cover your lens · phone camera as particle detector · muon streaks from cosmic ray showers · per-pixel noise floor · runs locally
cover your lens. wait. the universe is shooting particles through your phone right now. this tool catches them.
high energy cosmic rays from exploding stars billions of light years away hit the upper atmosphere and produce muons — heavy electrons moving at 98% the speed of light. they pass through walls, your body, your phone. when one hits a cmos camera sensor it leaves a streak or spot for one frame. this is a demonstration not a calibrated instrument · real detectors use coincidence between multiple sensors to eliminate false positives. results here are indicative.
cover your camera lens completely before starting. use tape, a coin, a finger held firmly over the lens. the camera must be in complete darkness. any light leaking in produces false results.