Foucault

French physicist who estimated the speed of light and determined that it travels more slowly in water than in air (1850). He also employed a pendulum to prove the rotation of the earth (1851) and invented the gyroscope (1852).

French philosopher and historian who explored the role played by power in shaping knowledge. His works include Madness and Civilization (1961) and the multi-volume History of Sexuality (1976-1986).