Can lab-based rock rheology produce plate-like convection?
In plain words
Computer models only produce Earth-like plates if the outer shell is assumed several times weaker than lab rocks. Whether a realistic weakening process closes that gap is unknown.
Precise statement
Mantle convection models give plate-like behavior only for lithospheric yield stresses of roughly $1e9 \text{ to } 3e9\,\mathrm{dyn}/\mathrm{cm}^{2}$, while laboratory-derived lithospheric strength is of order $1e10\,\mathrm{dyn}/\mathrm{cm}^{2}$. Determine whether a lab-calibrated rheology (grain damage with Zener pinning, low-temperature plasticity, fluid effects) yields plate-like convection in 3D spherical models at Earth parameters. An answer is such a model or a proof that the gap remains.
What would settle it
Spherical convection simulations with only experimentally constrained rheological parameters showing or failing to show plate-like surface motion.