In mathematics and physics, a small-world network is a type of mathematical graph in which most nodes are not neighbors of one another, but most nodes can be reached from every other by a small number of hops or steps. A small world network, where nodes represent people and edges connect people that know each other, captures the small world phenomenon of strangers being linked by a mutual acquaintance.
We've all heard of 'six degrees of separation', the idea that everyone in the world can be connected in just a few steps. But what if those steps don't just relate to people but also to viruses, neurons, proteins and even to fashion trends? What if this 'six degrees of separation' allowed us an insight into something at the core of Nature?