Cosmic clockwork
The movement of the
earth on its elliptical path
around the sun and its own
axis is the gigantic cosmic
clockwork, which powers the
sundial - accurately and consistently.
The pointer is the sun's rays, which every
single moment are arriving from a different
direction to land on the sundial's mirror.
Look at a snapshot of 1 May 2002
at 16:00 hours CET (summer time) and
follow the sun's rays from the sun until they
land on the sundial's scale in three zoom
illustrations.
First zoom: The sun's ray, extended to go through the
centre of the earth, shows the location at which the
sun stands in its zenith. Its direction is called the
geocentric position of the sun.
