In 1851, Leon Foucault demonstrated the Earth's rotation to the world with a magnificent pendulum in the Paris Pantheon. In 2010, that pendulum crashed to the Musée des Arts et Métiers' marble floor. The damage, as they say, is irreparable.
Of course, a horribly dented brass bob—despite being busted up in three places—will still swing. The bigger damage may be to the reputation of the curators, who've swung down this road before: in 2009, a cocktail party attendee swung Foucault's Pendulum directly into a security barrier.
While museum officials have owned up to that incident, they aren't saying what caused the cable to snap last month. Meaning it was either something even more negligent than a drunken overture at a black tie soirée... or they simply don't know. Hard to say which is worse. [Times Higher Education via Nature]