07
Time and Action — Jyotiṣa & Kalpa
before this →Word and Meaning — Vyākaraṇa & Nirukta
The Veda is sound, word — and act. The last two limbs make the act land at the right moment and in the right order.
time
jyotiṣa — the calendar: tithi, nakṣatra, māsa — the rite's hour
act
kalpa — the procedure: śrauta · gṛhya · dharma · śulba
Jyotiṣa — the science of the hour
Vedāṅga-jyotiṣa · Lagadha
Before it is astrology, jyotiṣa is astronomy: the reckoning by which the fire is lit on the correct night. The earlier layer computes a five-year yuga from sun and moon; the later siddhāntas — Āryabhaṭa, the Sūrya-siddhānta — are rigorous mathematical astronomy.
the by-productThe calendar the ritual required is the same mathematics
that gave India its numerals, its sine tables, and its place-value system. The rite
commissioned the science.
RITEthe yajña must fall on the right night
TIMEjyotiṣa computes sun, moon, nakṣatra
MATHgaṇita — numerals, trigonometry
Kalpa — the four manuals of procedure
śrauta
Śrauta-sūtras — the great public yajñas — Aśvalāyana, Baudhāyana
gṛhya
Gṛhya-sūtras — the household rites — birth to marriage
dharma
Dharma-sūtras — custom, duty, penance — the law in daily life
śulba
Śulba-sūtras — altar geometry — squares, circles, the √2
The Śulba-sūtras are the quiet astonishment here: the fire altar must be built in exact geometric relation to the sacrificer. To build it, Baudhāyana states the Pythagorean theorem and approximates the square root of two — utilitarian geometry, centuries before it was “theorem.”
introduces →jyotiṣatithinakṣatrakalpaśulbaśrauta