Last month, millions of viewers used Twitter to watch live streams of NFL football and the presidential debates. If you weren’t one, here’s how it works: After opening the Twitter app and selecting Moments, you click “watch live” to join the live stream, which also integrates a Twitter feed of hashtags related to the event. Amanda Lotz, professor of Communication Studies and Screen Arts & Cultures, examines what these “Twittercasts” might mean for the future of live TV.