The eccentric Hungarian mathematician Paul Erdős demonstrated that, considering all the inhabitants of the Earth and drawing out their relationships using a random graph, the number of links needed to connect one person with any other was around six. His studies, along with those of the American psychologist Stanley Milgram (and others in the following years) brought to life the small world theory, or the theory of six degrees of separation. Today, we know that thanks to social networks and our global society, the number of links needed to connect with anyone can even be fewer than six.
