If you've been sitting around all week wondering how you could combine smoke, speakers, and a love of novel physics experiments into an excuse to tinker in your workshop this weekend, building a smoke-shooting vortex cannon should cover everything nicely.
Over at Make, the DIY-centric magazine, they've put together a video tutorial on how to build your own vortex cannons, with two models on offer. The second model they create however is powered not by an elastic membrane stretched across the back of the tube but by the kick of a big speaker. Check out the video below to see the construction of the vortex cannon and the cannons in action:
It's a really hard thing to capture on video but having built my own smoke-ring-shooting vortex cannon several years ago I can attest to how fun playing with one is. On a still day you can easily shoot a nice tight smoke ring 9-12 metres before it breaks apart and the actual vortex will extend well beyond the visibility range. Using a small hand held cannon I was able to easily ruffle the leaves on the tops of trees.
Have your own experience with vortex cannons or other showy home science experiments? Let's hear about it in the comments.