c_seismic
plain-language theorem explainer
The declaration fixes the reference seismic velocity scale at unity in RS-native dimensionless units. Plate-boundary modelers cite it to anchor subduction and ridge velocities on the phi-ladder. The definition is a direct constant assignment with no further computation or lemmas.
Claim. $c_ {seismic} := 1$ (dimensionless reference scale in RS-native units).
background
The module treats plate-boundary velocities as points on the phi-ladder of geological timescales. Subduction speed is defined as c_seismic / phi^7 and ridge spreading as c_seismic / phi^9, with their ratio equal to phi^2. The module doc states that the mantle convection rate supplies the seismic velocity scale and that Wilson-cycle periods lie in the interval (phi^9, phi^10) times 45 Myr. All subsequent definitions and certificates in the file unfold c_seismic to obtain these relations.
proof idea
Direct definition that sets the constant to 1. No lemmas or tactics are invoked; the body is a single assignment.
why it matters
The definition supplies the c_seismic_one field required by the master certificate PlateBoundaryDynamicsCert. It thereby anchors the entire suite of velocity theorems (subduction_speed, ridge_spreading, subduction_to_ridge_ratio) that realize the phi-ladder predictions for geological timescales. The choice is consistent with the Recognition framework's use of phi as the self-similar fixed point and the eight-tick octave structure.
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