Small Worlds: The Dynamics of Networks Between Order and RandomnessEveryone knows the small world phenomenon: soon after meeting a stranger, we are surprised to discover that we have a mutual friend, or we are connected through a short chain of acquaintances. In his book, Duncan Watts uses this intriguing phenomenon colloquially called six degrees of separation as a prelude to a more general exploration: under what conditions can a small world arise in any kind of network? The networks of this story are everywhere: