Convert Sidereal Months to Shakes
Convert Sidereal Months (sid.mo) to Shakes (sh) instantly and accurately.
Conversion Formula
sh = sid.mo × 236059157000000
About Sidereal Months
The sidereal month = Moon's orbital period relative to the fixed stars = 27.3217 days = 2,360,591.6 s - the shortest lunar month. It is ~2.21 days shorter than the synodic month (29.53 d) because Earth advances ~27° along its orbit in the same period; the Moon must travel further to re-align with the Sun. Used in GPS orbit design, tidal modelling, and lunar laser ranging. 1 sid.mo = 27.3217 d.
About Shakes
A shake = exactly 10 ns (10⁻⁸ s) - the informal unit for fission prompt-neutron generation time, coined at Los Alamos during the Manhattan Project (1943-1945). A prompt-neutron generation in a supercritical core takes ~1-10 shakes; a full explosive chain reaction unfolds over ~50-100 shakes. The name alludes to 'two shakes of a lamb's tail'. Still used in reactor physics and weapons-design calculations. 1 shake = 10 ns.
Quick Reference Table
| Sidereal Months (sid.mo) | Shakes (sh) |
|---|---|
| 1 sid.mo | 2.361 × 1014 sh |
| 2 sid.mo | 4.721 × 1014 sh |
| 5 sid.mo | 1.18 × 1015 sh |
| 10 sid.mo | 2.361 × 1015 sh |
| 25 sid.mo | 5.901 × 1015 sh |
| 50 sid.mo | 1.18 × 1016 sh |
| 100 sid.mo | 2.361 × 1016 sh |