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Comment by sandworm101 | Hacker News Reader

>> standing next to the all of the horn players blowing their spit all over the place.

That's an aspect of the universal 6-foot rule that everyone seems to forget. It originally appeared as advice for business (restaurants). You don't want to sit too close to someone else in still air. But if we are spitting, singing, shouting, coughing, panting, playing in a Jazz band, or are simply downwind of someone, that 6-foot distance is probably not enough. Airlines have basically said as much about their cabins. If the air is being circulated artificially in a closed environment, specific measured distances are probably irrelevant.

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The "universal 6-foot rule" is anything but universal. Other countries have recommended 1m, 1.5m, 2m, etc. The distance rules are almost entirely arbitrary and not based on sound science.

Distances can be both arbitrary and based on sound science. You can scientifically determine that your chances of infecting someone at 1.5m and 2m are e.g. 40% and 50%, but you still have to pick one to recommend.

No one has scientifically determined the infection risk at various distances. Such an experiment with human subjects would never pass ethical review due to the serious risk. Some scientists have created mathematical models of virion distribution, but those models are basically a joke and don't appear to align with observed reality.

I do appreciate that public health authorities have to make clear and simple recommendations to avoid confusing people. But let's not pretend there is anything scientific about it.

IMO it’s scientific as soon as someone uses data to get an edge in prediction over random chance. It’s technologically relevant when it can outperform an average person’s guess.

People have looked at well documented super spreader events as real world evidence even if it’s not a formal experiment. Aka infected person A sitting at X with local airflow Y infected N people at these locations without infecting people at K other locations.

Such data is much harder to collect after an infection has become endemic, but early contact tracing can provide great data.

It is scientific, but only partly. It has to include practicality, adherence, and every other human factor. They can’t say 2 miles because nobody could comply. They can’t say “2 meters minus the (square root of the outside temperature in Kelvin) in centimeters” because everyone would be flummoxed by the math. When getting a large group of people to coordinate an action, communication clarity/effectiveness is more important than the specific recommendation itself.

My understanding is that the six foot distance is based on the expected air speed of a cough/sneeze and distribution of droplet sizes in a cough/sneeze. Given these two factors you can calculate how far droplets are expected to travel from a cough before hitting the ground.

When a person stands in a checkout line and breathes into the air and all over the plexiglass that stands between you and the cashier...and you carefully stand 6 feet back and then walk into the same exact airspace the person occupied just seconds prior...believe me, you're breathing in droplets from that other person. Our bodies contract diseases all day every day. There are millions of viruses and bacteria that but for our immune system, would bring us to our knees in a matter of days or weeks. We cannot carry on like this. Social distancing will tear society apart and destroy the economy, resulting in far more deaths and misery.

Well, it seems to have worked out well for some of the Asian countries (and countries like Australia/NZ) which have gotten COVID-19 under control. The US still ha a major problem with deaths in the tens of thousands, as do many of the European countries.

I take your point that there will be economic paint - but I think you're being a bit hyperbolic about "tearing society apart" and "resulting in far more deaths and misery". This is the sort of rhetoric that Trump has been using - whilst I agree in principle there is economic pain - please don't treat people's lives as meaningless, or that the almighty dollar is all that matters. It's the job of governments to guide the country through these crises - this is where government stimulus and spending should be used - not just letting people die needlessly.

COVID-19 is a new and novel disease that's highly spreadable, has no known vaccine, and is killing an unprecedented number of people.

And we're not just talking about yourself - perhaps you're young/healthy and are prepared to contract COVID-19 and roll the dice.

However, those around you - family, or friends - may not be so lucky, or it could be a potentially life-threatening condition. Please think about people around you.

The US death toll is nearly 100,000....

https://www.abc.net.au/news/2020-05-24/coronavirus-update-co...

That is absolutely heartbreaking.

That is over 30x the death toll from the 9/11 plane attacks - and look what lengths the government went to combat that?

I just got my second COVID-19 test (fortunately came back negative) - my parents (who are older and vulnerable) are paranoid I'll give it to them. So when I got a sore throat, I went to get the test. And a few weeks back, my son had a cough, so I got myself tested.

Our government (Australia) is encouraging people with any symptoms to get tested - and I think that's a good thing, towards eradicating this illness.

>> and is killing an unprecedented number of people.

Black death.

Bubonic plague.

Smallpox.

Malaria.

Measles.

Polio.

There have been many more virulent and many more destructive diseases than this one. Malaria in particular has been so destructive over thousands of years that it has modified human populations, forcing observable natural selection for traits such as sickle-cell anemia. https://en.wikipedia.org/wiki/History_of_malaria

Those aren't killing people in rich countries with good healthcare and sanitation though

You're correct that historically, there have been other illnesses hundreds of years ago that killed more people.

And in many developing countries, there are tragically many deaths caused by poor sanitation or healthcare.

However, this is a disease that has - even with incredibly draconian lockdowns and a global effort from every country to combat it - tragically killed nearly 350,000 people in a matter of months. And this is often in countries with state of the art healthcare systems, and every effort made to keep those people alive.

And as another commenter pointed out, this is often in countries not used to such scale of health disasters, as they have healthcare and good sanitation. Ironically, I read that things like air travel and holidays actually worsened illnesses like this.

Imagine if we'd simply let the diseases run its course.

The thing that baffles me is the US - advanced Western nation - with a death toll of nearly 100,000 people. How is that even possible?

I am hoping we've seen the worst of it.

Nursing home outbreaks are a huge chunk of those deaths.

> historically, there have been other illnesses hundreds of years ago that killed more people.

AIDS has killed around 34 million people since 1981.

That’s .. staggering.

> AIDS has killed around 34 million people since 1981.

That's on average 100k deaths per year since 1981.

Right now we are in our first quarter of covid19 and the official death count is at 340k.

And the response to AIDS was malicious neglect for years in many countries. A large portion of those deaths were due to bigotry.

So I suppose somewhat like the situation in the US with COVID-19 today.

>> And as another commenter pointed out, this is often in countries not used to such scale of health disasters, as they have healthcare and good sanitation.

Polio.

"On Saturday, June 17, 1916, an official announcement of the existence of an epidemic polio infection was made in Brooklyn, New York. That year, there were over 27,000 cases and more than 6,000 deaths due to polio in the United States, with over 2,000 deaths in New York City alone.[15] The names and addresses of individuals with confirmed polio cases were published daily in the press, their houses were identified with placards, and their families were quarantined."

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

Measles too. These are diseases that hit the western world, the rich countries, killed thousands, in living memory. They causes panic. They caused quarantines. They caused social change. Polio lead directly to the disability rights movement. Wheelchair ramps as mandatory in all buildings: that's from polio.

I think if smallpox was spreading in America today it might also be a good idea close restaurants and offices to slow that down.

It's not just about the dollar. We are social creatures, we thrive off of social interaction and contact and we benefit from community. Businesses, schools, churches, concerts, dancing, sporting events, all these things that give people joy and fun are shut down. We only get a few dozen trips around the sun. I do not want to spend my life cowering in fear and in a society that cowers in fear. I want kids playing in neighborhoods and playing ball, I want concerts on the regular, dancing in public squares and I want to live.

But to your point about the economy, we are seeing unprecedented damage to the worldwide economy from the shutdowns. It's not the virus that's doing this. It's the shutdowns. 40 million people are unemployed in the U.S. alone and rising, rapidly. This is unsustainable. The economy has to function or everything falls apart. And a big part of that functioning is travel and tourism and restaurants and it creates value and moves trade along. It's very important to re-establish those things.

Much of those deaths are in nursing homes with extremely vulnerable populations. I think its a tragic shame that many of these outbreaks occurred especially in nursing homes all over the northeast (NY, NJ, PA, CT, etc). However, once a patient gets moved to a nursing home, the average length they live is about 1 year. We can make nursing homes cleaner and safer and we should probably get those patients outside a bit more, but there's also only so much that can be done for people in the last months of their life.

Lockdowns vs no lockdown is an false dichotomy. The lockdown didn’t impact many people like myself, and many people can still be financially impacted even without a lockdown. Some people and businesses have actually been thriving. So your model is too black and white and doesn’t really match reality.

Or the one that makes me laugh is the sterilization of the credit card keypad versus the handling of cash without sterilization.

I don't see what's funny about that. If you have some measures that are feasible and at least somewhat helpful (wiping the keypad, encouraging people to use contactless payment instead of cash) and some measures that are infeasible (sanitizing cash), obviously you do the feasible stuff and not the infeasible stuff.

It's hypocritical. Much like the medical advice pandered by the media.

That argument only works if everyone caught the disease if they were exposed to even a single infected droplet. In fact, infection is highly non linear: below a certain concentration, the probability of infection is practically zero. That's because if you're exposed to a very small amount of the virus then most people's immune systems can fight it off immediately without "catching" the disease.

If you walk into the space previously breathed in by an infected person (or even if you just stand a couple of metres away from them) you will still indeed be breathing some infected droplets, but far less than if you stood closer to them. The result is not just that you chance of being infected is less, but that it is disproportionately less. This is born out in the observed consequences of social distancing in many countries. It's pointless to dispute it.

Forgive me for being presumptuous, but I suspect that this isn't really the point of your comment or the main reason for your view. I suspect that you think social distancing is a bad policy even if it does prevent infection. So I suggest against tacking on "oh and by the way it doesn't really prevent infection anyway", which is obviously not true; you're only weakening your credibility which undermines your main point.

There are a handful of unscientific experiments circulating around, like this Mythbusters one: https://www.youtube.com/watch?v=0f4sUNWkq60 . Tl;dr: 6 feet is optimistic. But, compared to 2 feet it's probably worlds better. It's a numbers game.

the experiments done were on how far these sorts of particles can travel, not on how infectious they are. so if we know a potentially infectious particle can travel 2m then we know the best chance to avoid infection is to not get in that radius.

it doesn't mean you won't get it outside that radius or that you will get it inside that radius, just that the opportunity to catch it is increased or decreased based on distance.

The fact that it's an arbitrary cutoff point still matters, though. If there's a cliff of infectiousness at the 2 meter line, you'd better send out people with rulers; if it's an arbitrary cutoff, you can give some wiggle room to restaurants where some tables are only 1.8 meters on a diagonal.

They are based on science, the further you are apart the longer that interaction is (probabilistically) safe for. Different governments are a) using different models; b) choosing different (and yes, arbitrary) times over which they want interactions to be safe ('enough').

It also depends on motion and speed. In France at some point there were talks about a rule of 10 meters when people are in motion, for skateparks or jogging for example. Because the droplet of the person in front of you takes sometime to fall to the ground, depending on your speed you can end up breathing it.

Imagine someone smoking a cigar. If you could smell it, then you are in contagious range.

The virus survives in water droplets or aerosol which fall down faster than smoke.

You can easily smell cigar smoke at 10 meters but you are ver unlikely to get infected at the same distance, current estimates put it to 4 meters in hospital settings.

Also,the amount of virus you receive matters, and distance decreases it.

You are right about viral load being a factor. You are not right about only macro droplets being a problem. Micro dropplets, that are suspended in air and do not "fall to the ground" soon carry enough of the virus to be infectious in accumulation. This is why indoor areas are problematic regardless of the 6 foot spacing, as the air just gets saturated over time unless you have a continual strong crossdraft.

The smoke analogy is not perfect, as it's composition is less moist, but it is closer to the truth than the '6 foot' model that was itself already a compromise between the now accepted as disproved macro fluid projectile model and economic concerns.

And that strong cross draft can be blowing it directly into someone else’s airspace anyway.

Is smoke water droplets?

Vape is, isn't it?

In case of tobacco smoke, Wikipedia says yes:

"The particles in tobacco smoke are liquid aerosol droplets (~ 20% water), ..."

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

There is not much difference between smelling cigars and smelling my neighbours smoking weed, is there? It never occurred to me, that being able to smell this might indicate danger.

A disturbing claim, for sure. Any pointers to evidence for it?

Not OP, but I had the same theory but with cigarettes. According to Google results, cigarette smoke particles are 0.25 micron at the largest, Sars-CoV-2 virus is 0.12 micron, so about half. They're both so light that gravity probably has little effect.

So, sharing a room with someone sick probably gives you a high chance of encountering the virus, but outdoors one hopes the concentrations would be so low that our bodies can fight it off.

And if you're wearing a mask and can still smell cigarette smoke, then surely it means that mask would let the virus particles through as well.

And in fact, this is how you test the respirator fit in professional setting. You don your respirator, and then somebody sprays a funny-smelling substance. If you can smell it, it means it doesn't have a proper seal on your face.

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