February 17, 2009, is D-day-- when the term "digital divide" will take on a whole new meaning unrelated to computer access. That is when the nation's 1,700 analog television stations will shut down in the long-promised changeover to all-digital broadcasting. Cable and satellite viewers or those whose TV has a digital tuner will be able to watch CSI and American Idol unaware that anything has changed. But the 21 million households using a conventional set with rabbit ears or a rusty roof antenna--typically people who are poor, elderly or living in rural America--will turn on their TVs and see ... nothing.

Not since color made black-and-white sets pass? has a new technology so compelled consumers to replace their primary entertainment appliance. In contrast to the variable radio waves of analog broadcasting, digital TV (or DTV) uses electrical pulses to transmit information precisely and efficiently. Thus, DTV offers startlingly sharp pictures, capable of revealing individual blades of grass on a field or the writing on a ransom note held in a fictional detective's hand. DTV also will enable new interactive features, thanks to its ability to pack enormous amounts of information in scarce bandwidth. For instance, it could let viewers call up stats on a ballplayer during the game or view a recipe from a cooking show. Broadcasters will be able to offer even more channels in the available bandwidth, too. The freed-up space will make room for better communications for public safety agencies during emergencies such as hurricanes and for next-generation cellular services.