Load this page {link no longer active} and wait for the entire universe to load. Click “Start,” and then use the slider across the bottom, or the wheel on your mouse, to zoom in — and in and in and in… or out and out and out… It will take you from the very smallest features postulated by scientists (the strings in string theory)  {link no longer active}  to the very largest (the observable universe.) If you want background music, click on the musical note in the upper right corner. But a lot of work went into it. It turns out that “Scale of the Universe 2” {link no longer active} was created by Cary Huang, a 14-year-old ninth grader from Moraga, Calif., with technical help from his twin brother Michael. Cary said he worked on the project, on and off, for a year and a half, getting information from Wikipedia and astronomy books. It is now spreading virally online.