Michel Siffre


Michel Augustin Francis Siffre was a French geologist, speleologist and underground explorer. He is especially known for the chronobiology experiments he conducted on himself.

Early life, family and education

Siffre was born and raised in Nice, France. His parents were Jean and Lucie Siffre.
He earned a degree in geology in 1960 at the Sorbonne.

Career

Siffre founded the Institut français de spéléologie in 1962.
Initially, Siffre was planning to study a newly discovered glacier from Nice by remaining within it for 15 days. However, inspired by the space race, he extended the duration and examined how humans experience time by spending 62 or 63 days without time cues, cloistered below the surface in the abyss of Scarasson in the Maritime Alps between France and Italy. beginning July 1962. Subsequently, he designed or organized over a dozen underground experiments for other speleologists.
In 1972, Siffre performed a more extensive underground experiment, staying six months in Midnight Cave in southern Texas. After the experiment, he concluded that without time cues, he adjusted to a 48-hour rather than a 24-hour cycle. NASA studied his work, as did the French Army and the US government.
He conducted geology work in Sri Lanka and Guatemala, and he wrote books and delivered lectures about caves.
Siffre underwent an additional cave excursion from November 1999 to February 2000. He celebrated the New Year there, but missed the actual date by three days.

Personal life and death

After his 1972 experiment, Siffre suffered both acute and lasting effects, recovering from the isolation physically, mentally and emotionally only partially. In debt from the experiment's significant costs, Siffre and his wife Nathalie divorced.
Siffre died from pneumonia at age 85 in Nice on 25 August 2024.

Publications

Hors du temps. L'expérience du 16 juillet 1962 au fond du gouffre de Scarasson par celui qui l'a vécue, Julliard, 1963Des merveilles sous la terre, Hachette, cop. 1976Stalactites, stalagmites, cop. 1984L'or des gouffres: découvertes dans les jungles mayas, Flammarion, 1979Dans les abîmes de la terre, Flammarion, 1975La France des grottes et cavernes, Privat, 1999A la recherche de l'art des cavernes du pays Maya, A. Lefeuvre, 1979Découvertes dans les grottes mayas, Arthaud, 1993Beyond Time, translated by Herma Briffault, McGraw-Hill, New York, 1964