Proposed by Hungarian writer Frigyes Karinthy in 1929, you probably know the theory of six degrees of separation in respect to the number of steps needed to link Kevin Bacon to any other actor or actress. It should be noted, however, that the theory is actually intended to apply to everyone, everywhere. Any one person can be linked to another through a chain of five or less intermediate friends/acquaintances, supposedly.
While it's dubious that I could be connected to Zlad, a hypothetical eastern European farmer who dreams of one day owning a goat, I've created a similar theory that is true without a doubt.
Eric's theory of one-tenth of a degree of separation states that if you don't have an iPod, then you can take a look at your friends and find at least 10 who do. If you don't have friends, take a moment and initiate a conversation with the person next to you using 'What's up with the popped collar'? for a guy and 'What's up with the boots'? for a girl. If they seem put off, quickly follow up with 'No, I'm serious. I don't get it. Do you think you are (Freddie Prinze Jr./in a vodka commercial)'?
This way you either have friends, or you're well on your way to making some. Now consider any one of these friends and ask yourself the question: how good of friends exactly are we? The true glory of Eric's theory of one-tenth of a degree of separation comes in the fact that the inundation of iPod people makes friendship readily quantifiable.
Doubters can note that the iPod friendship test is a fully accredited assessment of the level of acquaintanceship you are at with your iPod-wielding friend of choice, or so I say.
There are four easily discernible levels of friendship revealed via the iPod friendship test. The best case scenario is that your friend, upon noticing you, takes out their ear buds and talks to you. If this person goes so far as to actually initiate the conversation, all the better. In either case, congratulations! This person places the value of your organic noise-producing function ahead of that of a usually more melodic, electrical noise-producing device. You two are very good friends.
Then there's the similar case of them stopping to chat, minus the removal of their head phones. As they stare at you with a somewhat blank and vacant expression, you are left to wonder if they are actually listening to you and if they know how annoying they're being. The answer to both questions is of course, yes. This person is actually out to slowly drive you insane, just ask the neighbors' dog.
Another possible response is the simple head nod or wave with the possibility of them mouthing the word 'hi' to you. It could be nothing more than the fact that you are both going different directions that keeps interaction to this minimal level. But it begs the question, 'What do they have to do that's more important than me'? You will then giggle at the innuendo inherent in this question and go on your merry way because you two are friends and all is well.
The last possibility is that your 'friend' completely ignores you, lost in the fantasy of their shadow or reflection pop-lockin' and groove-bustin' along beside them. Don't worry, they're lost to the world. Be happy because they're ignoring everybody, but sad because you're friends with someone who fantasizes about a commercial.