An international team of researchers led by Princeton’s Howard Stone have found that ordinary conversation creates a jet-like airflow that quickly carries tiny droplets from a speaker’s mouth across many feet of an interior space. To study the flow of exhaled material, researchers filmed the movement of breath in front of a person speaking several different phrases. https://www.princeton.edu/news/2020/10/01/research-shows-conversation-quickly-spreads-droplets-more-six-feet-inside-buildings