Āryabhaṭīya

The Āryabhaṭīya is a composition of Āryabhaṭa.

This Āryabhaṭa is a different person from his namesake of the tenth century A.D., the author of the Mahā-Siddhānta. To distinguish between the two, the author of the Āryabhaṭīya is called Āryabhaṭa I, and the author of the Mahā-Siddhānta is called Āryabhaṭa II.

It is Āryabhaṭa I, author of the Āryabhaṭīya , after whose name the first Indian satellite was designated 'Āryabhaṭa' and put into orbit on April 19, 1975.

Contents

The Āryabhaṭīya deals with both mathematics and astronomy. It contains 121 stanzas in all, and is marked for brevity and conciseness of composition. At places its style is aphoristic and the case endings are dispensed with. Like the Yoga-darśana of Patañjali, the subject matter of the Āryabhaṭīya is divided into 4 chapters, called Pāda (or Section).

Pāda 1 (viz., Gītikā-pāda), consisting of 13 stanzas (of which 10 are in gītikā metre), sets forth the basic definitions and important astronomical parameters and tables. It gives the definitions of the larger units of time (Kalpa, Manu and yuga), the circular units (sign, degree and minute) and the linear units (yojana, hasta and aṅgula); and states the number of rotations of the Earth and the revolutions of the Sun, Moon and the planets etc. in a period of 43,20,000 years, the time and place from which the planets are supposed to have started motion at the beginning of the current yuga as well as the time elapsed since the beginning of the current Kalpa up to the beginning of Kaliyuga, the positions of the apogees (or aphelia) and the ascending nodes of the planets in the time of the author, the orbits of Sun, Moon and the planets including the periphery of the so-called sky, the diameters of the Earth, Sun, Moon and the planets, the obliquity of the ecliptic, and and the inclinations (to the ecliptic) of the orbits of the Moon and the planets, the epicycles of the Sun, Moon and the planets, and a table of sine-differences.

Pāda 2 (viz. Gaṇita-pāda), consisting of 33 stanzas, deals with mathematics. The topics dealt with are the geometrical figures, their properties and mensuration; problems on the shadow of the gnomon; series; interest; and simple, simultaneous, quadratic and linear indeterminate equations. The arithmetical methods for extracting the square root and the cube root and rules meant for certain specific mathematical problems including the method of constructing the sine table are also given.

Pāda 3 (viz. Kālakriyā-pāda), containing 25 stanzas, deals with the various units of time and the determination of the true positions of the Sun, Moon and the planets. It gives the divisions of the year (month, day, etc.) and those of the circle; describes the various kinds of year, month and day; defines the beginning of the time-cycle, the so-called circle of the sky, and the lords of hours and days; explains the motion of the Sun, Moon and the planets by means of eccentric circles & the epicycles and gives the method for computing the true longitudes of the Sun, Moon and the planets.

Pāda 4 (viz. Gola-pāda), consisting of 50 stanzas, deals with the motion of the Sun, Moon and the planets on the celestial sphere. It describes the various circles of the celestial sphere and indicates the method of automatically rotating the sphere once in twenty-four hours; explains the motion of the Earth, Sun, Moon and the planets; describes the motion of the celestial sphere as seen by those on the equator and by those on the north and south poles; and gives rules relating to the various problems of spherical astronomy. It also deals with the calculation and graphical representation of the eclipses and the visibility of the planets.

See Also

आर्यभटीय