Deep Time Experiment

If you had no watch or phone to tell you what time it was, and you couldn’t see the sun at all for days on end, how would you experience the passage of time? In March, fifteen people went into a dark cave without anything to help them keep track of time, and they stayed there for 40 days. Explorer Christian Clot led the expedition–which they called the Deep Time Experiment. He’s president of the Human Adaptation Institute in France.