Lasers can be used to test the authenticity of what?

Whiskey has become a very popular substance in the past year, particularly those of the rare and expensive variety. As is the case with just about anything, though, this increase in popularity has also led to an increase in counterfeits. Up until now, a bottle of whiskey had to be opened in order to test its contents to make sure they were legit, but this is something that no one wants to do with very expensive bottles.

Fortunately, a group of physicists at the University of St. Andrews in Scotland have come up with a solution: lasers. Using a cone-shaped lens, the team found they could shine a laser light into sealed bottles of whiskey and determine the chemical composition of the liquid based on the wavelengths the light produced.  

The cone-shaped lens was the key to their breakthrough, as it allowed the light to be shone as a ring rather than a direct beam, therefore ensuring that the chemical makeup of the bottle itself didn’t interfere with their reading of what was inside. As a bonus, they found that this technique also worked with bottles of gin and vodka.