Go to Google's homepage today and users will notice that the internet giant has incorporated a particle movement simulator logo.

A number of colored balls in motion make up the Google Doodle that spells out the company name.   As soon as users move their mouse cursor along the name, the balls disperse.   

The bubbly logo is a celebration of some sort, but there is only speculation on what the super search engine is celebrating today.  Google regularly changes its display name on the homepage to mark significant dates, holidays, and world events.   When users have clicked on the Doodle in the past, the reason for the design shows up as a generated search result.  

Google may be celebrating its anniversary --- the company usually marks this event on September 7 or 27 according to Softpedia.  The balls appear to be divs styled with the CSS border radius attribute making them round with JavaScript code controlling movement.

There is also speculation that the Google is touting HTML5, the latest version of HTML which offers more capabilities for demonstrating interactive content on the internet.  It could also be Google's latest attempt at showcasing its Chrome browser.

Today's bubbly display is the third interactive Google Doodle that the company has produced this year.  In May, Google helped celebrate the 30th anniversary of the arcade game classic Pac Man.  An animated sphere was incorporated into the logo last week to help celebrate the 25th anniversary of the discovery of the "buckyball" carbon molecule.