The Prediction

The gravitational constant is:

G = α_em²¹ × (1 + 1/π) × ℏc / m_e²

Using CODATA values for α_em, ℏ, c, and m_e — all known to high precision:

α_em = 7.29735 × 10⁻³

α_em²¹ = 1.338 × 10⁻⁴⁵

1 + 1/π = 1.31831

α_em²¹ × (1 + 1/π) = 1.764 × 10⁻⁴⁵

This gives:

G_predicted = 6.721 × 10⁻¹¹ N·m²/kg²

The current measured value:

G_measured = 6.674 × 10⁻¹¹ N·m²/kg² (CODATA 2018)

Discrepancy: 0.69%.

The gravitational constant is the least precisely measured fundamental constant in physics. The CODATA uncertainty is roughly 22 parts per million, but individual experiments scatter by far more than this. Different laboratories obtain persistently different values depending on their apparatus. The reason for this scatter is unknown.

The axioms offer a structural explanation: every measurement apparatus is a leaky boundary (AP06 — the Leakage Constant). No absorber is perfect; no measurement channel is lossless. The leakage is systematic and apparatus-dependent. Different apparatuses leak differently. The experimental scatter is the leakage signature. The axiom prediction may be closer to the true value of G than current measurements are.