May 8th, 2012

Friends of Friends and Friends of Friends' Friends, etc.

Here's a game.  Of the seven billion people on the planet pick two at random.  Ask one of them to get a message to the other.  The only rule is that person number one can give the message only to a person with whom she or he is personally acquainted.  That person can give the message only to a person with whom he or she is personally acquainted, and so on..  How many times will the message have to change hands  before it gets to the intended recipient?  

Of course the answer will vary.  Some people are at the center of vast networks of communication while others are quite isolated.  Some have a language in common with only a few other people while others speak a language spoken by billions and still others are multilingual.  But the answer is that the message will have to change hands fewer times than one might think.  Six (maybe seven) times.

I was thinking of this as i glanced at a new feature (or one i just found out about) on LJ; The Friends of Friends Page.  This page contains all of the recent journal entries of the people who are on the friends lists of the people who are on my friends list.  Looking at about 300 entries for May 6 and 7 2012 i found none that i recognized which probably means that all overlaps with my own friends' list was excluded.  About one third of the entries were in languages i could not read (or in some cases even recognize) others were on subjects i could not begin to understand or topics about which i had no interest.  A few were interesting, five or six were fun or memorable, two or three made me wish that that person were my friend also.  The friends of friends page was a whole new experience: a new world opening itself to me.

I read about 15 entries on my friends page each day.  There were about 150 entries on the friends of friends page for each of the two days i looked at.  What if there were a "Friends of Friends' Friends Page"  How many entries would be on it? 1500?, 15,000?
What about a "fourth degree of separation"  15,000, 150,000, 1.5 million?  Live Journal is a "closed" population, only people with journals and friends lists are eligible.  I am within "five degrees of separation" of  being acquainted with any other person on LJ.