They have tested everything from simple cloth masks to surgical grade masks, to full-on respirators. It's how they provide recommendations for use of any given type.
It's called the scientific method.
I brought up god in the context of people who will stick to a completely unproved and so far unprovable belief, but will fight tooth and nail against science (masks) because their leader told them that masks are for the weak, which then became some idiotic cry of "freedom" and "patriotism", neither of which has anything to do with science.
I have never claimed a god exists. When it comes to claiming god exists without any proof, it is up to the claimant to provide proof, not for everyone else to DISprove. When ANY type of claim is made, it is incumbent upon the person making the claim to back it up if they expect that claim to be believed.
You made a claim about how seatbelts work. Show something to prove it, or it's nothing more than a feeling, opinion, faith, belief.
This is not a new concept by any stretch of the imagination.
Yes, you will say you don't CARE who believes what YOU believe, but this is a case where there are societal impact from your beliefs. It's not a case of whether you think chocolate is better than vanilla, it's a case of public health and whether wearing masks may help the public in a time of crisis (yes, it's "only" 1%, but 700,000 dead from a novel virus is a bit of a problem).
Masks have been accepted (and proved) as a way to slow or prevent the spread of disease since the 1900's or before. It is only since Trump said they are for the "weak" that there has been question of their efficacy. A man with no medical training whatsoever turns a "medical device" (for lack of a better term) into a statement of strong vs. weak, and his followers (who also have no medical training) hop on the bandwagon.
Imagine if he said "chemotherapy is for the weak". I GUARANTEE there would be followers who would die of cancer instead of getting treatment. I can guarantee it b/c people DIED from taking an untested and unproved drug based on his lie of personal use and success, and people are fighting masks based on his claim of being "weak" by using one.
Certain people don't CARE about science when it goes against their beliefs.
*I* am not "thinking" how masks work. *I* am trusting in the experts who have done scientific studies to prove it. The same way I can say chemotherapy works without having tested it myself. The experts have done the hard work. I can refer to the results of their work and state those results. I can do the same about the solar system, about Ohm's law, about gravity (thanks, Newton), about an electric filament glowing in a vacuum chamber, liquid crystal displays, relativity, and a host of other things.
All stuff that has been proved.
If I want to disagree with it, then I get to PROVE my alternate theory. Beliefs, feelings, faith, opinions have never been proof of anything, and they certainly cannot be used to disprove something that HAS been proved.
It's how it is.
Here's just one study that is fairly recent. They used things like laser light scattering chambers and
"portable isolation box attached to an Andersen Sampler and used to measure orally expelled bacterial contaminants before and after masking to measure the air."
Buck will post a YouTube video of a guy exhaling with a mask on outdoors in cold weather and say the YouTube "study" is accurate, but this one is bogus.
Beliefs vs science.
The science around the use of masks by the public to impede COVID-19 transmission is advancing rapidly. In this narrative review, we develop an analytical framework to examine mask usage, synthesizing the relevant literature to inform multiple areas: population impact, transmission...
www.pnas.org
