Object Details
Creator
Harrell, Alfred
Subject
Smithsonian Institution Office of Printing and Photographic Services
National Museum of History and Technology
Summary
On exhibition January 1, 1964 - October 30, 1998.
Modeled after French physicist J. B. L. Foucault's 1851 pendulum, the museum's pendulum demonstrates the axial rotation of the earth. The 240-pound brass, hollow bob is suspended by a 54-ft. steel cable from the ceiling of the 4th floor. Although the pendulum's vertical plane seems to change, in fact it remains fixed. What is actually moving is the floor, which rotates under the pendulum because of the Earth's rotation. As the Earth moves, the red markers, arranged in a circle around an inlaid compass rose, move into the path of the pendulum, and the bob knocks them over one by one.
Cite as
Smithsonian Institution Archives, Acc. 11-009, Image No. 75-3965
Repository Loc.
Smithsonian Institution Archives Capital Gallery, Suite 3000, MRC 507; 600 Maryland Avenue, SW; Washington, DC 20024-2520
Date
1975
March 13, 1975
Local number
SIA Acc. 11-009 [75-3965]
Restrictions & Rights
No access restrictions Many of SIA's holdings are located off-site, and advance notice is recommended to consult a collection. Please email the SIA Reference Team at osiaref@si.edu
No Copyright - United States
Type
Color negatives
Physical description
4 x 5;
Data Source
Smithsonian Institution Archives
Topic
Exhibitions
Foucault's pendulum
Record ID
siris_arc_398143