
The Math of Social Distancing Is a Lesson in Geometry - theafh
https://www.quantamagazine.org/the-math-of-social-distancing-is-a-lesson-in-geometry-20200713/
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dvt
This is a pretty bad premise. If you're packing people in cubicles in a
building/floor that most likely uses central air and air conditioning, you
already lost the game -- sphere packing or not.

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cmsonger
+1 came here to say this.

Indoor HVAC air flows seem way more important than distance. I can probably
sit right next to you as long as the airflow has each of our exhalations taken
away from the other.

My employer has mentioned potential plans to bring people back to the office
in small numbers for short times. Until these discussions include analysis of
building HVAC, I want no part of it.

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darkarmani
We all need downdraft hoods. Eating out with friends will be like going to
hibachi, but instead of a grill between your friends, it will be a downdraft
vent pulling all of your exhalations away.

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tengbretson
I think the most efficient solution would be to have a series of snorkel lines
come down from the ceiling that terminate outside of the building, 6 feet
apart.

This would allow the occupants inside to pack as closely as possible without
worrying about breathing any hazardous air.

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Enginerrrd
Or for an actually efficient solution, just oversize the shit out of the HVAC.
Can it still spread via droplet in a wind-tunnel? Sure, but not very well.

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tengbretson
Pasteurization occurs at roughly 145 degrees Fahrenheit, so another solution
could be to increase the ambient temperature of the office to 145F or higher,
and to simply have all of your workers wear personal temperature controlled
suits to keep them at their preferred comfort level.

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dr_zoidberg
Jokes aside, couldn high intensity UV lamps be placed inside the HVAC tubes
and have that sterilize the shirt out of the air?

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Enginerrrd
That's not really the issue although it does matter for some aerosols sizes.
It's the flow rate in the room. You need more air exchanges. When someone
coughs, how long are those infectious particles floating around the room.

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dr_zoidberg
Good point. As for coughing/talking/anything that makes droplets I was
thinking masks first and then other measures on top of it, like proper
ventilation.

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gigama
Sphere packing is a genuinely interesting math problem. But it really should
not be thought of as any kind of solution to a serious public health threat.
Six feet apart is only a recommendation. The virus can transfer based on many
other factors such as airflow, shared surface contamination, and spending time
in proximity to asymptomatic carriers.

Leave such math topics for home school study questions.

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jinglebells
The rule is supposed to encourage being apart from each other, not how many
can you pack into an arbitrary measurement from Some Agency.

In the UK it's 2m which is MORE than 6ft.

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sokoloff
For this purpose, 6 feet and 2 meters are the same measure.

It's "about this far apart" and the UK isn't going to advise their population
to "stay at least 185cm apart" anymore than the US is going to advise "stay at
least 6'6" apart".

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hermitcrab
The next release of our PerfectTablePlan seating software
([https://www.perfecttableplan.com](https://www.perfecttableplan.com)) will
have a social distancing feature. This will allow you to check social
distancing at seated events (such as wedding receiptions and galas). It wasn't
too difficult to add as we know the x,y position of each seat and the group
each occupant belongs to.

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elil17
I worry that a feature like that could give people a false sense of security.
In an indoor area, transmission is possible regardless of distance.

The 6’ rule was intended for the outdoors and situations where contact is
unavoidable, not parties.

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hermitcrab
Spacing guidelines are always going to be imperfect. But, assuming they are
based on some science, they are better than nothing. You can also record all
the guest details in PerfectTablePlan for later track and trace!

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NotACop182
So it’s more on the lines of imperfect table plans. My worry is circulating
air flow.

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hermitcrab
I don't think we'll be adding a CFD model. ;0)

