Ben Rubin's San Jose Semaphore is a "multi-sensory kinetic artwork that illuminates the San Jose skyline with the transmission of a coded message"

"Each wheel of the Semaphore can assume four distinct positions: vertical, horizontal, and left and right-leaning diagonal; together, the four wheels have a vocabulary of 256 possible combinations. The San Jose Semaphore transmits its message at a steady rate; its four wheels turn to new positions every 7.2 seconds."

The installation occupies the top floors of Adobe's headquarters in San Jose. The piece is based on the semaphore telegraphs of the 18th century.

The challenge: To crack the code.

It took three weeks for techies Bob Mayo and Mark Snesrud to crack it. "Computational brute force" is how the artist summed up their process.

The answer:

The semaphore was transmitting Thomas Pynchon's Crying of Lot 49, taking several months to transmit the entire text.

On why Crying of Lot 49 Rubin says:

Pynchon's setting is a fictional California city filled with high-tech industrial parks and the kind of engineering sub-culture that we now associate with the Silicon Valley. The book follows the heroine's discovery of latent symbols and codes embedded in this landscape and in the local culture. Is there a message here, she wonders, and what are these symbols trying to tell me? At its heart, San Jose Semaphore is an expression of what Pynchon calls "an intent to communicate."

Story in the San Jose Mercury News (registration required)
Mayo and Snesrud's Decoding the San Jose Semaphore (pdf)
Rubin's San Jose Semaphore: The Solution (pdf)