We've all heard the term "six degrees of separation." Basically, it's the idea that everyone in the world is separated by at least 6 acquaintances. (For example, your brother's wife's boss's mechanic's sister's hairdresser went to school with your mom, or something like that.) But since Facebook came around, the distance between two people became even shorter than that.

According to a joint study by Facebook and the University of Milan, the degree of separation between any two Facebook users in the world is actually 4.74 degrees. The number was determined by calculating the average distance between any two of Facebook's 800 million users. (that's nearly one-tenth of the world's total population) The study also found that in the United States, the degree of separation was even lower: 4.37.

It's kind of a cool thought, isn't it? No matter where a person is in the world, a friend of your friend probably knows a friend of their friend. It's nice to think that a world full of 7 billion people just got a little bit smaller.