I have a question which has been on my mind for a long time- it might be a stupid question but i am going to ask anyway: if the coronavirus is in the air, why don't we get it from just breathing the air: why do we only get it from person to person transmission?
It's a virus. It's made of a tiny molecule called RNA. Air is gases in our environment (oxygen, nitrogen, CO2, etc). The virus "rides" mostly on tiny water droplets that are suspended in air. Air also contains water (called humidity - right now, there's a lot of humidity where I live).
It's not the "air" that's the problem, it's that CoVid floats in the air. In dry air, it stays aloft longer, in humid air, it drifts more quickly to the floor.
It isn't only airborne. But it can't replicate in air, only inside a human body - with the longs being the most available and hospital host for CoVid.
A CoVid+ person breathes about 100,000 virions (individual CoVid units) into the air with each breath. Children, while hosting CoVId, expel far less per breath (but as they get older - by around 12-14, they're pretty much capable of breathing out 100,000 per breath).
We do not get CoVid from breathing in non-CoVid infected air. Unless someone comes to my house (who has CoVid) the air in my house is safe, it has no CoVid.
When we are outdoors, the volume of air recirculated is quite high (especially if there's a breeze). So a person exhaling CoVid has those 100,000 virions dispersed over a very wide area - quickly.
Indoors, well, you can do your own experiments (but be careful). Bl0w out a candle and watch the smoke plume - it may just hang above the candle, slowly disappearing (the particles are still there - but dispersed). If I do this in my home, I can see smokey particles at about 5 feet off the ground linger for a long time (because the draft in my house is near the floor and it takes a while for the smoke to go to ground. If there were CoVid in my house, it would do the same thing (hang out right where my nose is).
It's estimated that one is 1000X more likely to get CoVid indoors. A 6 minute conversation with an infected person (with neither wearing masks) can easily result in the uninfected person getting CoVid. Sitting next to someone on an airplane for 6 minutes can result in tranmission. This is with "normal" conversational distances.
With masks, we can have a 50-60 minute conversation and be unlikely to get CoVid. At 6 feet away, our chances of remaining healthy go up even further. If outdoors, even further. If it's breezy or humid, even better.
Dry indoor air - well, those CoVid-containing aerosol droplets can remain aloft for as long as a day - maybe longer. If 20 people were breathing out CoVid in, say, a large classroom, people might get CoVid from that space for the next 24 hours. A/C experts say that in older buildings (most buildings), the volume of air that turns over is about 10-25% of what it needs to be to prevent CoVid.