Solar Tracking

For many centuries, the time of day was found using stars and the sun.Sundials could be found on many public buildings, so that people could easily find out what time it was. A sundial is a very simple device to build. An inclined stick, called a gnomon, is attached to a flat surface, known as the dial plate. The angle that the gnomon will make with the dial plate is equal to the degrees of latitude. The gnomon will always be aligned with the longitude lines of the earth, pointing toward true north, which can be found using the location of Polaris, the North Star. The dial plate will have lines on it, each indicating an hour. The position of the lines depends on the latitude of the position of the sundial.

When the sun is shining on the sundial, the gnomon will cast a shadow on the dial plate. If the hour lines are placed correctly, the shadow will be show the time on the dial plate. Because different locations have different latitudes and elevations, a sundial must be created for each specific area.

Some More Information on Sundials

Sundials

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