Does COVID six-foot-rule work?

[gounion]

MASKS are what works. Study:

Although the “six-foot rule” has been a staple of coronavirus safety measure since 2020, is it really doing anything to keep people healthy? A new study finds the answer to that appears to be a resounding no. Scientists from the University of Cambridge say the social distancing rule of six feet does not protect against catching COVID-19, even outdoors.

The team calls the social distancing rule an “arbitrary measurement” of safety in the absence of masks. It could have been set anywhere between three to 10 feet, depending on the risk tolerance of the local public health authority putting out the mandate.

Infected individuals spread the virus through coughing, speaking, and even breathing. People expel larger droplets that eventually settle on surfaces or break into smaller aerosols that may float through the air. The study used computer modelling to quantify how these infectious particles travel. Results show coughs vary widely when it comes to expelling particles.

What does work?

The six-foot rule is an effective and easy-to-remember message for the public. However, the study finds it isn’t a mark of safety given the large number of variables associated with an airborne virus. Vaccination, ventilation, and masks – while not 100 percent effective – are vital for containing the pandemic.

“We’re all desperate to see the back of this pandemic, but we strongly recommend that people keep wearing masks in indoor spaces such as offices, classrooms and shops,” Mastorakos concludes. “There’s no good reason to expose yourself to this risk as long as the virus is with us.”

The researchers are carrying out similar simulations for spaces such as lecture rooms to assess the risk as people spend more time indoors. The World Health Organization recommends a distance of at least three feet (one meter) from others — even if they don’t appear to be sick. WHO also advises people to avoid crowds and close contact and to wear a properly fitted mask in poorly ventilated rooms.

I got back from Vegas, where masks were mandatory, and everyone wore them. Funny, there seemed to be no problems, no one was fainting from lack of air, no one even seemed to be in discomfort. The city wants everyone to keep coming to Vegas, they don't want there to be any superspreader events, so they are doing the SMART thing, not the ideological thing.

Mask work. That's why businesses are mandating them in Vegas.

[Drak]

I’ve personally never really trust a 6 foot rule. Aerosol can have a pretty wide area effect and I’ve seen a number of videos showing the size of a cough or sneeze cloud. I don wear a mask on walks around my neighborhood but I might go back to doing so. But I always wear a mask in a grocery stores and shop early in the morning when I need supplies.

[gounion]

I’ve personally never really trust a 6 foot rule. Aerosol can have a pretty wide area effect and I’ve seen a number of videos showing the size of a cough or sneeze cloud. I don wear a mask on walks around my neighborhood but I might go back to doing so. But I always wear a mask in a grocery stores and shop early in the morning when I need supplies.

If you're out in the neighborhood, and there's a breeze, you should be fine. But yes, any time I'm inside a public place, I've got one on. Wore one all week in Vegas. Never once fainted for lack of oxygen.

Hey Joe Memphis, maybe you're into weird shit. Wear a paper or cloth mask, not a leather one. Maybe THAT'S your problem!

[ZoWie]

The right turned masks and vaccines into yet another of their sexy government interference issues. That's the problem. 6 foot separation was always at best an oversimplification, and it's most relevant in places where people used to sit right next to one another. Better ventilation helps, but it's expensive. Masks work well enough to justify their use. Many, perhaps most, of the people who think they're a commie plot would be wearing them if their purported leaders told them that only commies and anarchists don't.

[Number6]

MASKS are what works. Study:



What does work?



I got back from Vegas, where masks were mandatory, and everyone wore them. Funny, there seemed to be no problems, no one was fainting from lack of air, no one even seemed to be in discomfort. The city wants everyone to keep coming to Vegas, they don't want there to be any superspreader events, so they are doing the SMART thing, not the ideological thing.

Mask work. That's why businesses are mandating them in Vegas.

The link to the study doesn't quantify the distance needed to avoid catching COVID. The overall point of the study is air flow is more important concerning how the aerosol droplets can spread. This isn't something new because we've seen the video demonstrations of how droplets in a sneeze travel. Is the six-foot rule valid? That's up to each individual to decide. Personally, I try to maintain a six-foot distance when indoors whenever possible. IMO. if I'm six-feet away from someone who sneezes, the concentration of amount of droplets will disperse as the distance increases. Statically, six-feet may not be significant but even if it's just 10% effective then keeping six-feet distance means 10% less chance of becoming infected.

[carmenjonze]

MASKS are what works. Study:



What does work?



I got back from Vegas, where masks were mandatory, and everyone wore them. Funny, there seemed to be no problems, no one was fainting from lack of air, no one even seemed to be in discomfort. The city wants everyone to keep coming to Vegas, they don't want there to be any superspreader events, so they are doing the SMART thing, not the ideological thing.

Mask work. That's why businesses are mandating them in Vegas.

Same for San Francisco.

These confederates like JoeMemphis who live in places where nobody wants to go are the first to say masks don't work, whereas those of us who live in cities that are world destinations know better, because we cannot afford NOT to know better.

[sam lefthand]

Yes, there's is a reason for the six foot rule. But is isn't a "work," or "not work" kind of measure. The 6 foot rule works with masks to help make the masks work better.

What is behind it air velocity. Air has little mass so minute forces can accelerate air to tremendous velocities.

You've seen someone put two fingers in their mouth and blow air across them just so and have heard it produce a hell of a sound, an extremely loud whistle. What makes that whistle so loud is the fingers and shape of the mouth are working together to focus the energy of an exhaled breath up to and beyond the velocity of the sound barrier. The kind of speeds that fighter jets fly at when they generate a sonic boom.

Lots of times when people are talking in order to make the sounds necessary for speech, the escape velocities generated of the air leaving the lips will be on the order of hundreds of miles an hour. And a loud whistle may be so fast that it breaks the sound barrier.

Now to explain why there is a 6 foot rule. Air which is moving fast can penetrate filter material further than air which has been drawn through the filter fibers by a partial vacuum on the other side of the filter media. Basically filters (masks) work when air is drawn through by vacuum, but do not work well when air is blown through the filter media from the outside.

The best way to clean air filter media in a auto shop is to blow compressed air on it. Cleans it up, and a filter can be used again.

So to get back to the 6 foot rule. We don't want masks to be subjected to high velocity air from the outside. Otherwise Covid droplets trapped in the mask might be pushed through to infect the wearer of the mask. High velocity exhaled air from the inside is beneficial, it keeps the mask clean, blows those accumulated Covid droplets off.

And this is why it is 6 feet, in about 3 feet air which was moving at the speed of sound will interact with air which is not moving and that fast moving air will loose it's high velocity. It can be accelerated very fast and be decelerated very fast because air has so little mass.

The reason they doubled the 3 feet to make it 6 feet is two people talking to each other each need to have a 3 foot deceleration zone around them, 3 + 3 = 6.

[gounion]

You've seen someone put two fingers in their mouth and blow air across them just so and have heard it produce a hell of a sound, an extremely loud whistle. What makes that whistle so loud is the fingers and shape of the mouth are working together to focus the energy of an exhaled breath up to and beyond the velocity of the sound barrier. The kind of speeds that fighter jets fly at when they generate a sonic boom.

Lots of times when people are talking in order to make the sounds necessary for speech, the escape velocities generated of the air leaving the lips will be on the order of hundreds of miles an hour. And a loud whistle may be so fast that it breaks the sound barrier.

I'd love to see the proof of this.

[ProfX]

It's a rule of thumb that's easy to remember.

It's much harder to make people memorize "well it depends on what space you're in, how well it's ventilated, what kind of setting is it standing/walking vs. sitting, whether people are talking, singing, shouting, or sneezing" ...

Yeah. Forget it. "6 feet" is what they can remember. Probably often should be more, sometimes could be less, but public health has to work with what can realistically be given to remember by a big mass of people.

I'll be honest. It probably would be more effective to say "the people who most need to wear a mask are those with COVID," but uh, come on, people often are asymptomatic or pre symptomatic, or don't believe they have it, ... could keep going .... ya know what: just tell everybody to wear masks, because it even benefits the people who don't have it, but less so.

The scenario of least transmissibility: infected person is 6 feet from other (unvax'd) person, both are wearing masks (yes can be cloth), I think current research says the infection chance is under 1%, at least for non mutant variants.

[sam lefthand]

I'd love to see the proof of this.

The physics of a whistle is something studied in the third or forth year. In my case it was forth year, It is quite advanced:



Here is a run down of the factors which create a whistle. The second characteristic listed is the Mach number.

Strouhal number

The first number is the ratio of unsteady inertial forces to steady inertial forces. The number was named in honor of Vincenc Strouhal, who first deduced the relationship between the vortex shedding frequency around a cylinder and the flow speed. The characteristic variables were the cylinder diameter L1 and the speed U of the flow over it.

This number permits relationships to be developed between the different sizes and speeds. This equation may be referred to as a fluid mechanical Strouhal number in comparison with the second version, which may be referred to as the acoustical Strouhal number. The first version is used for dynamic similarity of the fluid motion in whistles, while the second version is used for dynamic similarity of the acoustical motion in whistles. Many whistles require use of both numbers.

Mach number

It is the ratio of the steady speed to the speed of sound. The number was named in honor of Ernst Mach, who first studied (among other things) supersonic flow and shock waves. This number describes the range between flows that can be considered incompressible and flows where compress

Reynolds number

It is the ratio of the steady inertial forces to the steady viscous forces. The number was named in honor of Osborne Reynolds, an engineer who did pioneering studies on the transition of laminar to turbulent flow in pipes.

Rossby number

It is the ratio of linear velocity to tangential velocity for swirl flows. The frequency is characteristic of the rotation rate of the flow. The number was named in honor of Carl-Gustaf Rossby, a meteorologist who first described the large-scale motions of the atmosphere in terms of fluid mechanics.

Dimensionless force

The ratio of the actual dynamic force to the steady momentum.

Dimensionless volumetric flow rate

The ratio of the dynamic volumetric flow rate to the steady volumetric flow rate.

https://en.wikipedia.org/wiki/Physics_of_whistles

[gounion]

The physics of a whistle is something studied in the third or forth year. In my case it was forth year, It is quite advanced:



Here is a run down of the factors which create a whistle. The second characteristic listed is the Mach number.



https://en.wikipedia.org/wiki/Physics_of_whistles

I saw the page when I did a search. I can't find anywhere that it says a human being can move air from their mouth beyond the speed of sound.

[sam lefthand]

I saw the page when I did a search. I can't find anywhere that it says a human being can move air from their mouth beyond the speed of sound.

It's implied grunion. There wouldn't be a mach number if there wasn't a reason for a mach number.

If you want to dive into the details in depth go back to college, study Physics, and about the third or forth year you'll grok it.



By then you will also understand why light shines through glass but not through stainless steel.

[gounion]

It's implied grunion. There wouldn't be a mach number if there wasn't a reason for a mach number.

If you want to dive into the details in depth go back to college, study Physics, and about the third or forth year you'll grok it.



By then you will also understand why light shines through glass but not through stainless steel.

No, it's not implied. It could be .0001 mach.

I didn't think you could prove it. Sorry, I'm not taking your word for shit. You aren't credible. You're a blowhard know-it-all.

[sam lefthand]

I wasn't aware that in just few moment of time a simple Internet search could turn up all human knowledge.

[gounion]

I wasn't aware that in just few moment of time a simple Internet search could turn up all human knowledge.

You could just say "I can't prove it".

Because that's what it is. You know, maybe you should change your avatar out. Cliff Clavin would be appropriate.

[gounion]

It's implied grunion. There wouldn't be a mach number if there wasn't a reason for a mach number.

Not implied. For instance, when Cessna built the Citation X, an airplane I'm proud to have played a tiny part in bringing to market (and the fastest private jet in the world), it's top speed was listed at .92 Mach, not 700 MPH. Using the Mach number did NOT imply that it flew faster than the speed of sound. It did not.

A newer model could fly .935.

That's why a mach number doesn't imply shit.

[sam lefthand]

Not implied. For instance, when Cessna built the Citation X, an airplane I'm proud to have played a tiny part in bringing to market (and the fastest private jet in the world), it's top speed was listed at .92 Mach, not 700 MPH. Using the Mach number did NOT imply that it flew faster than the speed of sound. It did not.

A newer model could fly .935.

That's why a mach number doesn't imply shit.

When I was 15 I took flying lessons in a Cessna 170 and learned to fly.



When I was 16 I went to the DMV and got my drivers licence. I already knew how to drive, I learned that when I was about 12.

[gounion]

When I was 15 I took flying lessons in a Cessna 170 and learned to fly.



When I was 16 I went to the DMV and got my drivers licence. I already knew how to drive, I learned that when I was about 12.

Thanks, Cliff, for that proof of the sheer intellect you show us every day!

[Number6]

It's a rule of thumb that's easy to remember.

It's much harder to make people memorize "well it depends on what space you're in, how well it's ventilated, what kind of setting is it standing/walking vs. sitting, whether people are talking, singing, shouting, or sneezing" ...

Yeah. Forget it. "6 feet" is what they can remember. Probably often should be more, sometimes could be less, but public health has to work with what can realistically be given to remember by a big mass of people.

I'll be honest. It probably would be more effective to say "the people who most need to wear a mask are those with COVID," but uh, come on, people often are asymptomatic or pre symptomatic, or don't believe they have it, ... could keep going .... ya know what: just tell everybody to wear masks, because it even benefits the people who don't have it, but less so.

The scenario of least transmissibility: infected person is 6 feet from other (unvax'd) person, both are wearing masks (yes can be cloth), I think current research says the infection chance is under 1%, at least for non mutant variants.

Easy rule of thumb to remember six-foot distance. It's better to have six-feet distance between us than six-feet under us.

[Number6]

I saw the page when I did a search. I can't find anywhere that it says a human being can move air from their mouth beyond the speed of sound.

Well, if the burrito I ate at Taco Bell can cause the wind I break to hit Mach then it's not unreasonable to think you could break Mach at the other end.

[Libertas]

Same for San Francisco.

These confederates like JoeMemphis who live in places where nobody wants to go are the first to say masks don't work, whereas those of us who live in cities that are world destinations know better, because we cannot afford NOT to know better.

And it would NEVER have occurred to that con to EVER allege masks aren't what they are if it were not for something uttered by the proven dumbest human on earth.

If TFG, dumbest human on earth, doesn't react worse than any world leader, doesn't allow the virus to expand because it is mostly killing democrats (proven), and reacts to it with the group he disbanded and reacted to it like Hillary would have and the South Koreans did, he wouldn't have had to later imply the virus wasn't real.

He then wouldn't have had to bad mouth masks...then board con NEVER thinks to bad mouth masks...we know this as fact.

[gounion]

If you're out in the neighborhood, and there's a breeze, you should be fine. But yes, any time I'm inside a public place, I've got one on. Wore one all week in Vegas. Never once fainted for lack of oxygen.

Hey Joe Memphis, maybe you're into weird shit. Wear a paper or cloth mask, not a leather one. Maybe THAT'S your problem!

The best thing is if everyone has masks, as keeping the coughs of infected people from being released is best.

But unlike Joe, I don't faint when I wear a mask, so I'm fully back to wearing them in public.

[ZoWie]

The problem is that the virus is frequently passed by people who don't know they're infected, and who may never get sick at all. One idea is to have mandatory, reliable, and instant daily testing done without fail by the entire population and then acted upon properly all the time. That is never going to happen. The means are there, but not the will.

The second best solution is for everyone to mask up in dense public spaces all the time. The virus can mutate all it wants, but the physics of aerosol and droplet circulation will never let enough of it pass through a properly worn mask made of decent materials. Unfortunately, universal masking will never happen either, because people will say their rights are being infringed. A lot of the same people don't seem to mind Americans losing their right to choose whether to carry pregnancies to term, but then no one ever said that all humans are rational.

New ideas would be nice, but offhand I don't know what they'd be.

[Libertas]

The problem is that the virus is frequently passed by people who don't know they're infected, and who may never get sick at all. One idea is to have mandatory, reliable, and instant daily testing done without fail by the entire population and then acted upon properly all the time. That is never going to happen. The means are there, but not the will.

The second best solution is for everyone to mask up in dense public spaces all the time. The virus can mutate all it wants, but the physics of aerosol and droplet circulation will never let enough of it pass through a properly worn mask made of decent materials. Unfortunately, universal masking will never happen either, because people will say their rights are being infringed. A lot of the same people don't seem to mind Americans losing their right to choose whether to carry pregnancies to term, but then no one ever said that all humans are rational.

New ideas would be nice, but offhand I don't know what they'd be.

I always wear a mask indoors other than at home.

Today I went to a grocery store I dont usually go to, and it is a discount store and I know from experience they can be more crowded than your Safeway's or Raley's. So I wore two masks. I wear only N95 masks like this

https://shop.projectn95.org/demetech-dt ... ox-of-20/p

but when I wear two the other is an N95 I got at Costco.

I dont suppose two makes a big difference, but I am more comfortable in those situations because of the new strains that are easier to catch.

I feel RAGE and HATE when I see someone without a mask but fortunately that is rare where I live.