(1884–1962), Swiss physicist, known for his exploration of the stratosphere and the deep sea. He was born in Basel, Switzerland, and educated at the Federal Polytechnic School. He became professor of physics at the University of Brussels in 1922. In 1931 he attracted worldwide attention by making the first balloon ascension into the stratosphere, reaching an altitude of 15,787 m (51,793 ft), a new world record. During this flight Piccard acquired valuable information regarding the intensity of cosmic rays in the stratosphere; he also recorded stratospheric temperatures ranging between –55° and –60° C (–67° and –76° F). In the following year he made another ascension, bettering his previous record by attaining an altitude of 16,940 m (55,577 ft). He later became interested in undersea exploration and in 1947 built his first BATHYSCAPHE, (q.v.), with which he made a series of descents, including one in 1954 at a depth of 4000 m (13,125 ft). In 1953, he launched his second bathyscaphe, Trieste, with which he reached a depth of 3150 m (10,300 ft). In 1960 his son, Jacques Piccard (1922–    ), in Trieste set the world record descent into the deepest place on earth—the Marianas Trench—at 10,916 m (35,814 ft). See DEEP-SEA EXPLORATION,.

Another notable member of the family, Bertrand Piccard (1958–    ), Jacques's son, achieved the first round-the-world nonstop balloon flight (March 1–21, 1999), with his British copilot Brian Jones (1947–    ).