In the 1930’s when astronomers were busy measuring the distance to nearby stars, Arcturus was believed to be 40 light-years distant. With emergent photocell technology employed at the 1933 World Fair in Chicago, the light from Arcturus was collected and used to activate a series of switches. Light believed to originate at the time of the previous Chicago World Fair — the city had hosted it 40 years prior — was used to illuminate and officially open the Fair in 1933.