Greek Astronomy

Humans’ perpetual fascination with what lies beyond our own horizons have translated into a process of philosophical and scientific search for truth, and formed the foundations of modern astronomical science and astrophysics.

The study of space, its objects and characteristics has in fact been one of the oldest systematic pursuits of human knowledge and understanding, and it can be traced back to some of the most ancient civilizations. Knowledge of the stars was never merely a fancy of dreamers or philosophers; it had consequences in practical affairs, most notably in seafaring and navigation.

While certainly not the first, Greek astronomy is one of the best and most influential efforts of man to understand the vast reaches of the universe. In fact, the very term “astronomy” comes from the combination of two Greek terms, “astron” (star) and “nomos” (law), meaning “law(s) of the stars.” The Greek astronomers and mathematicians–since in Greece and the Hellenistic world, astronomy was a subdivision of mathematics–have devised the two-sphere model of the universe, consisting of the “sublunar” sphere of the Earth as a round, motionless object, on which the celestial sphere with all the celestial objects (the planets, stars, the Moon, the Sun) were centered. This is known as geocentrism, i.e. Earth-centrism, since the Earth was the center of the Universe.

The European Renaissance period saw a resurgence in scientific endeavor, including astronomy, and the use of increasingly precise optical technology to observe celestial objects otherwise outside the natural sight of the eye. Renaissance and early modern astronomers, such as Copernicus, Galileo, and Kepler made tremendous theoretical and observational innovations in the field of astronomy, including the discovery that the Earth revolves around the Sun, rather than the other way around (also known as a heliocentric theory of the universe).

Contemporary astronomy, which makes full use of all that optical physics and modern technology has to offer, has made extensive space exploration, the discovery and mapping of billions of celestial objects and phenomena, and even such phenomenal achievements as man’s landing on the Moon possible.