This technical note uses the formal term Binary Flat Earth Model.
The public nickname Janus Earth is not used in this note except as a terminology boundary. The Meridian Boundary Institute does not use mythological nomenclature in technical material.
This note describes the stability relation between Mutual Planar Gravitation and Opposed Dome Polarity in the Binary Flat Earth Model. Mutual Planar Gravitation is treated as the attractive planar field relationship between the Primary Plane and Counterplane. Opposed Dome Polarity is treated as the separating polar behaviour of the Paired Firmaments. Their coupled behaviour defines the stability window of Bilateral Magnetostatic Equilibrium.
The note does not propose a mechanical support condition. It models stability as a magnetogravitic coupling problem in which attraction and separation remain field-bound, dynamically constrained, and non-contacting across the Equilibrium Void.
The purpose of MBI-TN-05.02 is to define the preliminary stability conditions under which a binary planar cosmological system remains separated while gravitationally coupled.
This note introduces:
The Binary Flat Earth Model requires two opposed behaviours to coexist.
First, the Primary Plane and Counterplane must remain gravitationally related. Without a mutual attractive condition, the model becomes two unrelated planar systems rather than one binary planar cosmological system.
Second, the Primary Plane and Counterplane must remain non-contacting. Without a separating field condition, Mutual Planar Gravitation would imply progressive convergence across the Equilibrium Void.
The model therefore depends on the stable coupling of attraction and separation. That coupling is described here as Bilateral Magnetostatic Equilibrium.
Mutual Planar Gravitation is the attractive gravitational relationship between the Primary Plane and Counterplane, and the local planar acceleration experienced by observers on each plane.
It is not modelled as radial attraction toward a spherical mass-centre. It is treated as a planar relationship distributed across opposed terrestrial surfaces.
Opposed Dome Polarity is the opposing polar field behaviour of the Paired Firmaments that prevents collapse of the planes under Mutual Planar Gravitation.
The term describes separating field behaviour. It does not imply any rigid intervening support.
Bilateral Magnetostatic Equilibrium is the stable separation state in which Mutual Planar Gravitation is counterbalanced by Opposed Dome Polarity.
Magnetogravitic coupling is the interdependent relationship between planar gravitational attraction and firmamental polarity. Coupling produces equilibrium but is not identical to equilibrium.
The Binary Flat Earth Model cannot rely on attraction alone. A purely attractive binary planar system would reduce the Equilibrium Void until the interplanar non-contact condition failed.
It also cannot rely on separation alone. A purely separating system would lose the coupled architecture required for a single Apparent Spherical Envelope.
The equilibrium requirement is therefore narrow:
Bilateral Magnetostatic Equilibrium is the name for this constrained state.
The stability window is the range of magnetogravitic coupling values within which the binary planar cosmological system remains coherent.
Below the window, the system is under-coupled. The Primary Plane and Counterplane remain insufficiently bound, and the Apparent Spherical Envelope cannot be treated as a unified envelope condition.
Within the window, Mutual Planar Gravitation and Opposed Dome Polarity remain mutually constraining. The Equilibrium Void persists, and the Paired Firmaments maintain an envelope-producing relationship.
Above the window, attractive coupling exceeds polar separation. The interplanar non-contact condition becomes unstable, and the model predicts compression stress within the Equilibrium Void.
The preliminary model identifies four stabilising contributors:
The stabilising condition is not a static lock. It is a constrained field relation. A stable binary planar system may still contain local variation, boundary noise, and unresolved gradients.
This distinction matters because a perfectly rigid system would imply mechanical support. The institute does not use that interpretation.
Destabilisation occurs when one field term ceases to constrain the other.
Preliminary destabilising conditions include:
These are model states, not currently direct measurements.
The Equilibrium Void is the field-interaction zone in which Mutual Planar Gravitation and Opposed Dome Polarity converge.
The void should not be described as an empty gap. In this note it functions as the active region where magnetogravitic coupling is compressed, occlusion is generated, and the interplanar non-contact condition is maintained.
A stable Equilibrium Void separates the planes while preserving the bilateral relationship required by the model.
The Counterplane enters this note as an inferred structural requirement of binary planar equilibrium.
This note makes no claim regarding Counterplane surface conditions, biological status, civilisational properties, or direct observation. It concerns only the equilibrium equations that require an opposing plane if Mutual Planar Gravitation is to be defined as a bilateral field relation.
This note is limited by:
These limitations should remain visible. They prevent the stability model from being mistaken for completed field physics.
Mutual Planar Gravitation and Opposed Dome Polarity define the central force constraint of the Binary Flat Earth Model. Attraction binds the Primary Plane and Counterplane into one binary planar cosmological system. Opposed polarity prevents collapse. Bilateral Magnetostatic Equilibrium names the narrow field condition in which both requirements remain satisfied without mechanical interpretation.