Foreword by the mathematician Christina Fili , Professor at the National Technical University of Metsovia.

The work of Geminus of Rhodium "Introduction to the study of celestial phenomena" regardless of any interventions by the various later copyists is an elegant and strictly founded astronomical treatise, which contains 18 sections and a zodiacal calendar with the weather indications of various astronomers.

Geminis presents in this work the astronomical knowledge of his time which causes admiration to every scholar for their scientific breadth and correctness. Except that the astronomy presented by Gemini is based on geocentric theory, almost all of Gemini 's astronomical observations, observations and presentations are correct. And if we still consider the solstices, equinoxes, the movements of the Sun, the Earth and the Moon, the zones of the celestial sphere and the Earth, the phases of the Moon, etc. as trivial theories, since they were raised by earlier astronomers, ., we must confess that findings of this kind cause great excitement to every scholar:

a) The Earth is spherical.

b) The Sun is a fiery spherical mass.

c) The simple stars consist of the same "substance" as that of the Sun.

d) The Moon is a heteroluminous body.

e) The Earth has a point position with respect to the Universe.

f) The number of plain stars is infinite, etc.

Findings that astonish all those historians of science, who, from the point of view of astronomical knowledge of the 19th or 20th century, naively characterize this monumental work of the 1st BC. century as a modest work of descriptive astronomy.