Turns out there might not be a proper distance.
According to research from MIT, the “6-foot” rule was based on an understanding dating from the 1930s and quite obsolete.
In fact, atomized droplets containing the coronavirus can travel from 23 to 27 feet from the source, and remain suspended in the air for several hours, risking infection to anyone who walks through the invisible mass.(1)
Further, a Massachusetts study of the virus in wastewater suggests that the number of infections may be as little as 4 times what’s being reported, and as much as 70 times what being reported. Meaning that a state reporting 2,000 infected people could have between 8,000 and 140,000 who are actually carrying the virus.
With this virus, looking for people with obvious symptoms is insufficient. Even tracing their known contacts is only a partial job. The technology that Apple and Google are sharing to use cell phones to identify potentially exposed individuals may be the only real way to identify the infected.
Meanwhile, how do you protect yourself? Wear a mask. And glasses if you have them, as the virus can enter your other ways than through the mouth and nose.
You need to have the mask on virtually anytime you are outside, not just in a store. (OK, if you’re on a high mountain and no people or animals have been in that location for days, maybe you can do without one. Get the point?)
Of course, be thorough when washing up.