Huh? I do wear them if anyone is around but how does a cluster sit there for 3 hours 27 feet away???
27 feet is the worst case distance for a sneeze. Here is an article on related study:
https://economictimes.indiatimes.co...s-mit-scientist-says/articleshow/74928356.cms
However, inside there is ventilation. Outside, there is wind. So, a mere cough outside with additional environmental factors can also go far.
A cough or sneeze is like a mini-cloud of vapor and little things small enough to bounce around on other little things. The virus may bounce around a short time or a long time. Before the coronavirus was even pandemic this was common knowledge in regard to flu and common cold. Here's an example about flu:
https://www.flu65plus.com/stories/can-flu-spread-through-air
It isn't expected to be that different. The virus isn't going to hit the ground in a second or two. 30 minutes, 1 hour, 3 hours...if I want to be risk averse, I would assume 3 hours.
Imagine, for example, Person A is jogging in the park with no mask, they cough to their right side. A brief gust of wind was present rightward to the person. Note the wind isn't even necessary...
Now, imagine 5 minutes later, person B is strolling in the park. They don't see anyone so they don't wear a mask. They walk a path parallel to the previous jogger, Person A...but they are 7 feet away to the right....perhaps on the opposite side of a wide public path.
Do you think Person B has 0.0% of walking through a cloud of cough? I'm going to claim it's more like 10%. I can't "prove" it but consider a cloud isn't an inch but more like a foot, two, or three....and if the center were randomly between 1 foot and 27 feet to the right of Person A, there's some approx 10% of this range where Person B's body comes into contact with the cloud.
Of course, there may be other environmental factors that destroy the clouds like heat, UV, strong winds, but in experiments sneezes can go 27 feet and virus can be in the air a long time. So, at a minimum, the 6 foot social distancing thing isn't 100% sure thing. It's a personal choice on how risk averse beyond that that people want to be.