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> The largest Covid-19 particles can fit 2 wide straight through a N95 mask.

Do they tend to float free in the air? I thought at least the optimistic take on masks was that much of the COVID virus that an infected person sheds isn't loose individual particles, but inside respiratory droplets that are much larger than the virus itself. Like if I'm spilling lemonade, the sugar molecules in the lemonade are extremely small, but most of them are in solution in the liquid and not very much sugar would tend to pass through something that didn't allow much liquid to pass through.

So I thought that while the masks can't block the virus particles, they can often block liquids in which most of the virus particles are present.

edit: the USA Today article that someone else posted in this thread suggests this is broadly right, e.g.

> The virus attaches to water droplets or aerosols (i.e. really small droplets) that are generated by breathing, talking, coughing, etc. These consist of water, mucus protein and other biological material and are all larger than 1 micron.

> “Breathing and talking generate particles around 1 micron in size, which will be collected by N95 respirator filters with very high efficiency,” said Lisa Brosseau, a retired professor of environmental and occupational health sciences who spent her career researching respiratory protection.

The trick is that the middle layer of N95 masks is an electret, a material that will hold an electric charge. It's the electrostatic equivalent of a permanent magnet. It's not a very strong charge, but it's enough to pull particles a few microns out of line and catch them in the filter.[1]

It's a mini version of an electrostatic precipitator, which has a coarse charged mesh and a strong charge. Those are good for pulling particles out of air.

If you want to test this, there are standard "fit test kits" for respirators. They're little packets of scented smoke particles. You put on the mask, break the ampule to let the smoke out, and if you can smell it, the respirator isn't working, or, more likely, is leaking.

[1] https://youtu.be/426IpWoEQsc

Besides all that, it's obviously false because if it were true then masks wouldn't work, and yet empirically, emphatically, demonstrably, masks do work. Like, every single person in a hospital setting treating COVID-19 patients would be immediately coming down with it if their protective equipment were worthless. But that's not what we observe at all, hence it's not correct.

Saying "empirically, emphatically, demonstrably, masks do work" in the context of talking about N95 masks might make sense. I hope you aren't implying that because hospital workers are protected by N95 masks that we therefore know beyond a shadow of a doubt that all the other masks people are wearing are effective. After all, the bigger context is the question about gators.

If you turn on "show dead comments" you'll see that the grandparent post to my reply was indeed specifically saying that N95 masks don't work for some reasoning having to do with relative size of the fabric mesh vs the COVID-19 viral particles. So yes, the context for this conversation has indeed always been N95 masks.

Please check your facts before posting. This is misinformation that's been flying around the internet, and it's going to harm people. There's a rundown here: https://www.usatoday.com/story/news/factcheck/2020/06/11/fac...

This isn't true.

Fact check: https://www.usatoday.com/story/news/factcheck/2020/06/11/fac...

Really, USA Today is your fact checker ?

That fact check is actually well written and explains the relevant underlying principles of how n95 masks work. It cites experts in their fields and gives a complete list of sources used, so it’s again verifiable. As far as my understanding of these things goes goes, the explanation holds up.

Whether it’s published in USA Today or not does not impact that.

In my mind, I see the screen door doing better than the chain link fence.

Yeah. Consider how much more light a chain link fence lets in than a screen door.

Does the mask need to present a physical barrier to the virus particles? Is there any electrostatic force, for instance, which would trap viruses as they passed close to the mask material?

Yes. Also N95 filter .15 micron particles better than .3 micron particles because their motion tends to be more Brownian and less ballistic, leading to more particle/masks interactions where they can get caught.

Was that a 'yes' to the first question or the second? Thanks in either case for the reply.

Oh, the second.

That's the theory. At the same time, in physics and generally in science any theory must be verified through experiments (rather not falsified, but that's a different story). I'd love to see some experimental data on your assertions.

If this is the study I remember reading months ago they found some strange results from the gaiter, it was effectively WORSE than wearing no mask. Essentially it aresolized droplets that were caught in other masks, at least that was the common read of their findings. I have yet to read this followup.

Because of the confusion between a results and a methods paper: https://twitter.com/joelindsey/status/1293593320657162243?s=...