When you’re lying awake at night, it’s alright: BBC’s Stephanie Hegarty delves into pre-industrial sleep habits and discovers that eight hours of uninterrupted sleep may be a recent invention. “Much like the experience of Wehr’s subjects, these references describe a first sleep which began about two hours after dusk, followed by waking period of one or two hours and then a second sleep. ‘It’s not just the number of references – it is the way they refer to it, as if it was common knowledge,’ Ekirch says.”