For centuries, humans slept in two distinct shifts. Biphasic sleep.
The Forgotten Common Medieval Habit of ‘Two Sleeps‘. “For centuries, humans slept in two distinct shifts, separated by a period of nighttime activity. In this video, we explore the fascinating history of biphasic sleep, a once-common practice where people divided their nights into a “first sleep” and a “second sleep.” — Medieval Sleep. BBC. 9… Read More For centuries, humans slept in two distinct shifts. Biphasic sleep.


