Westinghouse Sign

The Westinghouse Sign was a large, animated, electric sign advertising the Westinghouse Electric company and located in Pittsburgh, Pennsylvania, U.S.A. The sign was best known for the essentially infinite number of combinations in which (it was popularly believed) 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.

The various corporations which have carried the Westinghouse name have erected countless signs and other promotional devices during the past 140 years, including many in the corporate hometown of Pittsburgh. A cubic Westinghouse sign stood in downtown Pittsburgh for approximately thirty five years and was so familiar that it was allowed to remain in place until 2002, even after the building it marked (the Westinghouse Tower) was no longer owned or occupied by Westinghouse. Nonetheless, "The" Westinghouse Sign" is widely understood to refer specifically to the structure discussed here.

The image above is an animation representing one possible lighting sequence of the Westinghouse Sign. (It does not, however, represent either set of patterns described below.)

Construction and operation

The Westinghouse Sign was mounted atop the WESCO building in Pittsburgh's North Shore neighborhood. WESCO began as the Westinghouse Electrical Supply Company, an offshoot of the original Westinghouse Electric founded by George Westinghouse in 1886. The sign consisted of nine repetitions of the familiar "Circle-W" logo created by graphic designer Paul Rand, each one eighteen feet in diameter. Each Circle-W was divided into ten sections—the top and bottom of 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 ninety individual elements. It is described as having been lit by neon tubes, but as the sign was blue it is likely that argon tubes were actually used.

The WESCO building stood near Three Rivers Stadium on the banks of the Allegheny River just opposite Downtown Pittsburgh, and the sign was one of several large illuminated corporate billboards that became a fixture of Pittsburgh's evening skyline. (The Alcoa sign atop Mount Washington was another.)

What distinguished the Westinghouse sign was the common perception that there was a practically infinite number of sequences in which the sign's elements could be lit, and that no sequence was ever repeated. The Westinghouse corporation encouraged this perception. In reality, only a very small number of lighting combinations—perhaps fewer than thirty—were actually displayed. This was because the sign was controlled by Westinghouse's own Numalogic Programmable Logic Controllers, which were well-suited to controlling repetitive tasks but were not designed to generate an ever-changing sequence of new instructions.

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 intended to save at least one of the Circle-W units for eventual display at the Senator John Heinz History Center. However, both the physical structure and electrical components were in such a state of decay that this was not possible, and the sign literally fell apart as it was dismantled. While newspaper accounts of the time report that at least one Circle-W was saved, individuals involved in the project report that nothing was salvagable.

Other signs

Smaller versions of the sign were erected in Atlanta, Georgia; Cleveland, Ohio, and New York City. The latter was located along Queens Boulevard on the approach to LaGuardia Airport. These each included three repetitions of the Circle-W insignia.

Combinations

The Pittsburgh sign

As noted above, only a few dozen lighting sequences were actually programmed into the sign's controller. Some online discussions of the sign reveal comments from individuals observant enough to have noted the repetition. [http://www.pittsburghcitypaper.ws/gyrobase/Content?oid=oid%3A28976 Pittsburgh City Paper] ,accessed 16 July 2007.] Nonetheless, most of those familiar with the sign believed that it was slowly cycling through an essentially infinite number of possible lighting combinations.

In order to determine what the number of combinations "could have been" it is necessary to determine what parameters, if any, governed the lighting of the sign. If the only stipulation were "one element at a time" the number of combinations 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 13.7 billion years ago there have been "only" about 4.5 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. [http://www.madsci.org/posts/archives/oct98/905633072.As.r.html How many atoms make up the universe?] , accessed 16 July 2007.] [http://pages.prodigy.net/jhonig/bignum/qagalaxy.html Atoms in our galaxy] , accessed 16 July 2007.] [http://www.burtleburtle.net/bob/crypto/magnitude.html#brute Orders of magnitude] , accessed 16 July 2007.]

However, the few available photographs of the Westinghouse Sign in operation suggest that there were two specific patterns guiding the illumination of the sign (and thus a smaller number of possible lighting combinations):

* The same element (e.g., 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 (e.g., the bottom of the enclosing circle), and so on, until all ten elements in all nine units were lit.

* The central Circle-W unit first would be lit in its entirety; the remaining eight units would then be lit in a manner similar to that in the first scenario (i.e., all of one element, then all of a second, etc.), except that illumination would begin with the outermost units and work its way toward the center, alternating side to side.

If these were in fact the "only" lighting schemes for the sign the number of possible combinations becomes 2(10!²+10!), or 26,336,386,137,600 (approximately 26.3 trillion). This is still a very large number—if a complete illumination of the sign were completed exactly once every minute it would take over fifty million years to display all possible combinations. But the number is infinitesimal when compared to the previous figure. The total amount of United States federal budget submissions, in U.S. Dollars, for just the Clinton and G.W. Bush administrations far exceeds 26.3 trillion.

The small signs

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.

If the two patterns described above in respect to the nine-unit sign are taken to have governed the smaller signs as well, the number of possible combinations would be identical to that of the Pittsburgh sign—approximately 26.3 trillion. In fact, given these particular lighting instructions, the number would be 26.3 trillion for "any" odd number of circle-W units greater than two (given an even number there would be no center circle-W, making the second of the above lighting scenarios impossible). For any single "pass" through the circle-W units, after the first element is chosen all remaining instances of that element (regardless of how many there are) will then be lit in an entirely predetermined order according to the given pattern (i.e., left to right, right to left, left-right-left, or right-left-right). For example, if one is considering left-to-right patterns, the first element lit may be any one of the ten elements in unit #1; but the second element "must" be the corresponding element in unit #2; the next "must" be the corresponding element in unit #3, and so on—the only opportunity for variation is in the selection of the first element. As a result, a change in the number of circle-W units may effect the "time" required for a single complete illumination, but it will have no effect on the total number of possible lighting combinations.

ee also

Neon sign

Orders of magnitude (numbers)

Names of large numbers

Observable universe

External links

* [http://pittsburghsigns.org/archives/2004/12/westinghouse.html Pittsburgh Signs bulletin board]
* [http://www.pghhistory.org/ Senator John Heinz History Center]
* [http://www.karenware.com/powertools/ptcalc.asp Karen's Power Tools calculator] , used to calculate the exact value of 90!

References