This looks like harmless fun: Building one’s own “vortex cannon.”
Category: Science
Erich Vieth is an attorney focusing on consumer law litigation and appellate practice. He is also a working musician and a writer, having founded Dangerous Intersection in 2006. Erich and his wife, Anne Jay, live in the Shaw Neighborhood of St. Louis, Missouri, where they are raising their two extraordinary daughters.
The movie is already gone, but here is another one:
Another try:
From Make Magazine, two smoke ring cannons.