On earth, if you want to find the relationship between any two people, you only need to go through five people at most (that is, at most
No more than six).
Six degrees of separation, six degrees of separation
"six degrees of separation" is a concept put forward by sociologists when studying social networks. This problem stems from the experiment made by Stanley milgram, a sociologist and professor of psychology at Harvard University (1934 ~ 1984) in 1967: "Tracking the shortest path in American social networks". He asked each participant to try to send a letter to the "target person" who lives near Boston, stipulating that each participant can only forward it to one person they know. Milgram found that the average length of a complete chain is 6 people. For example, we can imagine sending a letter to Lewinsky. Is it far enough? The path I imagine is: first, I send a letter to my classmate, whose father is a diplomat, and he sends a letter to his father. Diplomats naturally know our foreign minister, and our foreign minister must know Clinton. Finally, Clinton can write to Lewinsky. It happens to be six people. According to this concept, everyone living in this world only needs a few intermediaries (6 on average) to establish contact with anyone in the world. We can regard everyone as a node, draw an edge between people we know, and finally form a network. How many sides can each node have? Or how many friends can everyone have? If we do this survey, it may be difficult. Everyone has a different definition of a friend. You think you are friends, but I don't think so. The data thus obtained is questionable, and there are many unclear places. However, with the Internet now, it is much easier. As long as you add it to the QQ friends column, you will be considered a friend. If such statistics are really made, I estimate that this number may be greater than 6, 8, 9 and so on. After all, many people have only a few names on QQ, but in real life, we definitely know more people than "a few". Now, many people are considering using "six degrees separation" as a dating site. In addition, P2P software downloads also use six degrees of separation. Computers all over the world are connected into a network. Any two computers on the network can download each other's resources through a path containing six computers.