Newsweek‘s cover story examines the sleep deficit of America and the solutions available to resolve it.

Humans have been screwing with their body clocks—and getting less sleep—ever since the Wizard of Menlo Park had his very bright idea. Indeed, our classic eight-hour-night only dates back to the invention of the light bulb in the late 1800s. Historians believe that before the dawn of electric lighting most people got plenty of sleep, and practiced what they call “segmented sleep,” snoozing for several hours in the first part of the night, when darkness fell, then waking in the middle of the night for a few hours of eating, drinking, praying, chatting with friends or maybe even canoodling, before ducking back under the covers again until morning. The arrival of electricity, argues sleep historian A. Roger Ekirch, led to later bedtimes and fewer hours of sleep overall.