Eternal India Encyclopedia

Eternal India encyclopedia

Ancient Concepts, Sciences & Systems

ASTRONOMY

copied within the 17th, 18th and 19th centuries; for manuscripts cannot long survive in India except under exceptional circum- stances. We have, therefore, essentially those texts selected for study or composed by the scholars of the Mughal and British rajyas." The sun was regarded in Vedic literature as the most important heavenly object and its path, the ecliptic, was considered sacred. The moon was the next most important and became the obvious choice for time calculation. It was referred to as "maker of the month" - the interval between two consecutive new moons or full moons. There were two systems of reckoning the month based on the new moon ( amanta ) and the full moon ( pumimanta ). The moon's path was observed in relation to the 27 Nakshatras (Lunar mansions) or asterisms and the lunar zodiac was well determined. The moon spends a day in each nakshatra and momen- tarily comes into a state of conjunction with the most conspicuous star in the group of stars. The names of the lunar months were given on the basis of the Nakshatra on which the full moon occurred. The 12 lunar months were divided into six seasons of two months each. There were also special names for the solar months.

Curiosity about the celestial objects arose in the human mind from the very dawn of consciousness. Systematic efforts to under- stand the celestial phenomena were made in all the advanced civilisations in the past. Obvious manifestations of these are in the form of day-night cycles, seasonal north-south movements of the sun, and systematic motions of the moon and planets among the stars. Only in recent centuries studies included distant stars, stellar systems and galaxies. Cosmology or the studies of the universe was in the human mind from the very early days but the form and content of the subject have undergone a sea-change in recent times. In India the earliest records of such thinkings can be found among the Vedas (Vedanga Jyotisha, earlier than 1st millenium B.C.) as well as in following eras (Jaina Jyotisha, 1st millenium B.C. and Siddhanta Jyotisha 1st Millenium A.D.) until the days when a feedback of Arabian studies influenced Indian astronomical efforts - Zij Astronomy, 2nd millenium A.D. Development in this field during the Siddhanta period had greatly influenced Arab ef- forts during the middle ages. Modern Astronomy may be stated to begin with Copernicus (1473-1542), followed by Tycho Brahe (1546-1601), Kepler (1571-1630), Galileo (1564-1642), and Newton (1642-1727). The subject in its new form was introduced by the Europeans from the seventeenth century onwards in India. The ancient Indian astronomers were primarily interested in the study of the motions of the sun and moon in order to develop a working calendar to determine the time for the performance of sac- rifices, religious observances, festivities, marriages and agricul- tural operations. Improved astronomical knowledge following the invasion of India by Alexander in 326 B.C and subsequent contacts with for- eign savants gave place to a new system of astronomy called the Surya Siddhanta which superseded the Vedanga Jyotisha by A.D. 400. The Vedic people took the Sun as the sole light giver of the universe, the cause of the seasons, winds, controller and the lord of the world. The Moon was described as suryarashmi, one which shines by the Sun's light. Different phases of the Moon viz raka (full-moon day), anumati (day preceding full-moon), kuhu (new moon day), sinivali (day preceding new moon) etc. were known. The Taittiriya Brahmana gives a full list of names of 15 days of the light half (purva paksha ) and also of dark half ( aparapaksha ). The day was called vasava or aha and reckoned from sun-rise to sun- rise. The day was further divided into different parts. The period from one moon-rise to the next or from one moon-set to the next was known as tithi (lunar day), which is somewhat different from the present concept of a tithi of fixed time. That the phenomenon of new and full-moon is related to Moon's elongation from the Sun was also correctly guessed. The invisibility of the Moon on the new-moon day is explained by its being swallowed by the Sun and its appearance by its being released by the Sun. The importance attached to the study of astronomy is borne out by the number of surviving manuscripts on various aspects of Jyotishastra. David Pingree who has conducted an extensive sur- vey of the literature of Indian astronomy states : "At present there exist in India and outside of it some 100,000 manuscripts of the various aspects of Jyotishastra. The great majority of these were

The 12 lunar months and the corresponding solar months were:

Caitra (Mar. - Apr.)

- Madhu

Vaishakha (Apr. - May)

- Madhava

Jyaishtha (May - June)

- Shukra

Ashadha (June - July)

- Shuci

Shravana (July - Aug.)

- Nabha

Bhadrapada Prausthapada (Aug. - Sept.) - Nabhasya

Ashvina or Ashvayuja (Sept. - Oct.)

- Isa

Kartika (Oct. - Nov.)

- Urja

Margashirsa or Agrahayana (Nov. - Dec.) - Saha

Pausha or Taisha (Dec. - Jan.)

- Sahasya

Magha (Jan.- Feb.)

- Tapa

Phalguna (Feb. - Mar.)

- Tapasya

The six seasons of the year were:

Vasanta

(Spring, Mar. - May)

Grishma

(Summer, May - July)

Varsha

(the rains, July - Sept.)

Sharad

(Autumn, Sept. - Nov.)

Hemanta

(Winter, Nov. - Jan.)

Shishira

(the cool season, Jan. - Mar.)

In recording dates the basic unit was the tithi or lunar day, ap- proximately 30 of which formed a lunar month of 29 1/2 solar days. The month was divided into two halves (paksha) of 15 tithis each beginning with the full (purnamavasya) or new ( amavasya ) moons respectively. In northern India and most of the Deccan the month began and ended with the full moon, while in the Tamil and south- ern parts the new moon marked the beginning of the month. Twelve lunar months total about 354 days. Sixty-two lunar months are approximately equal to sixty solar months. So every thirty months an extra month was added to the year. This leap