The technology available to image light as it moves through space continues to advance. Recently, we saw a new high-speed camera capture a small pulse reflected from a mirror; now, it's possible to image the entire flight path of a laser as it bounces around a laboratory.
This footage shows a new experimental set-up developed by researchers at Heriot-Watt University in Edinburgh, UK. It uses a 32 by 32 grid of detectors, used to record when photons arrive at a precise location. A little number crunching allows the sensor data to be turned into the video footage you see here — equivalent to recording the laser pulse's flight path at 20 billion frames per second.
While it's a neat academic achievement, there are some plausible applications for the detection system, too; the researchers reckon it could be used to measure the behaviour of plasmas, for instance. But, for now, let's just watch that pulse bounce back and forth. Isn't it great? [New Scientist]