You are not watching inert grains of sand. This is a simulation of Active Matter.
Unlike passive matter (like water or rocks), these particles possess internal energy and specific "urges."
They actively herd together and climb on top of their neighbors, fighting gravity to form dynamic, emergent structures.
The Science (1925–2025)
The Pauli Exclusion Principle
Exactly 100 years ago, Wolfgang Pauli formulated the rule that prevents electrons from occupying
the same quantum state simultaneously.
In this simulation: The "Pauli Exclusion" slider represents this force.
It gives the particles volume and prevents them from occupying the same space.
The Experiment: Try dragging Pauli Exclusion to 0%.
Without exclusion, matter loses its volume and collapses into a dense singularity.
Emergent Behavior
The "Ghost" you see isn't hard-coded. It emerges from three simple local rules:
Herding: "Move laterally toward the group center."
Climbing: "If a neighbor is higher, climb on their shoulders."
Pressure: "If crushed by weight, stop climbing to stabilize the foundation."
Controls: The God Hand
The simulation reacts to your presence.
Hover (Desktop): The particles fear the cursor. Hovering creates a gentle repulsive field.
Click & Drag (Desktop) / Touch (Mobile): Creates a massive gravitational singularity.
Use this to "grab" chunks of the ghost, throw them, or drag them up walls.
Topology Modes
Flat Earth: Standard gravity. Particles accumulate on a flat floor.
Planetoid: Radial gravity. Particles orbit and settle on a central core.
Note how they slide around the ring to find each other instead of tunneling through the ground.