Michel Siffre is a French

French people

The French are a nation that share a common French culture and speak the French language as a mother tongue. Historically, the French population are descended from peoples of Celtic, Latin and Germanic origin, and are today a mixture of several ethnic groups...

 underground explorer, adventurer and scientist

Scientist

A scientist in a broad sense is one engaging in a systematic activity to acquire knowledge. In a more restricted sense, a scientist is an individual who uses the scientific method. The person may be an expert in one or more areas of science. This article focuses on the more restricted use of the word...

. He was born January 3, 1939 in Nice

Nice

Nice is the fifth most populous city in France, after Paris, Marseille, Lyon and Toulouse, with a population of 348,721 within its administrative limits on a land area of . The urban area of Nice extends beyond the administrative city limits with a population of more than 955,000 on an area of...

, where he spent his childhood. At just 10 years of age he explored the Imperial Cave Park, and discovered a passion for caving.

He received a postgraduate degree at the Sorbonne

Sorbonne

The Sorbonne is an edifice of the Latin Quarter, in Paris, France, which has been the historical house of the former University of Paris...

 six months after completing his baccalauréat

Baccalauréat

The baccalauréat , often known in France colloquially as le bac, is an academic qualification which French and international students take at the end of the lycée . It was introduced by Napoleon I in 1808. It is the main diploma required to pursue university studies...

. His many achievements include the creation of the French Institute of Speleology

Speleology

Speleology is the scientific study of caves and other karst features, their make-up, structure, physical properties, history, life forms, and the processes by which they form and change over time...

 in 1962.

Main Achievements

• In his youth he became interested in the space race and decided to find a way to contribute. Imagining situations faced by astronauts noticed that some of them could play in a deep cave, that motivated him to start his experiments.
• The experience of time
  Time
  Time is a part of the measuring system used to sequence events, to compare the durations of events and the intervals between them, and to quantify rates of change such as the motions of objects....
  
  , two months cloistered in the abyss of Scarasson without time cues on a glacier
  Glacier
  A glacier is a large persistent body of ice that forms where the accumulation of snow exceeds its ablation over many years, often centuries. At least 0.1 km² in area and 50 m thick, but often much larger, a glacier slowly deforms and flows due to stresses induced by its weight...
  
  , from July 1962. He then organized several similar underground experiments for other speleologists. In 1972, Siffre went back underground for a six-month stay in a cave
  Cave
  A cave or cavern is a natural underground space large enough for a human to enter. The term applies to natural cavities some part of which is in total darkness. The word cave also includes smaller spaces like rock shelters, sea caves, and grottos.Speleology is the science of exploration and study...
  
   in Texas
  Texas
  Texas is the second largest U.S. state by both area and population, and the largest state by area in the contiguous United States.The name, based on the Caddo word "Tejas" meaning "friends" or "allies", was applied by the Spanish to the Caddo themselves and to the region of their settlement in...
  
  . He found that without time cues, several people including himself adjusted to a 48 hour rather than a 24-hour cycle
• The notes of his experiments were used by NASA. Several astronauts reported experiences similar to those experienced in underground experiments such as loss of short-term memory to be isolated from external time references.

Publications

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