" The CDC defined a close contact of a person with coronavirus as someone who was “within 6 feet of an infected person for at least 15 minutes starting from 48 hours before illness onset until the time the patient is isolated.” This is a somewhat arbitrary criterion, given that the virus can spread much farther than six feet.57 "

― Nicholas A. Christakis , Apollo's Arrow: The Profound and Enduring Impact of Coronavirus on the Way We Live