I normally ignore these scrums, but (shrug)
Vitamin is the contraction of the term 'vital amino acids' - enunciate accordingly.
Masks will prevent the violent expulsion of large droplets from, sneezing, coughing, yelling, singing, etc. being flung about the room. It also prevents the dripping into the patient's open body cavity of things such as drool, nasal drip, sweat, and spittle, and flecks of dead skin - All of this is good.
Now we need to understand a bit of physics and chemistry. A Corona virus is roughly 3 nm to 4 nm in diameter. What's a nanometer you ask (well ask me so I can go on - sheeeze)
Pluck a hair off your head. look at the cross section of the end of the hair. Now divide that cross section in half 70,000 times. That is a nanometer (roughly)
The fabric in a cloth mask has a weave density comparable to a 4 nm Virion as is my assuming that a chain link fence will stop a mosquito.
The exhaled air from you escapes from under the mask mostly around the edges ( under my glasses fogging them, dimmit! ) And the final bit goes through the fabric.
If it did not you would pass out shortly.
The side light pictures of folks sneezing, showing the blast of aerosol DROPS are dramatic. It shows that a mask will stop most of that (like the particle separator on your spanking new TBM-950
The virions being expelled are invisible. Why? Because they are smaller than the wavelengths of visible light. Basic physics.
The microscope on the stand next to me will not show them either for the same reason. It requires an electron scanning microscope to visualize virions.
OK. Now to the point ( he finally got there, jeez Louise )
Assume you are in a small room. Just outside is a guy who is handed a lit cigarette. He fills his lungs with a long drag, drops the butt, slaps on a mask, steps through the door 6 feet away from you, and exhales.
Do you assume, or believe, you won't smell the cigarette smoke?
Smoke particles are thousands of times larger than a virion. The mask should stop it, right? (any non smoker knows better from experience)
If you can smell it you are engaged in second hand smoking.
And engaged in second hand virion inhalation. Annoying, eh wot?
So, will masks protect the public?
Maybe a teeny bit (shrug). Otherwise they are just virtue signalling .
Only herd immunity will protect us. We will have herd immunity when roughly 20% of the population has antibodies. In a population of 350 million that is 70 million people.
Assuming the true infection rate is ten time the reported rate, we are about half way there. Round two this fall will be about half as severe . (Fauci knows this but saying it will cost him his job)
I could make a long post on this topic (but I won't - He said)
Whew, saved