Sep 02 2009
Surfing the vortex. The toroidal vortex.
By David Finnigan
I know what you’re thinking: skip the talking and get straight to the dolphins. I completely agree. Just bear with me for three paragraphs, and we’ll be armpit deep in Ceteceans, I promise.
Soon, I promise. Image: wikipedia
There was a series of highlights at the ABC Family Science Funday in the ABC Foyer on Saturday 29 August, but the highlight of my highlights was Ruben Meerman (aka The Surfing Scientist). For 45 minutes, Ruben held several hundred people in rapt attention as he used his home-made air cannon (one shower curtain and a plastic bin) to fire smoke rings into the air and blow paper cups off people’s heads from 10 metres.
The Surfing Scientist. Image: abc.net.au
The point of the exercise (other than to prove his skill as a marksman) was to show how smoke rings form. Smoke rings are an example of a ‘toroidal vortex’. To spare you the embarrassment of reading me attempt to explain what a toroidal vortex is, I’m going to quote directly from Meerman himself on the ABC’s Surfing Scientist website:
A vortex is formed when a fluid swirls around a central point. Whirlpools and tornadoes are two familiar types of funnel shaped vortexes (or vortices). The mathematical name for a donut or ring shape is a toroid.
The jaw-dropping part is that humans aren’t the only creatures to make toroidal vortices for fun and amusement.
From Seaworld in Orlando, Florida, this spectacular demonstration of vortices is thanks to our favourite mammalian sea-dwellers:
