Al-Beruni reserved his praise for the Hindu scientific knowledge of the age. Incidentally, it is actually a testimony to the openness of Indian learned community of the age that in spite of being a mlechcha (at the sight of whom Indians supposedly clammed up) Al-Beruni could gather all these details: “….the number of Hindu sciences is great but the science of astronomy is the most famous and most cherished of all.
Astronomical literature consists of the Siddhantas called the Sind-Hind by the Muslims….The Siddhantas are derived from the book- Pitamaha-so called from the first father, i.e., Brahman of the five Siddhantas, enumerated by him…”
He was presumably aware that in the eighth century Arab scholars came to India to learn astronomy, chemistry, mathematics, medicine, philosophy, etc. and that the Brahma-sphuta-siddhanta and Khanda-Khanduka of Brahmagupta were taken to
Baghdad during the caliphate of Mansur and were translated into Arabic by Indian scholars. “…The Hindus unlike other nations go beyond the thousand in their arithmetical terms….according to some, bhuri or the nineteenth order is the limit of reckoning while -according to others the koti…”
ADVERTISEMENTS:
Al-Beruni stated that the place value system of writing numbers is a Hindu contribution to mathematics (positional notation) and knew of the advances made by Indian mathematicians in the science of measurements when he said that “….(the Hindus) hold that the circumference of a circle is three times its diameter, but, according to Brahmagupta 3 1/3 times the diameter….”
The astronomical knowledge of the Indians, perfected over the centuries, was expressed in the famous work the Surya Siddhanta. It contained accurate values of astronomical constants like the periods of revolutions of the sun, the moon and the planets and the methods for the prediction of eclipses, planetary conjunctions, etc., Al-Beruni referred to all this in his work.