But today people move great distances in short time periods, as well as short distances, and they use variable means of transportation.

Since we can't track people with tracking devices, like we do animals, we needed to get data that provided us with millions of movements of individuals. What is amazing about these particular scaling laws is the fact that they are determined by two universal parameters only. This result surprised us all.

How likely they are to travel ten miles compared to traveling across the country. Human travel within the United States can be described by very simple mathematical laws and these laws do not depend on if you live in a small or large city. So they're universal within the United States.

We were confident that we could learn a lot from the data collected at the http://www.wheresgeorge.com bill-tracking website, but the results turned out far beyond our expectations.

We were confident that we could learn a lot from the data collected at the http://www.wheresgeorge.com bill-tracking Web site, but the results turned out far beyond our expectations.

We were confident that we could learn a lot from the data collected at the www.wheresgeorge.com bill-tracking website, but the results turned out far beyond our expectations.