It might be difficult to remember now, but there was a time when the news wasn’t 24/7. There were morning and evening editions of the paper; the nightly news was, well, nightly; radio offered updates from time to time. But there’s a whole lot of difference between that world and today’s never-stop cavalcade of heartbreak, tragedy, excitement, and despair.

And one of the biggest dividing lines between those two realities was the creation of CNN. Journalist Lisa Napoli is the author of “Up All Night: Ted Turner, CNN, and the Birth of 24-Hour News,” and she argues that CNN didn’t just change television, or cable, or even news… it changed our entire world.