Soondial

This is a delightful timepiece to embellish the wall of your home or office. As the earth rotates around the sun, it acts as an hour hand; as it spins on its on axis, the minutes can be read; as the moon rotates around the earth, it becomes a secondhand. The “sunlamp” causes shadows that depict earth night and new moon.

The opaque, convex, sun disc supports, illuminates and provides power to the moving earth and moon. The sun, with roman numerals on its rim, is circled by the earth disc twice a day, and the thin rod that connects them points to the hour. The earth also spins counterclockwise, one revolution per hour, so that the numbers on its edge, lined up against the same rod, reveal the minutes.

From the earth’s axis extends a second rod that moves the moon clockwise around the earth once every minute. Pointing to the numbers on the earth’s perimeter, it acts as a secondhand.

This clock is not an astronomical model, reflecting relative speeds, sizes, directions, etc., but telling time has never been so enlightening or so much fun.