One of the scarier aspects of COVID-19 is its changing weirdness, not only in the quickly sprouting variants and mutations of the original coronavirus, but how science can do so much in the time we have — COVID is only about 18-19 months old, we here in the US have known about it now for just a bit more than a year, so the shit has a near-vaporous shape-shifting existence in its spread.

And the shit won’t let up — India is experiencing a nigtmare, while the conditions to live within its presence seems to change, too. Although masks have really proven to be a major factor in controlling the spread, now the social-distancing parameters appear to have been modified to a more complex view.
Six feet is about the same as 60 feet without proper ventilation (h/t tweet BJ):

New modelling showing that the minimum amount of virus typically needed to become infected is only 10 virus particles. This is an order of magnitude greater than SARS.

Without masks and ventilation, physical distancing rapidly becomes inadequate indoors.https://t.co/e4yaTru29j pic.twitter.com/7wg6B26zzI

— Dr Zoë Hyde (@DrZoeHyde) April 24, 2021

Two recent studies had appeared to show that while indoors the major factor is air flow, or the lack of it. Stores, offices, anywhere inside, really, depends on the openess of the venilarion.
First, research results from a MIT study show the phyical openness of COVID — via CNBC last Friday afternoon:

MIT professors Martin Z. Bazant, who teaches chemical engineering and applied mathematics, and John W.M. Bush, who teaches applied mathematics, developed a method of calculating exposure risk to Covid-19 in an indoor setting that factors in a variety of issues that could affect transmission, including the amount of time spent inside, air filtration and circulation, immunization, variant strains, mask use, and even respiratory activity such as breathing, eating, speaking or singing.

Bazant and Bush question long-held Covid-19 guidelines from the Centers for Disease Control and Prevention and the World Health Organization in a peer-reviewed study published earlier this week in Proceedings of the National Academy of Science of the United States of America.

“We argue there really isn’t much of a benefit to the 6-foot rule, especially when people are wearing masks,” Bazant said in an interview.
“It really has no physical basis because the air a person is breathing while wearing a mask tends to rise and comes down elsewhere in the room so you’re more exposed to the average background than you are to a person at a distance.”

The important variable the CDC and the WHO have overlooked is the amount of time spent indoors, Bazant said.
The longer someone is inside with an infected person, the greater the chance of transmission, he said.

Opening windows or installing new fans to keep the air moving could also be just as effective or more effective than spending large amounts of money on a new filtration system, he said.

Bazant also says that guidelines enforcing indoor occupancy caps are flawed.
He said 20 people gathered inside for 1 minute is probably fine, but not over the course of several hours, he said.

“What our analysis continues to show is that many spaces that have been shut down in fact don’t need to be. Often times the space is large enough, the ventilation is good enough, the amount of time people spend together is such that those spaces can be safely operated even at full capacity and the scientific support for reduced capacity in those spaces is really not very good,” Bazant said.
“I think if you run the numbers, even right now for many types of spaces you’d find that there is not a need for occupancy restrictions.”

Six-feet social distancing rules that inadvertently result in closed businesses and schools are “just not reasonable,” according to Bazant.

“This emphasis on distancing has been really misplaced from the very beginning. The CDC or WHO have never really provided justification for it, they’ve just said this is what you must do and the only justification I’m aware of, is based on studies of coughs and sneezes, where they look at the largest particles that might sediment onto the floor and even then it’s very approximate, you can certainly have longer or shorter range, large droplets,” Bazant said.

“The distancing isn’t helping you that much and it’s also giving you a false sense of security because you’re as safe at 6 feet as you are at 60 feet if you’re indoors. Everyone in that space is at roughly the same risk, actually,” he noted.

Major point: ‘For example, if someone infected with Covid-19 is wearing a mask and singing loudly in an enclosed room, a person who is sitting at the other side of the room is not more protected than someone who is sitting just six feet away from the infected person. This is why time spent in the enclosed area is more important than how far you are from the infected person.‘

Might be a game-changer:

Put more time/money into rehabing ventilation systems for schools, churches and whatnot. Safe is beter than not safe — duh!
The second study comes from the University of Central Florida and also suggests ventilation is key — per SciTechDaily earlier this month:

The research, published recently in the journal Physics of Fluids, comes at a critical time when schools and universities are considering returning to more in-person classes in the fall.

“The research is important as it provides guidance on how we are understanding safety in indoor environments,” says Michael Kinzel, an assistant professor in UCF’s Department of Mechanical and Aerospace Engineering and study co-author.

“The study finds that aerosol transmission routes do not display a need for six feet social distancing when masks are mandated,” he says.
“These results highlight that with masks, transmission probability does not decrease with increased physical distancing, which emphasizes how mask mandates may be key to increasing capacity in schools and other places.”
…
Masks were shown to be beneficial by preventing direct exposure of aerosols, as the masks provide a weak puff of warm air that causes aerosols to move vertically, thus preventing them from reaching adjacent students, Kinzel says.

Additionally, a ventilation system in combination with a good air filter reduced the infection risk by 40 to 50% compared to a classroom with no ventilation.
This is because the ventilation system creates a steady current of air flow that circulates many of the aerosols into a filter that removes a portion of the aerosols compared to the no-ventilation scenario where the aerosols congregate above the people in the room.

These results corroborate recent guidelines from the U.S. Centers for Disease Control and Prevention that recommend reducing social distancing in elementary schools from six to three feet when mask use is universal, Kinzel says.

“If we compare infection probabilities when wearing masks, three feet of social distancing did not indicate an increase in infection probability with respect to six feet, which may provide evidence for schools and other businesses to safely operate through the rest of the pandemic,” Kinzel says.

“The results suggest exactly what the CDC is doing, that ventilation systems and mask usage are most important for preventing transmission and that social distancing would be the first thing to relax,” the researcher says.

Best bet, though, is vaccination. However, research or best guess on required ‘herd immunity‘ to stop the spread is a toss up. One analysis says we could achieve it by end of summer; menawhile, another says no way; and may never have ‘true herd immunity — so how do we feel?

End song for the question:

“Clouds of mystery pourin’ confusion on the ground…”

(Illustration: ‘This Why Nurses Do What They Do,’ by visual journalist Emily Thomas, and found here).