Conventional wisdom may say playing with fire is dangerous, but the members of the Yale Anti-Gravity Society say otherwise.
For YAGS, fire-juggling is more than throwing torches in the air, the performers of YAGS employ a wide assortment of props ranging from devil-sticks to staves that have been lit on both ends. A flaming ball swung on a rope or chain, called the poi, is frequently featured in fire shows, as are diablos or burning hourglass-shaped objects spun rapidly on a string.
As in regular juggling, the trick is to begin with one club and work up to tossing three clubs at once. YAGS members are not allowed to flare up until they have practiced extensively with their unlit prop and received the approval of all officers, said Evan Orenstein ’08, who is responsible for running this year’s YAGS Halloween fire show.
“The trick is to do everything responsibly,” Orenstein said. “The most dangerous thing you can do with a [lit] prop is panic.”
YAGS members soak their props in fuel in a specified location, which is bounded by eight to ten feet of clearance area where performers are not permitted to light fire.
“We have a special set up where the fueling area is clearly separate from where we perform,” said YAGS president Greg Jordan ’07, who has been fire-juggling since the age of 12. “There is always someone fuel-spotting to make sure no one approaches the area with a live prop.”
By approaching the science of fire-juggling from a hands-on perspective, performers learn the mechanics of their art from experience.
Juggling torches, for example, teaches YAGS members that speed is less important than timing and catching the torch from the right side, Jordan said. With practice, catching a prop correctly becomes a matter of instinct rather than calculation, he said.
“Because you’re performing in the dark, you tend to focus on the image of the flame itself and the fire making a distinct noise as it moves,” Jordan said. “You’re hearing and seeing these things and it all just sort of clicks.”
Props are generally fueled using either white gas or lamp oil. White gas burns quickly, creates a large flame, and ignites easily because it has a low flash point which renders it less volatile. Lamp oil, on the other hand, is the effective opposite of white gas — with a higher flash point and greater volatility, lamp oil is more difficult to ignite, but its longer-lasting and more contained flame makes it ideal for fire-breathing stunts.
Fire-repellent duvatene cloths are available in case of an emergency, although they are typically used to conveniently smother flames at the end of a stunt. Two jugglers are on hand with duvatene at every practice, Orenstein said.
Performers also retain one chemical and one water fire extinguisher in case of emergency, although former YAGS president Melody Lu ’06 said the group prefers using duvatene.
The metal parts of the props are the most dangerous because they can become extremely hot, even though they are fireproofed, said Lu, who describes herself as the only “non-group IV, physics-obsessed” member of YAGS.
“Hitting a prop with water from an extinguisher can cause steam burns, which are more serious than burns from an actual flame,” Lu said.
Once a prop is lit, the stunt’s success relies on performers’ coordination and the laws of physics.
“The key with the poi, for example, is to keep it swinging so that centripetal force keeps it in a circular motion,” Jordan said. “The same idea goes for spinning the staff. Using more arm gets it higher and spinning with your wrist gets it going faster, so it’s a question of striking the right balance between the arm and the wrist.”
Lu said that a precise computation called site-swap notation can be used to estimate how high an object will go, which arm it is thrown with and the arc’s projected angle. But YAGS performers said they acquire their skill more through physical practice than technical study of such formulas.
“When you juggle, it’s more of a tactile thing, [it is] more of an art form than a science,” Lu said. “We operate more through muscle-memory, where we do it over and over until it’s impressed in our cerebellum.”