NINDA

Definition

NINDA is the Sumerian sign for the smallest standard unit of arc and time in Babylonian schematic astronomy. Sixty NINDA make one UŠ, so a single NINDA is one-sixtieth of a degree of arc — one arc-minute — and roughly four seconds of time. The same sign also named a unit of distance (about 6 cubits, or 3 m) for land surveying, but in astronomy it always means this fine subdivision of arc and time.

In Tradition

Hunger-Pingree and Hunger-Steele identify NINDA as the smallest measuring unit of Babylonian schematic astronomy — the floor of the system. EAE Tablet 14 Table D records sunset-to-moonset durations in daily steps of 0;40 UŠ, which is 40 NINDA. MUL.APIN II ii 23 gives a midday-shadow scheme of "1 bēru 7 UŠ 30 NINDA daytime," and the Hilprecht-Text problem on the Moon and seven stars sums to 2,0 bēru = 1,0,0,0 NINDA.

In Practice

When you work through a Babylonian astronomical procedure text or a modern edition, treat NINDA as the precision unit for fine steps smaller than one UŠ. The step-differences in zigzag tables are often given in NINDA — MUL.APIN II ii 43-iii 12, for instance, lists a step-difference of 1 UŠ 20 NINDA in the fifteenth-day sunrise-to-moonrise scheme. The Sun's drift between the solstices is stated in NINDA per day: MUL.APIN II i 11-13 gives 40 NINDA per day of southward drift. The Hilprecht-Text problem reduces a total of 1,0,0,0 NINDA to per-interval star-distance values. Modern reconstructions of Babylonian time and arc treat NINDA as the standard floor — much as we use the arc-second — sitting at the bottom of the sixty-based ladder NINDA → UŠ → bēru.

Historical Origin

NINDA is attested across the cuneiform astronomical record from the second-millennium BCE precursors of EAE Tablet 14 through the Late Babylonian ACT ephemerides; it is used in MUL.APIN (composed around 1000 BCE) and the Neo-Assyrian Reports and Letters. Modern critical treatments: Hunger-Pingree, *Astral Sciences in Mesopotamia* (1999); Hunger-Steele, *The Babylonian Astronomical Compendium MUL.APIN* (2019); Neugebauer, *A History of Ancient Mathematical Astronomy* (1975).

Further Reading

• Hermann Hunger & David Pingree, Astral Sciences in Mesopotamia
• Hermann Hunger & John Steele, The Babylonian Astronomical Compendium MUL.APIN
• Otto Neugebauer, A History of Ancient Mathematical Astronomy