Nonuniqueness and resolution in gravity inference
Different subsurface density structures can yield the same external gravitational field.
Key knowledge
Different subsurface density structures can yield the same external gravitational field. For example, concentric spherically symmetric bodies of different radii/densities but the same total excess mass produce the same exterior −GΔM/r potential wherever the observer is outside them. Finite noisy anomaly observations add further resolution limits; geological constraints narrow admissible models rather than guarantee uniqueness.
Conditions and scope
- The example assumes Newtonian gravity, spherical symmetry, common centre, equal total contrast mass and observation points exterior to all compared bodies.
- Distinguish exact nonuniqueness from ill-conditioning and incomplete sampling. An imposed smoothness or shape family is a modeling prior; low residuals or a regularized numerical solution do not independently verify that prior.
Sources · 1
References
Sources retain their recorded scope. A source link alone does not establish verification of every statement.
Evidence and review
Read printed55 exterior-sphere potential and57–59 forward-kernel/resolution discussion. The explicit equal-mass sphere counterexample is a disclosed consequence of the inspected Newtonian exterior model, not a quoted full inverse-problem theorem. No all-potential-fields classification, current software or quantitative universal resolution limit claimed.
2026-10-10 · Independent AI editorial review: All73 exact supplement compact statements, conditions, displayed equations and247 origin semantic links read; all109 combined original36+supplement73 author-source rows, exact locators, hypotheses, exclusions and disclosed derivations assessed. Original36 exact scientific content is independently approved in the linked receipt. All18 inherited Earth compact references and shared Math/Physics/Measurement methods were considered in the full practical Earth inventory. Targeted actual primary sections listed below; not every source body/proof or every possible university elective independently reread. AI editorial reference review, not human certification, full-degree proficiency, new experimental validation or a claim of whole combined Earth-and-Cosmos approval. Receipt: earth-completion-independent-content-inventory-review.1.
Entry details
Permanent link to this entry ↗- Record identity
- uni-earth-gravity-nonuniqueness
- Revision
- core.1
- Structured reference record
- University core expansion