Retrograde motion and repeated boundary crossings
A frame-preserving chronology for direct ingress, retrograde re-entry, and final direct ingress without cherry-picking one crossing.
Frame comparison · released 2026-08-18
Shared fact substrate
Stations and reversals describe the same planetary motion in both zodiac frames, although a station can fall inside differently named signs.
Required shared inputs
- Full search interval
- Longitude and speed function
- Tropical and Lahiri boundaries
- Crossing direction
- Station chronology
Tropical view
Every crossing of the tropical boundary is retained in chronological order with direct or retrograde direction, including the solver bracket and station context.
Lahiri-sidereal view
Every crossing of the Lahiri-sidereal boundary is retained independently; its sequence can occur weeks or months away from the tropical sequence.
Where they agree
Both models agree that deleting retrograde crossings distorts the trajectory and that all roots inside the declared interval belong in the event record.
Where they disagree
The two frames disagree on which boundary is being crossed and when. They may also produce different counts inside a short reporting window.
Preservation policy
Publish two complete crossing arrays and connect them only through the shared body and ephemeris, not through nearest-date matching.
Prohibited synthesis
Do not call the first, final, or closest crossing uniquely operative unless that selection policy was declared before the target outcome.
What empirical comparison requires
Treat tropical and sidereal outputs as separate candidate models. Any performance claim requires preregistered features, outcomes, horizons, baselines, model-selection policy, multiplicity control, and prospective scoring that retains misses and abstentions.
Method sources
These sources define calculation and namespace policy. They do not determine which astrology system is true.
- Celestial timing reference library
Maha Celestial
Frame-explicit ingress, station, lunation, repeated-crossing, and Vimśottarī chronology conventions.
Boundary: A deterministic event date is not evidence that the event predicts a real-world outcome.
- Tropical versus sidereal astrology
Maha Celestial
The policy that tropical and sidereal charts remain parallel declared models with separate feature and rule namespaces.
Boundary: The guide is a methodology declaration, not an adjudication between traditions.