A. Roger Ekirch "Sleep We Have Lost: Pre-industrial Slumber in the British Isle" http://www.historycooperative.org/journals/ahr/106.2/ah000343.html http://www.h

A. Roger Ekirch "Sleep We Have Lost: Pre-industrial Slumber in the British Isle" http://www.historycooperative.org/journals/ahr/106.2/ah000343.html http://www.historycooperative.org/journals/ahr/106.2/ah00034... This is the seminal article on segmented sleep. Pretty fascinating stuff. And a shorter TED video: http://www.ted.com/talks/jessa_gamble_how_to_sleep.html http://www.ted.com/talks/jessa_gamble_how_to_sleep.html