Kevin Bacon Effect - Web Pages Are Separated By 19 Clicks
February 20, 2013

The Web’s 19 Degrees Of Separation

redOrbit Staff & Wire Reports - Your Universe Online

The familiar “six degrees of separation” concept, which posits that any two people on Earth are no more than six acquaintance links apart, applies to the Internet as well, according to new research that finds any two Web pages are separated by no more than 19 clicks.

That conclusion is quite remarkable given the estimated 14 billion Web pages and 1 trillion Web documents in existence today.

Hungarian physicist Albert-Laszlo Barabasi led the work, which was published Monday in the journal Philosophical Transactions of the Royal Society. He began by creating a simulated model of the Web to better understand its structure, and found that the vast majority of Web sites in existence today are poorly connected, and are linked to only a few other pages or documents.

However, he noticed that a minority of pages distributed throughout the entire web, such as search engines, indexes and aggregators, are extremely well connected, and can be used to move between one area of the Web and another. In other words, these hyper-connected nodes serve as the central characters of the Web, making ℠introductions´ that allow Web users to navigate from area to area in just 19 clicks or less.

Barabasi attributes this phenomenon to people´s natural tendencies to form communities, whether in real life or the virtual world. As a result, Web pages aren´t organized randomly, but rather in an interconnected hierarchy of organizational themes, such as region or subject area, he says. Remarkably, this same interconnectedness will apply regardless of how large the Web grows.

Indeed, Barabasi analyzed the Internet at a number of different levels, and found that regardless of scale, the same 19 click (or less) rule applied.

While fascinating, the findings also reveal potential security risks. For instance, taking out a fairly small number of vital nodes could make it difficult or impossible for Web users to navigate from one site to another. Fortunately, these critical sites are among the best protected on the Web.

Barrett Lyon, who founded the Opte Project in 2003 to create publicly available visualizations of the Web, is working on an updated image to demonstrate Barabasi's findings. In the meantime, his most recent map, which is a few years old, provides a good illustration of the Web´s vast interconnectivity:

The green lines in this image depict links between Web pages in Europe, the Middle East and Africa, while the red lines represent links between web pages in Asia, blue for North America, yellow for Latin America and white for unknown IP addresses, according to an analysis by the Smithsonian.