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The original was posted on /r/todayilearned by /u/Xenial81 on 2024-08-02 10:13:25+00:00.
Original Title: TIL the human body can naturally settle into a sleep-wake cycle of up to 50 hours, when there’s no day/night cycle to observe. In 1962 geologist Michel Siffre entered a darkened cave, where he planned to remain for two months tracking time assuming 1 sleep equals one day, but he was off by 2 weeks.
“The human body” is wrong. The cycadian rythm is different between all people.
Owls have a cycle longer than the normal 18h, larks have one that is shorter.
This guy is clearly an ultra-owl.