15 people spend 40 days in cave, lose the sense of time

‘Deep Time’ project aimed at studying how people adapt to changes in living conditions, environments

Published - April 25, 2021 09:57 pm IST - LOMBRIVES CAVE

Study time:  Members of the team taking part in the “Deep Time” study in the Lombrives Cave , France.

Study time: Members of the team taking part in the “Deep Time” study in the Lombrives Cave , France.

Ever wonder what it would feel like to unplug from a hyperconnected world and hide away in a dark cave for 40 days?

Fifteen people in France did just that, emerging on Saturday from a scientific experiment to say that time seemed to pass more slowly in their cavernous underground abode in southwestern France, where they were deprived of clocks and light.

With big smiles on their pale faces, the 15 left their voluntary isolation in the Lombrives cave to a round of applause and basked in the light while wearing special glasses to protect their eyes after so long in the dark.

“It was like pressing pause,” said Marina Lançon,33, one of the seven female members in the experiment, adding she didn’t feel there was a rush to do anything.

Although she wished she could have stayed in the cave a few days longer, she said she was happy to feel the wind blowing on her face again and hear the birds sing in the trees of the French Pyrénées. And she doesn’t plan to open her smartphone for a few more days, hoping to avoid a “too brutal” return to real life.

For 40 days and 40 nights, the group lived in and explored the cave as part of the Deep Time project. There was no sunlight inside, the temperature was 10 degrees Celsius and the relative humidity stood at 100%. The cave dwellers had no contact with the outside world, no updates on the pandemic nor any communications with friends or family.

Scientists at the Human Adaption Institute leading the $1.5 million “Deep Time” project say the experiment will help them better understand how people adapt to drastic changes in living conditions and environments.

As expected, those in the cave lost their sense of time.

30 days, 23 days?

“And here we are! We just left after 40 days... For us it was a real surprise,” said project director Christian Clot, adding for most participants, “in our heads, we had walked into the cave 30 days ago.”

At least one team member estimated the time underground at 23 days.

Johan Francois, 37, a math teacher, ran 10-km circles in the cave to stay fit. He sometimes had “visceral urges” to leave.

With no daily obligations and no children around, the challenge was “to profit from the present moment without ever thinking about what will happen in one hour, in two hours,” he said.

In partnership with labs in France and Switzerland, scientists monitored the 15 member’s sleep patterns, social interactions and behavioural reactions via sensors. One sensor was a tiny thermometer inside a capsule that participants swallowed like a pill. It measured body temperatures and transmitted data to a computer until it was expelled naturally.

The team followed their biological clocks to know when to wake up, go to sleep and eat.

0 / 0
Sign in to unlock member-only benefits!
  • Access 10 free stories every month
  • Save stories to read later
  • Access to comment on every story
  • Sign-up/manage your newsletter subscriptions with a single click
  • Get notified by email for early access to discounts & offers on our products
Sign in


Comments have to be in English, and in full sentences. They cannot be abusive or personal. Please abide by our community guidelines for posting your comments.

We have migrated to a new commenting platform. If you are already a registered user of The Hindu and logged in, you may continue to engage with our articles. If you do not have an account please register and login to post comments. Users can access their older comments by logging into their accounts on Vuukle.