Foucault Pendulum, Introduction Latest change 2019-12-15
All pages on this
site are under construction and may change without notice.
You can use the 'refresh' button of you browser to obtain the
most recent version of a page.
A Foucault Pendulum consists
of a thin wire on which a weight is suspended. The weight
can swing freely in any direction, and suppose it is swinging in
direction at a certain moment, a few hours later it will swing in
another direction because the earth is rotating below it.(*)
The behaviour of a Foucault Pendulum gives a rather direct
the earth is rotating.
The challenges are:
- Mounting and driving the pendulum such that there is no
preference for a certain direction.
- Suppressing the elliptical orbit any free hanging pendulum
tends to develop.
- The technique for tracking and logging the behaviour of
- The web technique to stream real-time images and
to present the logged data.
My plan was to:
- Build a pendulum in my home and evaluate the requirements
for driving and tracking (winter - summer 2016/2017)
- Mount a pendulum in the Chapel
at Vrijland. Here we
implement the web-technique.
(dec 2019) Due to all kind of circumstances the work has been
delayed severely. The setup in the Vrijland Chapel became a once
only experiment and it is now sure that there will be no follow-up
is a short movie of the pendulum at my home.
(*) Only at the North- or Southpole the plane of swinging will
in 1 day(**). At lower lattitudes it goes slower, with
1/sin(lattitude) and on the equator it does not work at all
sin(lattitude) will be zero and the swinging plane will take
(**) This is the siderial day, that is the time in which the earth
makes one revolution w.r.t. the far, fixed stars. That time is