Biot was born in Paris in 1774, and died there in 1862. As a young man he attended the college of Louis-le-grand in Paris, and later the École Polytechnique. In the early 1800s, he studied the polarisation of light passing through chemical solutions, as well as the relationship between electrical current and magnetism. The Biot–Savart law, which describes the magnetic field generated by a steady current, is named after him and Félix Savart. The cgs unit of electric current, the Biot was also named after him. Biot was the first to confirm the reality of meteorites, hitherto regarded with scepticism by many astronomers, following his investigation of a substantial meteor storm over Normandy, at L'Aigle, in 1803. He was also the first to discover the unique optical properties of mica, and therefore the mica-based mineral biotite was named after him. In 1804 Biot and Joseph Gay-Lussac made a hot-air balloon ascent to a height of five kilometres in an early investigation of the Earth's atmosphere. (The Biot who helped make and fly the Massia-Biot glider is a different person. See this list of early flying machines.) Biot played an important role in the discovery of optical activity of tartaric acid. Late in his life, Pasteur demonstrated to him the opposite optical rotations (equal angle, but opposite direction) of polarized light passing through aqueous solutions of mirror-image crystals of this compound. There is a small crater named for Biot on the Moon.
|This page was a Featured Article on June 5, 2009.|