From the 2018 Averaging Rule to the 2026 Force Balance — Two Generations of Tests on the Galactic Rotation Curve

B.6 Continuity with the 2018 Version B.6.1 Not a Change of Theory, but Bringing the Same Model to Life The 2018 and 2026 versions use the same force formula, the same Earth model, and the same equilibrium condition. The only difference is: · 2018: constant, constant; · 2026: , varies with radius. The Earth model was not wrong; what was wrong was that the 2018 version did not let its variation happen. B.6.2 Contribution of the 2018 Version The 2018 version was the first to write the STLT dark matter force as a point-by-point rotation-curve model and to give results in basic agreement with the data available at the time. It demonstrated that the dark matter force can be calculated and compared with observations. B.6.3 Contribution of the 2026 Version The 2026 version restores the most essential feature of the Earth model — the latitude variation of — and demonstrates that the Earth model can come alive: the curve can flatten first and then decline, instead of rising forever. The dark matter force in Space-Time Ladder Theory (STLT) is written as , a form analogous to the Lorentz force. This analogy can give the impression that the formula is a purely formal construction. However, the empirical content of this force does not come from electrodynamics. It comes from a longer and more established route: from the deflection of a pendulum, to cyclones on weather maps, to the civilization belt around N, to flat galactic rotation curves and the perihelion precession of Mercury. This paper reconstructs the “prehistory” of the dark matter force along this route. It argues that is not an a priori postulate, but a structural term that gradually emerges in rotational equilibrium, geostrophic balance, and galactic component balance. The contribution of STLT is to collect this empirical route into a single formula at the equilibrium point , , and to identify the residual as a testable interface for new physics. Even when STLT reproduces general relativity, it does so within its own framework, using and the term of the qi spacetime, rather than borrowing spacetime curvature.