Anyone who attended this year's Maker Faire Austin had the joy of catching electrifying live performances by Arc Attack, a team that makes music with two gigantic transformer coils (AKA "Tesla coils"). They're a popular staple of the festival circuit. Now Caleb Kraft, senior editor for Make, has captured one of those live performances in full 360 degree video, letting you watch in any direction — up, down, at the crowd or smack between those massive coils. It's like being plopped down right in the middle of all the action. As dangerous as it looks, it's actually quite safe. That chain mail suit the guitarist is wearing isn't just for show: It's actually a wearable Faraday cage (also known as a Faraday shield), an enclosure specifically designed to exclude electromagnetic fields. There's also a metal mesh on the stage floor. As I wrote back in 2006:
The British scientist Michael Faraday built the first one in 1836 to demonstrate his assertion that the charge on a charged conductor travels along the exterior surface and doesn't influence anything enclosed within it. It's essentially an application of Gauss's Law: since like charges repel each other (opposites attract), electrical charge will "migrate" to the surface of a conducting form, such as a sphere. Faraday's 19th century version was an entire room coated with metal foil; he built it himself. Then he blasted the walls with high-voltage discharges from an electrostatic generator, and used an instrument called an electroscope to prove that no charge was present inside the actual room.
It's the same reason aeroplanes can withstand lightning strikes in the air, or passengers in a car struck by lightning will be unharmed (so long as they don't stick their hand out the window or touch a metal surface). The current will travel along the highly conductive aluminium surface. As long as there are no gaps in this conductive "path", the electrical current from the lightning will never have much of an impact.
Faraday cages make for show-stopping physics demonstrations, but Arc Attack has carved out a niche for themselves with their musical performances. Usually there's even a bit of education thrown in for good measure. "When you have multiple shows per day, you just can't do all of the educational stuff we typically do. Our full set is closer to an hour long and teaches a bunch of lessons too," Arc Attack's "subliminal optimist", Joe DiPrima, told Make.
As a bonus, audience volunteers at Maker Faire Austin were encouraged to come on stage and dance inside a Faraday cage while being blasted with tens of thousands of volts. But Kraft admits that despite his best efforts, "Even 360 video doesn't capture the awesomeness of massive tesla coils vaporizing the air to make music." Check it out: