Ditch Day Is Today

Students donning sumo suits, racing shopping carts, rappelling down buildings and wielding slingshots, sledgehammers, and bows took over campus for this year's Ditch Day.

Ditch Day is one of Caltech's oldest traditions. During the spring rite, seniors ditch their classes and vanish from campus, leaving behind complex, imaginative scavenger hunts, puzzles, and other challenges that are carefully planned out to occupy the underclassmen and prevent them from wreaking havoc in the seniors' unoccupied rooms. Although similar such hijinks are apt to occur any day of the year at Caltech, Ditch Day—the timing of which is kept secret until the last minute—inspires some of the most inventive manifestations of Techers' pranking impulses.

Follow along with the underclassmen on Caltech's Facebook and Twitter pages as they tackle mind-boggling clues and elaborate contraptions.

Here's a primer of what you'll need to know to even begin to understand what Ditch Day is all about.

The Art of Stacking

The original Ditch Day "stacks"—a Caltech euphemism for locks—were devices installed, or measures taken, by seniors to keep underclassmen out of their rooms when they were off campus for the day. Traditionally, there were three different kinds of stacks, each named for the approach required to undo it:

• The Brute Force Stack entails exerting physical energy to deconstruct cars or break through rebar-fortified cement, and other such barriers. This stack has fallen out of popularity to some degree because seniors have to make good on any damages.
• The Finesse Stack requires solving puzzles and defeating sophisticated electronic, optical, chemical, or biological locks and puzzles to gain entry into a senior's room.
• The Honor Stack is more of a role-playing stack, often mixing elements of brute force and finesse; the "honor" component of the stack requires that a student play along with the creator's storyline, even when that means dressing up in character and participating in silly acts across campus and town.

The first room stacking was in 1931-32. The late Chuck Lewis (B.S. '31) described stacking as being quite literal: it was the act of stacking all the furniture in one tight configuration in the center of the room. As often happens in the English language, though, the definition has expanded with time. These days, stacks typically involve elaborate trails of clues and puzzles that have themes inspired by books, video games, TV shows, or movies. They also often combine elements from all three types of stacks.

As Caltech's stacks have evolved, so have the stories and tales of past feats. Some stacks have become lore and are either captured in Legends of Caltech—a collection of infamous stacks written by Techers over the years—or described online. They include:

The Laser Maze Stack

In 2006, six underclassmen had to navigate, crawl, and contort their way through a laser maze in one of the darkest segments of the steam tunnels. To unlock the next clue, all six participants had to simultaneously touch a portion of a wall to activate the maze and then work their way through without obstructing any beams. Blocking a beam would cause the maze to turn off, forcing the team to start over. The maze used more than 100 mirrors spanning roughly 70 feet of tunnel.

The Apocalypse Now Stack

The challenge was to operate a remotely controlled helicopter inside one senior's room. The helicopter was outfitted with a hanging scoop. The undergraduates had to navigate the helicopter to a ball located in one part of the room, use the scoop to pick up the ball, then transport it to the middle of the room and drop the ball into a box with a device that would unlock the door and give the group of underclassmen entry. A couple of obstacles made this task more complicated: the remote control was attached to a wire that ran out the back window, which was covered to block the view inside. So, one person on the team had to get a ladder and climb up to the back window to operate the remote control while another teammate looked through a peephole in the door and provided directions on where to fly. The moment the helicopter was activated, however, Wagner's "Ride of the Valkyries" (which is played as loudly as possible at 7 a.m. each morning during finals week) started blaring at full volume, making communication between the two individuals nearly impossible. Ultimately, the group of students formed a 10-person fire brigade to pass instructions from the peephole to the operator.

Bank-vault Style Room Stack

A collective effort by Page House seniors in 1970, the stack was a framework of 4-foot-by-4-foot timbers running the length of the room. The timbers held in place a window blockade and a vertical post positioned next to the latch-side of the door. Three half-inch holes were drilled into the vertical post, at 3-foot intervals, and the post was reinforced with steel framing. Three electromagnetically driven pins mounted on angle frames set in the door hinges met the holes and latched the door shut, bank-vault style.

To get into the room, the underclassmen had to complete three complicated steps:

Step 1: Locate an invisible plug of spackle in the tile mortar in the adjoining bathroom wall, which opened onto the back mirror above the sink in the senior's room. Run a long stiff wire from the back of the mirror, through a 12-volt battery, to the senior's doorknob.

Step 2: Correctly connect two of 24 color-coded wires that had been run out underneath the door.

Step 3: Activate a receiver for an old garage door opener, located inside the room, using a pocket transmitter to retract the pins of the bank vault arrangement on the door, once steps 1 and 2 were complete.

The Counterstack

The stacking tradition also includes the so-called "counterstack"—the innovative puzzles, obstacles, and hijinks of underclassmen produced in response to the senior's challenges. Among the most famous:

A room "rotation"

In Fleming House, a group of underclassmen rotated one senior's room 90 degrees, attaching the bed, desk, chair, and lamp to the wall and affixing paintings and wall decorations to the floor and ceiling, respectively. The light switch was also transplanted, and the door was taken off its hinges and hinged at the top. With this arrangement, a student lying down on the floor appeared to be standing in the middle of the room.

Lights out … or on?

In the 1960s, two rooms in Ricketts House were rewired so the light switches simultaneously worked both rooms—but when the light in one room was turned on, the light in the other was off, and vice versa.