Two Months Without Time

In 1962, speleologist Michel Siffre locks himself alone for two months in the icy abyss of Scarasson, near Mont Granier, without a watch or daylight. Deprived of any reference, his internal clock drifts: he believes he emerges much earlier than the actual date.

Installed in the icy abyss of Scarasson, in the Alps, Siffre has no external indicator. He eats and sleeps according to his body's rhythm and signals each awakening by telephone to a surface team, alone in knowing real time. In 1962, speleologist Michel Siffre locks himself alone for two months in the icy abyss of Scarasson, near Mont Granier, without a watch or daylight.

The result founds human chronobiology. Left to himself, his wake-sleep cycle spontaneously calibrates to a day of approximately twenty-four to twenty-five hours. Upon resurfacing, he estimates having remained far less time than in reality: his day count has taken considerable delay. Deprived of any reference, his internal clock drifts: he believes he emerges much earlier than the actual date.

These "out of time" experiences, which Siffre will repeat later underground, show that duration perception has no absolute clock. It depends on an internal biological rhythm, normally reset daily by light; deprived of this signal, subjective time detaches from real time.