A laser pointer at 2 billion fps makes the speed of light look... kinda weird

A detailed walkthrough of building a 2 billion frames-per-second camera capable of visualizing light propagation. The system uses a single-pixel sensor that scans scenes by repositioning a mirror, collecting data one pixel at a time and reconstructing HD video through synchronized measurements. Key technical challenges include precision motor control with belt-driven servos, custom torque limiters, signal processing at 2 gigasamples/second using oscilloscopes, and managing photomultiplier tube sensitivity. The camera reveals optical artifacts where light appears to move at different speeds depending on viewing angle—an effect caused by varying path lengths to the camera rather than actual changes in light speed.