History of Astronomy

Since ancient days people used to look at the sky with a sense of wonder. The tried to explain what the saw in the sky. From the rising and setting of the sun, the twinkling of the stars, shooting stars, comets, all these caught their imagination as the tried to device theories to explain their observations. The field of Astronomy thus began.

Many ancient civilizations are known to have observed and studied the heavens. They are, the ancient Indians, The Babylonians, the Greeks, the Chinese, the Persians and the Egyptians. Modern astronomy has it roots in ancient Greek Astronomy. However Greeks borrowed many of their ideas from other civilizations.

An ancient Chinese star chart:Modern Astronomy can be classified into three major periods

1. First Period: Ancient Greek (500BC to 150AD)

2. Second Period: Ptolemy to Copernicus and Islamic Astronomy (150AD to 1545AD)

3. Third Period: Copernicus to the 20th century

First Period

During this period, The physics of Aristotle and the assumptions of Plato were highly regarded. It was believed that we live in a Geo-centric universe, i.e The Earth lies in the centre of the universe and the heavenly bodies revolve around the Earth.

Using this system there were discrepancies between theory and observation. To solve this Ptolemy brought forward the theory of epicycle and deferent.

During this time Greek astronomer Aristarchus presented a Helio-centric model of the universe but was immediately rejected.

Important Achievements during this period include, Preparation of star catalogs and the compilation of Ptolemy's "Almagest" the great mathematical and astronomical treatise.

The Geo-centric model:

Second Period

During this period the Islamic civilization took a wide ranging interest in the Sciences and produced a vast range of Scientific and technological advancements. During this period, the Greek texts including the Almagest was translated into Arabic. The added onto the existing knowledge improving the star catalogs prepared by the Greeks.

Also for the first time in history the Islamic astronomers built Observatories in order to observe the skies better.

The Arabic texts were also translated to Latin Through which many sciences were communicated during this period.

Third Period

Nicolaus Copernicus presented the helio centric system but was met by serious rejection.

Galileo Galilei constructed the first telescope and used it to observe the moon and the planets. He was the first person to see the moons of Jupiter.

Galileo stood by and supported Copernicus's ideas and faced opposition by the Catholic Church.

Kepler, by using Brahe's data and by careful observation cemented the understanding of the universe and also devised three laws governing planetary motion.

Sir Isaac Newton with his laws of motion an theory of Gravity explained planetary motion. He also contributed to the development of optics and constructed the reflective telescope.

During the times of Herschel and Caroline telescopic astronomy boomed and it marked the discovery of Uranus and Neptune.

With the development of Spectroscopy it was used in astronomy to determine the composition of the universe.

With Albert Einstein's theory of Relativity and Quantum Theory Picture we have of the universe was further clarified while uncovering more horizons to explore.

With the development of technology, increasingly powerful telescopes, like the Hubble Space telescope which is placed in earths orbit., our understanding of the universe is still expanding.