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Comment by Vysero | Hacker News Reader

No, the virus doesn't just float around in the air, at least, not for any appreciable amount of time. It's much more likely that people in these apartments are touching the same elevator buttons and then wiping their eyes and contracting the virus.

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There are multiple lines of evidence that suggest airborne transmission is the primary form of transmission. For example: https://twitter.com/JeremyKonyndyk/status/125372588101882675...

"Lines of evidence" and "twitter.com" do not belong in the same sentence. If there's something of substance in a tweet, link the substance.

If this were an academic journal, I would. But this is a casual web forum.

The setup of this whole thread is 'trustable data and scientific method'.

Also, please be aware that a name is often not enough to show that a source is relatively trustworthy, some credentials can help; this is a worldwide forum.

Surely that depends on whose tweets they are? If its Jeremy Konyndyk or Scott Gottlieb or such that's a pretty decent source. If it's a celebrity or political figure or some random person less so.

It's precisely because of the way infections cluster in cases like that that we can tell that we're not seeing (much at least) long range airborne transmission. It this was a true aerosol like you see with chickenpox, measles, or TB you wouldn't be seeing such a nice separation as that. It looks like the furthest away you should be able to be infected someone is maybe 20 or 30 feet if you sneeze without covering your nose. That's the significance of Mr. Konyndyk talking about droplets rather than aerosols. Though it was a big deal in the original SARS outbreak that you could generate aerosols via intubation which caused some nurses wearing surgical masks to get sick in that outbreak.

Unfortunately, even talking and breathing generates micro-droplets that remain airborne for hours: https://www.youtube.com/watch?v=H2azcn7MqOU

> No, the virus doesn't just float around in the air, at least, not for any appreciable amount of time.

Here is a pretty approachable summary of how transmission happens that contains a review of some specific cases where airflow was critical to transmitting the infection: https://erinbromage.wixsite.com/covid19/post/the-risks-know-.... None of these occurred in isolated spaces connected by shared ventilation but I would be cautious about saying flatly that it can't happen.

I didn't say flatly that it can't happen. I said it can't happen at any appreciable distance. Obviously, if someone sneezes in your mouth your going to get sick.

That's not what you said, and why don't you take a look at that article I linked. The restaurant case and the call center case it looks at were hardly in the category of "someone sneezes in your mouth."

> No, the virus doesn't just float around in the air

I'd be interested in any references you can point to that explain why that doesn't happen. A priori I would expect virus particles to be able to remain airborne indefinitely. Viruses are very small, much smaller than pollen grains that I believe are well known to remain airborne over long distances so I would think Brownian motion from collisions with air molecules would suffice to keep them aloft.

> No, the virus doesn't just float around in the air, at least, not for any appreciable amount of time.

Can you share what degree of certainty you ascribe to that claim?

Edit: Also, does this change it? https://erinbromage.wixsite.com/covid19/post/the-risks-know-...

That agrees that the virus is mostly transmitted via droplets rather aerosolized virus particles. A bare virus can float in the air for quite a while but all the evidence we have, especially stuff like form that site, seems to show that that isn't a route by which people are being infected. Instead its being transmitted over shorter distances, generally around 6 feet but longer if someone is shouting, singing, coughing without covering, or just directly downwind.

??? It talks about miniscule droplets that could stay in the air for minutes, and move downwind quite easily.

I think what the parent commenter is saying is that maybe the virus stays in the air like that but it's not a way in which people get infected, otherwise the clusters wouldn't be so tight. Any tracing would be impossible for example. One possibility is that you need a threshold amount of virus to infect you so close contact is necessary.

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