This article was adapted from the Aug. 4 edition of the Border Chronicle. Subscribe to the Border Chronicle here. Today, most travelers entering the U.S. have to undergo this weird thing: After officials take a headshot, software determines the geography of your face, including the distance between your eyes, the distance from your forehead to chin, and different facial landmarks. Your facial signature then becomes a mathematical formula that can be compared to a database of tens of millions (hundreds of millions?) of known faces—or, if you are crossing the border, with your visa, passport, or even driver’s license photo.