Expo '74 Symbol

Another significant appearance of the Möbius strip, albeit briefly in the spotlight, was the logo for the environmentally-themed Expo '74 World Fair, held in Spokane, Washington State, which ran from 4 May 1974 to 3 November 1974. The design arose as a result of a 'competition among several Spokane artists', won by Lloyd L. Carlson (Fig. 1).

The logo, albeit far from clear to the uninitiated,  is a stylised Möbius strip, which was chosen to symbolise the continuity of life and mankind's relationship with the environment. The three colours, blue, green, and white, also symbolised the environmental theme of the fair, representing the purity of clean water, the unspoiled natural beauty of growing plants and trees, and the cleanliness of fresh air, respectively. 

President Nixon (at the height of the Watergate scandal) opened the fair, with the symbol in the background, in a ceremony attended by 85,000 people (Fig. 2). About 1,200 journalists were accredited for the opening. Attendance averaged about 35,000 per day over the summer months. The fair ultimately drew 5.1 million visitors, nearly identical to the organisers' projections.

Promotional Material

Great play was made of the symbol, with it appearing on all promotional and commemorative material (Fig. 3). You name it, and it was used;  booklets, medals,  plates, pennants. and more!  

The Designer of the Symbol, Lloyd L. Carlson

Relatively little is known of the designer, Lloyd L. Carlson (1919-2009). An obituary at least gives some basic details, which the following largely borrows from. Carlson was a well-known graphic designer and Spokane artist. He also designed the seal for the city of Spokane. He was the Vice-President and Art Director at Devine, Miller, Carlson and Donaldson, the award-winning advertising agency he co-founded in 1968 until his retirement in 1980. Pictures of Carlson in association with the symbol are few and far between. Indeed, there is only one known photo of Carlson at the World's Fair (Fig. 4).

However, even here this is not entirely satisfactory, as the Möbius strip logo in the background is unfortunately mostly obscured. Further, without any known sketches, quite how he arrived at the design is not known. A brief background is given by his son, Steven, in the Inlander, where he credits a 'Time-Life book', without being more specific. Possibly, this is David Bergamini's Mathematics, Life Science Library, of 1963. This is a popular book, which could readily be imagined Carlson saw. However, he has at least explained the rationale behind it, in a detailed account given to Jack Geraghty, on the committee who selected the design. 

What is the Type of Möbius Strip?

Of interest is the logo itself (as with the recycling symbol); what type of Möbius strip is it? It is a clockwise (single) half-twist Möbius strip. As can be seen, it portrays a Möbius strip within a broad regular hexagon (with rounded corners). The design itself is minimal, without any suggestion of dimensionality. 

References

Bovey, Chris. 'What Goes Around. The story behind the iconic Expo '74 logo'. Inlander, April 30, 2014.

https://www.inlander.com/culture/what-goes-around-2297323