Indian Astronomy After the fall of the Roman Empire and decline of ancient Middle-Eastern science as a whole, science began to thrive (c.320 AD onward) in India. This transfer of science was as a saving grace, fostering knowledge during the dark age of barbarism that afflicted Europe and the Middle East after the final collapse of the Roman Empire. The contributions made by Indian mathematicians and astronomers towards world scientific achievement were second only to those of the Greeks. Indians developed the number symbols which served as a basis for our own 'Arabic' numerals. These were only called 'Arabic' numerals by Western medieval scholars; they were really Hindi in origin and were adopted and carried westward by Arab traders and invaders. Indian scholars pioneered the decimal system and (apart from the Maya Indians) were probably the first Eurasians to employ a symbol for zero, which the Arabs later developed the use of.
Arabic Astronomy. The Arabs once ruled an empire that stretched from central Asia to Spain. This empire reached its zenith between the eighth and thirteenth centuries AD. Arab scholars of that period knew more about science and the arts than any other contemporary peoples. They also translated many classical (Greco-Roman) works of literature and science.
Rhazes (al Razi-C. ninth century), Vienna (Ibn Sina-c. tenth century) and Averroes (1126-1198) were among the best known of Muslim philosophers. They studied the great Greek writers, particularly Plato and Aristotle. Eventually much of the scientific knowledge that the Muslims had gathered from the ancient classical world and from India was passed to the west, through Spain and southern Italy, around the time of the Crusades. At that time most European scholars realized the tremendous scientific and technological superiority of the Islamic world and eagerly sought translations of Muslim works.
Greek and Arab writings that flowed into Europe, especially after the beginning of the twelfth century, made up a rich legacy of scientific and philosophical knowledge. Arabic (Hindi) numerals and the zero symbol made possible a decimal system of computation. Euclidean geometry, together with algebra and trigonometry from the Arab world, greatly increased the scope and accuracy of mathematics, useful for astronomical applications during and after the Renaissance. Some modern historians believe the writings of the great Copernicus (the first westerner to propose an heliocentric planetary system) show much attributable to early Muslim astronomers.