Aquest dibuixa la ruta traçada per un punt en la vora d' un cercle. Aquest cercle gira al voltant de la vora d' un altre cercle i així vàries vegades. Aquestes eren les bases del model de moviment planetari pre- heliocèntric. http: // en. wikipedia. org/ wiki/ Deferent_ and_ epicycle Escrit per James Youngman; 1998.
This draws the path traced out by a point on the edge of a circle. That circle rotates around a point on the rim of another circle, and so on, several times. These were the basis for the pre-heliocentric model of planetary motion. http: / /en. wikipedia. org/ wiki/ Deferent_and_epicycle Written by James Youngman; 1998.