Facebook invented a “holiday” called “Friends Day.” If you use Facebook, you probably have seen some auto-generated slideshows in the news feed of random photos a person has uploaded the past year.

It’s also interesting that Facebook’s data crunching found that we are all much closer than the “six degrees of separation” that you have probably heard before. Facebook claims  that each person in the world is separated from every other by “an average of three and a half other people.”

In the old version of  “six degrees,” six refers to the number of links you would have to find in your friends and acquaintances that link you to a stranger.  You would need at most five intermediaries to complete that chain.

Facebook picked today because it is an anniversary for the company, but there is a nice synchronicity that today is also the birthday of the playwright John Guare whose best-known work is Six Degrees of Separation. In that 1991 play, the character Ouisa says: “I read somewhere that everybody on this planet is separated by only six other people. Six degrees of separation. Between us and everybody else on this planet. The president of the United States. A gondolier in Venice. Fill in the names. I find that a) extremely comforting that we’re so close and b) like Chinese water torture that we’re so close.”

(I’ll mention here that there is a very good film version of Six Degrees of Separation with a young Will Smith, Stockard Channing, Donald Sutherland, Ian McKellen, and Mary Beth Hurt.)

Guare did not invent the theory and the “somewhere” or someone that the character read is usually credited to the Hungarian writer Frigyes Karinthy. He wrote a short story in 1929 concerning the shrinking of the planet. Characters in the story play a game of picking a famous stranger and then plot  the line between themselves and those strangers. In the story, no one needed more than five links complete the chain to the stranger.

This is not a scientific study or theory, though since then researchers have tried  to test the results and find some validity to it.

Facebook “friends” are often people you have never met or rarely ever see. By their calculations (and the explanation on their announcement is confusing about the math on those intermediary links) we can interpret this shortening of the degrees of separation in several ways.

Does it show how connected we are via social media to people we really don’t know? Is the world (or the online social one at least) shrinking? Does it mean anything about the real world offline and relationships?

LinkedIn does this same sort of connecting game and it likes to show me that someone is a “1st” level connection or a “3rd” level one. It shows me who and what I have in common with strangers. It tries to predict “people I may know” and might want to connect with online.

But LinkedIn and Facebook make these predictive analyses only using the network’s users. Yes, in Facebook that is 1.59 billion users, but there are about 5.7 billion other people without accounts that it can’t connect me to.

If you have a Facebook account, log in and go to this Facebook blog post. It will automatically do the calculation for your average degree of separation “from everyone.” It tells me that “Ken Ronkowitz’s average degrees of separation from everyone is 3.22.  The average for U.S. users is 3.46. Mark Zuckerberg beat me a bit at 3.17 degrees of separation, but Sheryl Sandberg (Facebook COO) beat both of us at 2.92 degrees of separation.

You may remember when the six degrees game was popularized online with “Six Degrees of Kevin Bacon.”  The Oracle of Bacon website let’s you connect Kevin to any other actor.

I haven’t look at that site for a few years, so I tried a connection search yesterday. I thought this would be a tough one: connect Kevin Bacon to Charlie Chaplin. Turns out that Chaplin was in A Countess in Hong Kong with Tippi Hedren and Bacon was in Jayne Mansfield’s Car with Tippi. Wow, only 2 degrees of separation.

I may be connected to everyone by only a small number of “degrees” but those connections seem very weak.