This is a pretty darn cool video.
What’s happening here is the platforms that the men are standing on are Tesla coils, which produce large (seriously large) electricity voltages. Like lightning, or any other form of electricity, the voltage produced wants to travel down the easiest path. The two men in the red and blue are wearing metal suits – probably chain-links, in a similar way to medieval knights – and conducting the electricity around the outside of their bodies. The electricity then wants to get to the ground, so it’ll go out the lowest point or try to jump the gap to reach the other, equally conductive, man, making for an awesome electricity fight!
How does a Tesla coil make so much electricity? In essence, it’s similar to a transformer. One coil of wire (the primary), is wrapped around a metal core and current is run through it, creating an electromagnet (a magnet powered by electricity). Another coil of wire, the secondary, is also wrapped around a core, and the magnetic field from the primary causes a current to flow in the secondary coil. Depending on the number of turns in each coil, the voltage is “stepped up” (increased – which occurs when the secondary coil has more turns than the primary) or “stepped down”. Transformers (not the action heroes, sadly!) are used for transmitting electricity, so that it runs at a high voltage through the main lines on the pylons with minimum resistance, but gets “stepped down” before it reaches houses so that it’s safe.
A Tesla coil works on a similar principle, but its coils are wrapped loosely so that there’s air between the turns. This makes the process of transferring energy to the second coil less efficient, but the extra insulation from the air means that the system can handle much larger voltages before it overloads. So with a normal amount of household voltage (240V) in the first coil, you can produce a ton of voltage in the second coil. Big Tesla coils can produce up to around 500,000 volts, or even more!
Those are definitely two brave guys, to wear suits sparking with that much electricity! Makes for an awesome show though!