Arthur C. Clarke

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Sir Arthur C. Clarke CBE FRAS
Clarke in February 1965, on one of the sets of 2001: A Space Odyssey
Born	Arthur Charles Clarke 16 December 1917 Minehead, Somerset, England, United Kingdom
Died	19 March 2008 (aged 90) Colombo, Sri Lanka
Pen name	Charles Willis E. G. O'Brien
Occupation	Writer, inventor, futurist
Nationality	British
Alma mater	King's College London
Period	1946–2008 (professional fiction writer)
Genre	Hard science fiction Popular science
Subject	Science
Notable works	Childhood's End 2001: A Space Odyssey Rendezvous with Rama The Fountains of Paradise
Spouse	Marilyn Mayfield (m. 1953; div. 1964)
Website
clarkefoundation.org

Sir Arthur Charles Clarke CBE FRAS (16 December 1917 – 19 March 2008) was a British science fiction writer, science writer and futurist, inventor, undersea explorer, and television series host.

He is famous for being co-writer of the screenplay for the 1968 film 2001: A Space Odyssey, widely considered to be one of the most influential films of all time. Clarke was a science writer, who was both an avid populariser of space travel and a futurist of uncanny ability. On these subjects he wrote over a dozen books and many essays, which appeared in various popular magazines. In 1961 he was awarded the Kalinga Prize, an award which is given by UNESCO for popularising science. These along with his science fiction writings eventually earned him the moniker "Prophet of the Space Age". His other science fiction writings earned him a number of Hugo and Nebula awards, which along with a large readership made him one of the towering figures of science fiction. For many years Clarke, Robert Heinlein and Isaac Asimov were known as the "Big Three" of science fiction.

Clarke was a lifelong proponent of space travel. In 1934, while still a teenager, he joined the British Interplanetary Society. In 1945, he proposed a satellite communication system using geostationary orbits. He was the chairman of the British Interplanetary Society from 1946–47 and again in 1951–53.

Clarke emigrated from England to Sri Lanka (formerly Ceylon) in 1956, largely to pursue his interest in scuba diving. That year he discovered the underwater ruins of the ancient Koneswaram temple in Trincomalee. Clarke augmented his fame later on in the 1980s, from being the host of several television shows such as Arthur C. Clarke's Mysterious World. He lived in Sri Lanka until his death.

Clarke was appointed Commander of the Order of the British Empire (CBE) in 1989 "for services to British cultural interests in Sri Lanka". He was knighted in 1998 and was awarded Sri Lanka's highest civil honour, Sri Lankabhimanya, in 2005.

Biography

Early years

Clarke was born in Minehead, Somerset, England, and grew up in nearby Bishops Lydeard. As a boy, he lived on a farm, where he enjoyed stargazing, fossil collecting, and reading American science fiction pulp magazines. He received his secondary education at Huish Grammar school in Taunton. Early influences included dinosaur cigarette cards, which led to an enthusiasm for fossils starting about 1925. Clarke attributed his interest in science fiction to reading three items: the November 1928 issue of Amazing Stories in 1929; Last and First Men by Olaf Stapledon in 1930; and The Conquest of Space by David Lasser in 1931.

In his teens, he joined the Junior Astronomical Association and contributed to Urania, the society's journal, which was edited in Glasgow by Marion Eadie. At Clarke's request, she added an Astronautics Section, which featured a series of articles by him on spacecraft and space travel. Clarke also contributed pieces to the Debates and Discussions Corner, a counterblast to an Urania article offering the case against space travel, and also his recollections of the Walt Disney film Fantasia. He moved to London in 1936 and joined the Board of Education as a pensions auditor. He and some fellow science fiction writers shared a flat in Gray's Inn Road, where he got the nickname "Ego" because of his absorption in subjects that interested him, and would later name his office filled with memorabilia as his "ego chamber".

Second World War

During the Second World War from 1941 to 1946 he served in the Royal Air Force as a radar specialist and was involved in the early-warning radar defence system, which contributed to the RAF's success during the Battle of Britain. Clarke spent most of his wartime service working on ground-controlled approach (GCA) radar, as documented in the semi-autobiographical Glide Path, his only non-science-fiction novel. Although GCA did not see much practical use during the war, it proved vital to the Berlin Airlift of 1948–1949 after several years of development. Clarke initially served in the ranks, and was a corporal instructor on radar at No. 2 Radio School, RAF Yatesbury in Wiltshire. He was commissioned as a pilot officer (technical branch) on 27 May 1943. He was promoted flying officer on 27 November 1943. He was appointed chief training instructor at RAF Honiley in Warwickshire and was demobilised with the rank of flight lieutenant.

Post-war

After the war he attained a first-class degree in mathematics and physics from King's College London. After this he worked as assistant editor at Physics Abstracts. Clarke then served as president of the British Interplanetary Society from 1946 to 1947 and again from 1951 to 1953.

Although he was not the originator of the concept of geostationary satellites, one of his most important contributions in this field may be his idea that they would be ideal telecommunications relays. He advanced this idea in a paper privately circulated among the core technical members of the British Interplanetary Society in 1945. The concept was published in Wireless World in October of that year. Clarke also wrote a number of non-fiction books describing the technical details and societal implications of rocketry and space flight. The most notable of these may be Interplanetary Flight: An Introduction to Astronautics (1950), The Exploration of Space (1951) and The Promise of Space (1968). In recognition of these contributions, the geostationary orbit 36,000 kilometres (22,000 mi) above the equator is officially recognised by the International Astronomical Union as the Clarke Orbit.

Following the 1968 release of 2001, Clarke became much in demand as a commentator on science and technology, especially at the time of the Apollo space program. On 20 July 1969 Clarke appeared as a commentator for CBS for the Apollo 11 moon landing.

Sri Lanka and diving

Clarke lived in Sri Lanka from 1956 until his death in 2008, first in Unawatuna on the south coast, and then in Colombo. Initially, he and his friend Mike Wilson travelled around Sri Lanka, diving in the coral waters around the coast with the Beachcombers club. In 1957, during a dive trip off Trincomalee, Clarke discovered the underwater ruins of a temple which would subsequently make the region popular with divers. He subsequently described it in his 1957 book The Reefs of Taprobane. This was his second diving book after the 1956 The Coast of Coral. Though Clarke lived mostly in Colombo, he set up a small diving school and a simple dive shop near Trincomalee. He dived often at Hikkaduwa, Trincomalee and Nilaveli.

The Sri Lankan government offered Clarke resident guest status in 1975. He was held in such high esteem that when fellow science fiction writer Robert A. Heinlein came to visit, the Sri Lanka Air Force provided a helicopter to take them around the country. In the early 1970s, Clarke signed a three-book publishing deal, a record for a science-fiction writer at the time. The first of the three was Rendezvous with Rama in 1973, which won all the main genre awards and spawned sequels that along with the 2001 series formed the backbone of his later career. 

Clarke receiving Marconi International Fellowship Award from Prince Claus of the Netherlands in 1982

 

In 1986 Clarke was named a Grand Master by the Science Fiction Writers of America.

In 1988 he was diagnosed with post-polio syndrome, having originally contracted polio in 1962, and needed to use a wheelchair most of the time thereafter. Clarke was for many years a Vice-Patron of the British Polio Fellowship.

In the 1989 Queen's Birthday Honours Clarke was appointed Commander of the Order of the British Empire (CBE) "for services to British cultural interests in Sri Lanka". The same year he became the first Chancellor of the International Space University, serving from 1989 to 2004. He also served as Chancellor of Moratuwa University in Sri Lanka from 1979 to 2002.

In 1994, Clarke appeared in a science fiction film; he portrayed himself in the telefilm Without Warning, an American production about an apocalyptic alien first-contact scenario presented in the form of a faux newscast. 

Clarke also became active in promoting the protection of gorillas and became a patron of the Gorilla Organization which fights for the preservation of gorillas. When tantalum mining for cell phone manufacture threatened the gorillas in 2001, he lent his voice to their cause. The dive shop that he set up continues to operate from Trincomalee through the Arthur C Clarke foundation.

Television series host

In the 1980s Clarke became well known to many for his television programmes Arthur C. Clarke's Mysterious World, Arthur C. Clarke's World of Strange Powers and Arthur C. Clarke's Mysterious Universe.

Personal life

On a trip to Florida in 1953 Clarke met and quickly married Marilyn Mayfield, a 22-year-old American divorcee with a young son. They separated permanently after six months, although the divorce was not finalised until 1964. "The marriage was incompatible from the beginning", said Clarke. Clarke never remarried, but was close to a Sri Lankan man, Leslie Ekanayake (13 July 1947 – 4 July 1977), whom Clarke called his "only perfect friend of a lifetime" in the dedication to his novel The Fountains of Paradise. Clarke is buried with Ekanayake, who predeceased him by three decades, in Colombo's central cemetery. In his biography of Stanley Kubrick, John Baxter cites Clarke's homosexuality as a reason why he relocated, due to more tolerant laws with regard to homosexuality in Sri Lanka. Journalists who enquired of Clarke whether he was gay were told, "No, merely mildly cheerful." However, Michael Moorcock wrote:

Everyone knew he was gay. In the 1950s I'd go out drinking with his boyfriend. We met his protégés, western and eastern, and their families, people who had only the most generous praise for his kindness. Self-absorbed he might be and a teetotaller, but an impeccable gent through and through.

In an interview in the July 1986 issue of Playboy magazine, when asked if he had had a bisexual experience, Clarke stated "Of course. Who hasn't?" In his obituary, Clarke's friend Kerry O'Quinn wrote: "Yes, Arthur was gay ... As Isaac Asimov once told me, 'I think he simply found he preferred men.' Arthur didn't publicise his sexuality—that wasn't the focus of his life—but if asked, he was open and honest."

Clarke accumulated a vast collection of manuscripts and personal memoirs, maintained by his brother Fred Clarke in Taunton, Somerset, England, and referred to as the "Clarkives". Clarke said that some of his private diaries will not be published until 30 years after his death. When asked why they were sealed, he answered, "Well, there might be all sorts of embarrassing things in them."

Knighthood

On 26 May 2000 he was made a Knight Bachelor "for services to literature" at a ceremony in Colombo. The award of a knighthood had been announced in the 1998 New Year Honours list, but investiture with the award had been delayed, at Clarke's request, because of an accusation, by the British tabloid The Sunday Mirror, of paedophilia. The charge was subsequently found to be baseless by the Sri Lankan police. According to The Daily Telegraph (London), the Mirror subsequently published an apology, and Clarke chose not to sue for defamation. Clarke himself said that "I take an extremely dim view of people mucking about with boys", and Rupert Murdoch promised him the reporters responsible would never work in Fleet Street again. Clarke was then duly knighted.

Later years

Clarke at his home in Sri Lanka, 2005

 

Although he and his home were unharmed by the 2004 Indian Ocean earthquake tsunami, his "Arthur C. Clarke Diving School" (also called "Underwater safaris") at Hikkaduwa near Galle was destroyed. He made humanitarian appeals, and the Arthur C. Clarke Foundation worked towards better disaster notification systems. The school has since been rebuilt.

Because of his post-polio deficits, which limited his ability to travel and gave him halting speech, most of Clarke's communications in his last years were in the form of recorded addresses. In July 2007, he provided a video address for the Robert A. Heinlein Centennial in which he closed his comments with a goodbye to his fans. In September 2007, he provided a video greeting for NASA's Cassini probe's flyby of Iapetus (which plays an important role in the book of 2001: A Space Odyssey). In December 2007 on his 90th birthday, Clarke recorded a video message to his friends and fans bidding them good-bye.

Clarke died in Sri Lanka on 19 March 2008 after suffering from respiratory failure, according to Rohan de Silva, one of his aides. His aide described the cause as respiratory complications and heart failure stemming from post-polio syndrome.

Just hours before Clarke's death a massive gamma-ray burst (GRB) reached Earth. Known as GRB 080319B, the burst set a new record as the farthest object that could be seen from Earth with the naked eye. It occurred about 7.5 billion years ago (roughly equal to half the time since the Big Bang), taking the light that long to reach Earth. Larry Sessions, a science writer for Sky and Telescope magazine blogging on earthsky.org, suggested that the burst be named "The Clarke Event". American Atheist Magazine wrote of the idea: "It would be a fitting tribute to a man who contributed so much, and helped lift our eyes and our minds to a cosmos once thought to be province only of gods."

A few days before he died, he had reviewed the manuscript of his final work, The Last Theorem, on which he had collaborated by e-mail with his contemporary Frederik Pohl. The book was published after Clarke's death. Clarke was buried alongside Leslie Ekanayake in Colombo in traditional Sri Lankan fashion on 22 March. His younger brother, Fred Clarke, and his Sri Lankan adoptive family were among the thousands in attendance.

Science fiction writer

Clarke's novella "The Road to the Sea" was originally published in Two Complete Science-Adventure Books in 1951 as "Seeker of the Sphinx"

Beginnings

While Clarke had a few stories published in fanzines, between 1937 and 1945, his first professional sale appeared in Astounding Science Fiction in 1946: "Loophole" was published in April, while "Rescue Party", his first sale, was published in May. Along with his writing Clarke briefly worked as assistant editor of Science Abstracts (1949) before devoting himself in 1951 to full-time writing.

Clarke began carving out his reputation as a "scientific" science fiction writer with his first science fiction novel, Against the Fall of Night, published as a novella in 1948. It was very popular and considered ground-breaking work for some of the concepts it contained. Clarke revised and expanded the novella into a full novel which was published in 1953. Clarke would later rewrite and expand this work a third time to become The City and the Stars in 1956, which rapidly became a definitive must-read in the field. His third science fiction novel, Childhood's End, was also published in 1953, cementing his popularity. Clarke capped the first phase of his writing career with his sixth novel, A Fall of Moondust, in 1961, which is also an acknowledged classic of the period.

During this time, Clarke corresponded with C. S. Lewis in the 1940s and 1950s and they once met in an Oxford pub, The Eastgate, to discuss science fiction and space travel. Clarke voiced great praise for Lewis upon his death, saying that the Ransom trilogy was one of the few works of science fiction that should be considered literature.

"The Sentinel"

Clarke's novelette "Jupiter Five" was cover-featured on the May 1953 issue of If

 

In 1948 he wrote "The Sentinel" for a BBC competition. Though the story was rejected, it changed the course of Clarke's career. Not only was it the basis for 2001: A Space Odyssey, but "The Sentinel" also introduced a more cosmic element to Clarke's work. Many of Clarke's later works feature a technologically advanced but still-prejudiced mankind being confronted by a superior alien intelligence. In the cases of Childhood's End, and the 2001 series, this encounter produces a conceptual breakthrough that accelerates humanity into the next stage of its evolution. This also applies in the far-distant past (but our future) in The City and the Stars (and its original version, Against the Fall of Night). 

In Clarke's authorised biography, Neil McAleer writes that: "many readers and critics still consider Childhood's End Arthur C. Clarke's best novel." But Clarke did not use ESP in any of his later stories, saying "I've always been interested in ESP and, of course, Childhood's End was about that. But I've grown disillusioned, partly because after all this time they're still arguing about whether these things happen. I suspect that telepathy does happen."

A collection of early essays was published in The View from Serendip (1977), which also included one short piece of fiction, "When the Twerms Came". Clarke also wrote short stories under the pseudonyms of E. G. O'Brien and Charles Willis. Almost all of his short stories can be found in the book The Collected Stories of Arthur C. Clarke (2001).

"Big Three"

Clarke as depicted in Amazing Stories in 1953.

 

Clarke's novelette "The Songs of Distant Earth", the cover story for the June 1958 issue of If, was expanded to novel length almost three decades later

 

For much of the later 20th century, Clarke, Asimov, and Heinlein were informally known as the "Big Three" of science fiction writers. Clarke and Heinlein began writing to each other after The Exploration of Space was published in 1951, and first met in person the following year. They remained on cordial terms for many years, including visits in the United States and Sri Lanka.

Clarke and Asimov first met in New York City in 1953, and they traded friendly insults and gibes for decades. They established an oral agreement, the "Clarke–Asimov Treaty", that when asked who was better, the two would say Clarke was the better science fiction writer and Asimov was the better science writer. In 1972, Clarke put the "treaty" on paper in his dedication to Report on Planet Three and Other Speculations.

In 1984, Clarke testified before Congress against the Strategic Defense Initiative (SDI). Later, at the home of Larry Niven in California, a concerned Heinlein attacked Clarke's views on United States foreign and space policy (especially the SDI), vigorously advocating a strong defence posture. Although the two later reconciled formally, they remained distant until Heinlein's death in 1988.

2001 series of novels

2001: A Space Odyssey, Clarke's most famous work, was extended well beyond the 1968 movie as the Space Odyssey series. In 1982, Clarke wrote a sequel to 2001 titled 2010: Odyssey Two, which was made into a film in 1984. Clarke wrote two further sequels that have not been adapted into motion pictures: 2061: Odyssey Three (published in 1987) and 3001: The Final Odyssey (published in 1997). 

2061: Odyssey Three involves a visit to Halley's Comet on its next plunge through the Inner Solar System and a spaceship crash on the Jovian moon Europa. The whereabouts of astronaut Dave Bowman (the "Star Child"), the artificial intelligence HAL 9000, and the development of native life on Europa, protected by the alien Monolith, are revealed.

Finally, in 3001: The Final Odyssey, astronaut Frank Poole's freeze-dried body, found by a spaceship beyond the orbit of Neptune, is revived by advanced medical science. The novel details the threat posed to humanity by the alien monoliths, whose actions are not always as their builders had intended.

2001: A Space Odyssey

Clarke's first venture into film was 2001: A Space Odyssey, directed by Stanley Kubrick. Kubrick and Clarke had met in New York City in 1964 to discuss the possibility of a collaborative film project. As the idea developed, they decided to loosely base the story on Clarke's short story, The Sentinel, written in 1948 as an entry in a BBC short story competition. Originally, Clarke was going to write the screenplay for the film, but Kubrick suggested during one of their brainstorming meetings that before beginning on the actual script, they should let their imaginations soar free by writing a novel first, on which they would base the film. "This is more or less the way it worked out, though toward the end, novel and screenplay were being written simultaneously, with feedback in both directions. Thus I rewrote some sections after seeing the movie rushes—a rather expensive method of literary creation, which few other authors can have enjoyed." The novel ended up being published a few months after the release of the movie. 

Due to the hectic schedule of the film's production, Kubrick and Clarke had difficulty collaborating on the book. Clarke completed a draft of the novel at the end of 1964 with the plan to publish in 1965 in advance of the film's release in 1966. After many delays the film was released in the spring of 1968, before the book was completed. The book was credited to Clarke alone. Clarke later complained that this had the effect of making the book into a novelisation, that Kubrick had manipulated circumstances to downplay Clarke's authorship. For these and other reasons, the details of the story differ slightly from the book to the movie. The film contains little explanation for the events taking place. Clarke, on the other hand, wrote thorough explanations of "cause and effect" for the events in the novel. James Randi later recounted that upon seeing the premiere of 2001, Clarke left the theatre at the intermission in tears, after having watched an eleven-minute scene (which did not make it into general release) where an astronaut is doing nothing more than jogging inside the spaceship, which was Kubrick's idea of showing the audience how boring space travels could be.

In 1972, Clarke published The Lost Worlds of 2001, which included his accounts of the production, and alternative versions of key scenes. The "special edition" of the novel A Space Odyssey (released in 1999) contains an introduction by Clarke in which he documents the events leading to the release of the novel and film.

2010: Odyssey Two

In 1982 Clarke continued the 2001 epic with a sequel, 2010: Odyssey Two. This novel was also made into a film, 2010, directed by Peter Hyams for release in 1984. Because of the political environment in America in the 1980s, the film presents a Cold War theme, with the looming tensions of nuclear warfare not featured in the novel. The film was not considered to be as revolutionary or artistic as 2001, but the reviews were still positive. 

Clarke's email correspondence with Hyams was published in 1984. Titled The Odyssey File: The Making of 2010, and co-authored with Hyams, it illustrates his fascination with the then-pioneering medium of email and its use for them to communicate on an almost daily basis at the time of planning and production of the film while living on opposite sides of the world. The book also included Clarke's personal list of the best science-fiction films ever made. 

Clarke appeared in the film, first as the man feeding the pigeons while Dr. Heywood Floyd is engaged in a conversation in front of the White House. Later, in the hospital scene with David Bowman's mother, an image of the cover of Time portrays Clarke as the American President and Kubrick as the Soviet Premier.

Rendezvous with Rama

Clarke's award-winning novel Rendezvous with Rama (1973) was optioned for filmmaking in the early 21st century but this motion picture is in "development hell" as of 2014. In the early 2000s, the actor Morgan Freeman expressed his desire to produce a movie based on Rendezvous with Rama. After a drawn-out development process – which Freeman attributed to difficulties in getting financing – it appeared that in 2003 this project might be proceeding, but this is very dubious. The film was to be produced by Freeman's production company, Revelations Entertainment, and David Fincher has been touted on Revelations' Rama web page as far back as 2001 as the film's director. After years of no progress, Fincher stated in an interview in late 2007 (in which he also credited the novel as being influential on the films Alien and Star Trek: The Motion Picture) that he is still attached to helm. Revelations indicated that Stel Pavlou had written the adaptation. 

In late 2008, Fincher stated the movie is unlikely to be made. "It looks like it's not going to happen. There's no script and as you know, Morgan Freeman's not in the best of health right now. We've been trying to do it but it's probably not going to happen." However, in 2010 it was announced that the film was still planned for future production and both Freeman and Fincher mentioned it as still needing a worthy script.

Science writer

Clarke published a number of non-fiction books with essays, speeches, addresses, etc. Several of his non-fiction books are composed of chapters that can stand on their own as separate essays.

Space travel

In particular, Clarke was a populariser of the concept of space travel. In 1950 he wrote Interplanetary Flight, a book outlining the basics of space flight for laymen. Later books about space travel included The Exploration of Space (1951), The Challenge of the Spaceship (1959), Voices from the Sky (1965), The Promise of Space (1968, rev. ed. 1970) and Report on Planet Three (1972) among others.

Futurism

His books on space travel usually included chapters about other aspects of science and technology, such as computers and bioengineering. He predicted telecommunication satellites (albeit serviced by astronauts in space suits, who would replace the satellite's vacuum tubes as they burned out).

His many predictions culminated in 1958 when he began a series of magazine essays that eventually became Profiles of the Future, published in book form in 1962. A timetable up to the year 2100 describes inventions and ideas including such things as a "global library" for 2005. The same work also contained "Clarke's First Law" and text that became Clarke's three laws in later editions.

In a 1959 essay Clarke predicted global satellite TV broadcasts that would cross national boundaries indiscriminately and would bring hundreds of channels available anywhere in the world. He also envisioned a "personal transceiver, so small and compact that every man carries one." He wrote: "the time will come when we will be able to call a person anywhere on Earth merely by dialling a number." Such a device would also, in Clarke's vision, include means for global positioning so that "no one need ever again be lost." Later, in Profiles of the Future, he predicted the advent of such a device taking place in the mid-1980s.

In a 1974 interview with the Australian Broadcasting Corporation, the interviewer asked Clarke how he believed the computer would change the future for the everyday person, and what life would be like in the year 2001. Clarke accurately predicted many things that became reality, including online banking, online shopping, and other now commonplace things. Responding to a question about how the interviewer's son's life would be different, Clarke responded: "He will have, in his own house, not a computer as big as this, [points to nearby computer], but at least, a console through which he can talk, through his friendly local computer and get all the information he needs, for his everyday life, like his bank statements, his theatre reservations, all the information you need in the course of living in our complex modern society, this will be in a compact form in his own house ... and he will take it as much for granted as we take the telephone."

 

An extensive selection of Clarke's essays and book chapters (from 1934 to 1998; 110 pieces, 63 of them previously uncollected in his books) can be found in the book Greetings, Carbon-Based Bipeds! (2000), together with a new introduction and many prefatory notes. Another collection of essays, all previously collected, is By Space Possessed (1993). Clarke's technical papers, together with several essays and extensive autobiographical material, are collected in Ascent to Orbit: A Scientific Autobiography (1984).

Geostationary communications satellite

Geostationary or Clarke orbit

Clarke contributed to the popularity of the idea that geostationary satellites would be ideal telecommunications relays. He first described this in a letter to the editor of Wireless World in February 1945 and elaborated on the concept in a paper titled Extra-Terrestrial Relays – Can Rocket Stations Give Worldwide Radio Coverage?, published in Wireless World in October 1945. The geostationary orbit is now sometimes known as the Clarke Orbit or the Clarke Belt in his honour.

It is not clear that this article was actually the inspiration for the modern telecommunications satellite. According to John R. Pierce, of Bell Labs, who was involved in the Echo satellite and Telstar projects, he gave a talk upon the subject in 1954 (published in 1955), using ideas that were "in the air", but was not aware of Clarke's article at the time. In an interview given shortly before his death, Clarke was asked whether he had ever suspected that one day communications satellites would become so important; he replied:

I'm often asked why I didn't try to patent the idea of a communications satellite. My answer is always, 'A patent is really a license to be sued.'

Though different from Clarke's idea of telecom relay, the idea of communicating via satellites in geostationary orbit itself had been described earlier. For example, the concept of geostationary satellites was described in Hermann Oberth's 1923 book Die Rakete zu den Planetenräumen (The Rocket into Interplanetary Space), and then the idea of radio communication by means of those satellites in Herman Potočnik's (written under the pseudonym Hermann Noordung) 1928 book Das Problem der Befahrung des Weltraums – der Raketen-Motor (The Problem of Space Travel — The Rocket Motor), sections: Providing for Long Distance Communications and Safety, and (possibly referring to the idea of relaying messages via satellite, but not that 3 would be optimal) Observing and Researching the Earth's Surface, published in Berlin. Clarke acknowledged the earlier concept in his book Profiles of the Future.

Undersea explorer

Clarke was an avid scuba diver and a member of the Underwater Explorers Club. In addition to writing, Clarke set up several diving-related ventures with his business partner Mike Wilson. In 1956, while scuba diving, Wilson and Clarke uncovered ruined masonry, architecture and idol images of the sunken original Koneswaram temple – including carved columns with flower insignias, and stones in the form of elephant heads – spread on the shallow surrounding seabed. Other discoveries included Chola bronzes from the original shrine, and these discoveries were described in Clarke's 1957 book The Reefs of Taprobane. In 1961, while filming off Great Basses Reef, Wilson found a wreck and retrieved silver coins. Plans to dive on the wreck the following year were stopped when Clarke developed paralysis, ultimately diagnosed as polio. A year later, Clarke observed the salvage from the shore and the surface. The ship, ultimately identified as belonging to the Mughal Emperor, Aurangzeb, yielded fused bags of silver rupees, cannon, and other artefacts, carefully documented, became the basis for The Treasure of the Great Reef. Living in Sri Lanka and learning its history also inspired the backdrop for his novel The Fountains of Paradise in which he described a space elevator. This, he believed, would make rocket-based access to space obsolete and, more than geostationary satellites, would ultimately be his scientific legacy.

Views

On religion

Themes of religion and spirituality appear in much of Clarke's writing. He said: "Any path to knowledge is a path to God—or Reality, whichever word one prefers to use." He described himself as "fascinated by the concept of God". J. B. S. Haldane, near the end of his life, suggested in a personal letter to Clarke that Clarke should receive a prize in theology for being one of the few people to write anything new on the subject, and went on to say that if Clarke's writings did not contain multiple contradictory theological views, he might have been a menace. When he entered the Royal Air Force, Clarke insisted that his dog tags be marked "pantheist" rather than the default, Church of England, and in a 1991 essay entitled "Credo", described himself as a logical positivist from the age of ten. In 2000, Clarke told the Sri Lankan newspaper, The Island, "I don't believe in God or an afterlife," and he identified himself as an atheist. He was honoured as a Humanist Laureate in the International Academy of Humanism. He has also described himself as a "crypto-Buddhist", insisting that Buddhism is not a religion. He displayed little interest about religion early in his life, for example, only discovering a few months after marrying that his wife had strong Presbyterian beliefs. 

A famous quotation of Clarke's is often cited: "One of the great tragedies of mankind is that morality has been hijacked by religion." He was quoted in Popular Science in 2004 as saying of religion: "Most malevolent and persistent of all mind viruses. We should get rid of it as quick as we can." In a three-day "dialogue on man and his world" with Alan Watts, Clarke stated that he was biased against religion and said that he could not forgive religions for what he perceived as their inability to prevent atrocities and wars over time. In his introduction to the penultimate episode of Mysterious World, entitled "Strange Skies", Clarke said: "I sometimes think that the universe is a machine designed for the perpetual astonishment of astronomers," reflecting the dialogue of the episode, in which he stated this concept more broadly, referring to "mankind". Near the very end of that same episode, the last segment of which covered the Star of Bethlehem, he said that his favourite theory was that it might be a pulsar. Given that pulsars were discovered in the interval between his writing the short story, "The Star" (1955), and making Mysterious World (1980), and given the more recent discovery of pulsar PSR B1913+16, he said: "How romantic, if even now, we can hear the dying voice of a star, which heralded the Christian era."

Clarke left written instructions for a funeral that stated: "Absolutely no religious rites of any kind, relating to any religious faith, should be associated with my funeral."

Politics

Regarding freedom of information Clarke believed "In the struggle for freedom of information, technology, not politics, will be the ultimate decider".

Clarke also wrote "It is not easy to see how the more extreme forms of nationalism can long survive when men have seen the Earth in its true perspective as a single small globe against the stars."

Regarding human jobs being replaced by robots Clarke said "Any teacher that can be replaced by a machine should be!"

Clarke supported the use of renewable energy saying "I would like to see us kick our current addiction to oil, and adopt clean energy sources... Climate change has now added a new sense of urgency. Our civilisation depends on energy, but we can't allow oil and coal to slowly bake our planet."

Intelligent life

Clarke believed "The best proof that there's intelligent life in outer space is the fact that it hasn't come here...the fact that we have not yet found the slightest evidence for life — much less intelligence — beyond this Earth does not surprise or disappoint me in the least. Our technology must still be laughably primitive; we may well be like jungle savages listening for the throbbing of tom-toms, while the ether around them carries more words per second than they could utter in a lifetime"

Clarke also believed "Two possibilities exist: Either we are alone in the Universe or we are not. Both are equally terrifying."

Paranormal phenomena

Early in his career, Clarke had a fascination with the paranormal and stated that it was part of the inspiration for his novel Childhood's End. Citing the numerous promising paranormal claims that were shown to be fraudulent, Clarke described his earlier openness to the paranormal having turned to being "an almost total sceptic" by the time of his 1992 biography. During interviews, both in 1993 and 2004–2005, he stated that he did not believe in reincarnation, saying that there was no mechanism to make it possible, though he stated "I'm always paraphrasing J. B. S. Haldane: 'The universe is not only stranger than we imagine, it's stranger than we can imagine.'" He described the idea of reincarnation as fascinating, but favoured a finite existence.

Clarke was well known for his television series investigating paranormal phenomena – Arthur C. Clarke's Mysterious World (1980), Arthur C. Clarke's World of Strange Powers (1985) and Arthur C. Clarke's Mysterious Universe (1994) – enough to be parodied in an episode of The Goodies in which his show is cancelled after it is claimed that he does not exist.

In Arthur C. Clarke's Mysterious World he gives three kinds of "mysteries".

• Mysteries of the First Kind: "something that was once utterly baffling, but is now completely understood." Clarke gives the example of a rainbow.
• Mysteries of the Second Kind: Something that is currently not fully understood and can be in the future.
• Mysteries of the Third Kind: Something of which we have no understanding.

Themes, style and influences

Clarke's work is marked by an optimistic view of science empowering mankind's exploration of the Solar System and the world's oceans. His images of the future often feature a Utopian setting with highly developed technology, ecology and society, based on the author's ideals. His early published stories usually featured the extrapolation of a technological innovation or scientific breakthrough into the underlying decadence of his own society. 

A recurring theme in Clarke's works is the notion that the evolution of an intelligent species would eventually make them something close to gods. This was explored in his 1953 novel Childhood's End and briefly touched upon in his novel Imperial Earth. This idea of transcendence through evolution seems to have been influenced by Olaf Stapledon, who wrote a number of books dealing with this theme. Clarke has said of Stapledon's 1930 book Last and First Men that "No other book had a greater influence on my life ... [It] and its successor Star Maker (1937) are the twin summits of [Stapledon's] literary career".

Awards, honours and other recognition

Clarke won the 1963 Stuart Ballantine Medal from the Franklin Institute for the concept of satellite communications, and other honours. He won more than a dozen annual literary awards for particular works of science fiction.

• In 1956, Clarke won a Hugo award for his short story, "The Star".
• Clarke won the UNESCO–Kalinga Prize for the Popularization of Science in 1961.
• He won the Stuart Ballantine Medal in 1963.
• Shared a 1969 Academy Award nomination with Stanley Kubrick in the category Best Writing, Story and Screenplay – Written Directly for the Screen for 2001: A Space Odyssey.
• The fame of 2001 was enough for the Command Module of the Apollo 13 craft to be named "Odyssey".
• Clarke won the Nebula (1973) for his novella, "A Meeting with Medusa."
• Clarke won both the Nebula (1973) and Hugo (1974) awards for his novel, Rendezvous with Rama.
• Clarke won both the Nebula (1979) and Hugo (1980) awards for his novel, The Fountains of Paradise.
• In 1982, he won the Marconi Prize for innovation in communications and remote sensing in space.
• In 1985 the Science Fiction Writers of America named him its 7th SFWA Grand Master.
• In 1986, he was elected to the National Academy of Engineering For conception of geosynchronous communications satellites, and for other contributions to the use and understanding of space
• In 1988, he was awarded an Honorary Degree (Doctor of Letters) by the University of Bath.
• Readers of the British monthly Interzone voted him the all-time second best science fiction author in 1988–1989.
• He received a CBE in 1989, and was knighted in 2000. Clarke's health did not allow him to travel to London to receive the latter honour personally from the Queen, so the United Kingdom's High Commissioner to Sri Lanka invested him as a Knight Bachelor at a ceremony in Colombo.
• In 1994, Clarke was nominated for a Nobel Peace Prize by law professor Glenn Reynolds.
• The Science Fiction and Fantasy Hall of Fame inducted Clarke in 1997, its second class of two deceased and two living persons. Among the living, Clarke and Andre Norton followed A. E. van Vogt and Jack Williamson.
• In 2000, he was named a Distinguished Supporter of the British Humanist Association.
• The 2001 Mars Odyssey orbiter is named in honour of Clarke's works.
• In 2003, Clarke was awarded the Telluride Tech Festival Award of Technology, where he appeared on stage via a 3-D hologram with a group of old friends that included Jill Tarter, Neil Armstrong, Lewis Branscomb, Charles Townes, Freeman Dyson, Bruce Murray, and Scott Brown.
• In 2004, Clarke won the Heinlein Award for outstanding achievement in hard or science-oriented science fiction.
• On 14 November 2005 Sri Lanka awarded Clarke its highest civilian award, the Sri Lankabhimanya (The Pride of Sri Lanka), for his contributions to science and technology and his commitment to his adopted country.
• Clarke was the Honorary Board Chair of the Institute for Cooperation in Space, founded by Carol Rosin, and served on the Board of Governors of the National Space Society, a space advocacy organisation founded by Wernher von Braun.

Named after Clarke

Awards

• Arthur C. Clarke Awards for science fiction writing, awarded annually in the United Kingdom.

In 1986, Clarke provided a grant to fund the prize money (initially £1,000) for the Arthur C. Clarke Award for the best science fiction novel published in the United Kingdom in the previous year. In 2001 the prize was increased to £2001, and its value now matches the year (e.g., £2005 in 2005).

• Sir Arthur Clarke Award, for achievements in space, awarded annually in the United Kingdom.

In 2005 he lent his name to the inaugural Sir Arthur Clarke Awards—dubbed the "Space Oscars". His brother attended the awards ceremony, and presented an award specially chosen by Arthur (and not by the panel of judges who chose the other awards) to the British Interplanetary Society.

• Arthur C. Clarke Foundation awards: "Arthur C. Clarke Innovator's Award" and "Arthur C. Clarke Lifetime Achievement Award"
• The Sir Arthur C. Clarke Memorial Trophy Inter School Astronomy Quiz Competition, held in Sri Lanka every year and organised by the Astronomical Association of Ananda College, Colombo. The competition first started in 2001 as "The Sir Arthur C. Clarke Trophy Inter School Astronomy Quiz Competition" and was later renamed after his death.
• Arthur C. Clarke Award for Imagination in Service to Society

Other

• An asteroid was named in Clarke's honour, 4923 Clarke (the number was assigned prior to, and independently of, the name – 2001, however appropriate, was unavailable, having previously been assigned to Albert Einstein).
• A species of ceratopsian dinosaur, discovered in Inverloch in Australia, was named after Clarke, Serendipaceratops arthurcclarkei. The genus name may also be an allusion to his adopted country, Sri Lanka, one of whose former names is Serendip.
• The Learning Resource Centre at Richard Huish College, Taunton, which Clarke attended when it was Huish Grammar School, is named after him.
• Clarke was a distinguished vice-president of the H. G. Wells Society, being strongly influenced by Wells as a science-fiction writer.
• Arthur C. Clarke Institute for Modern Technologies, one of the major research institutes in Sri Lanka is named after him.
• The main protagonist of the Dead Space series of video games, Isaac Clarke, takes his surname from Arthur C. Clarke, and his given name from Clarke's friendly rival and associate, Isaac Asimov.
• A proposed outer-circular orbital beltway in Colombo, Sri Lanka, is to be named 'Arthur C. Clarke Expressway' in honour of Clarke.
• 'The Clarke Event' is a proposed name for GRB 080319B, a gamma-ray burst detected just hours before Clarke's death that set a new record for the most intrinsically bright object ever observed by humans in the universe. The name would honour Clarke and his award-winning short story "The Star".
• Clarke Montes, a mountain on Pluto's moon Charon is named after Clarke.

Selected works

Novels

• Against the Fall of Night (1948, 1953) original version of The City and the Stars
• Prelude to Space (1951)
• The Sands of Mars (1951)
• Islands in the Sky (1952)
• Childhood's End (1953)
• Earthlight (1955)
• The City and the Stars (1956)
• The Deep Range (1957)
• A Fall of Moondust (1961)
• Dolphin Island - A Story of the People of the Sea (1963)
• Glide Path (1963)
• 2001: A Space Odyssey (1968) (film with Stanley Kubrick)
• Rendezvous with Rama (1973)
• Imperial Earth (1976)
• The Fountains of Paradise (1979)
• 2010: Odyssey Two (1982)
• The Songs of Distant Earth (1986)
• 2061: Odyssey Three (1987)
• The Ghost from the Grand Banks (1990)
• The Hammer of God (1993)
• 3001: The Final Odyssey (1997)

Short story collections

• Expedition to Earth (1953)
• Reach for Tomorrow (1956)
• Tales from the White Hart (1957)
• The Other Side of the Sky (1958)
• Tales of Ten Worlds (1962)
• The Nine Billion Names of God (1967)
• Of Time and Stars (1972)
• The Wind from the Sun (1972)
• The Best of Arthur C. Clarke (1973)
• The Sentinel (1983)
• Tales From Planet Earth (1990)
• The Collected Stories of Arthur C. Clarke (2001)

Non-fiction

• Interplanetary Flight: an introduction to astronautics (1950) London: Temple Press, ISBN 0-425-06448-4
• The Exploration of Space (1951) New York: Harper & Brothers
• The Exploration of the Moon (1954) with R. A. Smith, New York: Harper Brothers
• The Coast of Coral (1955) London: Frederick Muller
• Boy Beneath the Sea (1958) New York: Harper, ISBN 0060212667
• Voice Across the Sea (1958) New York: Harper
• Profiles of the Future: An Inquiry into the Limits of the Possible (1962) New York: Harper & Row
• The Treasure of the Great Reef (1964) with Mike Wilson, New York: Harper & Row
• Voices from the Sky: Previews of the Coming Space Age (1965) New York: Harper & Row
• The Promise of Space (1968) New York: Harper & Row
• The View from Serendip (1977) New York: Random House, ISBN 0-394-41796-8
• 1984: Spring - A Choice of Futures (1984) collected non-fiction writings, New York: Del Rey / Ballantine, ISBN 0-345-31357-7
• Astounding Days: A Science Fictional Autobiography (1989) London: Gollancz, ISBN 0-575-04446-2
• How the World Was One: Beyond the Global Village (1992) London: Gollancz, ISBN 0-575-05226-0
• Greetings, Carbon-Based Bipeds! : Collected Essays, 1934–1998 (1999) New York: St. Martin's Press, and London: Voyager

Documentaries

• To Mars by A-Bomb: The Secret History of Project Orion (2003)

Gregory Benford

From Wikipedia, the free encyclopedia

Gregory Benford
Born	January 30, 1941 (age 78) Mobile, Alabama
Occupation	Scientist, writer
Nationality	United States
Genre	Science fiction
Notable works	Galactic Center Saga novels
Website
www.gregorybenford.com

Gregory Benford (born January 30, 1941) is an American science fiction author and astrophysicist who is Professor Emeritus at the Department of Physics and Astronomy at the University of California, Irvine. He is a contributing editor of Reason magazine.

Benford wrote the Galactic Center Saga science fiction novels, beginning with In the Ocean of Night (1977). The series postulates a galaxy in which sentient organic life is in constant warfare with sentient electromechanical life.

In 1969 he wrote "The Scarred Man", the first story about a computer virus, published in 1970.

Biography

Benford was born in Mobile, Alabama and grew up in Robertsdale and Fairhope. Graduating Phi Beta Kappa, he received a Bachelor of Science in physics in 1963 from the University of Oklahoma in Norman, Oklahoma, followed by a Master of Science from the University of California, San Diego in 1965, and a doctorate there in 1967. That same year he married Joan Abbe. They are the parents of two children. Benford modeled characters in several of his novels after his wife, most prominently the heroine of Artifact. She died in 2002.

Benford has an identical twin brother, Jim Benford, with whom he has collaborated on science fiction stories. Both got their start in science fiction fandom, with Gregory being a co-editor of the science fiction fanzine Void. Benford has said he is an atheist.

He has been a long-time resident of Laguna Beach, California.

Writing career

Gregory Benford's first professional sale was the story "Stand-In" in the Magazine of Fantasy and Science Fiction (June 1965), which won second prize in a short story contest based on a poem by Doris Pitkin Buck. In 1969, he began writing a science column for Amazing Stories. 

Benford tends to write hard science fiction which incorporates the research he is doing as a practical scientist. He has worked on collaborations with authors William Rotsler, David Brin and Gordon Eklund. His time-travel novel Timescape (1980) won both the Nebula Award and the John W. Campbell Memorial Award. The scientific procedural novel eventually loaned its title to a line of science fiction published by Pocket Books. In the late 1990s, he wrote Foundation's Fear, one of an authorized sequel trilogy to Isaac Asimov's Foundation series. Other novels published in that period include several near-future science thrillers: Cosm (1998), The Martian Race (1999) and Eater (2000).

Benford has served as an editor of numerous alternate history anthologies as well as collections of Hugo Award winners. 

He has been nominated for four Hugo Awards (for two short stories and two novellas) and 12 Nebula Awards (in all categories). In addition to Timescape, he won the Nebula for the novelette "If the Stars Are Gods" (with Eklund). In 2005 the MIT SF Society awarded him the Asimov Prize.

Benford was a guest of honour at Aussiecon Three, the 1999 Worldcon. He remains a regular contributor to science fiction fanzines, for example Apparatchik (defunct as of 1997). 

In 2016 Benford was the recipient of the Los Angeles Science Fantasy Society Forry Award Lifetime Achievement Award in the Field of Science Fiction.

Contributions to science and speculative science

Gregory Benford, 2008

 

Gregory Benford is Professor Emeritus of Physics at the University of California, Irvine. With more than 200 scientific publications, his research encompassed both theory and experiments in the fields of astrophysics and plasma physics. His research has been supported by NSF, NASA, AFOSR, DOE and other agencies. He is an ongoing advisor to NASA, DARPA (Defense Advanced Research Projects Agency) and the CIA. 

Benford's work in physics at the University of California focused on theoretical and experimental plasma physics, including studies of extremely strong turbulence, particularly in astrophysical contexts, and studies of magnetic structures from the galactic center to large-scale galactic jets. Working in collaboration with, among others, science fiction writers Cramer, Forward, and Landis, Benford worked on a theoretical study of the physics of wormholes, which pointed out that wormholes, if formed in the early universe, could still exist in the present day if they were wrapped in a negative-mass cosmic string. Such wormholes could potentially be detected by gravitational lensing. 

In 2004, Benford proposed that the harmful effects of global warming could be reduced by the construction of a rotating Fresnel lens 1,000 kilometres across, floating in space at the Lagrangian point L1. According to Benford, this lens would diffuse the light from the Sun and reduce the solar energy reaching the Earth by approximately 0.5% to 1%. He estimated that this would cost around US$10 billion. His plan has been commented on in a variety of forums. A similar space sunshade was proposed in 1989 by J. T. Early, and again in 1997 by Edward Teller, Lowell Wood, and Roderick Hyde. In 2006, Benford pointed out one possible danger in this approach: if this lens were built and global warming were avoided, there would be less incentive to reduce greenhouse gases, and humans might continue to produce too much carbon dioxide until it caused some other environmental catastrophe, such as a chemical change in ocean water that could be disastrous to ocean life.

Benford serves on the board of directors and the steering committee of the Mars Society. 

He has advocated human cryopreservation, for example by signing an open letter to support research into cryonics, being a member of Alcor, and by being an advisor to a UK cryonics and cryopreservation advocacy group.

Gregory Benford retired from the University of California in 2006 in order to found and develop Genescient Corporation. Genescient is a new generation biotechnology company that combines evolutionary genomics with massive selective screening to analyze and exploit the genetics of model animal and human whole genomes. This enables Genescient to develop novel therapeutics that target the chronic diseases of aging.

Scientific awards and recognition

• Phi Beta Kappa
• Woodrow Wilson Fellow
• Fellow of the American Physical Society
• Visiting Fellow
  • Cambridge University
  • University of Turin
  • University of Bologna.
• 1995 Lord Prize for contributions to science
• 2006 Professor Emeritus at the University of California, Irvine

Benford's law of controversy

Not to be confused with Benford's law.

 

Benford's law of controversy is an adage from the 1980 novel Timescape, stating:

Passion is inversely proportional to the amount of real information available.

The adage was quoted in an international drug policy article in a peer-reviewed social science journal.

Selected bibliography

Galactic Center Saga

• In the Ocean of Night (1977)
• Across the Sea of Suns (1984)
• Great Sky River (1987)
• Tides of Light (1989)
• Furious Gulf (1994)
• Sailing Bright Eternity (1996)
• "A Hunger for the Infinite" a novella published in the anthology Far Horizons (1999)

Stochastic computing

From Wikipedia, the free encyclopedia

Stochastic computing is a collection of techniques that represent continuous values by streams of random bits. Complex computations can then be computed by simple bit-wise operations on the streams. Stochastic computing is distinct from the study of randomized algorithms.

Motivation and a simple example

Suppose that ${\displaystyle p,q\in [0,1]}$ is given, and we wish to compute ${\displaystyle p\times q}$. Stochastic computing performs this operation using probability instead of arithmetic.

Specifically, suppose that there are two random, independent bit streams called stochastic numbers (i.e. Bernoulli processes), where the probability of a one in the first stream is ${\displaystyle p}$, and the probability in the second stream is ${\displaystyle q}$. We can take the logical AND of the two streams. 

${\displaystyle a_{i}}$	1	0	1	1	0	1	...
${\displaystyle b_{i}}$	1	1	0	1	1	0	...
${\displaystyle a_{i}\land b_{i}}$	1	0	0	1	0	0	...

The probability of a one in the output stream is ${\displaystyle pq}$. By observing enough output bits and measuring the frequency of ones, it is possible to estimate ${\displaystyle pq}$ to arbitrary accuracy. 

The operation above converts a fairly complicated computation (multiplication of ${\displaystyle p}$ and ${\displaystyle q}$) into a series of very simple operations (evaluation of ${\displaystyle a_{i}\land b_{i}}$) on random bits. 

More generally speaking, stochastic computing represents numbers as streams of random bits and reconstructs numbers by calculating frequencies. The computations are performed on the streams and translate complicated operations on ${\displaystyle p}$ and ${\displaystyle q}$ into simple operations on their stream representations. (Because of the method of reconstruction, devices that perform these operations are sometimes called stochastic averaging processors.) In modern terms, stochastic computing can be viewed as an interpretation of calculations in probabilistic terms, which are then evaluated with a Gibbs sampler. It can also be interpreted as a hybrid analog/digital computer.

History

The RASCEL stochastic computer, circa 1969

 

Stochastic computing was first introduced in a pioneering paper by John von Neumann in 1953. However, the theory could not be fully developed until advances in computing of the 1960s, mostly through a series of simultaneous and parallel efforts in the US and the UK. By the late 1960s, attention turned to the design of special-purpose hardware to perform stochastic computation. A host of these machines were constructed between 1969 and 1974; RASCEL is pictured in this article. 

Despite the intense interest in the 1960s and 1970s, stochastic computing ultimately failed to compete with more traditional digital logic, for reasons outlined below. The first (and last) International Symposium on Stochastic Computing took place in 1978; active research in the area dwindled over the next few years. 

Although stochastic computing declined as a general method of computing, it has shown promise in several applications. Research has traditionally focused on certain tasks in machine learning and control. Somewhat recently, interest has turned towards stochastic decoding, which applies stochastic computing to the decoding of error correcting codes. More recently, stochastic circuits have been successfully used in image processing tasks such as edge detection  and image thresholding.

Strengths and weaknesses

Although stochastic computing was a historical failure, it may still remain relevant for solving certain problems. To understand when it remains relevant, it is useful to compare stochastic computing with more traditional methods of digital computing.

Strengths

Suppose we wish to multiply two numbers each with ${\displaystyle n}$ bits of precision. Using the typical long multiplication method, we need to perform ${\displaystyle n^{2}}$ operations. With stochastic computing, we can AND together any number of bits and the expected value will always be correct. (However, with a small number of samples the variance will render the actual result highly inaccurate). 

Moreover, the underlying operations in a digital multiplier are full adders, whereas a stochastic computer only requires an AND gate. Additionally, a digital multiplier would naively require ${\displaystyle 2n}$ input wires, whereas a stochastic multiplier would only require 2 input wires. (If the digital multiplier serialized its output, however, it would also require only 2 input wires.) 

Additionally, stochastic computing is robust against noise; if a few bits in a stream are flipped, those errors will have no significant impact on the solution. 

Furthermore, stochastic computing elements can tolerate skew in the arrival time of the inputs. Circuits work properly even when the inputs are misaligned temporally. As a result, stochastic systems can be designed to work with inexpensive locally generated clocks instead of using a global clock and an expensive clock distribution network.

Finally, stochastic computing provides an estimate of the solution that grows more accurate as we extend the bit stream. In particular, it provides a rough estimate very rapidly. This property is usually referred to as progressive precision, which suggests that the precision of stochastic numbers (bit streams) increases as computation proceeds.  It is as if the most significant bits of the number arrive before its least significant bits; unlike the conventional arithmetic circuits where the most significant bits usually arrive last. In some iterative systems the partial solutions obtained through progressive precision can provide faster feedback than through traditional computing methods, leading to faster convergence.

Weaknesses

Stochastic computing is, by its very nature, random. When we examine a random bit stream and try to reconstruct the underlying value, the effective precision can be measured by the variance of our sample. In the example above, the digital multiplier computes a number to ${\displaystyle 2n}$ bits of accuracy, so the precision is ${\displaystyle 2^{-2n}}$. If we are using a random bit stream to estimate a number and want the standard deviation of our estimate of the solution to be at least ${\displaystyle 2^{-2n}}$, we would need ${\displaystyle O(2^{4n})}$ samples. This represents an exponential increase in work. In certain applications, however, the progressive precision property of stochastic computing can be exploited to compensate this exponential loss. 

Second, stochastic computing requires a method of generating random biased bit streams. In practice, these streams are generated with pseudo-random number generators. Unfortunately, generating (pseudo-)random bits is fairly costly (compared to the expense of, e.g., a full adder). Therefore, the gate-level advantage of stochastic computing is typically lost.

Third, the analysis of stochastic computing assumes that the bit streams are independent (uncorrelated). If this assumption does not hold, stochastic computing can fail dramatically. For instance, if we try to compute ${\displaystyle p^{2}}$ by multiplying a bit stream for ${\displaystyle p}$ by itself, the process fails: since ${\displaystyle a_{i}\land a_{i}=a_{i}}$, the stochastic computation would yield ${\displaystyle p\times p=p}$, which is not generally true (unless ${\displaystyle p=}$0 or 1). In systems with feedback, the problem of decorrelation can manifest in more complicated ways. Systems of stochastic processors are prone to latching, where feedback between different components can achieve a deadlocked state. A great deal of effort must be spent decorrelating the system to attempt to remediate latching. 

Fourth, although some digital functions have very simple stochastic counterparts (such as the translation between multiplication and the AND gate), many do not. Trying to express these functions stochastically may cause various pathologies. For instance, stochastic decoding requires the computation of the function ${\displaystyle f(p,q)\rightarrow pq/(pq+(1-p)(1-q))}$. There is no single bit operation that can compute this function; the usual solution involves producing correlated output bits, which, as we have seen above, can cause a host of problems. 

Other functions (such as the averaging operator ${\displaystyle f(p,q)\rightarrow (p+q)/2}$) require either stream decimation or inflation. Tradeoffs between precision and memory can be challenging.

Stochastic decoding

Although stochastic computing has a number of defects when considered as a method of general computation, there are certain applications that highlight its strengths. One notable case occurs in the decoding of certain error correcting codes.

In developments unrelated to stochastic computing, highly effective methods of decoding LDPC codes using the belief propagation algorithm were developed. Belief propagation in this context involves iteratively reestimating certain parameters using two basic operations (essentially, a probabilistic XOR operation and an averaging operation). 

In 2003, researchers realized that these two operations could be modeled very simply with stochastic computing. Moreover, since the belief propagation algorithm is iterative, stochastic computing provides partial solutions that may lead to faster convergence. Hardware implementations of stochastic decoders have been built on FPGAs. The proponents of these methods argue that the performance of stochastic decoding is competitive with digital alternatives.

Variants of stochastic computing

There are a number of variants of the basic stochastic computing paradigm. Further information can be found in the referenced book by Mars and Poppelbaum. 

Bundle Processing involves sending a fixed number of bits instead of a stream. One of the advantages of this approach is that the precision is improved. To see why, suppose we transmit ${\displaystyle s}$ bits. In regular stochastic computing, we can represent a precision of roughly ${\displaystyle O(1/{\sqrt {s}})}$ different values, because of the variance of the estimate. In bundle processing, we can represent a precision of ${\displaystyle 1/s}$. However, bundle processing retains the same robustness to error of regular stochastic processing. 

Ergodic Processing involves sending a stream of bundles, which captures the benefits of regular stochastic and bundle processing. 

Burst Processing encodes a number by a higher base increasing stream. For instance, we would encode 4.3 with ten decimal digits as

4444444555

since the average value of the preceding stream is 4.3. This representation offers various advantages: there is no randomization since the numbers appear in increasing order, so the PRNG issues are avoided, but many of the advantages of stochastic computing are retained (such as partial estimates of the solution). Additionally, it retains the linear precision of bundle and ergodic processing.