The Westinghouse Sign was the first computer-controlled sign in the United States. Located in Pittsburgh, Pennsylvania, the large animated display advertised the Westinghouse Electric Company, and was best known for the seemingly endless number of combinations in which its individual elements could be illuminated. The sign was removed in 1998 when the building on which it was mounted was demolished to make way for the construction of PNC Park.
On December 9, 1948, the Westinghouse Electric Supply Company (Wesco) moved into a new building located at 209 West General Robinson Street in the North Shore section of Pittsburgh. Wesco was a wholesale distributor of electrical apparatus, and a subsidiary of the Westinghouse Electric Company founded by George Westinghouse in 1886.
For many years, a large orange and blue sign on the Wesco roof proclaimed the company's advertising slogan: "You can be sure…if it’s Westinghouse." The sign was pointed to the south, across the Allegheny River, making it easy to see from Downtown Pittsburgh.
Early in 1966, Westinghouse decided to replace the aging advertising sign on the Wesco Building. The idea was to remove the slogan from the existing 200-foot (61 m) support structure, and replace it with a modern view of the Westinghouse corporate identity.
In due course, Richard Huppertz, manager of design coordination at Westinghouse, developed a concept that would bring greater recognition to the 'circle w' logo created by graphic designer Paul Rand. Rather than using words, the sign Huppertz had in mind would rely solely on the Westinghouse corporate mark. The concept was then presented to Paul Rand, who produced a design emphasizing the nine elements of the logo he had illustrated in a 1960 graphics standards guide.
The Pittsburgh Outdoor Advertising Corporation installed the Westinghouse sign in June 1967 using 3,000 feet (910 m) of neon tubing filled with an argon gas, giving the display its characteristic blue color. The sign was composed of nine repetitions of the familiar 'circle w' logo, each of which was 17.5 feet (5.3 m) in diameter and initially divided into nine sections—the enclosing circle, the four diagonal strokes of the W, the three dots above the W, and the bar below—meaning that the entire sign comprised eighty-one individual elements. In later years, an extra element was added to each logo by allowing the top and bottom of the enclosing circle to be independently illuminated. The ninety element configuration increased the number of possible display combinations, but sacrificed the elegance of the original design.
The Wesco Building stood near Three Rivers Stadium, and its sign was one of several large illuminated corporate billboards that became a fixture of Pittsburgh's evening skyline. Among the others were the Alcoa sign atop Mount Washington, and the Clark Bar sign on the D. L. Clark Company Building.
What distinguished the Westinghouse sign was the common perception that there were practically an infinite number of sequences in which the sign's elements could be lit, and that no sequence was ever repeated. The Westinghouse Electric Corporation encouraged this perception. In reality, the cycle of display patterns would repeat every six minutes, employing a subset of 120 lighting combinations created by Westinghouse designers. To heighten interest in the sign, lighting patterns would be changed from time to time by selecting different sequences from the 120 available displays. A Westinghouse Prodac 50 computer controlled the sign, since it was well-suited to handling repetitive tasks.
The sign was demolished when the Wesco Building was razed in the autumn of 1998 to make way for PNC Park, which succeeded Three Rivers as the home of the Pittsburgh Pirates. Preservationists attempted to save at least one of the 'circle w' units for eventual display at the Heinz History Center. Alas, both the physical structure and electrical components were in such a state of decay that nothing was salvageable.
A second sign was located in Emeryville, California, facing the San Francisco Bay.
Smaller versions of the sign, using three repetitions of the 'circle w' insignia, were erected atop the Westinghouse Outdoor Lighting Plant in Cleveland, Ohio, and on the north side of the Long Island Expressway in Queens, New York.
Only a few dozen lighting sequences were actually programmed into the sign's controller at any given time. Some online discussions of the sign reveal comments from individuals observant enough to have noted the repetition. Nonetheless, most of those familiar with the sign believed that it was slowly cycling through an essentially infinite number of possible lighting combinations.
If the only stipulation were that one element at a time would be lit, the number of possible sequences is simply:
90! = (90•89•88•87...3•2•1) ≈ 1.486 x 10138, or 1.486 quintoquadrogintillion. (The exact value is 1 485 715 964 481 761 497 309 522 733 620 825 737 885 569 961 284 688 766 942 216 863 704 985 393 094 065 876 545 992 131 370 884 059 645 617 234 469 978 112 000 000 000 000 000 000 000.)
Such a number may be incomprehensibly huge. If the Big Bang is reckoned to have occurred 13.8 billion years ago, there have been "only" about 4.35 x 1017 seconds since the birth of the universe. It is estimated that the Earth is made up of roughly 5.5 x 1050 atoms; the number of atoms in the Milky Way Galaxy is approximately 5 x 1068, and the number of atoms in the universe is estimated to be 3.5 x 1079.
However, the sequences programmed into the sign's controller suggested to some that the possible total was guided by one or more patterns (e.g., the same element—perhaps the bar below the W--would be lit in each of the nine units, working either left to right or right to left, followed by all nine instances of a second element, and so on, until all ten elements in all nine units were lit). It became a sort of mathematical puzzle to determine what the total number of sequences would be, given these (imagined) patterns.
For the smaller three-unit signs, the number of possible combinations under the "one at a time" scenario would have been:
30! ≈ 2.653 x 1032, or 265.3 nonillion. (The exact number is 265 252 859 812 191 058 636 308 480 000 000.)
This number may be quite small when compared to the figure for the nine-unit sign (it is 1.785 x 10−106 the size of the larger number—or 178 quintrigintillionths) but it nonetheless represents a number that may be well beyond a familiar human scale. One nonillion is approximately the number of bacteria living on Earth.