Embedded in the facade of In a tall office building in downtown San José, four digital yellow circles rotate every few seconds, apparently without any purpose. This display has been in operation since 2006 and can easily be dismissed as an unusual artistic choice by the building’s resident, software company Adobe. In fact, this light installation, the San José Semaphore, emits a code through the city. Artist Ben Rubin replaces the code every time it’s cracked, which has happened twice so far.
The first time two technicians attending a downtown seminar on flirting with girls discovered the semaphore and spent the next several months breaking the code. In the summer of 2007 they announced that with references to James Joyce’s Ulysses and the Vigenère cipher, the entire text of Thomas Pynchon’s novel The Crying of Lot 49 had been hidden.
The second time, in 2017, a math professor from Tennessee cracked the next code and found that the circles had broadcast an audio recording of the first moon landing. That’s the code that is still beaming across the city, despite the fact that artist Rubin is working on a new one from early 2021.