GPS Is Not Just a Location Service

The global positioning system consists of 24 satellites that all carry clocks synchronized to an extreme degree of precision. When your smartphone uses GPS to locate you on a map, it's picking up signals from some of those satellites. A glitch of just a hundred thousandth of a second can cause problems. Bank payments, stock markets, power grids and cloud computing all depend on different locations agreeing on the time. If GPS were to fail, how well and how widely would backup systems keep these various shows on the road? Nobody really seems to know. No wonder GPS is sometimes called the invisible utility. Trying to put a dollar value on it has become almost impossible.