Michel Foucault of left-wing groups involved in campaigns against racism and human rights abuses and for penal reform. Foucault later published "Discipline and Punish" (1975) and "The History of Sexuality" (1976), in which he developed archaeological and genealogical methods which emphasized the role that power plays in society. Foucault died in Paris of neurological problems compounded by HIV/AIDS; he became the first public figure in France to die from the disease. His partner Daniel Defert founded the AIDES charity in his memory. Paul-Michel Foucault was born on 15 October 1926 in the city of Poitiers, west-central France, as the second of three
Pendulum observations, and a "pendulum mania" broke out, as Foucault pendulums were displayed in many cities and attracted large crowds. Around 1900 low-thermal-expansion materials began to be used for pendulum rods in the highest precision clocks and other instruments, first invar, a nickel steel alloy, and later fused quartz, which made temperature compensation trivial. Precision pendulums were housed in low pressure tanks, which kept the air pressure constant to prevent changes in the period due to changes in buoyancy of the pendulum due to changing atmospheric pressure. The best pendulum clocks achieved accuracy of around a second per year. The timekeeping