MOTION · AN OPEN PHYSICS EXPERIMENT
Afterimage.
Turn a moving point in a video into measurements and a motion graph.
WHAT’S HAPPENING HERE
Observation.
Prediction. Difference.
Samples are generated from stated models. A projectile follows constant acceleration; the pendulum uses a small-angle approximation with a 2 m length; the bouncing ball uses a restitution of 0.72. Air resistance is omitted.
For your own clip, mark a known distance and track at least four positions at different times. The tool fits horizontal constant velocity and vertical constant acceleration. The residual reports disagreement with that model. Perspective, camera movement, occlusion, and tracking errors can all affect the result.
Automatic tracking compares a small image patch between frames. It can lose the object; inspect the dots and correct them manually. The app does not infer mass or unseen depth.
Research reference: Open Source Physics / Tracker ↗The person behind the project
A note from Luis.
A moving point becoming a graph is the kind of connection between observation and mathematics that interests me. The built-in examples are generated. Your own video provides an observation to compare with the model.
Who it helps
People who want to measure motion in a short video.
Try this
Change gravity in the sample and compare the predicted path. To measure your own clip, open the video tab and mark the moving object.
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