IN JULY 1962, French geologist lowered himself into a deep cave in the Alps for a stint of self-experimentation. He wanted to know what would happen to his bodily rhythms when deprived of the natural light cues of day and night.
Initially he marked the passage of time by playing Mario Lanza records, but they soon began to blend into one. “Time no longer has any meaning for me. I am detached from it, I live outside time,” Siffre wrote. When he was hauled out of his cave after the agreed two months, he still thought he had…
