You've probably seen a smoker blow smoke rings or you've created whirlpools in your tub or pool when you were little. These phenomena are known as Vortices, formed when a fluid swirls around a central point because of a complex combination of friction and pressure. These Vortex Rings are more common and widespread in nature than most people had probably thought; in fact, they are studied in great detail by aeronautical engineers and combustion scientists. But we just think they are cool! Take a look at the video and then read below as Physics Teacher Buzz Putnam of Whitesboro High School provides more commentary on these amazing natural occurrences:
The video illustrates Vortex Rings being formed by various sources including dolphins and volcanoes. You'll notice in the video that the Vortex Rings are quite stable until they slow down and then at some critical speed, the core enlarges very suddenly causing the vortex to breakdown. Dolphins make, watch and chase them, even using their flippers to stop them rising in what appear to be games similar to those we humans play with soap bubbles. Watch Mt. Etna emit gigantic ring-shaped clouds of steam and gas up to 200 m in diameter that can fly up to 1000 m high, lasting more than 10 minutes. Your students will realize that humans aren't the only ones who love to make and watch Vortex Rings, one of the coolest phenomena in nature!
Physics Teacher Magazine thinks it cool too!
The November 2011 cover for Physics Magazine shows the steam ring expelled by Etna's summit crater.
View Physics Teacher Article>>
If you want to bring the vortex ring right into your classroom, you can do so with an Airzooka Air cannon and a fog machine (or fog in a can). Here is our Airzooka Air cannon in action:
Do more with vortex rings right in your classroom, check out these great links:
Acknowledgements: Thank you to Dwight "Buzz" Putnam for his assistance in writing this Cool Stuff. Buzz is a 25-year veteran physics teacher at Whitesboro High School, New York Science Teacher of the Year and host of the Regents Physics Answers television show on PBS. You can also find him refereeing high school basketball games as well as presenting at the NSTA national conferences.
Airzooka Air Cannon
This amazing new vortex launcher sends a strong blast of air all the way across the room!
Super Fog Machine
A lab full of safe, non-toxic water-based fog in 2 minutes!
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Fog in a Can
Makes chemical fog quick and easy. Non-flammable and non-toxic. 8 oz. spray can.
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