdom's Labour Party, and actively supports the children's charity SOS Children's Villages UK.

He recently made the news for announcing that he believes colonization on other planets and/or the moon is imperative to ensure the continuation of the human race.

Comments on global warming

In the third week of June 2006, Stephen Hawking spoke in China and made the statement that humans might have already fried the atmosphere and inadvertently reconnected the planet Earth with her dead neighbours.

The China Daily asked Hawking about the environment, and he responded that he was "very worried about global warming." He said he was afraid that Earth "might end up like Venus, at 250 degrees Celsius and raining sulfuric acid." In the light of this discussion Hawking asked an open question on Yahoo Answers "How can the human race survive the next hundred years?" and received well over 25,000 responses . The validity of the question was confirmed by Hawking himself and the Yahoo Answers staff. An answer has already been chosen.

In an ABC News interview in August 2006, Hawking explained, "The danger is that global warming may become self-sustaining, if it has not done so already. The melting of the Arctic and Antarctic ice caps reduces the fraction of solar energy reflected back into space, and so increases the temperature further. Climate change may kill off the Amazon and other rain forests, and so eliminate one of the main ways in which carbon dioxide is removed from the atmosphere. The rise in sea temperature may trigger the release of large quantities of carbon dioxide, trapped as hydrides on the ocean floor. Both these phenomena would increase the greenhouse effect, and so further global warming. We have to reverse global warming urgently, if we still can."

Losing an old bet

Hawking was in the news in July 2004 for presenting a new theory about black holes which goes against his own long-held belief about their behaviour, thus losing a bet he made with Kip Thorne and John Preskill of Caltech. Classically, it can be shown that information crossing the event horizon of a black hole is lost to our universe, and that thus all black holes are identical beyond their mass, electrical charge and angular velocity (the " no hair theorem").

The problem with this theorem is that it implies the black hole will emit the same radiation regardless of what goes into it, and as a consequence that if a pure quantum state is thrown into a black hole, an "ordinary" mixed state will be returned. This runs counter to the rules of quantum mechanics and is known as the black hole information paradox.

Another bet — about the existence of black holes — was described by Hawking as an "insurance policy" of sorts. To quote from his book, A Brief History of Time, "This was a form of insurance policy for me. I have done a lot of work on black holes, and it would all be wasted if it turned out that black holes do not exist. But in that case, I would have the consolation of winning my bet, which would win me four years of the magazine Private Eye. If black holes do exist, Kip will get one year of Penthouse. When we made the bet in 1975, we were 80% certain that Cygnus was a black hole. By now, I would say that we are about 95% certain, but the bet has yet to be settled." (1988) According to the updated 10th anniversary edition of A Brief History of Time, Hawking has conceded the bet "to the outrage of Kip's liberated wife" due to subsequent observational data in favour of black holes.

Hawking had earlier speculated that the singularity at the centre of a black hole could form a bridge to a "baby universe" into which the lost information could pass; such theories have been very popular in science fiction. But according to Hawking's new idea, presented at the 17th International Conference on General Relativity and Gravitation, on 21 July 2004 in Dublin, Ireland, black holes eventually transmit, in a garbled form, information about all matter they swallow:

The Euclidean path integral over all topologically trivial metrics can be done by time slicing and so is unitary when analytically continued to the Lorentzian. On the other hand, the path integral over all topologically non-trivial metrics is asymptotically independent of the initial state. Thus the total path integral is unitary and information is not lost in the formation and evaporation of black holes. The way the information gets out seems to be that a true event horizon never forms, just an apparent horizon.

— GR Conference website summary of Hawking's talk

Having concluded that information is conserved, Hawking conceded his bet in Preskill's favour, awarding him Total Baseball, The Ultimate Baseball Encyclopedia. However, Thorne remains unconvinced of Hawking's proof and declined to contribute to the award.

Selected publications

Technical

• The Large Scale Structure of Spacetime with George Ellis, 1973
• The Large, the Small, and the Human Mind, (with Abner Shimony, Nancy Cartwright, and Roger Penrose), Cambridge University Press, 1997, ISBN 0-521-56330-5 (hardback), ISBN 0-521-65538-2 (paperback), Canto edition: ISBN 0-521-78572-3
• Information Loss in Black Holes, Cambridge 2005

Popular

• A Brief History of Time, (Bantam Press 1988)
• Black Holes and Baby Universes and Other Essays, (Bantam Books 1993)
• The Universe in a Nutshell, (Bantam Press 2001)
• On The Shoulders of Giants. The Great Works of Physics and Astronomy, (Running Press 2002)
• A Briefer History of Time, (Bantam Books 2005)

Foot note On Hawking's website, he denounces the unauthorised publication of The Theory of Everything and asks consumers to be aware that he was not involved in its creation.

Full lists of Hawking's publications are available on his website.

Awards

• 1975 Eddington Medal
• 1976 Hughes Medal of the Royal Society
• 1979 Albert Einstein Medal
• 1982 Order of the British Empire (Commander)
• 1985 Gold Medal of the Royal Astronomical Society
• 1986 Member of the Pontifical Academy of Sciences
• 1988 Wolf Prize in Physics
• 1989 Prince of Asturias Awards in Concord
• 1989 Companion of Honour
• 1999 Julius Edgar Lilienfeld Prize of the American Physical Society
• 2003 Michelson Morley Award of Case Western Reserve University
• 2006 Copley Medal of the Royal Society

Popular culture

List of former students

Further information about Hawking's former students may be found in the Mathematical Genealogy Project.

Quotes

• Even if there is only one possible unified theory, it is just a set of rules and equations. What is it that breathes fire into the equations and makes a universe for them to describe?
• I think computer viruses should count as life. I think it says something about human nature that the only form of life we have created so far is purely destructive. We've created life in our own image.
• It is not clear that intelligence has any long-term survival value.
• My goal is simple. It is a complete understanding of the universe, why it is as it is and why it exists at all
• Not only does God play dice, but... he sometimes throws them where they cannot be seen.
• Someone told me that each equation I included in the book would halve the sales.
• The usual approach of science of constructing a mathematical model cannot answer the questions of why there should be a universe for the model to describe. Why does the universe go to all the bother of existing?
• The whole history of science has been the gradual realisation that events do not happen in an arbitrary manner, but that they reflect a certain underlying order, which may or may not be divinely inspired.
• There are grounds for cautious optimism that we may now be near the end of the search for the ultimate laws of nature.
• To confine our attention to terrestrial matters would be to limit the human spirit.
• We are just an advanced breed of monkeys on a minor planet of a very average star. But we can understand the Universe. That makes us something very special.
• (While looking at the Warp core on the set of Star Trek: The Next Generation) I'm working on that.
• For millions of years mankind lived just like the animals. Then something happened which unleashed the power of our imagination. We learned to talk. (Also used by Pink Floyd on the song Keep Talking from the album The Division Bell.)
• It was my idea.
• When I hear of Schrödinger's cat, I reach for my gun.
• Personally, I prefer the Simpsons
• I call it a "Hawking Hole". (From his voiceover cameo on the television show Futurama; he is describing a tear in the fabric of space-time that the protagonist Philip J. Fry had originally dubbed a "Fry Hole". )
• I call it a "Hawking Chamber". (Spoken later in the same Futurama episode in reference to a cryogenic freezing chamber he obviously had not invented.)