TRENDING SCIENCE: Digital detox: Can you live unplugged in a dark cave for 40 days?

We live in a hyperconnected world. Disconnecting from a digital existence to experience the world through non-electronic screens is good for the soul. But could you hide away in a cave without sunlight, no mobile devices and no way of telling time for over a month?On 24 April, as part of a human isolation experiment led by the Human Adaptation Institute, 8 men and 7 women saw daylight and came into contact with the outside world for the first time after spending 40 days with no clocks or phones in a cave in south-western France. French and Swiss scientists entered the cave a day earlier to tell them the so-called Deep Time project was ending.

“Our future as humans on this planet will evolve,” project leader Christian Clot, who was also amongst the volunteers, told Canadian public broadcaster ‘CBC’. “We must learn to better understand how our brains are capable of finding new solutions, whatever the situation.”

The 15 volunteers aged 27 to 50 slept in tents and produced their own electricity from a bike-powered generator. Water came from a well 45 m below the earth. Four tonnes of provisions and other equipment were packed into the cavernous space. The underground temperature was constant at about 10 °C, with relative humidity at nearly 100 %. The cave dwellers depended on their internal clocks to sleep, eat and organise daily tasks. Days were counted in sleep cycles instead of hours, but their sense of time was lost quickly. Fitted with sensors, the participants’ brain activity was measured by the scientific team. They represented a cross-section of society, and included a jeweller, an anaesthesiologist, a security guard and a biologist.What were the reactions after emerging from the cave? “When they came to announce the end of the experiment after 40 days in the cave, it was kind of a shock,” noted Marina Lançon, an expedition guide. “I remember thinking, like, ‘Oh no, already?’ Time went by so fast and I still had, like, so [many] things I wanted to do in the cave.”

“It was like pressing pause,” Lançon added in ‘The Guardian’. “And here we are! We just left after 40 days … For us it was a real surprise,” explained Clot. “In our heads, we had walked into the cave 30 days ago.”

Johan Francois, a maths teacher and sailing instructor, occasionally had “visceral urges” to abandon the cave. Still, the experiment had its advantages: “to profit from the present moment without ever thinking about what will happen in one hour, in two hours.”

Surprisingly, two thirds of the subjects said they wanted to stay in the cave for longer. They were also given the option of leaving at any time during the confinement.