Time to nerd out thanks to a group of Scottish scientists at Heriot-Watt University.
Using an ultra-high-speed camera capable of detecting single particles of light, the team recorded two million laser pulses over a 10 minute period, as individual particles – known as photons – collided with the air.
The camera used is capable of filming 20 billion frames per second. Let’s see the PS4 play at that rate.
According to New Scientist,
Watching laser beams fly through the air makes for dramatic battles in sci-fi films, but they’re not so easy to see in real life. In order to observe a laser, or any other light source, photons from it must directly hit your eyes. But since laser photons travel in a tightly-focused beam, all heading in the same direction, you can only see them when the laser hits something that reflects a portion of the light and produces a visible dot.
A tiny proportion of photons scatter off air molecules, but normally these are too faint to see. You can get around this by firing a laser through smoke, giving the photons more molecules to scatter off – but that’s not the effect we see in the movies.
“The challenge was to have a movie of light moving directly in air,” says Genevieve Gariepy of Heriot-Watt University in Edinburgh, UK. “We wanted to look at light without interacting with it, just looking at it passing by.”
To make this work, she and her colleagues constructed a camera sensitive enough to pick up those few scattering photons. It is built from a 32 by 32 grid of detectors that log the time a photon arrives at them with incredible precision, equivalent to snapping around 20 billion frames a second.