View full lesson: http://ed.ted.com/lessons/how-to-spot-a-counterfeit-bill-tien-nguyen

Authentic dollar bills are equipped with many security features to make them difficult to forge. But that doesn’t stop counterfeiters from trying to fool people with fakes. Luckily, anyone can help catch a counterfeit; all you need are a few simple tools and a bit of chemistry. Tien Nguyen details the chemistry behind counterfeit cash.

Lesson by Tien Nguyen, animation by Lippy.