Six degrees of separation refers to the idea that, if a person is one "step" away from each person he or she knows and two "steps" away from each person who is known by one of the people he or she knows, then everyone is no more than six "steps" away from each person on Earth. Several studies, such as Milgram's small world experiment, have been conducted to empirically measure this connectedness. While the exact number of links between people differs depending on the population measured, it is generally found to be relatively small. Hence, six degrees of separation is somewhat synonymous with the idea of the "small world" phenomenon. Six degrees may refer to: Six degrees of separation, the theory that anyone on earth can be connected to any other person on the planet through a chain of acquaintances that has no more than five intermediaries Six degrees of freedom, motion in three dimensional space, with three translation motions... The Small world experiment refers to experiments conducted by Stanley Milgram to investigate the Small world phenomenon by examining the average path length for social networks of people in the United States. ... The small world phenomenon (also known as the small world effect) is the hypothesis that everyone in the world can be reached through a short chain of social acquaintances. ...

Early conceptions

The "shrinking world"

In 1929, a Hungarian author named Frigyes Karinthy published a volume of short stories titled "Everything is Different." One of these pieces was titled "Chains," or "Chain-Links." The story investigated in abstract, conceptual, and fictional terms many of the problems that would captivate future generations of mathematicians, sociologists, and physicists within the field of network theory ^[1]. In particular, Karinthy believed that the modern world was shrinking due to the ever-increasing connectedness of human beings. Due to technological advances in communications and travel, friendship networks could grow larger and span even greater distances. Karinthy posited that despite great physical distances between the globe's individuals, the growing density of human networks made the actual social distance far smaller. Frigyes Karinthy (June 25, 1887 in Budapest - August 29, 1938 in Siófok) was a Hungarian author, playwright, poet, journalist and translator. ...

As a result of this hypothesis, Karinthy's characters believed that any two individuals could be connected through at most five acquaintances. In his story, the characters create a game out of this notion. He writes:

A fascinating game grew out of this discussion. One of us suggested performing the following experiment to prove that the population of the Earth is closer together now than they have ever been before. We should select any person from the 1.5 billion inhabitants of the Earth—anyone, anywhere at all. He bet us that, using no more than five individuals, one of whom is a personal acquaintance, he could contact the selected individual using nothing except the network of personal acquaintances ^[2].

This idea both directly and indirectly influenced a great deal of early thought on social networks. Thus, Karinthy is often regarded as the originator of the notion of Six Degrees of Separation ^[3]. A social network is a social structure made of nodes (which are generally individuals or organizations) that are tied by one or more specific types of relations, such as values, visions, idea, financial exchange, friends, kinship, dislike, trade, web links, sexual relations, disease transmission (epidemiology), or airline routes. ...

The "small world" experiments

Stanley Milgram was an American researcher in experimental social psychology at Harvard University in Boston, USA. Beginning in 1967, he began a widely-publicized set of experiments to investigate the so-called "small world problem." This problem was rooted in many of the same observations made decades earlier by Karinthy. That is, Milgram and other researchers of the era were fascinated by the interconnectedness and "social capital" of human networks. While it is unknown how directly Milgram was influenced by Karinthy's work, the similarities between the two authors are remarkable ^[3]. However, while Karinthy spoke in abstract and fictional terms, Milgram's experiments provided evidence supporting the claim of a "small world." His study results showed that people in the United States seemed to be connected by approximately six friendship links, on average. Although Milgram reportedly never used the term "Six Degrees of Separation," his findings likely contributed to the term's widespread credence. Since these studies were widely publicized, Stanley Milgram is also, like Karinthy, often attributed as the origin of the notion of Six Degrees. Stanley Milgram Stanley Milgram (August 15, 1933 – December 20, 1984) was a psychologist at Yale University, Harvard University and the City University of New York. ...

Theoretical Basis and Proof

If you assume the world population is 6 billion people, and everyone has the same amount of friends or 'connections', and that each person is just as likely to know one person as any other person (save for geographic limitations), then measuring the degree of separation only becomes a simple mathematical formula of determining the exponent that will yield the population if you raise the average number of friends of each person by that exponent. In other words,

 (average number of friends per person) ^ (degrees of separation) = total population Let f = average number of friends Let d = degress of separation Let p = population f^d = p d * ln f = ln p d = ln p / ln f 

Finding the average number of friends can be determined by random sampling. However, since we already have a good idea what the degree of freedom is, let's determine 'f' and consider its reasonableness.

 f^d = p f = dth root of p 

If we take the 6th root of 6,000,000,000, we get approximately 42.

 6th root of 6,000,000,000 = 42.628 [4] ln(6,000,000,000) / ln(42) = 6.024 [5] 

Knowing 42 people is not unreasonable to a person. One class or workplace can contain 42 people. Thus, if 42 of your friends knows 42 other people, and they each know 42 more people, and so on and so on until 6 chains have been formed, then that will encompass 6 billion people.

In fact, if we take the 5th root of 6 billion, we get about 90, which in today's connected age is not unreasonable for some people. The 7th root is 24. So if we assume that everyone in the world knows between 24 to 90 people each, then we can prove the degree of separation is between 5 and 7.

The reason this works is because as the number of chains increase, the total percentage of the population 'known' increases exponentially. For example, if the population is 16, and each person is restricted to knowing at most 2 people, then the degree of separation is 4. 1 person who knows 2 people is 2. If those 2 people know 2 more people, the total is 4. If those 4 people know 2 people each, the total is 8. If those 8 people know 2 people each, the total is 16.

 4th root of 16 = 2 2^4 = 16 

If the population is split in two groups of 8, perhaps by geographic boundaries, then it would be impossible to 'know' the entire population or have a connection between all individuals.

The advent of affordable intercontinental air travel in the 20th century has reduced these geographic boundaries, such that even if one individual does not know someone on another continent, they are likely to know someone else who has been to another continent. The more the population intermixes and comingles, the more even and regular the degree of separation is between any two random people in that population.

Recent research

Internet and computer networks

In 2001, Duncan Watts, a professor at Columbia University, attempted to recreate Milgram's experiment on the internet, using an e-mail message as the "package" that needed to be delivered, with 48,000 senders and 19 targets (in 157 countries). Watts found that the average (though not maximum) number of intermediaries was around six. This finding is surprising, given the worldwide nature of the Internet. Year 2001 (MMI) was a common year starting on Monday (link displays the 2001 Gregorian calendar). ... Duncan J. Watts is an associate professor of sociology at Columbia University, head of the CDG Collective Dynamics Group and author of the book Six Degrees: The Science of a Connected Age (Norton, 2003). ... Columbia University is a private research university in the United States. ...

It has been suggested by some commentators that interlocking networks of computer mediated lateral communication could diffuse single messages to all interested users worldwide as per the 6 degrees of separation principle via Information Routing Groups, which are networks specifically designed to exploit this principle and lateral diffusion. An Information Routing Group (or IRG) is one of a semi-infinite set of similar interlocking and overlapping groups each IRG containing a group of ( maybe 3 to 200) individuals (IRGists) and each IRG loosely sharing a particular common interest; IRGists exchange information, as a group, a sub group, or...

Genealogy studies

The term "six degrees of separation" is often distorted to indicate that six generations is the maximum extent to which everyone in the world is related. This has been disproved in numerous genealogy circles, since six generations translates roughly to 250 years. Generation (From the Greek γιγνμαι), also known as procreation, is the act of producing offspring. ... Genealogy is the study and tracing of family pedigrees. ...

Find Satoshi

The UK-based game company, Mind Candy, is currently testing the theory by distributing a picture of a Japanese man named Satoshi. The puzzle was originally apart of Mind Candy's Perplexcity, but it has since grown into its own project. Billion2One.org,FindSatoshi.com. Mind Candy is a company that creates Alternate Reality Games. ... The Perplex City logo Perplex City is a long-term alternate reality game (ARG) presented by Mind Candy, a London-based development team. ...

Popularization

No longer limited strictly to academic or philosophical thinking, the notion of Six Degrees recently has become influential throughout popular culture. Further advances in communication technology—and particularly the Internet—have drawn great attention to social networks and human interconnectedness. As a result, many popular media sources have addressed the term. The following provide a brief outline of the ways such ideas have shaped popular culture.

Six degrees of Wikipedia

The basic idea of Six Degrees of Wikipedia is that any Wikipedia page can be linked to another with no more than six hyperlinks. The site six degrees of wikipedia allows anyone to test this idea, by putting in the names of two Wikipedia articles, and it will very quickly find the shortest path between them. (It uses a copy of the database which lags slightly behind the live Wikipedia site.) Wikipedia - Wikipedia, the free encyclopedia /**/ @import /skins-1. ... // A hyperlink (often referred to as simply a link), is a reference or navigation element in a document to another section of the same document, another document, or a specified section of another document, that automatically brings the referred information to the user when the navigation element is selected by...

The accuracy of the 'six degrees' claim of this concept is doubted. For example, the pages for rheumatism and belle and sebastian could not be linked in less than ten (let alone six) moves... until someone put these two pages on this page, thus linking them to one degree. Rheumatism or Rheumatic disorder is a non-specific term for medical problems affecting the heart, bones, joints, kidney, skin and lung. ... Belle and Sebastian (sometimes written as Belle & Sebastian) are a Scottish paper pop band formed in Glasgow in January 1996. ...

John Guare's Six Degrees of Separation

John Guare, an American playwright, is the author of the 1990 Six Degrees of Separation. This play, which was adapted for the screen in 1993, launched the term into everyday lexicon. It is considered to be Guare's most widely-known play. John Guare (pronounced gwâr, born 5 February 1938) is an American playwright. ... Six Degrees of Separation is a 1993 film based on the John Guare play, starring Stockard Channing, Donald Sutherland and Will Smith. ... For the Battlestar Galactica episode, see Six Degrees of Separation (Battlestar Galactica). ...

The piece ruminates upon the idea that any two individuals are connected by at most six others. And, similar to Karinthy's 1929 "Chains" (see section above), this leads the characters to feelings of awe, and in some ways, grief. As one of the characters states,

I read somewhere that everybody on this planet is separated by only six other people. Six degrees of separation between us and everyone else on this planet. The President of the United States, a gondolier in Venice, just fill in the names. I find it extremely comforting that we're so close. I also find it like Chinese water torture, that we're so close because you have to find the right six people to make the right connection... I am bound, you are bound, to everyone on this planet by a trail of six people ^[4].

Although this idea had been circulating in various forms for decades, it is this piece that is said to be responsible for popularizing, if not coining the phrase "six degrees of separation." Following Guare's lead, Many future television and film sources would later incorporate the notion into their stories.

Interestingly, J.J. Abrams, the executive producer of television series Six Degrees and Lost, played the role of Doug in the film adaptation of this play. Many of the play's themes are apparent in his television shows (see below). Jeffrey J. Abrams (usually credited as Jeffrey Abrams or J.J. Abrams) (born June 27, 1966) is an American film and television producer, writer, actor, composer and director. ... Six Degrees (or 6Ëš) is an American dramatic television series about six residents of New York City and their relationships, based on the idea of six degrees of separation. ... Lost is a popular American serial drama television series that follows the lives of plane crash survivors on a tropical island, after a passenger jet flying between Australia and the United States crashes somewhere in the South Pacific. ...

The Kevin Bacon game

The game "Six Degrees of Kevin Bacon" was invented in 1994 by two students at Albright College in Reading, Pennsylvania, as a play on the concept: the goal is to link any actor to Kevin Bacon through no more than six connections, where two actors are connected if they have appeared in a movie together. It has been suggested that this article or section be merged with Bacon number. ... This article needs additional references or sources for verification. ...

SixDegrees.org

On January 18, 2007, Kevin Bacon launched SixDegrees.org, a web site that builds on the popularity of the "small world phenomenon" to create a charitable social network and inspire giving to charities online. Bacon started the network with celebrities who are highlighting their favorite charities – including Kyra Sedgwick (Natural Resources Defense Council), Nicole Kidman (UNIFEM), Ashley Judd (YouthAIDS), Bradley Whitford and Jane Kaczmarek (Clothes off Our Back), Dana Delany (Scleroderma Research Foundation), Robert Duvall (Pro Mujer), Rosie O'Donnell (Rosie's For All Kids Foundation), and Jessica Simpson (Operation Smile) - and he encouraged everyone to be celebrities for their own causes by joining the Six Degrees movement. SixDegrees. ... Kyra Sedgwick (born August 19, 1965) is an Emmy nominated American actress. ... The Natural Resources Defense Council (NRDC) [1] is a leftist, New York City-based, non-profit, non-partisan environmental advocacy group, with offices in Washington, D.C., San Francisco, and Los Angeles. ... Nicole Mary Kidman AC (born June 20, 1967), is an Academy Award-winning Australian[1] actress. ... The United Nations Development Fund for Women, commonly known as UNIFEM, provides financial and technical assistance to innovative programmes and strategies that promote women’s human rights, political participation and economic security. ... Ashley Judd (born Ashley Tyler Ciminella on April 19, 1968) is an American actress. ... Bradley Whitford (born October 10, 1959 in Madison, Wisconsin) is an Emmy Award-winning American actor. ... Jane Kaczmarek (born December 21, 1955 in Milwaukee, Wisconsin) is an Emmy Award nominated American actress best known for playing the character Lois in Malcolm in the Middle. ... Dana Welles Delany (born March 13, 1956 in New York City, New York) is an American film, stage, and television actress. ... The Scleroderma Research Foundation (SRF) is a non-profit, 501(c)(3) organization. ... Robert Selden Duvall (born January 5, 1931) is an Academy Award and four-time Golden Globe winning American film actor and director. ... Pro Mujer (meaning, in Spanish, Pro Woman) is an organization aimed at improving the life conditions in Latin America, primarily though Microcredit programs. ... Rosie ODonnell (born March 21, 1962 in Bayside, Queens, New York) is an 11-time Emmy Award-winning American talk show host, television personality, comedienne, film, television, and stage actress. ... Jessica Ann Simpson (born July 10, 1980) is an American pop singer and actress who rose to fame in the late 1990s. ... Operation Smile is a private, not-for-profit volunteer medical services organization providing reconstructive surgery and related health care to indigent children and young adults in developing countries and the United States. ...

"SixDegrees.org is about using the idea that we are all connected to accomplish something good," said Bacon. "It is my hope that Six Degrees will soon be something more than a game or a gimmick. It will also be a force for good, by bringing a social conscience to social networking." The game, 'Six Degrees of Kevin Bacon,' made the rounds of college campuses over the past decade and lived on to be a shorthand term for the small world phenomenon.

Bacon created SixDegrees.org in partnership with the nonprofit, Network for good, AOL, and Entertainment Weekly. Through SixDegrees.org, which builds on Network for Good's giving system for donating to more than one million charities online and AOL's AIM Pages social networking service, people can learn about and support the charities of celebrities or fundraise for their own favorite causes with their own friends and families. Bacon will match the charitable dollars raised by the top six non-celebrity fundraisers with grants of up to $10,000 each^[5] This article or section does not cite any references or sources. ... It has been suggested that AOL search data scandal be merged into this article or section. ... Entertainment Weekly (sometimes abbreviated EW) is a magazine published by Time Inc. ...

Mathematics

Mathematicians use an analogous notion of collaboration distance (see AMS): two persons are linked if they are coauthors of an article. The collaboration distance with mathematician Paul Erdős is called the Erdős number. Erdős-Bacon numbers are a further extension of the same thinking. The ErdÅ‘s number, honouring the late Hungarian mathematician Paul ErdÅ‘s, one of the most prolific writers of mathematical papers, is a way of describing the collaborative distance, in regard to mathematical papers, between an author and ErdÅ‘s. ... A persons ErdÅ‘s-Bacon number is the sum of their ErdÅ‘s number and their Bacon number. ...

Film and television

• Six Degrees of Separation is a 1993 film drama featuring Will Smith, Donald Sutherland and Stockard Channing, about a fast-talking young man (Smith's entrée into mainstream cinema) who, out of the blue, prevails upon the good graces of a non-plussed NYC couple in the wake of his supposed mugging in Central Park, claiming to be Sidney Poitier's son and masquerading flamboyantly as a close friend & classmate of their Harvard-enrolled kids, and in the process upsetting their shallow uppercrust world.
• Six Degrees is a 2006 television series on ABC in the US. The show details the experiences of six New Yorkers who go about their lives without realizing they are affecting each other, and gradually meet one another. [6]
• The seventh episode of the first season of Battlestar Galactica was named "Six Degrees of Separation."
• The television program Lost also explores the idea of six degrees of separation, as almost all the characters have randomly met each other before the crash or someone the other characters know. On the Season 2 Bonus Material DVD, there is a special feature called "The Lost Connections". It has an intro that mentions Karinthy Frigyes and explains the theory, showing photographs of random people and proposing that "you or someone you know" probably knows them. The actual feature is an animated interface of video clips of character connections, the frames of the videos connected by multi-colored wires.
• Lonely Planet Six Degrees is a TV travel show that uses the "six degrees of separation concept: the hosts, Asha Gill and Toby Amies, explore various cities through its people, by following certain personalities of the city around and being introduced by them to other personalities.
• The movie My Date with Drew revolves around average Joe Brian Herzlinger getting a date with Drew Barrymore. To get in contact with her he uses a lot of determination and the Six Degrees of Separation.
• Another notable reference should be given to the show "The L Word" - which although not directly referencing to the 6 degrees of separation, deals with this theme in the 'web' in which all characters are linked via sexual events to others. Alice Pieszecki (played by Leisha Hailey) is the originator of this concept, and indeed the initial web is shown in her home, on a whiteboard before eventually being translated to the internet.
• ABC[7] - "Six Degrees of Martina McBride" [8] - 6 aspiring country singers from America's smallest towns try to connect themselves to Martina McBride [9] in under six points of human connection. Those that make it from "Nowhere to Nashville to New York," get a shot at a studio session with Martina McBride and a record deal with Sony BMG. The show is scheduled to air on Monday 7/30/2007 at 9pm / 8 central on ABC. Host: Jay Schadler, Executive Producer: David Sloan, Senior Broadcast Producer: Robert Lange, Senior Producer: Eric Ortner, Show Producer: Tom Berman, Associate Producer: Christine Murphy-Costello. Judges: Miranda Lambert, Ray Benson [10], Beverly Keel [11]

The winning single Produced by Martina McBride and ABC can be downloaded on iTunes. The show also tells Martina McBride's own unique story of six degrees which helped advance her from selling T-shirts for Garth Brooks to opening for him on stage to becoming one of Country music's biggest superstars. For the Battlestar Galactica episode, see Six Degrees of Separation (Battlestar Galactica). ... Six Degrees (or 6˚) is an American dramatic television series about six residents of New York City and their relationships, based on the idea of six degrees of separation. ... Battlestar Galactica is a science fiction television program created by Ronald D. Moore that first aired on October 18, 2004 in the United Kingdom and Ireland on Sky One, and January 14, 2005 in the United States on the Sci Fi Channel. ... Lost is a popular American serial drama television series that follows the lives of plane crash survivors on a tropical island, after a passenger jet flying between Australia and the United States crashes somewhere in the South Pacific. ... Karinthy Frigyes (June 25, 1887 in Budapest - August 29, 1938 in Siófok) was a Hungarian author, playwright, poet, journalist and translator. ... Lonely Planet Six Degrees is Lonely Planets flagship travel show, hosted by Asha Gill and Toby Amies. ... Promotional photo of Asha Gill for Tag Heuer Asha Anand Gill (born July 3, 1972 in Penbury, Kent, United Kingdom) is a Malaysia-based model, television host, deejay, veejay, writer, producer, film director, and womens rights activist. ... Toby Amies born 27th June 1967 in Birmingham, UK is an outsider television personality and photographer, best known for his work on MTV UKs Alternative Nation, Film Four and now as the host of Lonely Planets Six Degrees. ... My Date with Drew is a 2005 documentary film featuring Brian Herzlinger. ... The term Average Joe, Average Jane or Average Joe-Schmoe is used in the United States to refer to the average American. ... This article does not cite any references or sources. ... Drew Blyth Barrymore (born February 22, 1975) is an American actress and film producer, the youngest member of the Barrymore family of American actors. ... The L Word is a television drama series on Showtime that portrays the lives, loves and learnings of a group of lesbian and bisexual women and their friends, family and lovers in Los Angeles. ... Alice Pieszecki is a fictional character on the Showtime television network series The L Word, shown nationally in the United States. ... Leisha Hailey (born July 11, 1971) is an American actress, musician, and producer. ... This biographical article needs additional references for verification. ... Bertelsmann is a transnational media corporation founded in 1835, based in G tersloh, Germany. ... Jay Schadler is a correspondent on the ABC News program PrimeTime Live. ... This article needs additional references or sources for verification. ... Ray Benson is the front man of the legendary Western swing band Asleep at the Wheel. ... This biographical article needs additional references for verification. ... Look up ABC in Wiktionary, the free dictionary. ...

Show website http://abcnews.go.com/Entertainment/SixDegrees/

Other

• Six Degrees of Inner Turbulence is an album and song by Dream Theater
• SixDegrees.com was an early social networking site based on the concept.
• The No Doubt song "Full Circle" has a central theme dealing with six degrees of separation.
• Stuart Maconie on his BBC Radio 2 show on Saturday afternoons has a Six Degrees of Separation quiz in which listeners have to identify the links between six songs/artists. Song/Artist one links to song/artist two which links to three and so on. The winner gets a 'celebrity shopping basket' consisting of a book, a music CD and a DVD chosen by that week's guest celebrity.^[6], ^[7]
• Six Degrees Of Kurt Cobain is a song by MC Lars
• "Degrees of Separation" is a song by Badly Drawn Boy

Six Degrees of Inner Turbulence (often abbreviated to SDOIT or 6DOIT) is the sixth full-length studio album by progressive metal band Dream Theater. ... Dream Theater is an American progressive metal band comprised of James LaBrie, John Petrucci, Mike Portnoy, John Myung, and Jordan Rudess. ... SixDegrees. ... A social network is a social structure made of nodes (which are generally individuals or organizations) that are tied by one or more specific types of relations, such as values, visions, idea, financial exchange, friends, kinship, dislike, trade, web links, sexual relations, disease transmission (epidemiology), or airline routes. ... No Doubt is a third wave ska band from Anaheim, California, United States. ... Stuart Maconie (b. ... BBC Radio 2 is one of the BBCs national radio stations and is the most popular station in the UK. It broadcasts throughout the UK on FM radio between 88 and 91 MHz from its studios in Western House, adjacent to Broadcasting House in central London. ... Andrew Robert Nielsen (born October 6, 1982) is an American rapper, known by his stage name MC Lars. ... This article does not cite any references or sources. ...

See also

• Six Degrees of Kevin Bacon
• Travelling salesman problem
• Social network
• Small world phenomenon
• SixDegrees.org

It has been suggested that this article or section be merged with Bacon number. ... If a salesman starts at point A, and if the distances between every pair of points are known, what is the shortest route which visits all points and returns to point A? The traveling salesman problem (TSP) is a problem in discrete or combinatorial optimization. ... A social network is a social structure made of nodes (which are generally individuals or organizations) that are tied by one or more specific types of relations, such as values, visions, idea, financial exchange, friends, kinship, dislike, trade, web links, sexual relations, disease transmission (epidemiology), or airline routes. ... The small world phenomenon (also known as the small world effect) is the hypothesis that everyone in the world can be reached through a short chain of social acquaintances. ... SixDegrees. ...

Notes

1. ^ Newman, Mark, Albert-László Barabási, and Duncan J. Watts. 2006. The Structure and Dynamics of Networks. Princeton, NJ: Princeton University Press.
2. ^ Karinthy, Frigyes. Chain-Links. Translated from Hungarian and annotated by Adam Makkai and Enikö Jankó.
3. ^ ^{a b} Barabási, Albert-László. 2003. Linked: How Everything is Connected to Everything Else and What It Means for Business, Science, and Everyday Life. New York: Plume.
4. ^ Memorable quotes from Six Degrees of Separation. Accessed Nov. 11, 2006 from IMDB.com.
5. ^ Jan. 18, 2007 press release from Network for Good. [1].
6. ^ [2]
7. ^ [3]

This article or section does not cite any references or sources. ...

External links

• WhatIs.com has a thorough entry on the origins of the term, along with other helpful information.
• Sim6D is an online experiment based on the six degrees of separation where individuals can attempt to contact a stranger in another part of the world through their connections.
• Network for Good - a nonprofit organization where users can donate to more than one million charities and search from among more than 36,000 volunteer opportunities.
• iuGen - iuGen - The Internet User Genome Project to see how webconnected you are with your friends and their friends.
• The Million People Page - modern social networking experiment started in Feb 2006
• Six Degrees of Wikipedia - links Wikipedia articles in six degrees fashion
• E-mail Study Corroborates Six Degrees of Separation - a study by the journal Science.
• Six Degrees Black - Social networking site built on concept of Six Degrees of Separation. The site is "black" oriented.
• The Six Degrees of Kasparov - the six degrees of separation tested with Chess results.
• playtxt mososo - was the first mobile social network incorporating six degrees of separation.
• Could it be a big world? - 2001, Judith Kleinfeld, University of Alaska Fairbanks
• Connecting with people in six steps- BBC article contesting its existence
• Pumpthemusic Oracle- The 6 degrees theory applied to the musical universe
• [12] - The 6 degrees theory applied to movies and TV
• Knock, Knock, Knocking on Newton's DoorPDF (223 KiB), by Dan Ward - Journal article published by Defense Acquisition University, applies principles from Duncan Watts' book Six Degreesto technology innovation and scientific research.
• MySpace Page a new page to try and test out the theory of six degrees of separation whereby users add themselves to see if they come across someone they know and the author will calculate the degrees of separation.
• The Small World Experiment 54 jigsaw pieces travelling the world testing the small world theory.