After 40 days of research, a group of French volunteers left the cave and examined the limits of human adaptation to isolation.
The 15 participants lived in Lombrives Cave in southwestern France with no phones, watches and sunlight.
They sleep in tents, generate their own electricity and have no contact with the outside world.
The project aims to test people’s reactions to wasting time and space.
The so-called “deep time” experiment ended on Saturday when eight men and seven women between the ages of 27 and 50 were able to leave the cave.
Scientists overseeing the project entered the cave a day earlier and told them it was ending.
The band smiled, but looked dazed, leaving voluntarily and earning warm applause. They wear sunglasses to give their eyes time to adjust to the sun.
Project manager, Franco-Swiss explorer Cristian Clot says time seems to be slowly passing in the cave.
Volunteer Marina Lanyon, 33, said the experiment was “like a pause” in life.
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During periods of isolation, the team had to organize tasks and failed to use a specific time to set a deadline.
Instead, they have to rely on their biological clocks and sleep cycles to make their days.
There is little modern comfort in caves. For example, volunteers had to use pedal bikes to generate their own electricity and consume water from wells 45 meters (146 feet) underground.
Scientists behind the project say it will help them understand how people adapt to extreme living conditions.
Before entering the cave, the volunteers analyzed brain activity and cognitive function to collect data from comparative studies after their departure.
The purpose of this study was particularly relevant during the coronavirus pandemic, when blockages isolated millions of people.
Clot said our future as human beings on Earth would change. “We need to learn to better understand how our brains can find new solutions, no matter what the situation is,” he says.