Convert Tropical Years to Shakes
Convert Tropical Years (a_trop) to Shakes (sh) instantly and accurately.
Conversion Formula
sh = a_trop × 3.155692522e+15
About Tropical Years
The tropical year = time from March equinox to the next = 365.24219 days = 31,556,925.2 s - the year that governs the seasons. The Gregorian 97/400 leap rule approximates it as 365.2425 days, leaving a residual drift of only ~26.8 s/year. The tropical year shortens ~0.53 s per century due to tidal deceleration. Persian Solar Hijri and Mayan Haab' calendars also approximate it. 1 a_trop ≈ 365.24219 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
| Tropical Years (a_trop) | Shakes (sh) |
|---|---|
| 1 a_trop | 3.156 × 1015 sh |
| 2 a_trop | 6.311 × 1015 sh |
| 5 a_trop | 1.578 × 1016 sh |
| 10 a_trop | 3.156 × 1016 sh |
| 25 a_trop | 7.889 × 1016 sh |
| 50 a_trop | 1.578 × 1017 sh |
| 100 a_trop | 3.156 × 1017 sh |