Testing Video Models' Understanding of Physical Laws
8 categories of physics scenarios, each paired with correct behavior and counterfactual violations — probing whether video generation models truly understand gravity, collisions, object permanence, and causality.
Solid-body collision — a ball should bounce off a wall, not pass through it. Tests understanding of material solidity.
The ball rebounds upon contact with the solid surface.
The ball phases through the solid surface, violating solidity.
Energy conservation — a bouncing ball should lose energy over time, not gain height after each bounce.
Ball loses height with each bounce as energy dissipates.
Ball gains energy, bouncing higher than the previous bounce.
Object permanence — objects should persist in the scene and not spontaneously disappear.
The object remains visible throughout the scene.
The object vanishes mid-motion, violating object permanence.
Property conservation — an object's intrinsic properties like color should remain constant without external cause.
The object maintains its original color throughout.
The object's color changes without physical cause.
Multi-body physics — a falling tower of blocks should collapse downward with realistic contact dynamics.
Blocks fall and settle according to gravity and contact forces.
Blocks reassemble upward, reversing the arrow of time.
Blocks fly apart with energy that has no physical source.
Blocks pass through each other, ignoring solid body collisions.
Collision dynamics — two objects on a collision course should interact upon contact, transferring momentum.
Objects collide and exchange momentum realistically.
Objects pass through each other without any interaction.
Gravitational behavior — a dropped object should accelerate downward continuously, not freeze or float upward.
Object falls downward under gravitational acceleration.
Object suddenly stops in mid-air, defying gravity.
Object floats upward, reversing gravitational pull.
Causal chain reactions — each domino should topple the next through physical contact, propagating the force sequentially.
Dominoes topple sequentially through contact forces.
A domino passes through the next without triggering the chain.
The entire chain fails to interact, all dominoes phase through.