Earth: Day Zero • Paper 042 of 512

Great Circle Reconstruction II

Great-circle reconstruction depends upon how candidate domains are represented geometrically.

Because entrance and exit domains are spatial regions rather than exact points, centroid selection and uncertainty handling become essential methodological issues.

Centroid Selection

A domain centroid provides a simplified reference point for evaluating large-scale spherical relationships.

However, centroid choice must be justified by the geometry and structure of the domain rather than selected to force a preferred outcome.

Uncertainty Regions

Each candidate domain should be evaluated with an uncertainty region.

This allows reconstruction tests to determine whether geometric relationships persist across reasonable parameter variation.

Robustness

A strong great-circle relationship should not collapse when centroids shift slightly within plausible domain boundaries.

If small centroid changes destroy the relationship, the model becomes geometrically fragile.