At Caltech, Every Halloween Falls on a Splatterday

Following a hiatus, plummeting pumpkins have returned to campus as part of a nearly 50-year-old Halloween tradition.

Each year, students gather near midnight on Halloween to drop liquid-nitrogen-frozen pumpkins from the rooftop of the tallest building on campus. The reason for the drop? In theory, due to a phenomenon called triboluminescence, the frozen pumpkins should generate an eerie blue-green spark upon impact with the ground. In the event's history, no one has witnessed the brief flash, but that hasn't deterred students from their fun.

The tradition was launched by members of Dabney House, who started on a somewhat smaller scale, tossing pumpkins from the tallest point on their campus residence. Below is a slideshow of pictures from this year's event, courtesy of Chris Wang and Selina Zhou, student photographers from the Big T yearbook.

View a video of this renowned Caltech tradition.