I can see interference patterns in liquids and in light, but I don't see it in the air that surrounds us. I don't see leaves align in an interference pattern on the other side of a picket fence. The closest I could find after some googling was air moving over the surface of water. So I did this.The cigar smoke is drawn through the paint sprayer and shot through a double slit, made from razor blades and a very thin wire. A white piece of cloth is on the other side of the double slit. The smoke will stain where the air concentrates. Here's what I saw after burning four inches of a cigar. So the question is why no interference pattern on the cloth or in nature?