Where’s the science? Airzookas

16 01 2011

I have proposed that we can evaluate shows by asking three questions: where’s the science? who’s the audience? and what’s the story? You can read more about that here.

This is an example of an accomplished performer putting together an ambitious show for a large theatre audience and I applaud him for that. However, where’s the science?

At 44 seconds an attempt is made to explain what is going on but it is garbled and only lasts a couple of seconds. The vortex generator is a tricky piece of equipment to explain but a lovely demo. It is tempting to skip over a tricky explanation and just get on with making pretty smoke rings, especially when you have such powerful stage spotlights to fire the rings at, and that’s what has happened here.

If a vortex cannon is being used in a theatrical show as an effect then it wouldn’t matter that there was no explanation. Everyone likes seeing fog roll across a stage and we don’t need to know how it is being made. But if the vortex cannon is being used in a science show I think the science behind it should be explained. After all, isn’t that the point of going to a science show?

Here is Steve Spangler on Ellen, again where’s the science?

Steve Spanger is normally a great example of someone who gets the science right but again in this clip he avoids explaining what is really going on. Is the votex generator impossible to explain? Is it only possible to show it off without an explanation?

This is the only video I have found that attempts an explanation of the vortex cannon from BBC One’s Bang Goes the Theory.

Do you think Jem does a good job of explaining what a vortex ring is? Well at least he has tried. To evaluate it we need to ask our second question who’s the audience? and if we consider the audience are people who are searching for more information on the /bang website so I think this explanation works fine. The whole video can be found here.

But could either Dr Hal in the first video or Steve Spangler in the second have explained it like Jem did? Could they have taken the time Jem does in their presentations? No, probably not. But could they have tried to explain it better. Yes, I think they could. How’s about this:

A vortex is a spinning column of air or water. We see them as whirlpools in the bath or as tornadoes and hurricanes in the air. Sometimes instead of appearing as columns they form a circle like a smoke ring. The key to any vortex is the fact that it is spinning. The spin causes the vortex to appear and keeps it stable once it has.

A vortex generator works because when the air is forced out the front of the generator, some air hits the edges of the hole and slows down. This slower air is then pulled forward by the faster moving air in the center and starts swirling around itself in a ring. This spinning ring can travel great distances because the spin, like a frisbee’s spin, keeps it nice and stable.

I’m not saying this is perfect but I hope it gets across the basics without scaring anyone off. I think it is an explanation that is suitable for all but the youngest of audiences. I also think it would be suitable for the audiences in both Dr Hal’s and Steve Spangler’s shows.

Perhaps you have a better explanation that you use if you demonstrate Airzookas or other vortex cannons in your show in which case add it to the comments. If you use them and don’t explain what is going on then feel free to use the explanation in your show.




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