Six

pass the letter friend to friend. pull a thread across.

a string-art village where everyone knows only their neighbours: tie long threads across so a letter reaches a stranger in a handful of hand-offs

On a ring where everyone knows only the people beside them, a letter to the far side passes through many hands. A few long friendships across the ring cut that to a handful, for nearly every pair, not just the two people they join. In 1967 Stanley Milgram asked people in Nebraska to pass a letter, friend to friend, toward a stranger near Boston; of the 296 chains, 64 arrived, with about five people in between (Travers and Milgram, 1969). In 1998 Watts and Strogatz showed that rewiring a few random links in a ring of neighbours makes the average distance collapse while each neighbourhood stays as it was: a small world.

Concepts: networks, social-graphs.

An interactive you play with one thumb, on Wundr.