Gray code at the pediatrician's office

Last week we took Iris to the pediatrician for a checkup, during which they weighed, measured, and inoculated her. The measuring device, which I later learned is called a stadiometer, had a bracket on a slider that went up and down on a post. Iris stood against the post and the nurse adjusted the bracket to exactly the top of her head. Then she read off Iris's height from an attached display. viaThe Universe of Discourse : Gray code at the pediatrician's office.