======Air Cannon Smoke Rings======


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**Materials: **{{$demo.materials_description}}\\
**Difficulty: **{{$demo.difficulty_description}}\\
**Safety: **{{$demo.safety_description}}\\
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**Alternative titles:** Giant Smoke Cannon
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====Summary====                   
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====Procedure====  
  - Turn a large trash can upside down and cut an 8-inch (20 cm) circular hole in the center of the bottom.  
  - Cut a piece of plastic shower curtain large enough to extend about 10 inches (25 cm) over the can’s open edge.  
  - Secure the plastic tightly over the open end with a bungee cord to act as a flexible membrane.  
  - Strike the center of the membrane sharply with a hand or stick to send a blast of air through the hole, forming an invisible vortex ring.  
  - To make the vortex visible, fill the can with smoke (using a smoke machine or safe smoke source) before striking the membrane.
  - Observe the large, rolling smoke rings as they move through the air.

====Links==== 
Smoke ring demonstration | Giant vortex canon - Lab Luminaries: 
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Giant Smoke Rings - Cool Science Experiment - Sick Science!: 
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📄 How to Make Giant Smoke Rings - Steve Spangler: [[https://stevespangler.com/experiments/air-cannon-smoke-ring-vortex-launcher/]]\\
📄 Air Canon Smoke Ring - Rookie Parenting Science - a smaller scale, using incense as the smoke source: [[https://www.rookieparenting.com/air-canon-smoke-ring/]]\\


====Variations====
  * Try making smaller versions using a 5-gallon bucket with a 2–3 inch hole.  
  * Experiment with hole shapes (oval, square) to see how it changes the vortex.  
  * Compare different strike strengths to see how far and fast the smoke rings travel.


====Safety Precautions====
  * Adult supervision required when cutting plastic or using sharp tools.  
  * Never blow smoke directly into faces of people or animals.  
  * Perform the experiment outdoors or in a well-ventilated space to avoid triggering smoke alarms.  
  * Handle smoke sources with extreme care and follow all safety instructions.  
  * Keep water or a fire extinguisher nearby if using smoke sources that involve combustion.



====Questions to Consider====
  * Why does a vortex ring hold its shape as it moves through the air?  
  * How does Bernoulli’s principle explain the stability of the smoke ring?  
  * Why does air leaving the center of the hole move faster than air at the edges?  
  * What eventually causes the smoke ring to slow down and disappear?  
  * How do vortex rings in air compare to those formed in water (e.g., dolphins or whales blowing rings)?