English: Roger Ekirch, photographed 2012 by Tom Cogill. Ekirch is a Professor of History at Virginia Tech. He's well known as the historian who found out that the sleep pattern of humans before the Industrial Revolution and before electric lighting were mostly biphasic: The first sleep ended around midnight and led into an hour or two of leisure, sexual activity, reflection on dreams etc. The term "first sleep" used to be common and is now long forgotten. It appears in diaries, legal documents and high literature such as cervantes' don quijote. Ekirchs best known publication about this subject is "At Day's Close: A History of Nighttime".
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