San Jose Semaphore

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San Jose Semaphore

Artwork by Ben Rubin

https://video.tv.adobe.com/v/3451620/?autoplay=true&end=replay

The San Jose Semaphore is a public artwork created in partnership with the San Jose Public Art Program. From its position atop Adobe’s Almaden Tower, its four glowing wheels are a beacon on the downtown San Jose skyline. As the wheels slowly turn and come to rest, they send a message that is visible for miles. Like the semaphore telegraphs of the 18th century, the artwork is a large and beautiful machine that uses visible symbols — the positions of its wheels — to slowly transmit information. But even though the Semaphore is broadcasting its message in plain sight, the contents of the message remain a mystery until solved.

Each wheel of the Semaphore can assume four positions — vertical, horizontal, left-leaning diagonal, and right-leaning diagonal. Together, the four wheels have 256 possible combinations. The Semaphore transmits its message at a steady rate, with the wheels turning to a new position every 7.2 seconds. Sitting beneath the flight path for the San Jose Mineta International Airport, the Semaphore reacts visibly when a plane flies overhead. The disturbance breaks its rhythm, but when the plane has passed, the Semaphore returns to its steady transmission.

Cracking the code .

A third puzzle started transmitting at the top of Adobe’s Almaden Tower on May 11, 2023. Hear how artist Ben Rubin created the third puzzle and how Brian Vincent solved it in the Spring of 2026.

https://video.tv.adobe.com/v/3491620?hidetitle=true

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About.

In 2001, Adobe broke ground on its third office building — Almaden Tower — on the campus of the company’s world headquarters in downtown San Jose, California. As part of Adobe’s commitment to the city, plans were made to include public art as part of the long-term site development.

In 2003, the San Jose Public Art Program facilitated a process to select an artist for the project. A request for qualifications was submitted to over 100 new-media artists, and 44 artists submitted letters of interest. A panel composed of Adobe representatives and internationally recognized media arts professionals reviewed the artists’ materials and chose a short list for interviews. In July 2003, the panel selected Ben Rubin to design, fabricate, and install the Semaphore artwork for Almaden Tower. Ben Rubin is a leading American artist who pushes the traditional boundaries between art, science, and technology. The San Jose Semaphore began its first transmission on August 7, 2006.

Adobe’s San Jose Semaphore connects contemporary digital systems with the earliest practical telecommunications network — the Chappe semaphore telegraph developed in France in the late 18th century. The Chappe system employed a visual code created by Claude Chappe and his four brothers that used wooden panels, moved manually by ropes and pulleys, to transmit messages between relay towers 5 to 6 miles apart. Morse code, binary ASCII character representations, Adobe PostScript, and the coding systems used in 21st century digital communications all trace their lineage back to the Chappes’ system for encoding information.

Three messages have been transmitted and solved to date.

First message : The full text of Thomas Pynchon’s 1966 novel The Crying of Lot 49. It was solved by a team of two research scientists, Mark Snesrud and Bob Mayo.

Second message : Audio file of “One small step for man, one giant leap for mankind.” It was solved by Jimmy Waters, a high school math teacher from Knoxville, Tennessee.

Third message : Image of a rose from Sandro Botticelli’s “Birth of Venus” painting. It was solved by Brian Vincent, a software engineer from San Jose, California.

How it works.

The Semaphore consists of four wheels, and each wheel can assume four positions: vertical, horizontal, left-leaning diagonal, and right-leaning diagonal. Together, the four wheels have 256 possible combinations (1 byte of information). The Semaphore transmits its message at a steady rate, with its four wheels turning to new positions — and delivering the next byte of data — every 7.2 seconds.

The Semaphore is illuminated by approximately 24,000 high-brightness LEDs. Artist Ben Rubin worked with Will Pickering of Parallel Development in Brooklyn, New York, to design the artwork’s custom LED driver and display hardware. Each Semaphore disc unit contains a solid-state graphics processor that renders the image of the spinning disc to the array of LEDs. An app written in Max/MSP controls the LED panels across a LAN.

The Semaphore’s steady signal is subject to interference from planes flying overhead. Adobe’s Almaden Tower sits directly underneath the San Jose Mineta International Airport flight path and when a plane flies overhead, it sets the Semaphore discs spinning, causing a momentary break in the transmission.

Up for a challenge?

The puzzle’s content...