This model shows the solar system as it was believed to be in early times. The main focus of the Ptolemaic (geocentric) solar system is to explain the various motions of the nearest planets and the sun. Planets are moved by hand in epicycles. These motions were conceived by Ptolemy to explain the idea of a system in which the Earth was at the center of the universe - an idea which we know today to be erroneous. However wrong it was, this concept was accepted for many years. It was not until the 16th century that Nikalaus Kopernik (Copernicus) published a book which revolutionized the world of science with his concept of a sun centered universe. The Copernican Solar System model (SOL- 100) is also useful in comparison to the Ptolemaic Solar System, because it provides a more complete understanding of the earlier and later theories of our relationships in the solar system. An instruction book, Worlds in Motion, is included with this model.   Shipping Weight 5 lbs

Portable desktop Planetariums have been produced for over 90 years by Trippensee.  They provide many visual demonstrations that clarify the relationships of the solar system elements in motion, for children and adults interested in learning more about the universe around them. Perfect for school or as home planetarium.