The Secret Chamber
by Kevin J. Lin
While excavating an ancient Puzzlanian crypt, you discover an unusual column. The column has four narrow holes bored into it, all at the same height, evenly spaced around the column, just large enough for a human hand. Reading the inscriptions above and below the holes, you realize that this column is part of a complex mechanism that will open a secret chamber. Out of sight within each hole is a switch that can either be up or down; when all the switches are in the same position, the secret chamber will open before you. The column is small enough that you can reach all the way around, so using both hands you could flip any two switches at the same time. Here's the tricky part: As soon as your hand leaves a hole, the column will rapidly spin for a random number of quarter rotations. If you're not careful, you might lose a hand. But you can flip two switches at once, then quickly pull both hands out at the same time. What strategy can you use to open the chamber in a finite, and preferably small, number of attempts? Assume you cannot discriminate between holes after a spin without reaching into the column.
