You might think people all over the United States have wireless internet service and mobile phones. But there is no such service in Green Bank, West Virginia, a tiny town four hours from the U.S. capital, Washington, D.C. Fewer than 150 people live in Green Bank, which has two churches, an elementary school and a public library. It also is home to the largest fully steerable radio telescope in the world. There is a ban on Wi-Fi -- wireless internet service -- in Green Bank, along with anything else that can create electromagnetic waves. Officials say the waves could interfere with signals the telescope receives.