It鈥檚 hard to imagine, but 50 years ago it wasn鈥檛 TV, the Internet, Twitter or a myriad of social media that alerted people to breaking news, instead they probably heard it on the radio. But that all changed one afternoon in Dallas, Nov. 22, 1963, when President John F. Kennedy was assassinated. That鈥檚 when people discovered the power of live TV, says Rick Stevens, a professor of journalism at 抖阴旅行射-Boulder.