Nowadays, when we use electric lighting, we try to make sleep as efficient as possible.
Good sleep is considered to be when you can fall asleep practically after going to bed and sleeping for exactly seven and a half hours.
– explains James E. Gangwisch, PhD from Columbia University.
In the Middle Ages, when people did not have access to electricity, many people went to bed just after dark and slept for 3-4 hours, then woke up in the middle of the night for an hour or two and went back to sleep. References to the dream in two “segments” often appear in literature and archival documents of the time.
When the installation of street lights began in Paris in 1667, the natural sleep cycle began to slowly evolve, and doctors even advised against falling into a “second sleep.” Famous people who slept in intervals include: Leonardo da Vinci, Thomas Edison, Nikola Tesla and Margaret Thatcherwho often needed only four hours of sleep a day.
Specialists emphasize that it would be best if our sleep was adjusted to the sun cycle, but this is impossible. “Many of us still wake up at night and have trouble getting back to sleep,” explains Gangwisch.
Matt Bianchi, director of the sleep research department at a hospital in Massachusetts, points out that each of us is different.
Some people drink caffeine, which stimulates them, while for others it has no effect. It's similar with sleep – one person may sleep in short intervals throughout the day, while another person crashes the car he or she is driving as soon as he or she becomes sleepy.
– he explains in an interview with Psychology Today.
Therefore, waking up in the middle of the night does not necessarily mean problems with sleep. “If people don't try to overcome sleepiness, they will fall back to sleep after an hour,” explains Roger Ekrich, a sleep historian at Virginia Polytechnic University and Virginia State University.
