Nineteen or less, according to Hungarian physicist Albert-László Barabási, who analyzed the connections between the 14 billion pages of the World Wide Web.
Does 19 clicks seem small? Or surprisingly big to get between any two Web pages?
First, consider that search engines and aggregators put billions of Web pages just one click away. “These nodes serve as the ‘Kevin Bacons’ of the Web,” Joseph Stromberg writes for Smithsonian’s Surprising Science blog.
Other pages are obscure, uninteresting and poorly linked. But still, the Web’s culture of linking brings order to what looks like chaos. Stromberg writes that humans “tend to group into communities, whether in real life or the virtual world. The pages of the web aren’t linked randomly, [Barabási] says: They’re organized in an interconnected hierarchy of organizational themes, including region, country and subject area.”
And so the right 19 clicks will get you from one corner of digitized human knowledge to any other.