Principia: Relational Physics Tests for Video Models

TL;DR - Principia is a benchmark for testing whether video models preserve Newtonian relationships between paired objects without requiring camera calibration. Its results expose a substantial gap between standard video-quality scores and actual physical consistency.

• Covers eight phenomena, including gravity, friction, momentum, projectile motion, rotational inertia, and oscillatory systems.
• Introduces a calibration-independent score that measures relational physics violations directly in image space.
• Across thousands of samples from six leading video generators, no model scored above 0.42 on Principia, despite scoring around 0.8 on VBench.
• Vision-language models also struggled to identify physics violations: the best reached 67% accuracy, while most performed near chance.