Q: How are any two individuals on the earth connected to each other?

Vijay [ Delhi, India ] worked at an engineering firm with Sameer [ Kolkata, India ] whose daughter Prema [ Berkeley, USA ] goes to school in California and plays soccer with Christie [Berkeley, USA] whose best friend from high school William [New York, NY] is studying medicine with Alice [New York, USA].

It is a fictive case of the SMALL WORLD project conducted by Columbia University. You might have your own stories as better examples of Six Degrees of Separation. Don't get frightened by the name of the theory. It means that two randomly chosen persons in the world are connected by a chain of at most 6 acquaintances. You might be wondering "why six?" Jon Kleinberg, an associate professor of Computer Science at Cornell University tried to explain this phenomenon from an algorithmic perspective. He's also done a lot of other works on this issue.

Hey, six degrees of separation doesn't exist only in human world. Check this out and you will find the power of it!