Results: The geometric derivation proves that declination standstills arise strictly from projection effects for constant obliquity, providing a clean baseline against which small residuals can be measured. When the observed declination data are differenced from this baseline, the residuals exhibit a semiannual component aligned in phase with the semiannual GRACE residual and stable across multi-year windows. Matching amplitudes implies an external torque of order 10¹⁷ N m. A general effective field analysis shows that axially aligned, helically magnetised, inductive plasma structures can generate a torque with the required symmetry, magnitude, and long–term stability while remaining consistent with constraints on Earth’s rotation and orbit.
Conclusions: Within this framework, solar geometry, GRACE gravimetry, and helical inductive MHD dynamics emerge as three observational manifestations of a single weak external torque acting on the Earth–Sun system. The effective-field constraints define a closed “constraint maze” in which standard models reach a scientific dead-end, and the allowed parameter space narrows to a small class of helically inductive structures, one possible realisation of which corresponds to what has been termed the Interuniversal Machine.