Man lives like a 'timeless' caveman for experiment, discovers bizarre secret about the human mind

Michel Siffre undertook a radical self-experiment: to live in complete isolation inside a glacier cave in the Scarasson mountain in the Ligurian Alps—130 meters below the surface—for over two months. Inspired by the space race and the psychological challenges astronauts might face, Siffre aimed to understand how the human body perceives time in the absence of natural cues like sunlight or clocks.

“This idea came to me—this idea that became the idea of my life,” Siffre later told Cabinet Magazine. “I decided to live like an animal, without a watch, in the dark, without knowing the time.”

No Watch, No Light, Just the Body Clock

Siffre’s experiment was simple in structure but profound in outcome. He abandoned his watch, deprived himself of sunlight, and instructed his surface team not to share any time-based information. The only equipment he carried was basic camping gear and a flashlight. He would notify the surface crew whenever he woke up, ate, or went to sleep, helping them monitor his natural rhythm without interfering with it.

Through this extreme isolation, Siffre made an unexpected yet revolutionary discovery: the body runs on its own internal clock. “Without knowing it, I had created the field of human chronobiology,” he said.

Time, Warped by the Mind

To delve deeper into his own perception of time, Siffre conducted psychological tests during his stay. In one test, he was asked to count from 1 to 120 at the rate of one digit per second. He believed it took him two minutes. In reality, five minutes had