It goes on to say "However, there are microdroplets which stay in the air for 30+ minutes depending on the air currents."
It sounds like you're both in agreement that large droplets fall quickly to the ground, and that with COIVD the longer-lasting micro-droplets are a relevant factor.
There are no "microdroplets" which stay in the air for "30+" minutes.
First, water DRIES OUT unless the humidity is very close to 100% which is relatively rare in western countries. The smaller droplet the faster this happens.
Put a very, very small droplet on a flat surface like glass. Observe it disappear within couple of minutes. Then imagine that a smaller droplet is just larger droplet closer to drying out.
Volume increases with cube while surface with square of diameter. When the droplet gets smaller the drying out speeds up.
The only time there are persistent droplets of water in air is called fog and happens when air is supersaturated with water. This happens when you cool air that is already 100% humidity. In that circumstance water cannot evaporate and that is what makes it possible to have water droplets in air. Once the relative humidity falls below 100% even a tiny bit, the fog almost instantly disappears.
Ability of virus to be airborne means it can survive outside droplet of bodily fluid for an extended period of time. Once all water dries out it also becomes very light and can be moved by smallest currents of air.
"Airborne transmission is distinct from transmission by respiratory droplets. Respiratory droplets are large enough to fall to the ground rapidly after being produced (usually greater than 5 µm), as opposed to the smaller particles that carry airborne pathogens. Also, while respiratory droplets consist mostly of water, AIRBORNE PARTICLES ARE RELATIVELY DRY, which damages many pathogens so that their ability to transmit infection is lessened or eliminated."
Here, I capitalized it for you so you don't miss it.
Airborne virus is what happens after fine respiratory mist dries out, which happens quite quickly. It is "relatively" dry because some of the respiratory fluid is hygroscopic. Don't make a mistake, there is no free flowing liquid with virus happily swimming in it.
In your refusal to read the article, you're missing how sars-cov-2 is teaching us new science about how viruses may survive in aerosols, which behave differently from particles that travel in a ballistic motion.
Airborne viruses have been known for a long, long time. The physics is established. The whole reason we distinguish between airborne and non-airborne viruses is exactly because virus needs special arrangements to be able to survive outside of fluid.
While it is interesting how particles move in a room, it is completely different topic. The particles ARE NOT AEROSOL. The kind of aerosol that can flow in tiny air currents dries out in seconds and becomes small particles (not droplets) of "relatively dry" matter that is fine enough to stay in air for a very long time.
These threads are awful because "droplet" and "aerosol" don't have good fixed definitions, and because people misuse the word "airborne" to mean "aerosol".
I appreciate the distinction you're making here. I don't have enough facts to prove or disprove it.
But, I'd like to ask: are you suggesting that aerosolized droplets cannot be seriously spreading this disease because they will evaporate almost instantly?
I ask because there is quite a bit of research suggesting that aerosolized droplets are spreading the disease, and can hang int the air for a substantial period of time. Do you think this is wrong? If it is wrong, why do you believe people are suggesting aerosolized transmission?
There are two types of viruses: airborne and not airborne. Airborne can survive for some time outside bodily fluids.
Aerosol == bodily fluid that is still liquid. It is just in the form of very small droplets that are now drying out. Depending on conditions this lasts very shortly. It spreads the virus, of course, but aerosol dries out quickly and viruses that are not airborne die (well.. viruses do not live in the usual sense, basically their proteins get damaged).
Of course if somebody coughs in your direction some of the aerosol can be inhaled or reach your retina or get on your hands and you can get infected.
No, I am not suggesting droplets cannot spread the disease, the opposite is true. Droplets are much better transmitter of disease if they can reach the target.
It goes on to say "However, there are microdroplets which stay in the air for 30+ minutes depending on the air currents."
It sounds like you're both in agreement that large droplets fall quickly to the ground, and that with COIVD the longer-lasting micro-droplets are a relevant factor.
Am I missing a subtlety?
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