Woman allegedly threatened Apple CEO Tim Cook Dolly Parton cake mixes Supreme Court Justice Stephen Breyer plans to retire Stimulus check update: Watch for this IRS letter Free N95 masks Google Doodle honors sculptor

Google beefs up Knowledge Graph with Bacon number

The search giant traces the connections between Kevin Bacon and other actors -- and shows how its search engine is evolving.

There are few things in life that can't be improved by adding Bacon.

Google search results are the latest to learn this lesson. Queries containing an actor's name and "Bacon number" will show users the precise number of degrees between said actor and Kevin Bacon.

Playing with the new feature today, we found numbers for Leonardo DiCaprio (2), Humphrey Bogart (3) and Steve Jobs (2).

Steve Jobs has a Bacon number of 2.
Steve Jobs has a Bacon number of 2. Screenshot by Casey Newton/CNET

The Bacon number is a fun Easter egg -- and a highly useful tool for settling arguments at the pub. But it also represents Google's "Knowledge Graph" flexing its muscle. The Knowledge Graph, which began appearing in search results in May, marks Google's effort to improve search results by analyzing the connections between billions of people, places, and things. In this case, Google is pulling from its stored database of movies and actors to analyze the connections between them.

The idea for putting the Bacon number into search results came from engineers working on the Knowledge Graph, which was seeking ways to make connections between people more visible in search. The engineers were fond of a highly geeky calculation known as the Erdos number, which measures collaboration between mathematicians based on how close their collaborators were to the prolific Hungarian number theorist Paul Erdos.

Eventually, the engineers' interest in connections led them to develop a "Bacon number" calculator for Google. Based on the trivia game Six Degrees of Kevin Bacon, the calculator plays on the idea that any actor can be linked to the "Footloose" legend in six steps or less. They quietly launched the feature earlier this week; it gained widespread attention today when Google's Matt Cutts tweeted about it.

"We like to provide answers to questions that are popular and fun -- and, in some cases, useful to those who really need it," said Yossi Matias, Google engineering director and head of its Israeli engineering team. "A few months ago we enabled users to search for mathematical formulas and get a very colorful, lively, dynamic chart which actually shows the functions. Our objective is to provide more of those instances."

Google engineers are designing algorithms to crunch through all sorts of structured data: information about sports, weather, and finance. It's easy to envision a day soon when users will use Google browse connections between baseball players, or analyze weather patterns, or pick apart financial data. From the day Google launched the Knowledge Graph, the idea was to enable a high level of serendipity -- telling you an unexpected thing about something you had searched for in an effort to drive another click, and another, and another.

In that sense, the Bacon number is less an Easter egg than a core mission of the Knowledge Graph: a way to encourage users to spend more time inside Google, searching and searching again. Search is the main way Google makes money, and the more queries the better.

The Bacon number may look trivial on the surface. But it's the product of an overhaul of Google's defining product that took the company two years to build, and that will continue to become more prominent in search results.

"The connections are pretty fascinating, but they're also telling us a lot," Matias said. "While this is fun, this is also an illustration for what can be be derived by building this structure and starting to learn about the world."