The Almagest star catalog (ASC) has for centuries invited speculation about who actually compiled it. Of its many curious features, the fact that the catalog contains no stars which are visible in Alexandria but not visible in Rhodes suggested to Delambre that perhaps the catalog was actually compiled by Hipparchus, who is known to have lived in Rhodes (at about 36° north latitude), and not by ...

1. INTRODUCTION. In his Almagest, Ptolemy inscribes triangles in a unit circle, a circle with diameter d = 1 (see [5], pp. 90–92). This way the length of each side (now chord) represents the value of the trigonometric function sine of the opposite angle. A similar geometric interpretation of the cosine function is possible. In Figure 1 we present Ptolemy's famous sketch, juxtaposed with a " dua...

Zusammenfassung Der Almagest, das astronomische Hauptwerk des Klaudios Ptolemaios, arbeitet mit teilweise komplexen Bewegungsmodellen für die sieben Himmelskörper, keine Fixsterne sind. Zwei davon, nämlich Modelle Sonne und Mond, können als Paradigmen angesehen werden. Sie werden hier detailliert behandelt, wobei Bestimmung der Parameter sowie Bahnen Geschwindigkeiten besonders berücksichtigt

Contemporary research on the problem of chaotic motions in dynamical systems finds its roots in the Aristotelian idea, often presented as kind of funny in high schools, that motions can always be considered as composed by circular uniform motions,. The reason of this conception is the perfection and simplicity of such motions (of which the uniform rectilinear motion case must be thought as a li...

1. Chronological remarks. The main source for our knowledge of ancient astronomy is Ptolemy. His Mathematical composition, commonly known as the Almagest, quotes observations of his own ranging from 127 to 142 A.D. [35; 36; 37]. This work seems to be the earliest of a whole series of fundamental works, such as his Geography [41 ], the Tetrabiblos [39; 40], and so on, whose influence on mediaeva...