page_title: Foucault pendulum
section_title: Original Foucault pendulum
hierarchical_section_title: Foucault pendulum / Original Foucault pendulum
caption_attribution_description: English: Foucault Pendulum. Pendulum for Showing the Rotation of the Earth.
context_page_description: The Foucault pendulum or Foucault's pendulum is a simple device named after French physicist Léon Foucault and conceived as an experiment to demonstrate the Earth's rotation. The pendulum was introduced in 1851 and was the first experiment to give simple, direct evidence of the earth's rotation. Foucault pendulums today are popular displays in science museums and universities.
context_section_description: The first public exhibition of a Foucault pendulum took place in February 1851 in the Meridian of the Paris Observatory. A few weeks later, Foucault made his most famous pendulum when he suspended a 28-kilogram (62 lb) brass-coated lead bob with a 67-metre long (220 ft) wire from the dome of the Panthéon, Paris. The period of the pendulum was  seconds. Because the latitude of its location was  = 48°52' N, the plane of the pendulum's swing made a full circle in approximately  = 31.8 hours (31 hours 50 minutes), rotating clockwise approximately 11.3° per hour.
  The original bob used in 1851 at the Panthéon was moved in 1855 to the Conservatoire des Arts et Métiers in Paris. A second temporary installation was made for the 50th anniversary in 1902.
  During museum reconstruction in the 1990s, the original pendulum was temporarily displayed at the Panthéon (1995), but was later returned to the Musée des Arts et Métiers before it reopened in 2000. On April 6, 2010, the cable suspending the bob in the Musée des Arts et Métiers snapped, causing irreparable damage to the pendulum bob and to the marble flooring of the museum. The original, now damaged pendulum bob is displayed in a separate case adjacent to the current pendulum display.
  An exact copy of the original pendulum has been operating under the dome of the Panthéon, Paris since 1995.
caption: A Print of the Foucault Pendulum, 1895
exif: {"Image DateTime": "2017:08:03 04:17:30", "GPS GPSTimeStamp": "[8, 16, 40]", "GPS GPSAltitudeRef": "12/5", "GPS GPSDate": "2017:08:03", "Image GPSInfo": "711", "Image Model": "Coolpad 3622A", "Image ImageWidth": "1036", "Image YCbCrPositioning": "Centered", "Image ResolutionUnit": "Pixels/Inch", "Image ImageLength": "1730", "Image YResolution": "72", "Image ExifOffset": "204", "Image XResolution": "72", "Image Make": "Coolpad", "Thumbnail YResolution": "72", "Thumbnail Compression": "JPEG (old-style)", "Thumbnail ResolutionUnit": "Pixels/Inch", "Thumbnail XResolution": "72", "EXIF ColorSpace": "sRGB", "EXIF DateTimeDigitized": "2017:08:03 04:16:41", "EXIF FocalLength": "47/20", "EXIF ApertureValue": "12/5", "EXIF ExposureMode": "Auto Exposure", "EXIF SubSecTimeDigitized": "734875", "EXIF ExifImageLength": "2592", "EXIF FocalLengthIn35mmFilm": "0", "EXIF SceneCaptureType": "Standard", "EXIF SceneType": "Directly Photographed", "EXIF SubSecTimeOriginal": "734875", "EXIF ExposureIndex": "274", "EXIF ExposureProgram": "Unidentified", "EXIF ExifImageWidth": "1944", "EXIF SubSecTime": "734875", "EXIF ShutterSpeedValue": "2453/500", "EXIF MeteringMode": "Average", "EXIF DateTimeOriginal": "2017:08:03 04:16:41", "EXIF GainControl": "6", "EXIF ComponentsConfiguration": "YCbCr", "EXIF Flash": "Flash did not fire, compulsory flash mode", "EXIF ExifVersion": "0220", "Interoperability InteroperabilityIndex": "R98", "Interoperability InteroperabilityVersion": "[48, 49, 48, 48]", "EXIF InteroperabilityOffset": "681", "EXIF BrightnessValue": "0", "EXIF ISOSpeedRatings": "661", "EXIF SensingMethod": "0", "EXIF FlashPixVersion": "0100", "EXIF ExposureTime": "1/30"}