Facebook is a place that throws up all kinds of interesting previously unknown connections - like how the girl your cousin's best friend used to date is now married to a guy you are now team mates with in the pool league; or how your old English literature teacher has a child for whom your ex-work colleague now babysits. In a world that's complexly and intricately interconnected, we sample those connections very sparsely. But why is this so?
One explanation is that the butterfly effect in physics also occurs in the social world too - in that single events and actions engender causal links that spread out way beyond the immediacy of our perceptions, and probably eventually everywhere. A woman who crashes her motorbike into a car in
probably eventually has a knock on effect (pun intended) somewhere in China, where a Chinese businessman chooses
restaurant A over restaurant B and probably eventually changes the nature of a
board meeting in .
It's just that the vast majority of these links on the causal chains are invisible to us. Naturally, when we do notice a connection we focus on it and block out a lot of background noise and extraneous data not relevant to the connection.
I have a suspicion, actually, that pretty much everything anyone does in terms of an event or action is part of a causal nexus linked to everyone else's events and actions, rather like trillions of bees flying around, where all bees bump into some other bees (which indirectly causes further bumping) but not others. To apply that analogy to human societal interaction, we sometimes are reacquainted with past bumps via a succession of other bumps, but we notice because we never pay attention to all the other bumps that are not in our chain of connection.