Ancient India

"India was the motherland of our race and Sanskrit the mother of Europe's languages. India was the mother of our philosophy, of much of our mathematics, of the ideals embodied in christianity... of self-government and democracy. In many ways, Mother India is the mother of us all."

- Will Durant- American Historian 1885-1981

“We owe a lot to the Indians, who taught us how to count, without which no worthwhile scientific discovery could have been made”

Albert Einstein

India never invaded any country in her last 10,000 years of

history.

Astrology and astronomy

Astrology and astronomy were archaically one and the same discipline (Latin: astrologia), and were only gradually recognized as separate in Western 17th century philosophy(the "Age of Reason").Since the 18th century they have come to be regarded as completely separate disciplines

Astronomy: the study of objects and phenomena originating beyond the Earth's atmosphere, is a science

and is a widely-studied academic discipline.

Astrology: which uses the apparent positions of celestial objects as the basis for psychology, prediction of future events, and other esoteric knowledge, is not a science and is typically defined as a form of divination.

India's Contribution to - ASTRONOMY 

"In India I found a race of mortals living upon the Earth. but not adhering to it. Inhabiting cities, but not being fixed to them, possessing everything but possessed by nothing". - Apollonius Tyanaeus

Greek Thinker and Traveller 1st Century AD

In India the first references to astronomy are to be found in the Rig Veda which is dated around 2000 B.C

The Calculation of Eclipses And The Earth's Circumference

The Heliocentric Theory of Gravitation

This fascmile is from the Pancha-siddhantika (Five Principles) dated around the 5th century. This text graphically shows how eclipses are to be calculated.  Thus this text foreshadows  what Westeren Astronomers propounded nearly one thousand years later

Astronomers

Lagadha• The earliest astronomical text—named Vedānga Jyotiṣa

—dates back to around 1200 BCE, and details several astronomical attributes generally applied for timing social and religious events. The Vedānga Jyotiṣa also details astronomical calculations, calendrical studies, and establishes rules for empirical observation.Since the texts written by 1200 BCE were largely religious compositions the Vedānga Jyotiṣa has connections with Indian astrology and details several important aspects of the time and seasons, including lunar months, solar months, and their adjustment by a lunar leap month of Adhimāsa. Ritus and Yugas are also described. Tripathi (2008) holds that ' Twenty-seven constellations, eclipses, seven planets, and twelve signs of the zodiac were also known at that time.

(2nd–1st millennium BCE)

Map of northern India in the late Vedic period

Aryabhata

Statue of Aryabhata on the grounds of IUCAA, Pune.

Born 476Died 550Era Gupta eraRegion India

Main interests

math, astronomy

Major worksĀryabhaṭīya, Arya-siddhanta

Aryabhata was the author of the Āryabhatīya and the Aryabhatasiddhanta, which, according to Hayashi (2008): 'circulated mainly in the northwest of India and, through the Sāsānian dynasty (224–651) of Iran, had a profound influence on the development of Islamic astronomy. Its contents are preserved to some extent in the works of Varahamihira (flourished c. 550), Bhaskara I (flourished c. 629), Brahmagupta (598–c. 665), and others. It is one of the earliest astronomical works to assign the start of each day to midnight.

'Aryabhata explicitly mentioned that the earth rotates about its axis, thereby causing what appears to be an apparent westward motion of the stars. Aryabhata also mentioned that reflected sunlight is the cause behind the shining of the moon. Ayrabhata's followers were particularly strong in South India, where his principles of the diurnal rotation of the earth, among others, were followed and a number of secondary works were based on them.

Brahmagupta (598–668 CE)

Brahmasphuta-siddhanta (Correctly Established Doctrine of Brahma, 628 CE) dealt with both Indian mathematics and astronomy. Hayashi (2008) writes: 'It was translated into Arabic in Baghdad about 771 and had a major impact on Islamic mathematics and astronomy.' In Khandakhadyaka (A Piece Eatable, 665 CE) Brahmagupta reinforced Aryabhata's idea of another day beginning at midnight.Bahmagupta also calculated the instantaneous motion of a planet, gave correct equations for parallax, and some information related to the computation of eclipses. His works introduced Indian concept of mathematics based astronomy into the Arab world.

A simplified illustration of the parallax of an object against a distant background due to a perspective shift. When viewed from "Viewpoint A", the object appears to be in front of the blue square. When the viewpoint is changed to "Viewpoint B", the object appears to have moved in front of the red square.

Stellar parallax motion

Varāhamihira (505 CE)

was an astronomer and mathematician who studied and Indian astronomy as well as the many principles of Greek, Egyptian, and Roman astronomical sciences.His Pañcasiddhāntikā is a treatise and compendium drawing from several knowledge systems.

Bhāskara I (629 CE)

Authored the astronomical works Mahabhaskariya (Great Book of Bhaskara), Laghubhaskariya (Small Book of Bhaskara), and the Aryabhatiyabhashya (629 CE)—a commentary on the Āryabhatīya written by Aryabhata. Hayashi (2008) writes 'Planetary longitudes, heliacal rising and setting of the planets, conjunctions among the planets and stars, solar and lunar eclipses, and the phases of the Moon are among the topics Bhaskara discusses in his astronomical treatises.'Baskara I's works were followed by Vateśvara (880 CE), who in his eight chapter Vateśvarasiddhānta devised methods for determining the parallax in longitude directly, the motion of the equinoxes and the solstices, and the quadrant of the sun at any given time.

Lalla (8th century CE)

Author of the Śisyadhīvrddhida (Treatise Which Expands the Intellect of Students), which corrects several assumptions of Āryabhata. The Śisyadhīvrddhida of Lalla itself is divided into two parts:Grahādhyāya and Golādhyāya.Grahādhyāya (Chapter I-XIII) deals with planetary calculations, determination of the mean and true planets, three problems pertaining to diurnal motion of Earth, eclipses, rising and setting of the planets, the various cusps of the moon, planetary and astral conjunctions, and complementary situations of the sun and the moon.The second part—titled Golādhyāya —deals with graphical representation of planetary motion, astronomical instruments, spherics, and emphasizes on corrections and rejection of flawed principles.Lalla shows influence of Āryabhata, Brahmagupta, and Bhāskara I.His works were followed by later astronomers Śrīpati, Vateśvara, and Bhāskara II. Lalla also authored the Siddhāntatilaka.

Bhāskara II (1114 CE)

Authored Siddhāntaśiromaṇi (Head Jewel of Accuracy) and Karaṇakutūhala (Calculation of Astronomical Wonders) and reported on his observations of planetary positions, conjunctions, eclipses, cosmography, geography, mathematics, and astronomical equipment used in his research at the observatory in Ujjain, which he headed.

Bhaskaracharya calculated the time taken by the earth to orbit the sun hundreds of years

before the astronomer Smart.

Time taken by earth to orbit the sun: (5th century) 365.258756484 days

Using an astronomical model developed by Brahmagupta in the 7th century, Bhaskara accurately defined many astronomical quantities, including, for example, the length of the sidereal year, the time that is required for the Earth to orbit the Sun, as 365.2588 days which is same as in Suryasiddhanta. The modern accepted measurement is 365.2563 days, a difference of just 3.5 minutes.

Aryabhata II (c. 920 – c. 1000)

was an Indian mathematician and astronomer, and the author of the Maha-Siddhanta. The numeral II is given to him to distinguish him from the earlier and more influential Āryabhaṭa I.

Śrīpati (1045 CE)

Śrīpati was a astronomer and mathematician who followed the Brhmagupta school and authored the Siddhāntaśekhara (The Crest of Established Doctrines) in 20 chapters, thereby introducing several new concepts, including moon's second ineuqlity.

Mahendra Sūri (14th century CE)

Mahendra Suri authored the Yantra-rāja (The King of Instruments, written in 1370 CE)—a Sanskrit work on the astrolabe, itself introduced in India during the reign of the 14th century Tughlaq dynasty ruler Firuz Shah Tughluq (1351–1388 CE). Suri seems to have been a Jain astronomer in the service of Firuz Shah Tughluq.The 182 verse Yantra-rāja mentions the astrolabe from the first chapter onwards, and also presents a fundamental formula along with a numerical table for drawing an astrolabe although the proof itself has not been detailed.Longitudes of 32 stars as well as their latitudes have also been mentioned.Mahendra Suri also explained the Gnomon, equatorial co-ordinates, and elliptical co-ordinates.The works of Mahendra Suri may have influenced later astronomers like Padmanābha (1423 CE)—author of the Yantra-rāja-adhikāra, the first chapter of his Yantra-kirnāvali.

Nilakantha Somayaji (1444–1544 CE)

In 1500, Nilakanthan Somayaji of the Kerala school of astronomy and mathematics, in his Tantrasangraha, revised Aryabhata's model for the planets Mercury and Venus. His equation of the centre for these planets remained the most accurate until the time of Johannes Kepler in the 17th century.Nilakanthan Somayaji, in his Aryabhatiyabhasya, a commentary on Aryabhata's Aryabhatiya, developed his own computational system for a partially heliocentric planetary model, in which Mercury, Venus, Mars, Jupiter and Saturn orbit the Sun, which in turn orbits the Earth, similar to the Tychonic system later proposed by Tycho Brahe in the late 16th century.

Nilakantha's system, however, was mathematically more effient than the Tychonic system, due to correctly taking into account the equation of the centre and latitudinal motion of Mercury and Venus. Most astronomers of the Kerala school of astronomy and mathematics who followed him accepted his planetary model. He also authored a treatise titled Jyotirmimamsastressing the necessity and importance of astronomical observations to obtain correct parameters for computations.

Achyuta Pisharati (1550–1621 CE)

Sphutanirnaya (Determination of True Planets) details an elliptical correction to existing notions.Sphutanirnaya was later expanded to Rāśigolasphutānīti (True Longitude Computation of the Sphere of the Zodiac).Another work, Karanottama deals with eclipses, complementary relationship between the sun and the moon, and 'the derivation of the mean and true planets'.In Uparāgakriyākrama (Method of Computing Eclipses), Acyuta Pisārati suggests improvements in methods of calculation of eclipses.

THE END