Self: Diff for "Foucault Pendulum"

Foucault Pendulum

This project is suggested by Professor Cary Forest and is to hang a Foucault Pendulum in what was once an elevator shaft in the atrium of Chamberlin Hall (see photos). The pendulum requires a drive system to maintain constant amplitude and a method of recording the trajectory on the floor. It may be instrumented with a laser. For those unfamiliar with the Foucault pendulum, imagine a long simple pendulum at the north pole, the mass free to move over the surface of a sphere of radius equal to the pendulum length. The plane of a planar oscillation remains fixed in space in an inertial frame moving with the Earth around the Sun. The Earth rotates so, relative to an Earth observer, the plane of oscillation appears to rotate by 360 degrees daily, thereby demonstrating the rotation of the Earth. At mid latitudes, relative to the Earth, a similar rotation is observed and the rotation is ascribable in such a noninertial frame to the Coriolis (pseudo)force.

Participants: Prof. Cary Forest, Prof. Carlsmith, Peter Weix (Plasma physics), Joseph Sterle (Undergraduate Research Scholar 2013)

Resources

Wikipedia http://en.wikipedia.org/wiki/Foucault_pendulum

American Journal of Physics http://scitation.aip.org.ezproxy.library.wisc.edu/search?value1=foucault+pendulum&option1=all&option12=resultCategory&value12=ResearchPublicationContent

Failed attempt to power https://neil.fraser.name/news/2011/01/07/

Nother approach ‎www.calacademy.org/products/pendulum/pendspec.pdf

Progress

Status 23 Sep '13 Undergraduate Research Scholar and first year student Joseph Sterle will work on the Foucault pendulum project for 2 credits in Fall 2013 under Carlsmith's supervision under the auspices of Garage Physics.

Joseph will design and test the excitation mechanism for the Foucault pendulum in the atrium of Chamberlin Hall. In particular, he will study parametric excitation via lifting the support point as an alternate/supplement to magnetic excitation with a ring of magnetics. He will read the appropriate section of Landau and Lifshitz 'Mechanics' on parametric oscillations and the pdf from Princeton students posted at the Garage Physics 'Active mechanical stabilization of structures' suggested project. Joseph will measure the damping time of the actual pendulum in order to design the excitation mechanism and do model calculations of the design parameters needed to prevent the disruption of the Earth rotation signal in the pendulum motion, and to damp elliptical motion if necessary, and to ensure the drive (phased to support the intended slow rotation) does not force an unnatural motion. Joseph will attend 3rd Thursday garage meetings, create a poster about his project, and write a final 10-page paper.

30 Oct '13 Roof support installed.