Astronomy
Ptolemy (Claudius Ptolemaeus) [b. possibly at Ptolemais Hermae (Acre, Israel), c. 85 ce, d. c. 165] writes Syntaxis mathematica ("mathematical collection"), best known by its Arabic name, Almagest, about this time. It becomes the most important text on astronomy during the Middle Ages. In it, Ptolemy catalogs constellations, stars, and nebulae visible to the naked eye and provides a description of how planets move based on circles and epicycles of motion about a fixed Earth. See also 350 bce Astronomy; 1543 ce Astronomy. (See essay.)
Earth sciencePtolemy's Geographia ("geography"), written about this time, includes an atlas of the known world based on the travels of Roman legions. See also 20 ce Earth science.
PhysicsIn his Optics Ptolemy includes the earliest surviving table of the angles of incidence for refraction from air to water. Often called the most remarkable experimental research of Antiquity, the table, with probably the exception of the 40.5 degrees for the refraction angle for an angle of incidence of 60 degrees, is actually computed according to an arithmetic series of the second order (essentially a quadratic function) and is not especially close to measured values. See also 40 bce Physics
