An Historical Exploration of Modern Astronomy

Abstract

There were two principal factors which motivated the people of ancient times to concern themselves with the stars: the link of celestial objects with religious concepts, and the everyday need to determine the time. First cosmological ideas we see in the geocentric system of Claudius Ptolemy (100 – 160 BC) based on the physics of Aristoteles (384 – 322 BC) and the geometric thoughts of Greek thinkers during the fourth century BC. Ptolemy’s model was strong enough to survive more than 1400 years. The instruments and observing methods in astronomy remained basically the same throughout and past the Middle Ages. The study of the motions of celestial objects was paramount to ancient and medieval astronomers. With the invention of the telescope early in the seventeenth century, progress in astronomy underwent a spectacular advance: a detailed physical exploration of celestial bodies could now be pursued. The evolution of astronomy into a highly specialized science began in the nineteenth century, as the introduction of spectral analysis, photometry, and photography made astrophysics a major part of astronomy. The limitations of optical astronomy were overcome in the twentieth century, when radio telescopes and space-borne instruments made the entire spectrum of electromagnetic waves accessible.