傅科摆是1955年荷兰送给联合国的。傅科摆是一个镀金球体，球内装有一些铜，球体由一根不锈钢丝从75英尺高的天花板上悬吊下来。万向接头使它可以自由地朝任何方向摆动。傅科摆下方的电磁铁抵销了空气摩擦力，使摆可以持续地均匀摆动。由于地球的自转，摆在一天中摆动的方向似乎会变化。这个球体需要36小时45分钟才能完成一个周期。

A prominent feature of the General Assembly Lobby is the Foucault pendulum, given by theNetherlandsto the United Nations in 1955. The Foucault pendulum, named after the French physicist Jean Bernard Leon Foucault, gives visual proof of the rotation of the Earth.

It consists of a gold-plated sphere, partly filled with copper, suspended from the ceiling 75 feet above by a stainless steel wire. A universal joint allows it to swing freely in any direction. An electromagnet under the pendulum counteracts the friction in the air, thus keeping the pendulum swinging uniformly. During the course of a day, the direction in which the pendulum swings appears to change due to the rotation of the Earth. It takes the sphere 36 hours and 45 minutes to complete its cycle.