Stephen
Hawking
Stephen
William Hawking, CH, CBE, FRS, FRSA (/ˈstiːvən ˈhɔːkɪŋ/ (
listen); born 8 January
1942) is an English theoretical physicist, cosmologist, author and
Director of Research at the Centre for Theoretical Cosmology within
the University of Cambridge. His scientific works include a
collaboration with Roger Penrose on gravitational singularity
theorems in the framework of general relativityand the theoretical
prediction that black holes emit radiation, often called Hawking
radiation. Hawking was the first to set out a theory of cosmology explained
by a union of the general theory of relativity and quantum mechanics. He
is a vigorous supporter of the many-worlds interpretation of quantum
mechanics.
Hawking 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 US. In 2002, Hawking was
ranked number 25 in the BBC's poll of the 100 Greatest Britons. He was
the Lucasian Professor of Mathematics at the University of Cambridge
between 1979 and 2009 and has achieved commercial success with works of popular
science in which he discusses his own theories and cosmology in general;
his book A Brief History of Time appeared on the British Sunday
Times best-seller list for a record-breaking 237 weeks.
Hawking has
a rare early-onset, slow-progressing form of amyotrophic lateral sclerosis (ALS)
that has gradually paralysed him over the decades. He now communicates
using a single cheek muscle attached to a speech-generating device.
Early life
and education
Hawking was
born on 8 January 1942 in Oxford, England to Frank (1905–1986) and Isobel
Hawking (née Walker; 1915–2013).His mother was Scottish. Despite their
families' financial constraints, both parents attended the University of
Oxford, where Frank read medicine and Isobel read Philosophy,
Politics and Economics. The two met shortly after the beginning of
the Second World Warat a medical research institute where Isobel was
working as a secretary and Frank was working as a medical researcher. They
lived in Highgate; but, as London was being bombed in those
years, Isobel went to Oxford to give birth in greater safety. Hawking
has two younger sisters, Philippa and Mary, and an adopted brother, Edward.
In 1950,
when Hawking's father became head of the division of parasitology at
the National Institute for Medical Research, Hawking and his family moved
to St Albans, Hertfordshire. In St Albans, the family were considered
highly intelligent and somewhat eccentric; meals were often spent with
each person silently reading a book. They lived a frugal existence in a
large, cluttered, and poorly maintained house and travelled in a converted
London taxicab. During one of Hawking's father's frequent absences working
in Africa, the rest of the family spent four months in Majorca visiting
his mother's friend Beryl and her husband, the poet Robert Graves.
Primary and
secondary school years
Hawking
began his schooling at the Byron House School in Highgate, London. He later
blamed its "progressive methods" for his failure to learn to read
while at the school. In St Albans, 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.
Hawking
attended Radlett School, an independent school in the village of Radlett in Hertfordshire,
for a year, and from September 1952, St Albans School, an
independent school in the city of St Albans in Hertfordshire. The family placed
a high value on education. Hawking's father wanted his son to attend the
well-regarded Westminster School, but the 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. A positive consequence was that Hawking remained with a close
group of friends with whom he enjoyed board games, the manufacture of
fireworks, model aeroplanes and boats, and long discussions about Christianity and extrasensory
perception. From 1958 on, with the help of the mathematics teacher Dikran
Tahta, they built a computer from clock parts, an old telephone switchboard and
other recycled components.
Although
known at school as "Einstein", Hawking was not initially successful
academically. With time, he began to show considerable aptitude for
scientific subjects and, inspired by Tahta, decided to read mathematics at
university. Hawking's father advised him to study medicine, concerned that
there were few jobs for mathematics graduates. He also wanted his son 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. Despite his headmaster's advice to wait until the next
year, Hawking was awarded a scholarship after taking the examinations in March
1959.
Undergraduate
years
Hawking
began his university education at University College, Oxford in October
1959 at the age of 17. For the first 18 months, he was bored and
lonely – he found the academic work "ridiculously easy". 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." A change occurred during his second and
third year when, according to Berman, Hawking made more of an effort "to
be one of the boys". He developed into a popular, lively and witty college
member, interested in classical music and science fiction. Part of the
transformation resulted from his decision to join the college boat club,
the University College Boat Club, where he coxed a rowing team. The
rowing trainer at the time noted that Hawking cultivated a daredevil image,
steering his crew on risky courses that led to damaged boats.
Hawking has
estimated that he studied about a thousand 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 questions
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. 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 (oral
examination) necessary. Hawking was concerned that he was viewed as a lazy
and difficult student. So, when asked at the oral to describe his future plans,
he 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." He
was held in higher regard than he believed; as Berman commented, the examiners
"were intelligent enough to realise they were talking to someone far
cleverer than most of themselves". After receiving a first-class BA
(Hons.) degree in natural science and completing a trip to Iran with
a friend, he began his graduate work at Trinity Hall, Cambridge, in
October 1962.
Graduate
years
Hawking's
first year as a doctoral student was difficult. He was initially
disappointed to find that he had been assigned Dennis William Sciama, one
of the founders of modern cosmology, as a supervisor rather than noted
astronomer Fred Hoyle, and he found his training in mathematics
inadequate for work in general relativity and cosmology. After
being diagnosed with motor neurone disease, Hawking fell into a depression –
though his doctors advised that he continue with his studies, he felt there was
little point. However, his disease progressed more slowly than doctors had
predicted. Although Hawking had difficulty walking unsupported, and his speech
was almost unintelligible, an initial diagnosis that he had only two years to
live proved unfounded. With Sciama's encouragement, he returned to his work. 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.
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 Steady State theories. 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, he wrote his thesis on this topic. There were other positive
developments: Hawking received a research fellowship at Gonville and Caius
College; he obtained his PhDdegree in applied mathematics and
theoretical physics, specialising in general relativity and cosmology, in March
1966; and his essay titled "Singularities and the Geometry of
Space-Time" shared top honours with one by Penrose to win that year's
prestigious Adams Prize.
Career
1966–1975
In his work,
and in collaboration with Penrose, Hawking extended the singularity
theorem concepts first explored in his doctoral 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. 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. In
1969, Hawking accepted a specially created Fellowship for Distinction in
Science to remain at Caius.
In 1970,
Hawking postulated what became known as the second law of black hole
dynamics, that the event horizon of a black hole can never get smaller. With James
M. Bardeen and Brandon Carter, he proposed the four laws of
black hole mechanics, drawing an analogy with thermodynamics. To
Hawking's irritation, Jacob Bekenstein, a graduate student of John
Wheeler, went further—and ultimately correctly—to apply thermodynamic concepts
literally. 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. His essay titled "Black Holes" won the Gravity
Research Foundation Award in January 1971. Hawking's first
book, The Large Scale Structure of Space-Time,written with George
Ellis, was published in 1973.
Beginning in
1973, Hawking moved into the study of quantum gravity and quantum
mechanics. His work in this area was spurred by a visit to Moscow and
discussions with Yakov Borisovich Zel'dovich and Alexei
Starobinsky, whose work showed that according to the uncertainty principle,
rotating black holes emit particles. To Hawking's annoyance, his
much-checked calculations produced findings that contradicted his second law,
which claimed black holes could never get smaller, and supported
Bekenstein's reasoning about their entropy. 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. 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. Hawking was elected a Fellow of the Royal Society (FRS) in
1974, a few weeks after the announcement of Hawking radiation. At the time, he
was one of the youngest scientists to become a Fellow.
Hawking was
appointed to the Sherman Fairchild Distinguished visiting professorship at
the California Institute of Technology (Caltech) in 1970. He worked
with a friend on the faculty, Kip Thorne, and engaged him in a scientific
wager about whether the dark starCygnus X-1 was a black hole.
The wager was an "insurance policy" against the proposition that
black holes did not exist. 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. Hawking has maintained ties to Caltech, spending a month there
almost every year since this first visit.
1975–1990
Hawking
returned to Cambridge in 1975 to a more academically senior post, as reader in
gravitational physics. The mid to late 1970s were a period of growing public
interest in black holes and of the physicists who were studying them. Hawking
was regularly interviewed for print and television. He also received
increasing academic recognition of his work. 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. He was appointed a professor with a chair in gravitational
physics in 1977. The following year he received the Albert
Einstein Medal and an honorary doctorate from the University of Oxford.
In the late
1970s, Hawking was elected Lucasian Professor of Mathematics at the
University of Cambridge. His 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 to solve many of
the outstanding problems physicists were studying. His promotion coincided
with a health crisis which led to his accepting, albeit reluctantly, some
nursing services at home. 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. 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 led to years of debate, including "the Black Hole War"
with Leonard Susskind and Gerard 't Hooft.
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. 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 focused mainly on inflation theory. 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. He subsequently developed
the research in collaboration with Jim Hartle, and in 1983 they published
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. 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. 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."
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?" 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." In the same book he suggested that the existence of God was
not necessary to explain the origin of the universe. Later discussions
with Neil Turok led to the realisation that the existence of God was
also compatible with an open universe.
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. A paper by Don Page and independent calculations by Raymond
Laflamme led Hawking to withdraw this concept. Honours continued to
be awarded: in 1981 he was awarded the American Franklin Medal, and
in 1982 made a Commander of the Order of the British Empire(CBE). 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. Instead
of publishing with an academic press, he signed a contract with Bantam
Books, a mass market publisher, and received a large advance for his book. A
first draft of the book, called A Brief History of Time, was completed in
1984.
One of the
first messages Hawking produced with his speech-generating device was
a request for his assistant to help him finish writing A Brief History of
Time. Peter Guzzardi, his editor at Bantam, pushed him to explain his
ideas clearly in non-technical language, a process that required many revisions
from an increasingly irritated Hawking. The book was published in April
1988 in the US and in June in the UK, and it proved to be an extraordinary
success, rising quickly to the top of bestseller lists in both countries and
remaining there for months. The book was translated into many languages, and
ultimately sold an estimated 9 million copies. Media attention was
intense, and a 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. Hawking
travelled extensively to promote his work, and enjoyed partying and dancing
into the small hours. He had difficulty refusing the invitations and
visitors, which left limited time for work and his students. Some
colleagues were resentful of the attention Hawking received, feeling it was due
to his disability. He received further academic recognition, including
five more honorary degrees, the Gold Medal of the Royal Astronomical
Society (1985), the Paul Dirac Medal (1987) and,
jointly with Penrose, the prestigious Wolf Prize (1988). In
1989, he was appointed Member of the Order of the Companions of Honour (CH). He
reportedly declined a knighthood.
1990–2000
Hawking
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. In 1994, at
Cambridge's Newton Institute, Hawking and Penrose delivered a series of
six lectures that were published in 1996 as "The Nature of Space and
Time". In 1997, he conceded a 1991 public scientific wager made
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. After discovering his concession might have
been premature, a new, more refined, wager was made. This one specified that
such singularities would occur without extra conditions. The same year,
Thorne, Hawking and Preskill made another bet, this time concerning the black
hole information paradox. 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 theory 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.
Hawking also
maintained his public profile, including bringing science to a wider audience.
A film version of A Brief History of Time, directed by Errol Morris and
produced by Steven Spielberg, premiered in 1992. Hawking had wanted the
film to be scientific rather than biographical, but he was persuaded otherwise.
The film, while a critical success, was, however, not widely released. A
popular-level collection of essays, interviews, and talks titled Black
Holes and Baby Universes and Other Essays was published in 1993, and
a six-part television series Stephen Hawking's Universe and a
companion book appeared in 1997. As Hawking insisted, this time the focus was
entirely on science.
2000–present
Hawking
continued his writings for a popular audience, publishing The Universe in
a Nutshell in 2001, and A Briefer History of Time, which he
wrote in 2005 with Leonard Mlodinow to update his earlier works with
the aim of making them accessible to a wider audience, and God Created the
Integers, which appeared in 2006. Along with Thomas Hertog at CERN and
Jim Hartle, from 2006 on Hawking developed a theory of "top-down
cosmology", which says that the universe had not one unique initial state
but many different ones, and therefore that it is inappropriate to formulate a
theory that predicts the universe's current configuration from one particular
initial state. Top-down cosmology posits that 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.
Hawking
continued to travel widely, including trips to Chile, Easter Island, South
Africa, Spain (to receive the Fonseca Prize in 2008), Canada, and
numerous trips to the United States. For practical reasons related to his disability,
Hawking increasingly travelled by private jet, and by 2011 that had become his
only mode of international travel.
By 2003,
consensus among physicists was growing that Hawking was wrong about the loss of
information in a black hole. In a 2004 lecture in Dublin, he conceded his
1997 bet with Preskill, but described his own, somewhat controversial solution
to the information paradox problem, involving the possibility that black holes
have more than one topology. In the 2005 paper he published on the
subject, he argued that the information paradox was explained by examining all
the alternative histories of universes, with the information loss in those with
black holes being cancelled out by those without such loss. In January
2014 he called the alleged loss of information in black holes his "biggest
blunder".
As part of
another longstanding scientific dispute, Hawking had emphatically argued, and
bet, that the Higgs boson would never be found. The particle was
proposed to exist as part of the Higgs field theory by Peter
Higgs in 1964. Hawking and Higgs engaged in a heated and public debate
over the matter in 2002 and again in 2008, with Higgs criticising Hawking's
work and complaining that Hawking's "celebrity status gives him instant
credibility that others do not have." The particle was discovered in
July 2012 at CERN following construction of the Large Hadron
Collider. Hawking quickly conceded that he had lost his bet and said that
Higgs should win the Nobel Prize for Physics, which he did in 2013.
In 2007,
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. The book was followed by sequels in 2009, 2011 and 2014.
In 2002,
following a UK-wide vote, the BBC included Hawking in their list of
the 100 Greatest Britons. He was awarded the Copley Medalfrom
the Royal Society (2006), the Presidential Medal of Freedom,
which is America's highest civilian honour (2009), and the Russian Special
Fundamental Physics Prize (2013).
Several
buildings have been named after him, including the Stephen W. Hawking Science
Museum in San Salvador, El Salvador, the Stephen Hawking
Building in Cambridge, and the Stephen Hawking Centre at
the Perimeter Institute in Canada. Appropriately, given
Hawking's association with time, he unveiled the mechanical
"Chronophage" (or time-eating) Corpus Clock at Corpus
Christi College, Cambridge in September 2008.
During his
career, Hawking has supervised 39 successful PhD students. As required by
Cambridge University regulations, Hawking retired as Lucasian Professor of Mathematics
in 2009. Despite suggestions that he might leave the United Kingdom as a
protest against public funding cuts to basic scientific research, Hawking
has continued to work as director of research at the Cambridge University
Department of Applied Mathematics and Theoretical Physics, and indicated in
2012 that he had no plans to retire.
On 28 June
2009, as a tongue-in-cheek test of his 1992 conjecture that travel into the
past is effectively impossible, Hawking held a party open to all, complete with
hors d'oeuvres and iced champagne, but only publicized the party after it was
over so that only time-travellers would know to attend; as expected, nobody
showed up to the party.
On 20 July
2015, Hawking helped launch Breakthrough Initiatives, an effort to search
for extraterrestrial life. In 2015, Richard Branson offered Stephen
Hawking a seat on the Virgin Galactic spaceship for free. While no hard
date has been set for launch, Virgin Galactic's SpaceShipTwo is slated to
launch at the end of 2017. At 75, Hawking will not be the oldest person ever to
go to space (John Glenn returned to space at age 77), but he will be the first
person to go to space with amyotrophic lateral sclerosis (ALS). While
this will be Hawking's first time in space, it will not be the first time he
will have experienced weightlessness: in 2007, he had flown into zero gravity
aboard a specially-modified Boeing 727-200 aircraft. Hawking created Stephen
Hawking: Expedition New Earth, a documentary on space colonization, as a summer
2017 episode of Tomorrow's World.
In August
2015, Hawking said that not all information is lost when something enters a
black hole and there might be a possibility to retrieve information from a
black hole according to his theory. In July 2017, Hawking was awarded an
Honorary Doctorate from Imperial College London.
Disability
Hawking has
a rare early-onset slow-progressing form of amyotrophic lateral sclerosis (ALS),
also known as motor neurone disease or Lou Gehrig's disease, that has gradually
paralysed him over the decades.
Hawking had
experienced increasing clumsiness during his final year at Oxford, including a
fall on some stairs and difficulties when rowing. The problems worsened,
and his speech became slightly slurred; his family noticed the changes
when he returned home for Christmas, and medical investigations were begun. The
diagnosis of motor neurone disease came when Hawking was 21, in 1963. At the
time, doctors gave him a life expectancy of two years.
In the late
1960s, Hawking's physical abilities declined: he began to use crutches and
ceased lecturing regularly. As he slowly lost the ability to write, he
developed compensatory visual methods, including seeing equations in terms of
geometry. The physicist Werner Israel later compared the
achievements to Mozart composing an entire symphony in his head. Hawking
was, however, fiercely independent and unwilling to accept help or make
concessions for his disabilities. He preferred to be regarded as "a
scientist first, popular science writer second, and, in all the ways that
matter, a normal human being with the same desires, drives, dreams, and
ambitions as the next person." His wife, Jane Hawking, later
noted: "Some people would call it determination, some obstinacy. I've
called it both at one time or another." He required much persuasion
to accept the use of a wheelchair at the end of the 1960s, but ultimately
became notorious for the wildness of his wheelchair driving. Hawking was a
popular and witty colleague, but his illness, as well as his reputation for
brashness, distanced him from some.
Hawking's
speech deteriorated, and by the late 1970s he could be understood by only his
family and closest friends. To communicate with others, someone who knew him
well would translate his speech into intelligible speech. Spurred by a
dispute with the university over who would pay for the ramp needed for him to
enter his workplace, Hawking and his wife campaigned for improved access and
support for those with disabilities in Cambridge, including adapted
student housing at the university. In general, however, Hawking had
ambivalent feelings about his role as a disability rights champion:
while wanting to help others, he also sought to detach himself from his illness
and its challenges.His lack of engagement in this area led to some criticism.
During a
visit to CERN on the border of France and Switzerland in mid-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. The National
Health Service was ready to 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. Nurses were hired for the three shifts required to
provide the round-the-clock support he required. One of those employed was
Elaine Mason, who was to become Hawking's second wife.
For his
communication, Hawking initially raised his eyebrows to choose letters on
a spelling card. But in 1986 he received a computer program called the
"Equalizer" from Walter Woltosz, CEO of Words Plus, who had developed
an earlier version of the software to help his mother-in-law, who also suffered
from ALS and had lost her ability to speak and write. In a method he uses
to this day, Hawking could now simply press a switch to select phrases, words
or letters from a bank of about 2,500–3,000 that are scanned. The program
was originally run on a desktop computer. However, Elaine Mason's husband,
David, a computer engineer, adapted a small computer and attached it to his
wheelchair. 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." The voice he uses has an American accent and is no longer
produced. Despite the availability of other voices, Hawking has retained
this original voice, saying that he prefers it and identifies with it. At
this point, Hawking activated a switch using his hand and could produce up
to 15 words a minute. Lectures were prepared in advance and were sent
to the speech synthesiser in short sections to be delivered.
Hawking
gradually lost the use of his hand, and in 2005 he began to control his
communication device with movements of his cheek muscles, with a rate of
about one word per minute. With this decline there is a risk of his
developing locked-in syndrome, so Hawking collaborated with Intel researchers
on systems that could translate his brain patterns or facial expressions into
switch activations. After several prototypes that did not perform as planned,
they finally settled on an adaptive word predictor made by the London-based
startup SwiftKey, which utilized a system similar to his original
technology, so Hawking could adapt to it easier than a brand new complex system,
and after inputting large amounts of Hawking's papers and other written
materials, developed a satisfactory system that saves time by predicting words
and phrases he uses frequently, similar to typing software used on most
smartphones today. By 2009 he could no longer drive his wheelchair
independently, but the same people who created his new typing mechanics are
working on a method to drive his chair using movements made by his chin. This
has proven difficult, since Hawking cannot move his neck, and trials have shown
that while he can indeed drive the chair, the movement is sporadic and jumpy. He
is experiencing increased breathing difficulties, requiring a ventilator at
times, and has been hospitalised several times.
Disability
outreach
 |
Physicist Stephen Hawking in Zero Gravity NASA
|
Since the
1990s, Hawking has accepted the mantle of role model for disabled people,
lecturing and participating in fundraising activities. At the turn of the
century, he and eleven other luminaries signed the Charter for the Third
Millennium on Disability, which called on governments to prevent disability and
protect disability rights. In 1999, Hawking was awarded the Julius
Edgar Lilienfeld Prize of the American Physical Society. Motivated
by the desire to increase public interest in spaceflight and to show the
potential of people with disabilities, in 2007 he participated in zero-gravity
flight in a "Vomit Comet", courtesy of Zero Gravity Corporation,
during which he experienced weightlessness eight times.
In August
2012, Hawking narrated the "Enlightenment" segment of the 2012
Summer Paralympics opening ceremony in London. In 2013, the
biographical documentary film Hawking, in which Hawking himself is
featured, was released. In September 2013, he expressed support for the
legalisation of assisted suicide for the terminally ill. In
August 2014, Hawking accepted the Ice Bucket Challenge to promote
ALS/MND awareness and raise contributions for research. As he had pneumonia in
2013, he was advised not to have ice poured over him, but his children
volunteered to accept the challenge on his behalf.
