The issue is, the virus is riding on a 1 micron sized aerosol particle. It doesn’t float around in air as a “naked” virus. It has to be on the aerosol droplet (deceptive word).
The mask stops those. In both directions. If you’re infected and exhale, yes, a lot of virus will line the inside of your mask. That’s what it’s supposed to do. Stop it. You’ll wash that away or throw it away.
The issue of it going out the sides is of course there, but it won’t have much forward velocity. The 6 ft spacing then deals with the issue, certainly diluting it, and the guy next to you in a mask . . . it won’t get in.
Politically, no question, when people see masks on people they think virus. They think . . . if I’m going to the store I need to get in and out fast. If they see a mask they think . . . no way I’m going to sit in a crowded theater for 2 hours. Yes, seeing masks hurts business.
But it’s the only defense we have and it is not useless. That’s political preference in the other direction.
“The issue of it going out the sides is of course there, but it won’t have much forward velocity.”
What does FORWARD velocity have to do with squat? Is a virus particle squirted out the side as I walk through WalMart less infectious than one going forward? What if I turn my head? Or turn my body?
What about the stuff being forced UP instead of the normal downward velocity? Why is it better to thrust the virus up into the air instead of down toward the ground?
Is social distancing - what we call “being polite” in Arizona - something that only matters in front? Because no one can walk behind me? And no air conditioning system will pick anything up and thrust it all around the room?