
Eight hours of uninterrupted sleep in bed linen and on a comfortable mattress is a recent invention. Across different eras and cultures, night-time habits have considerable variety.
“Many Europeans don’t use a top sheet and instead sleep on a fitted sheet, underneath a comforter or duvet. (The duvet has its own cover, which can be taken off and washed just like sheets).” The mysterious bed habits of the continent of Europe were revealed to America by Time magazine only in 2017. To Europeans this all sounds as obvious as the fact that the human body is controlled by a biological clock. Yet if this was also so clear, three American scientists wouldn’t have won the Nobel Prize for its discovery in the not so distant past. Back in the 1980s, nothing was obvious. It is true that scientists have argued since the 18th century that mimosa leaves open in the morning and close at night (even when the plant is hidden from light), and in the mid-20th century a gene controlling the circadian rhythm in a fruit fly was identified. But only Jeffrey Hall, Michael Rosbash, and Michael Young examined this and two further genes (not only in fruit flies, but also in humans) more closely. They concluded that the proteins they produce connect with or block each other in a precise 24-hour rhythm—the same rhythm in which cortisol and melatonin dance in our bodies (controlled by the pineal gland regulated by the supply of light), managing the processes of waking up and falling asleep.
The Darkest Place Is Between the Street Lights
It seems that few things have changed society as much as mass access to light, also during the night. And