Léon Foucault is not a widely recognized figure like his namesake, Jean-Bernard Léon Foucault, who was a famous French physicist known for his work in the 19th century. Léon Foucault is best known for his demonstration of the rotation of the Earth using the Foucault pendulum, a simple device that elegantly shows the Earth's rotation relative to the plane of the pendulum's swing.
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A physicist appointed to the Paris Observatory in 1855 who developed telescopes.[ref]
Léon Foucault à l’Observatoire by Observatoire de Paris. Léon Foucault à l’Observatoire, p. 2: appointed physicist in 1855; telescope development
Portrait of Jean Bernard Léon Foucault
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