Eric Porter, the author of “A People’s History of SFO,” sees the nation’s No. 1 ranked large airport, San Francisco International, as a metaphor for the Bay Area. He explores how SFO and other airports mirror their cities’ art, culture, and values. While emphasizing the significant role public art plays in enhancing the airport experience, he explains how just observing people at any airport reveals much about the community, its workforce, and class structure.