The Internet's Kevin Bacon rule: new study finds web pages subject to just 19 clicks of separation

With more than 14 billion webpages clogging the Internet, the World Wide Web can seem a daunting place. But just like Kevin Bacon is the glue that holds Hollywood together, one scientist discovered that every individual website can be navigated to in 19 clicks or less.

Hungarian physicist Albert-László Barabási recently discovered that of the roughly 1 trillion web documents in existence — 14 billion-plus pages as well as every image, video, or other hosted file ever — most are linked to only a few other pages or documents.

But search engines, indexes, and aggregators have swooped in to offer a high-connectivity bridge; they function as what Smithsonian Magazine called "the 'Kevin Bacons' of the web."

Barabási's findings, published in Philosophical Transactions of the Royal Society, chalk the "small world after all" concept up to simple human nature. In the real and virtual worlds, people tend to group together into communities of like-mindedness. Webpages are no different, according to Smithsonian, which reported that sites are actually organised in an interconnected hierarchy of themes like region and subject area.

Without revealing specifics about the actual act of clicking 19 times or less to find yourself at a specific website, Barabási did point out that his rule remains intact no matter how big the web becomes.

His theory, however, opens cybersecurity risks — by eliminating a small number of crucial connections, hackers could isolate certain pages and make it impossible to move from one to another. Such an online revolution is not much of a concern, though, as Smithsonian said that those vital nodes are among the most protected, "but the findings still underline the significance of a few key pages," the magazine said.

Web giant Google is certainly a starting point for Barabási's research, but the site already joined the connectivity game last autumn when it introduced the Bacon Number — in the search bar, type "Bacon number" and the name of an actor, musician, politician, or your TAG-card-holding uncle, and find out their Bacon Number. The hidden game serves as the formal digitisation of the 1990s-era twist on the theory that everyone on the planet is connected by no more than six people.