Ptolemy, however, claimed to have derived his geometrical models from selected astronomical observations by his predecessors spanning more than 800 years, though astronomers have for centuries suspected that his models' parameters were adopted independently of observations.
Ptolemæus hævdede dog at have udledt sine geometriske modeller fra udvalgte astronomiske observationer fra hans forgængere spændende over mere end 800 år, men astronomerne har i århundreder haft mistanke om, at hans modellernes parametre blev taget uafhængigt af observationer.