At 11:30 p.m. Wednesday, after the streets were clear of trick-or-treaters and parties were winding down, a group of Caltech students were pushing crates of frozen pumpkins up the elevator in Millikan Library.
There were about 50 pumpkins of various shapes and sizes in all. As part of a Halloween tradition dating back to 1972, five students climbed a ladder to the tallest point of the roof and prepared to launch the pumpkins, frozen in liquid nitrogen, off the side of the nine-story building.
“I don’t know anywhere else where you can see a pumpkin drop from a building,” said Kelly Douglas, a development research specialist at the campus.
Hosted by Caltech’s Dabney House, the tradition began as an experiment to test the theory that dropping a frozen pumpkin from a significant height would produce blue-green sparks, an event called triboluminescence, when it shattered. The pumpkin-drop experiment is a play on the oil-drop experiment conducted in 1909 to measure an electron’s charge by Caltech co-founder Robert Millikan.
No one has seen the mythical light in the event’s 40-year run, but organizers continue to carry on the tradition. This year, they attached LED light strips to a few pumpkins to parody the theory.
“Primarily, it’s just a fun event,” said Jade Yang, a 19-year-old computer science sophomore who helped organize this year’s pumpkin drop. “We all know that it’s just fake science, so it’s funny.”
A group of trombone players dressed in skeleton costumes — a clever nod to the ‘bone’ in trombone — offered musical entertainment before the show started Wednesday. Students, some already in pajamas and others still in costume, gathered around the tallest building on campus.
At midnight, “The Final Countdown,” a song played in previous years during the annual pumpkin smashing, blared through a set of speakers as the crowd cheered and looked toward the roof.
The first pumpkin hit the ground, covered in plastic, with a loud plop. It broke into several pieces, splattering orange-colored entrails everywhere. The music changed to Tchaikovsky and the pumpkins were dropped occasionally in rhythm to the notes. Organizers said the event has never caused any injuries, but halfway through Wednesday’s drop, shards from a large pumpkin flew into the crowd, causing several people to duck and run out of the way.
Aashrita Mangu, an 18-year-old electrical engineering student attending the event for the first time, said some pieces flew right over her head. She wasn’t phased.
“It’s the Caltech way to do [Halloween],” she said, still dressed in her Aladdin costume.
Alan Smith, of Sherman Oaks, and Mark Jones, of West Hollywood, were some of the only people in the crowd who weren’t affiliated with Caltech. They said they like to do something different on Halloween every year. After the last pumpkin fell, they posed for a photo with a couple of broken-off pieces.
“It was absolutely awesome,” Smith said. “It makes a school very cool, literally."