There's no shortage of uses for steel wool, but the majority of them tend to be on the pyromaniacal side, like DIY fireworks. This trick by Mike Mikkelson is no different—it uses a homemade reusable "wool cage" to create a spinning vortex of light, like in the photo below.
You can do this with just a piece of steel wool on a cable, but Michael wanted something he could easily reuse no matter how many shots he took, so he built a small cage to house the steel wool out of chicken wire, a small piece of pipe, and the buckle from a dog leash.
After bending the chicken wire into a box, he used a spare piece of wire to make 3 hinges so it can open and close, then made a loop in the cable and attached it to the box.
The end of the cable is attached to the buckle, which is threaded through the pipe. The buckle is held in one hand, with the pipe in the other, which gives you control over the size of your fiery steel wool vortex.
Now, for the technique. Obviously, you need a big, open space with nothing flammable nearby. It's also a good idea to cover up (long pants, sweatshirt, no open-toed shoes) in case you get hit by any stray sparks.
You'll need 20 to 30 seconds of exposure, with a 10 second delay to get the vortex going. After lighting the wool, start to spin the cage in small circles, gradually increasing by lengthening the cord while walking towards the camera.
Michael also tried standing in one spot and keeping the same diameter the whole time, which ends up looking a little more chaotic.