Almost three stories above you is a large sky dome, the Foucault pendulum is attached at its center. This is the North point in the sky, and for us, at the North Pole, the pole star is pretty close to the zenith.
Here is what you see when you look up:
The line you see is the Foucault Pendulum wire connected to the North Point above, directly on the Earths axis. See if you can find Polaris, the North Star. You may want to select the sky view above with your mouse, and instead you will see a star map of the same sky. The star map has fewer stars, and you will see the constellations marked with stick figures.
The sky dome itself is motorized and kept synchronized with
the stars outside, even during the half a year that the sun is
in the northern hemisphere. So in this museum you can always see
the sky, no matter what the weather, no matter the time of year.
