To be honest, it would have been better to explain how they do the spectroscopy than to just say "you don't understand" and downvote. I should have raised a question instead of making a statement, the response should have been an explanation, instead of basically "you're an idiot" (which still no one has done as of this time). They are making the same error I did. The article posted didn't explain, the paper costs $9 to read. I wouldn't call this a productive discussion at this point.

Edit: someone just attempted to explain the technology behind it, thanks amluto