15 Volunteers Lost 10 Days in 40-Day French Cave Isolation Test
Updated
Updated · spacedaily.com · Aug 18
15 Volunteers Lost 10 Days in 40-Day French Cave Isolation Test
1 articles · Updated · spacedaily.com · Aug 18
Summary
Fifteen volunteers emerged from France’s Lombrives cave on April 24, 2021 believing roughly 30 days had passed, not the full 40 days of the Deep Time isolation experiment.
At 10 degrees Celsius and 100% humidity, the group lived without clocks, daylight or calendar cues while wearing sensors, testing how humans adapt when normal time markers disappear.
The result echoed geologist Michel Siffre’s 1962 cave study, when he surfaced after about two months insisting it was still August and helped found research into human internal clocks.
Later work showed cave isolation can distort both date perception and sleep cycles, while tighter laboratory controls eventually put the average human circadian period closer to 24.18 hours than 25.