BA PART I : PAPER 3.7

Basis Vedanga Astronomy

INFRASTRUCTURE OF THE KALPA PERIOD

Table III shows the infrastructure of the kalpa period. The kalpa period is 4320000000 sidereal years made up of 1000 caturyugas of 4320000 years or 10000 kaliyugas of 432000 years. An additional unit, the manu, an interval of 71 caturyugas with an added twilight of 1728000 years, is made to fit into the kalpa 14 times along with an introductory dawn of 1728000 years.

INTERVAL CATURYUGAS KALIYUGAS SIDEREAL YEARS

introductory dawn 0.4 4 1728000

71 caturyugas 71.0 710 306720000

a twilight 0.4 4 1728000

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1 manu 71.4 714 308448000

14 manus 999.6 7 (1428)=9996 4318272000

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1 kalpa 1000.0 10000 4320000000

7. BRAHMA'S LIFE

The kalpas are said to alternate between "days of Brahma" and "nights of Brahma". During the night of Brahma all sentient creatures meet their Maker. But after one hundred 360 day years of days and nights of Brahma, even the matter in the solar system, which has served as the "body" of Brahma, is resolved into chaos. Finally, after an interval of time equal to his life, Brahma and the solar system are again reborn.

day of Brahma 4320000000 sidereal years

night of Brahma 4320000000 sidereal years ----------

Total 8640000000 sidereal years

days in a year נ360 -----------

one year of Brahma 3.1104ױ012 sidereal years

one hundred years נ100 -----------

Brahma's Life 3.1104ױ014 sidereal years.

Brahma's Death 3.1104ױ014 sidereal years.

And thus, the Hindu cosmological time cycles are completed.

THREE MEAN MOTIONS OF THE SUNThe three mean motions of the Sun used in the construction of Hindu cosmological time cycles are

1 sidereal year = 360 (I)

6 (II)

0.2563795... (III)

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366.2563795... diurnal revolutions of the Earth.

As the number of diurnal revolutions of the Earth in a year is one greater than the number of mean solar days, we also have1 sidereal year = 365.2563795... mean solar days.The three mean motions are like the hour, minute, and second hands of a clock. Their cycles are completed and counted separately. Using the three mean motions, the ancients developed a system of time reckoning that put the day, year, and longer time intervals into exact correspondence with each other.

ASTRONOMICAL BASIS OF THE SEXAGESIMAL NUMBER SYSTEM

The first two mean Solar motions, a year consisting of 360 + 6 Earth revolutions, generate the sexagesimal number system in its entirety. These two mean motions of the Sun form the basis for the 366 day year of the Jyotisha Vedanga and are discernible in the SuryaSiddhanta from the fact that the radius of the orbit of the asterisms is given as 60 times that of the Sun. Since in this astronomical system the speed of rotation of a body varies as the inverse of the radius of its orbit, this implies that the asterisms should rotate six degrees while the Sun is rotating 360 degrees.11. DEMONSTRATION OF THE SEXAGESIMAL NUMBER SYSTEMA count of six for every 360 is equivalent to one for every 60. This is the basic counting principle behind the six Indian seasons.Counting six days per year , the second mean motion of the Sun completes a cycle of 360, the number of degrees in a circle, after 60 years (the Babylonian sossos).

YEAR 1ST MEAN MOTION 2ND MEAN MOTION TOTAL

1 360 6 366

2 720 12 732

3 1080 18 1098

4 1440 24 1464

5 1800 30 1830 . . . . . . . . . . . .

^

^

10 3600 60 3660 . . . . . . . . . . . . . . . . . . . . .3600 (saros) 1296000 21600 1317600TABLE IVIn the same interval the first mean motion (see Table IV) completes a count of 21600=360׶0, the number of minutes in a circle. A count of the nadis, 1/60ths of a day, in this interval for the first mean motion is 1296000, the number of seconds in a circle. A count of the nadis in this interval for the second mean motion is 21600, the number of minutes in a circle.A count of the first mean motion of the Sun for 600 years (the Babylonian neros) is 216000 (see Table IV), the number of long syllables (gurvaksharas) in a day. A count of the second mean motion of the Sun for 600 years is 3600 (see Table IV), the number of vinadis in a day.After 3600 years (the Babylonian saros), the first mean motion of the Sun has completed a count of 1296000 (see Table IV), the number of seconds in a circle, while the second mean motion of the Sun has completed 21600 (see Table IV), the number of minutes in a circle.