Detail from the Best Buy vending machine in JFK – as the credit card is swiped down it continues down – gradually wearing a groove through the hardened plastic.

Thoughts for today: the ubiquity of credit card slots as interfaces and the practices around known behaviour (and a corresponding decrease in instructions on how to swipe); the evolution of credit card design, in particular its size, form, and edges. In an age of touch screens, it is the original swipe.