Planetary Dynamics Explorer

Adjust parameters, scrub through 4.5 Gyr, compare scenarios

What This Tool Does

And what it does not do

Plate tectonics is very successful. It explains seafloor spreading, subduction zones, mountain building, earthquake patterns, and much more. Nothing in this tool aims to overturn that.

The question this tool explores is whether plate tectonics could be an emergent surface behavior — one regime within a larger planetary evolution system that might also include slow radial evolution, changing equilibrium shape, rotational effects, and time-varying tectonic modes.

It's worth noting that a surprising number of fundamental questions about plate tectonics remain open or actively debated: what initiates subduction, why Earth has plates at all while similar-sized Venus apparently does not, how the first continental crust formed, what drives the observed episodicity in supercontinent cycles, and whether plate tectonics even operated in the Archean in a form we'd recognize today. These aren't fringe puzzles — they're mainstream research frontiers, and they leave room for the possibility that the standard framework, while powerful, may be embedded in a larger dynamical story.

Think of the analogy to Newtonian physics: extremely useful, often correct within its domain, but potentially not the complete underlying story. This tool lets you test that analogy for planetary tectonics.

The goal is intuition-building, not proof. Every chart, slider, and computed value is clearly labeled with its epistemic status.

Epistemic Categories

How quantities are labeled throughout this tool

Observed

Observations

Directly measured quantities: present-day radius, gravity, day length, geodetic rates, seismic observations. These are the ground truth.

Inferred

Inferences

Derived from observations using accepted methods: paleomagnetic pole positions, ancient day length from tidal rhythmites, past tectonic regimes from the rock record.

Modeled

Model outputs

Computed from the physics engine given the user's parameter choices: gravity at past epochs, moment of inertia, oblateness. These depend on model assumptions.

Speculative

Speculative layers

Hypothetical or exploratory: radial expansion, pole reorientation from mass redistribution, tectonic regime transitions. These are the elements being tested.

Model Components

What the physics engine computes

Geometry & Mass

  • Radius R(t) — user-configurable evolution
  • Mean density ρ(t) from mass and volume
  • Surface gravity g(t)
  • Layered or uniform density model

Rotation & Figure

  • Angular velocity ω(t) — conserved L or tidal braking
  • Day length
  • Hydrostatic flattening (Darwin-Radau)
  • Viscoelastic relaxation toward equilibrium
  • Equatorial/polar radii

Dynamics

  • Moment of inertia I(t)
  • Pole drift / true polar wander (toy model)
  • Tectonic regime classification (heuristic)
  • Expansion rate dR/dt

Key Limitations

What this model does NOT capture

This is a simplified 1D radial model with rotational perturbation. It does not:

  • Simulate full 3D mantle convection
  • Model plate boundary dynamics or individual plate motions
  • Include thermal evolution, phase transitions, or compositional convection
  • Compute actual stress fields or rheological behavior
  • Account for lateral density heterogeneity
  • Model the Moon's orbital evolution self-consistently

Every equation is documented in the source code. The physics engine is deliberately modular so that better geophysics can replace any component.