Jean-Baptiste Biot
The young physicist whose report on the 1803 fall at L'Aigle convinced the scientific world that meteorites come from the sky.
Key facts
- Born
- 1774
- Died
- 1862
- Nationality
- French
- Field
- Physicist and astronomer
Jean-Baptiste Biot was one of the brightest French scientists of his age. He worked on light, magnetism and electricity, and the Biot–Savart law, which describes the magnetic field around an electric current, still carries his name. In 1804 he rose more than 4,000 metres in a hydrogen balloon with Joseph Louis Gay-Lussac to study the upper air.
On 26 April 1803 a fireball crossed Normandy and a shower of stones fell around the small town of L'Aigle. Thousands of fragments came down. The French government sent Biot, then 29, to find out what had happened. He treated the event like a modern investigation. He visited the villages, questioned farmers, priests and officials, collected stones and mapped where they had landed.
His evidence was hard to dismiss. Many independent witnesses described the same fireball and explosions. The stones were all of one kind, quite unlike any local rock, and they lay scattered over an oval area roughly ten kilometres long, just as pieces breaking from one body would. Chemical tests matched them to other stones said to have fallen elsewhere.
Biot presented his report to the Institut de France in 1803. After it, French scientists, and soon the rest of Europe, accepted that stones fall from the sky. The idea Chladni had argued for nine years earlier became established science, and Biot's careful method of mapping a strewn field is still how meteorite falls are studied today.
Did you know?
Biot's map of the L'Aigle stones is one of the first maps of a strewn field ever drawn.
He lived long enough to see the first photographs and the spread of railways, dying in Paris in 1862 aged 87.
On the timeline
- 26 April 1803L'Aigle: the fall that convinced science