Isn't the following simple experiment enough to show that wearing a mask should help?<p>1. Without a mask, I coughed while probing the space around my face with one of my hands, at a distance of maybe 9-12 inches away.<p>I could easily feel significant airflow from the cough in a cone in front of mouth. Nothing to the sides (for purposes of this discussion, "side" means significantly off-axis from from the line down the middle of the cone, so includes above and below the face, not just left and right).<p>2. Same test, with mask. I either did not detect any airflow or just detected a bare hint of some at the same test distance as unmasked. (I'd need an assistant to tell which, since I can't think of a good way to do a blind test alone).<p>There was definitely some airflow out the sides with the mask, as I could see by the coughs fogging my glasses, but it only seemed to be very close to my head.<p>3. I Repeated the above, but replacing "cough" with "blow as hard as I can". Same results.<p>How does one escape concluding from this that if I'm infectious wearing a mask will reduce the volume over which my releases of air containing virus laden droplets spread? Or that this means my chances of passing it on to someone I'm only spending a little time with (clerks helping with a purchase, people standing in the same line for something, etc) will be reduced?