The theory of six handshakes

Each of us has ever thought about how vast and immense the world is, how much on the Earth are absolutely different people. Despite the differences in age, sex, skin color, all people are connected. Sometimes you can even wonder how much each friend and acquaintance has.

Probably, deeply thinking about it, Hungarian science-fiction writer Fridesha Carinti in 1929 wrote a story "Links of the chain." This is the first time that the theory of six handshakes has been presented. He suggests conducting an unusual experiment and proving that every person can communicate with absolutely any inhabitant of the planet through people who are familiar to each other and, at the same time, their number does not exceed six.

In 1969, the theory of handshakes was finally formed by American sociologists Jeffrey Travers and Stanley Milgram. Their hypothesis was that every person is familiar with any other through a chain of acquaintances, which consists of an average of five people. An interesting experiment was conducted. Residents of a small American town were given 300 envelopes. They had to send them to a specific addressee through their friends. Only 60 letters were delivered. After carrying out some calculations and analyzes, experts came to the conclusion that each letter was an average of five people. Thus, the theory of six handshakes was proved.

Scientific and technological progress allowed scientists from Columbia University to repeat Milgram's experiment using e-mail. Twenty secret recipients were created. Participants were given their names, surnames, residences, education, occupation. Thousands of volunteers were invited to find them through friends and acquaintances. The first who managed successfully, was a resident of Australia, who found a secret address in Siberia through four friends.

The world famous corporation Microsoft was also interested in the theory of six handshakes. It took them about two years to check it. During this time, 242,720,596 messages from users were analyzed. As a result, it was found that any of the 240 million users of this service can find another through 6.6 people on average.

The theory of 6 handshakes formed the basis of a large number of popular games. For example, many famous scientists, including those with world names, play in the "Number of Erdos". This name was given in honor of the Hungarian mathematician Paul Erdos. He wrote a huge number of works, including co-authorship. The essence of the game is this: if a scientist has one work that is written with Erdos, then he gets one point; If co-authored with a scientist who wrote with Erdos, then two points. As you know, all Nobel Prize winners have large numbers of Erdos.

One of the largest social networks Facebook has also conducted research on this theory among its users. As a result, it was found that two any people registered on Facebook share 4.74 communications.

Popular social network in the CIS VKontakte launched the application "Chain friends - the theory of six handshakes." It allows you to compose chains of acquaintances among users of the network. Due to the fact that the VKontakte audience is somewhat limited, the results are slightly different. In general, chains have a size of three to four people. An interesting fact is that chains longer than six people do not occur. This, in turn, confirms the original theory.

In addition to various experiments, the theory of handshakes was reflected in the cinema. She was the basis of the plot of such famous films as "Fir-trees", "Real Love".

Thanks to all possible research of scientists and sociologists, a joke appeared that each of us through five people is familiar with the English queen.