dC_dx ↔ x
Tier II — Similarity CONJECTURAL
- Object
- diffusing_medium
- Property
- ConcentrationGradient
- Context
- dilute
- Object
- rigid_body
- Property
- Position
- Context
- inertial_frame
- Constraint
- displacement_from_equilibrium
Sieve rationale
Structural equation-level identity (sign=+1): the canonical forms of EQ-FICK-DIFFUSION and EQ-HOOKE are syntactically equal under rename, and dC_dx maps to x under the discovered bijection
Physical constraint filter
At least one variable is not a bond-graph port variable (role_a=gradient, role_b=state); Tellegen pairing is only defined for effort/flow.
Onsager reciprocity applies only to pairs of linear transport laws; at least one equation is not a linear PDE.
Energy conservation check is narrowly targeted at the Newton+Hooke → SHO composite in Medium m2; other composites require the Phase 7 Lyapunov/Noether machinery (not yet built).
Emergent properties
Emergent Buckingham Π groups
Dimensionless combinations that mix parameters from both equations — only appear in the composite system.
AI review board
3 REJECT vote(s); the coupling is demoted to conjectural per §12.2.
This coupling equates a concentration gradient (dimensions [substance]·[length]⁻⁴) with a displacement/position (dimensions [length]) via an identity transfer function, which is dimensionally inconsistent and physically meaningless. The semantic descriptors clearly identify entirely different quantities — a spatial derivative of concentration in a diffusing medium versus a displacement from equilibrium of a rigid body in a spring system. The fact that Fick's law and Hooke's law can be made syntactically identical under variable renaming (both being linear proportionality relations) is a trivial algebraic observation, not a genuine physical coupling. All physical constraint checks returned 'not_applicable,' meaning no filter actually validated the coupling — this should not be interpreted as passing. The claimed emergent pi groups are simply restating each equation's own dimensionless ratio and do not constitute emergent cross-domain physics. This is an artefact of purely syntactic pattern matching with no physical basis.
The proposed identity mapping dC_dx → x is not physically or semantically defensible: concentration gradient (a driving gradient/thermodynamic force with dimensions [substance]/L^4) is not the same type of quantity as mechanical displacement (a state with dimension L), and no named transform is provided to relate them. The claimed structural identity between Fick’s first law (J = −D∇C) and Hooke’s law (F = −kx) is merely formal; an appropriate analogy would pair flux with force and gradient with displacement over length/strain, not gradient with displacement itself. The physical-constraint filter offered no supporting checks (all not applicable), and the listed π-groups are trivial restatements of each constitutive law rather than genuine emergent properties. Therefore the coupling lacks physical plausibility and semantic alignment.
The proposed coupling is rejected due to a fundamental physical implausibility. It equates a concentration gradient with a mechanical displacement, which are quantities with incompatible physical dimensions and distinct semantic meanings. This coupling appears to be an artefact of a superficial syntactic similarity between the linear forms of Fick's law and Hooke's law, rather than a representation of a genuine physical interaction. The claimed emergent property is a trivial algebraic rearrangement of one of the original equations, not a novel feature arising from the coupling.