Foucault Pendulum - Foucault Pendulums Around The World

Foucault Pendulums Around The World

There are numerous Foucault pendulums around the world, mainly at universities, science museums and planetariums. A particularly famous and prominent one is located at the United Nations in Manhattan. The experiment has been carried out at the South Pole.

The South Pole Pendulum Project (as discussed in The New York Times and excerpted from Seven Tales of the Pendulum) was constructed and tested by adventurous experimenters John Bird, Jennifer McCallum, Michael Town, and Alan Baker at the Amundsen-Scott South Pole Station. Their measurement is probably the closest ever made to one of the earth’s poles. The pendulum was erected in a six-story staircase of a new station that was under construction near the pole. Conditions were challenging; the altitude was about 3,300 meters (atmospheric pressure only about 65 percent that at sea level) and the temperature in the unheated staircase was about −68 °C (−90 °F). The pendulum had a length of 33 meters and a 25 kilogram bob.

Only at the Pole will the experiment truly reveal the rotation rate of the earth, rotating one complete counterclockwise circle every twenty-four hours. Therefore, they were compelled to complete this tribute to science. The new station offered an ideal venue for the Foucault pendulum. Its height ensured an accurate result; no moving air could disturb it; and on weekends, the lack of pedestrian traffic ensured virtually no local vibrations. As an added bonus, at the Pole, low air pressure offered less air resistance. Installing even a crude pendulum in these conditions was challenging. But once they overcame the obstacles, these researchers did confirm a period of about 24 hours as the rotation period of the plane of oscillation.