Hi, I'm Dean Schutler. I discovered the setup for this two-inch diffraction experiment two years ago while working on a paper. It's a very simple experiment using a laser pointer on two edges. Almost any smooth parallel edge works for this experiment. In this video I use two razor blades. I've also used things like the curved surface of rolled-up newspaper, the edges of two bars of soap, and the curved surface of tin cans. Here's the setup for the experiment. Here's a laser pointer I got at staples. I have two razor blades held in binder clubs. The binder clubs I got at staples also. Make sure the razor blades are parallel to each other. There's an even gap between them. Take the first razor blade and put it about a third of the way into the beam. Then take the second razor blade between the first razor blade and the paper and put it into the beam. Just slightly into the beam. That creates a diffraction pattern on the paper. Here's an image of the two edge diffraction pattern. There are a little more than 100 interference nodes in the pattern. The two razor blades and laser pointer are about 20 feet away from the paper displaying the diffraction pattern. This picture was taken with a Canon 60D camera. Try the experiment yourself. Thanks for watching.