دانشنامه آزاد ۴ زبانه / εγκυκλοπαίδεια / licence

Elton پروژه‌ای چندزبانه برای گردآوری دانشنامه‌ای جامع و با محتویات آزاد است

دانشنامه آزاد ۴ زبانه / εγκυκλοπαίδεια / licence

Elton پروژه‌ای چندزبانه برای گردآوری دانشنامه‌ای جامع و با محتویات آزاد است

Stephen Hawking
Enlarge
Stephen Hawking

Stephen William Hawking (born 8 January 1942), CH, CBE, FRS, is considered one of the world's leading theoretical physicists. Hawking is the Lucasian Professor of mathematics at the University of Cambridge (a post once held by Sir Isaac Newton), and a fellow of Gonville and Caius College, Cambridge.

Despite enduring severe disability and, of late, being rendered quadriplegic by motor neurone disease (specifically, amyotrophic lateral sclerosis), he has had a successful career for many years, and has achieved status as an academic celebrity.

Contents

[hide]

[edit]

Biography

Stephen William Hawking was born in Oxford, England, on 8 January 1942. His parents were Frank and Isobel Hawking. He had two younger sisters, Philippa and Mary, and an adopted brother, Edward. Of his family, Hawking was closest to his mother, who was active in left-wing politics.

Hawking showed great talent in mathematics and physics at an early age. When he was eleven he went to St Albans School in Hertfordshire, near London. He then progressed to University College, Oxford, where he wanted to study mathematics. When mathematics wasn't available for him to study, he studied physics instead. He read for his Ph.D. at Trinity Hall, Cambridge, where he is currently an honorary fellow. Today, he holds the post of Lucasian Professor of Mathematics at Cambridge, a chair once held by Sir Isaac Newton.

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. He is a respected physicist, with many works recognised by both the International Association of Natural Physics and the American Physics-Astronomy Guild of Amherst.

[edit]

Research fields

Hawking's principal fields of research are theoretical cosmology and quantum gravity. In 1971, in collaboration with Sir Roger Penrose, he proved 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.

[edit]

Illness

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

When he was young, he was athletic and 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. 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[1], although he has become increasingly disabled by the gradual progress of the disease.

He has used an electronic voice synthesiser to communicate since a tracheostomy in 1985 that followed severe pneumonia. He gradually lost the use of his arms, legs, and voice, and is now almost completely paralysed. 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.

When Hawking (now using a wheelchair and unable to dress himself) and his wife were first living together, they received no outside assistance other than physics students, who helped in exchange for extra attention with their work. As he grew more disabled, Hawking needed a team of nurses to provide round-the-clock care. He also needed a wheelchair that would help him not be distracted by his disability.

Despite his disease, he describes himself as "lucky" — not only has the slow progress provided time to make influential discoveries, it has also afforded time to have, in his own words, "a very attractive family"[2]. 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 wife cared for him until 1991, when the couple separated under the pressures of fame, his increasing disability, and the consequent need to employ round-the-clock nurses, one of whom he became involved with. He and his nurse, Elaine Mason, were married in 1995. (Elaine Mason's first husband, David Mason, had designed the first version of Hawking's talking computer.) A 2004 Vanity Fair article by Judy Bachrach contains allegations of violence between the couple that were made by his first family, though a police investigation in the same year ended inconclusively.

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. Their daughter Lucy Hawking became a novelist. Their son Robert Hawking emigrated to the United States, married, and has one child, George Edward.

[edit]

Distinction

His belief that the average person should have access to these concepts led Hawking 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, and became a documentary in 1991 starring Hawking, his family and friends, and some leading physicists. [3] 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, 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 more accessible to a wider audience.

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 a 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[1].

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.

[edit]

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 behavior, 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 as a consequence 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. (For further detail see Thorne Hawking Preskill bet)

One other 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 (Kip Thorne) 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)

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, an encyclopedia from which information is easily retrieved. However, Thorne remains unconvinced of Hawking's proof and declined to contribute to the award.

[edit]

Awards

[edit]

Publications

[edit]

Technical

[edit]

Popular

N.B. 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 list of Hawking's publications [5] is available on his website.

[edit]

Popular culture

  • Bob & Tom Show. Hawking is portrayed (and his computerised voice simulated) in a spoof of the show I'm with Busey. At the end of the spoof, he's heard cursing his room-mate for being so stupid.
  • Computer Stew. Hawking's image was animated and used as a character in several episodes.
  • The Critic. Jay and his new trucker friends go to see "Ultimate Force" at a drive-in, which one of the truckers states will most definitely feature "a tough guy on wheels." The movie turns out to feature Hawking discussing his theories on relative force.
  • Dilbert. Was featured in an episode about Dilbert's project, the Gruntmaster 6000, creating a black hole to wipe out all life on Earth. During the episode, it is "revealed" that Hawking has the power to travel through both time and space via wormholes, and Dilbert learns the hard way that you should never bet money that a theoretical physicist can't do something.
  • Fairly Odd Parents. Hawking appeared throughout the episode "Remy Rides Again", in a mechanical flying wheelchair with a rocket on the back of it, which at the end of the episode, disappeared in a way similar to that in which the Delorean went back in time in Back to the Future. Hawking was played by Dee Bradley Baker in this episode. Hawking was hired by Remy to prove that 2 + 2 = 5, and was also Crocker's room-mate in college. Then Crocker found out that 2+2 actually equalled 6.
  • The Matthew Barnard Show a character called Steve Hawkins is in it who sits in a wheel chair and speaks with a computerized voice features in Episode 12: The end of time and in Episode 13: Matthew's new groove
  • Family Guy.
    • Hawking's persona has been featured in the episode "Peter, Peter, Caviar Eater"; it is a very brief cameo during the song "This House Is Freaking Sweet"; Hawking is presented as the man who will help Chris do his homework.
    • Additionally, a character known as Disabled Guy or "Paraplegic Guy" appears to be largely based on Hawking. The character made his first appearance in the episode "Ready, Willing, and Disabled", as a competitor in the Special People's Games.
  • The Friday Night Project. Every week in the 2006 series a voice purporting to be Hawking's, accompanied by a caption slide of a photograph of Hawking asks a contestant a quiz question, and confirms whether it is the correct answer.
  • MC Hawking. The imaginary alter-ego for the "theoretical physicist turned gangster-rapper", MC Hawking's songs parody Hawking's distinctive speech synthesiser. Song titles include "E=MC Hawking" (“I explode like a bomb/no one is spared/my power is my mass times the speed of light squared”), "Fuck the Creationists" ("Fuck the damn creationists I say it with authority/because kicking their punk asses be my paramount priority") and "Entropy" ("You down with entropy?") The success of the MC Hawking amongst internet users eventually led to a 'greatest hits' compilation CD entitled A Brief History of Rhyme (a play on Hawking's A Brief History of Time book title). Hawking himself is said to be flattered by the parody.
  • The Onion. Satirical newspaper ran an article claiming that Hawking had constructed himself a super-powered robotic exoskeleton, complete with a jetpack and claws that can rip through tanks. [7] Hawking, with his typical good humour, sent them a letter cursing them for exposing his evil plans for world domination. Hawking also had a printout of the article pinned up in his Cambridge office for some time after it was published.
  • Pinky and the Brain. In an episode in which a black hole is used as a weapon, Pinky throws it out of a hotel room window in defiance of the laws of physics. Brain notes that he must consult with Stephen Hawking.
  • Radiohead: A likeness of Stephen's computerized voice appears on the Radiohead album 'OK Computer' on the seventh track 'Fitter Happier'
  • Red Dwarf. Hawking appeared in a special program of the popular British science fiction series. He praised its creators for their witty use of (pseudo) scientific theories and said he enjoyed watching the show.
  • Robin Williams, on his 2002 DVD Robin Williams: Live at the Broadway, mentioned that "I called Stephen Hawking's house once. 'Hello this is Stephen Hawking' 'Yes, I'd like to leave a message.' 'No. This IS Stephen Hawking.'"
  • Shin Megami Tensei. In this videogame there is a wheelchair-bound character who is obviously based on Stephen Hawking, though he is never named.
  • The Simpsons. Made a few guest appearances on the long-running prime-time cartoon:
    • In "They Saved Lisa's Brain", he saves Lisa from the power-hungry Springfield chapter of Mensa in a special wheelchair, complete with an Inspector Gadget–style retractable helicopter attachment and a spring-loaded boxing glove. In the episode, Homer mistakenly refers to Prof. Hawking as Larry Flynt.
    • In "Treehouse of Horror VI", Homer makes a reference to Stephen Hawking when he is transported to a three-dimensional zone, and moans "I wish I read that book by that wheelchair guy."
    • Hawking is seen in a line of people about to board a space ship to Mars in "Life's A Glitch, Then You Die", a segment of "Treehouse of Horror X", in which the Earth is doomed by the millennium bug.
    • He is also referenced in the episode where Sideshow Bob is temporarily released to help Homer find a person who is trying to kill him. Homer lists Stephen Hawking as a guy who would want to kill him.
    • During the British Comedy Awards 2004, Hawking was presented with a one-off toy version of himself in Simpson form by Matt Groening, complete with boxing glove. Hawking presented Groening with a lifetime achievement award.
    • In the Season 16 episode "Don't Fear the Roofer", he is a friend of Lenny and the owner of the Little Caesars restaurant down the block from Moe's Tavern. Prof. Hawking shows up to explain that Bart couldn't see Ray (guest voice Ray Romano) during one scene because there was a black hole between the two of them, leading to Homer being put into a mental hospital.
  • Ultimate X-Men-- In Ultimate X-Men #25, there is a reference to Stephen Hawking having written an article on mutants, apparently stating that they were mankind's last hope against the rise of artificial intelligence. This makes him one of the rare humans who sympathize with mutants.
Hawking as himself on Star Trek: The Next Generation
Enlarge
Hawking as himself on Star Trek: The Next Generation
  • The Wrong Coast. A segment of the show tells about a movie called Party Time Continuum, in which Hawking is portrayed as a time-travelling party-animal played by Seth Green.
  • The Voyage. The New York City Metropolitan Opera commissioned an opera in 1992 by composer Philip Glass to commemorate the 500th anniversary of Columbus's arrival in the New World, which featured a wheelchair-bound scientist based on Stephen Hawking. Glass also wrote the music for the documentary A Brief History of Time.
[edit]

List of former students

Bruce Allen 1980–1983
Malcolm Perry 1974–1978
Gary Gibbons 1970–1972
[edit]

See also

[edit]

Notes and references

  1. ^ SOS Children's Villages - Our Friends. Retrieved on 2006-05-06.
  • Boslough, John (1985). Stephen Hawking's Universe. New York: Avon Books. ISBN 0-380-70763-2. A layman's guide to Stephen Hawking.
  • Ferguson, Kitty (1991). Stephen Hawking: Quest For A Theory of Everything. Franklin Watts. ISBN 0553-29895-X.
  • Morris, Errol (Director). (1991) A Brief History of Time [Documentary]. Triton Pictures.
  • Hawking, S. W. & Ellis, G. F. R. (1973). The Large Scale Structure of Space-time. Cambridge: Cambridge University Press. ISBN 0-521-09906-4.. Highly influential in the field.
  • Hawking, S. W. & Israel, W. (1979). General relativity: an Einstein centenary survey. New York: Cambridge University Press. ISBN 0-521-22285-0.. A much cited centennial survey.
  • Misner, Charles; Thorne, Kip S. & Wheeler, John Archibald (1973). Gravitation. San Francisco: W. H. Freeman. ISBN 0-7167-0344-0.; see Box 34.3 for a short biography. (This famous book is the first modern textbook on general relativity, and shows that even in the early seventies, Hawking was already regarded as an unusually intriguing personality by his colleagues.)
  • "Stephen Hawking", Microsoft® Encarta® Online Encyclopedia 2005 http://encarta.msn.com © 1997–2005 Microsoft Corporation. All Rights Reserved.
[edit]

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 of the Star Trek Enterprise set) 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.
  • It was my idea.
[edit]

External links

Wikiquote has a collection of quotations related to:


Persondata
NAME Hawking, Stephen
ALTERNATIVE NAMES
SHORT DESCRIPTION Theoretical physicist
DATE OF BIRTH 8 January 1942
PLACE OF BIRTH Oxford, England
DATE OF DEATH
PLACE OF DEATH
Retrieved from "http://en.wikipedia.org/wiki/Stephen_Hawking"
سپهر جمعه 26 خرداد‌ماه سال 1385 ساعت 02:25 ب.ظ
نظرات 0 + ارسال نظر
برای نمایش آواتار خود در این وبلاگ در سایت Gravatar.com ثبت نام کنید. (راهنما)
ایمیل شما بعد از ثبت نمایش داده نخواهد شد