Street Lighting and the End of Second Sleep
FOMO killed segmented sleep.
Prior to the seventeenth century, the cycles of night and day drove sleeping habits. Roger Ekirch, a professor at Virginia Tech, suggests in his 2005 book, At Day’s Close, Night in Times Past, that a segmented sleep cycle was the norm across most continents. The ‘first sleep’ would usually begin around two hours after dusk, last for around four hours, and would be followed by a one to two hour interlude. During the interlude, you might smoke, eat, converse or have sex. The second sleep would then commence for another four to five hours.
Ekhrich states that the many references to segmented sleep come to an abrupt end in the middle of the seventeenth century. He attributes the change to the rise of street lighting, coffee houses and the beginning of a legitimate night culture. As the night became safer and more navigable, individuals’ slowly changed their sleeping habits to allow for changing social norms — An early example of FOMO driven cultural shifts.
If you want to pursue biphasic sleep, check out The Polyphasic Sleep Society for great advice.