The costumes.

The candy.

The pumpkins…

… whizzing through the air.

For most of Chicago, Halloween is a spooky thrill. For students, faculty and alumni of Illinois Institute of Technology, it’s an opportunity to put science to work and make some pumpkins go squash.

“The splatter effect,” said student competitor Roman Kofman, 22, of the projectile pumpkin appeal. “Definitely the splatter effect.”

The third annual Pumpkin Launch is IIT’s jettisoned jack-o-lantern celebration of science. There are catapults, spinning flywheels and medieval artillery such as trebuchets, all scrupulously designed and built to hurl a 5 to 10 pound pumpkin as far across the 235 foot span of the campus’ Siegel Field as possible.

“We estimated that to get 200 or 230 feet, which is what we are aiming for ideally,” Kaufman explained, “we would need 120 RPMs on a seven-foot radius.”

Huh?

“Centrifugal motion,” he elaborated.

The seeds of science are pervasive in each of the designs -- from the pendulum-like arm of the trebuchet, which on its end is taller than a small house with a pitched roof -- to the counterweights, such as weight plates, sandbags and large rocks, used to build momentum and in turn, get those gourds going.

“I think with the momentum behind it, you get a lot more with it,” said Kaitlyn Conley, 21, head of the American Society of Civil Engineering team of her group’s trebuchet. “The tricky part is to get it accurately in the swing and whip it over at the right angle.”

“It takes more engineering skill,” she continued.

Skills of all stripes were apparent in the 17 teams, each consisting of between four and eight people, that competed Tuesday in this year’s event. The number of teams is three times that of last year’s entries. For each round of competition, six devices were set up, side by side, on the south end of the field and were allowed three launches a piece. After their longest launch was measured, off they would go and on would come six more contenders, making the field look like a medieval battleground cum frat party.

The teams, bearing names such as Red October, The Juggernauts and Knights of Elezar, competed for a grand prize of $1,000. The team with the most creative launcher won $250.

Hundreds of people turned out for the event that pre-empted classes for the day. Spectators wandered through pumpkin decorating tents, ate taffy apples and stopped to marvel at science in the form of pumpkin projectiles carving a path through the blue sky.

“I’m actually astonished with what I see,” said student Tim Schug, 23, who watched from the grassy sidelines. “I hope their grades are still good.”

The launchers, some taking up to a month to build, were a creative way to make scientific theories practical. Well, as practical as pumpkin comet can be.

“It’s a celebration of IIT,” said John Anderson, the new president of the school who was inaugurated at a reception earlier in the day. The Pumpkin Launch was part of the festivities and an auspicious way to welcome a new head to the school.

“I can’t say that I’ve had that happen before,” laughed Anderson of his flying pumpkin welcome wagon. “I’ve been dunked when I was dean of engineering at a different university.”

Anderson, who participated in the launch on the American Society of Civil Engineers team, is certainly not yellow when it comes to hurling the orange.

“It’s a momentum lever-arm principal, like a seesaw,” he said. “The key is the release point. Power and release.”

And release they did. The trebuchets whipped the pumpkins far and furiously. The catapults tended to catch more air. The spinning flywheels were a dervish of swinging arms and a chain gang of sorts pulling ropes in tandem to build up energy. The spring-generated launchers had teammates using brute force to pull the recoil mechanism back and release it, like a giant pool cue.

“We calculated that it’s pretty close to breaking the pumpkin,” said Purvag Patel of his team’s launching power.

It wasn’t all meteoric fruit-flinging madness. Several teams had to contend with breaking latches, unruly pendulums and a weight miscalculation that sent a sizable pumpkin rocketing backwards, cutting a swath through an unsuspecting crowd.

“I told you so!” admonished a young woman to her teammates.

At day’s end, with the American Society of Civil Engineers winning with their last launch of 234 feet, broken, bruised and battered pumpkins littered the field. Two student judges from the Department of Biomedical Engineering wearing lab coats and placing traffic cones on contending landing points, contemplated what inevitably came next: Clean up crew.

“We’re trying to figure that out actually,” one young man laughed, “and I’m hoping that it’s not me.”

To the victor, hopefully, doesn’t go the spoils.