“We are one in nine billion,” states a striking stainless steel sculpture at the entrance to the U.S. Pavilion at Milan Expo 2015: “Feeding the Planet, Energy for Life." That visual statement is intended to get visitors thinking about the fact that in 2050, the world’s population is estimated to reach 9 billion, and more sustainable ways to feed people must be found.

The Expo is not only to be experienced, but also remembered. As it is a concentrated temporal social occurrence, the outsized event rivets visitors’ attention and fascination. Transient as the Expo experience is, one’s impression of it can be long-lasting.