Reality Check

Reality Check catches AI-generated video by measuring whether it obeys real physics. AI video generators still get physics wrong: balls fall too slowly, gravity changes between bounces, and bounces gain energy from nowhere. Reality Check tracks a falling or bouncing object, fits each flight arc to the free-fall equation y(t) = y0 + v0·t + ½·g·t², and measures gravity directly. Real footage comes out near 9.8 m/s²; a clip where a ball falls at 2.9 m/s² is physically impossible, and Reality Check says so with the number to prove it. Two supporting checks cover files without measurable motion: a provenance check that reads AI labels generators write into files (C2PA Content Credentials, IPTC "trainedAlgorithmicMedia"), and a visual inspection for generator watermarks and AI artifacts. The evidence is combined into one clear answer, AI-generated or Real, with a confidence and the reason, instead of an opaque score. It runs as a web app and as an iPhone app that shows the answer in the Dynamic Island when you share a photo or video. Everything was built during the hackathon, with the help of an AI coding assistant. On synthetic test videos with known physics it scored 7/7 (4/4 fakes caught, 0 false alarms), measuring gravity on real-physics clips to within 3.1%.