Point a laser at someone's skin and they will react in fear, assuming it's going to burn. But researchers at the University of Washington have come up with a way to make a laser that cools, instead, successfully lowering the temperature of water by about 2C.
But don't go pointing your laser pointer at a can of soda, hoping to instantaneously chill it. The breakthrough here involved the use of an infrared laser that was, in a manner of speaking, working in reverse.
A single nano particle of laser crystal was suspended in water (using a sort of microscopic tractor beam making this all sound even cooler) and then illuminated with infrared laser light. The crystal then produces a high-energy glow which has more energy than the light being absorbed by the crystal. As a result, the glow works to carry heat away from the crystal, and the surrounding water.
Sounds pretty simple, right? Obviously not. The machine the researchers built to pull off this breakthrough is giant, and requires a lot of power to run. Far more than what would make it a practical way to cool down the inside of the refrigerator in your kitchen. But like with any breakthrough technology, the researchers are already working on ways to miniaturize it and make it more energy efficient.
The applications for this technology aren't just limited to being a more eco-friendly way to power a fridge or an air conditioner. Tiny cooling lasers could be built into electronics to cool specific components like processors, boosting their performance. And because the effect can be focused on a given area, tiny biological processes like cells dividing could be slowed and more easily studied in detail.
One day you might even see a character in a movie fire a laser blaster at something, and then shake your head when it blasts a hole right through it, instead of freezing it solid.