You'll go to jail if you try it in public, but it really is ingenious.
Russian model Sveta Bilyalova (somehow) devised a way to figure out if breasts are real or silicon by literally shining a light on them.
How she figured this out is anyone's guess, but you can watch her explanation below:
I guess science is just one of Bilyalova and her friends' many past-times.
You can follow her here.