Jesse Alpert and Nissan Hajaj just shared this discovery over at the Google Blog. The numbers are staggering: in ’96, the Internet contained ~26 million pages, then the count hit a billion in the year 2000. Just eight years later, that number has balooned to 1,000,000,000,000 unique URLs. This number leaves out pages that are automatically generated, or are very similar to other pages — if these results were left in, the total count could effectively be undefined. All of this information is continuously indexed:

Today, Google downloads the web continuously, collecting updated page information and re-processing the entire web-link graph several times per day. This graph of one trillion URLs is similar to a map made up of one trillion intersections. So multiple times every day, we do the computational equivalent of fully exploring every intersection of every road in the United States. Except it’d be a map about 50,000 times as big as the U.S., with 50,000 times as many roads and intersections.

I’m starting to think that this internets thing just might catch on.