Volunteers emerge after spending 40 days in a cave with no clocks, natural light

Cheryl Santa Maria
·4 min read
Volunteers emerge after spending 40 days in a cave with no clocks, natural light
Volunteers emerge after spending 40 days in a cave with no clocks, natural light
Volunteers emerge after spending 40 days in a cave with no clocks, natural light

Fifteen volunteers have emerged from a cave after spending 40 days in isolation without clocks, phones, or sunlight.

The group of eight men and seven women lived in the Lombvries cave in southwestern France as part of the Deep Time Project, a $1.4 million (US) initiative led by the Human Adaptation Project to explore how humans adapt to isolation.

The volunteers slept in tents and generated electricity using a pedal bike, while water was drawn from 44 metres below the Earth. They had to rely on their biological clocks to determined when it was time to sleep and eat and to estimate how many days had passed. There was no contact with the outside world and the use of electronic devices was banned.

As The Guardian reports, participants quickly lost track of time. Upon leaving the cave, one volunteer thought they had only been inside for 23 days.

Johan Francois, a math teacher who participated in the project, told the BBC he had "visceral urges" to leave and ran 10.2 km circles to stay fit.

But two-thirds of the team had a different reaction, saying they wanted to stay inside longer.

"For once in our lives, it was as if we could press pause," volunteer Marina Lançon said via The Guardian. "For once in our lives, we had time and could stop to live and do our tasks. It was great."

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As they left participants wore special sunglasses to protect their eyes from natural light following prolonged exposure to the dark.

Social media posts show them smiling and seemingly in good spirits after emerging.

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During the experiment the team's sleeping patterns, social interactions, and cognitive functions were logged via sensors. Brain activity was recorded before and after.

Project director Christian Clot, who was also one of the volunteers, said the findings will provide insight into how humans can adapt to extreme living conditions.

"Our future as humans on this planet will evolve," Clot told reporters after emerging.

"We must learn to better understand how our brains are capable of finding new solutions, whatever the situation."