Even in fairy tales, they couldnât get a blast out of air to knock down a house of bricks. This short video with Jem Stansfield of BBCâs Bang Goes The Theory features a vortex cannon that fires a 200mph cloud ring to knock down little huts of straw, sticks and bricks. The cannon has the worldâs most explosive gas mixes in there. The cloud ring is not a smoke ring; it is formed by the pressure drop within the vortex condensing the water out of the damp air above the lake. The explosion is an outcome when just the right amount of the molecules of setaline reacts with just the right amount of molecules of oxygen in the air.