Shiny metal balls swing hypnotically from museum ceilings worldwide, knocking over tiny objects arranged in a circle on the floor. These Foucault pendulums elegantly demonstrate that Earth is spinning ...

PROF. GREENHILL gives currency to quite an erroneous idea, in last week's NATURE (p. 50). He says “in the Foucault experiment of the pendulum which shows the rotation of the earth, the slightest ...

The 1 kg pendulum is held up to the demonstrator's face and released. Because of conservation of energy, the ball will not swing higher than the height at which it was released (in fact, because ...

Happy birthday, Jean Bernard Leon Foucault, and thanks for the pendulum. The French physicist and inventor was born in Paris on this day in 1819. It may be hard to fathom, but the idea of Earth ...

Next month a total solar eclipse will be seen across the United States. It is one of the few eclipses to trace a path through several densely populated areas, and that means there's plenty of ...