20th Century Technology
While televisions weren't widely owned until the 1950s, the basic technology was invented earlier in the century as scientists tested the properties of vacuum tubes. Even though it didn't spell the demise of radio, TV has probably had the most impact of any communications device during the 20th century. Just three households had TV in 1928 when television broadcasting made its debut; today the world boasts roughly 1 billion sets. Not only does it entertain, but it has radically transformed how we gather our news and information, bringing viewers closer to events as they happen.