Convert Nanoradians to Signs
Convert Nanoradians (nrad) to Signs (sign) instantly and accurately.
Conversion Formula
sign = nrad × 1.909859317e-9
About Nanoradians
A nanoradian (nrad) is one billionth of a radian (10⁻⁹ rad), the smallest angle unit in regular scientific use. LIGO and Virgo gravitational-wave observatories maintain mirror tilts to sub-nanoradian stability - a 1 nrad tilt on a 4 km mirror shifts the reflected beam by 4 nm. Earth-tidal deformation deflects the local plumb line by roughly 50 nrad over a full tidal cycle, measurable with superconducting gravimeters and ring-laser gyroscopes. Synchrotron X-ray beamline mirrors are steered to single-digit nanoradians by piezo actuators. 1 nrad = 10⁻⁹ rad ≈ 0.206 µas.
About Signs
An astrological sign equals 1/12 of a full circle - π/6 rad = exactly 30°. The zodiac divides the ecliptic into twelve 30° signs (Aries through Pisces), originating in Babylonian astronomy ~5th century BCE. Historical ecliptic longitude was expressed as sign + degrees: "Scorpio 12°" = 222°. The 30° spacing also appears in music theory: the circle of fifths has twelve equally spaced positions 30° apart, and the octave divides into 12 equal semitones. 1 sign = 30° = 1,800′ = π/6 rad = 533.3 NATO mils.
Quick Reference Table
| Nanoradians (nrad) | Signs (sign) |
|---|---|
| 1 nrad | 1.91 × 10-9 sign |
| 2 nrad | 3.82 × 10-9 sign |
| 5 nrad | 9.549 × 10-9 sign |
| 10 nrad | 1.91 × 10-8 sign |
| 25 nrad | 4.775 × 10-8 sign |
| 50 nrad | 9.549 × 10-8 sign |
| 100 nrad | 1.91 × 10-7 sign |