It's becoming clear that the SARS-CoV-2 virus will be around for a long time. We're probably much closer to the beginning than the end. Hotspots will shift and new variants arise so it makes sense to be ready to mitigate risks as much as possible. Vaccinating the world should be a high priority along with next generation vaccines, better treatments, testing, high quality masks when the risk is high, etc. etc.
Improving local air quality is low hanging fruit. To first order that means high quality masks in hotspots along with fresh air. Room air filtration and circulation can be a powerful tool. As living animals we exhale carbon dioxide. In pristine location, say a mountain top in Hawaii, you can measure the baseline concentration. Air is about 420 ppm (parts per million) carbon dioxide - a bit over 0.04%. Enclosed spaces with people have higher concentrations. You're breathing some of the air from other people. If people are the only source, you can calculate the percent of the total air in the room that's exhaled:
CO2 concentration (ppm) % of total air that is exhaled
420 0%
600 0.5%
800 1.0%
1000 1.5%
2400 5.0%
With these numbers it was believed the risk is low for up to an hour if everyone was wearing a simple cloth mask and one person was infected with the alpha variant with carbon dioxide concentrations as high as 800 ppm. The delta variant changes the threshold. Now the one hour number is about 600 ppm with everyone wearing a surgical mask.1 Of course the probability of an infected person being in the room is low if you're in an area where the infection rate is low.
It would be good to know the concentrations where ever you go: offices, classrooms, stores, theaters, taxis, airplanes etc.2 Consumer grade carbon dioxide meters can be purchased for $100 to $300. If you're really interested I can make a recommendation, but I've only used a few. We'll probably see a rapid improvement as these are going to be essential tools. Japan is requiring them in many public places and school rooms.3 It's important to have an NDIR sensor (basically it's doing spectroscopy with an infrared laser to measure concentration - there are many other techniques, but this is the cheapest with enough accuracy and repeatability). These are accurate to about 50 ppm, so ignore the more exact looking reading and just round up to the next multiple of 50 - if it reads 537 just call it 550. It takes about two minutes to get a stable reading and you'll want one that stores measurements. The model I like talks to an iPhone app which gives you a nice chart of the day. For businesses and schools it's a good way to check if the rooms are getting good airflow. I saw one schoolroom that exceeded 3000 ppm when students were present. It turned out an air return duct was blocked - a thirty minute fix gave the students clean air again.
High carbon dioxide concentrations make people drowsy and sap cognitive abilities. It hasn't been carefully studied, but readings over 1000 ppm can make you drowsy and perhaps a bit feeble minded. One Army study suggests 800 ppm should be a warning level. Half-jokingly I told a superintendent that he could justify the cost of measurement though improved test scores. It turned out that's what sold him. Maybe it's a way to upgrade the collective intellectual capacity of an office. Another benefit is a possible reduction in airborne diseases like the flu.
You can't always open windows and doors to get a solid draft, but HVAC systems can often have their fan settings increased and room vents adjusted. High quality filters can capture viruses along with other particulate like some from a fire. MERV-13 is a sweet spot for price, the ability to snare virus sized particles and not requiring more powerful fans. And you can buy or build portable air cleaners.
The hot ticket for rolling your own is a very simple design known as the Corsi-Rosenthal cube. Here's the public domain diagram we used to build 84 of them for about $5,000 (the cost shown in the drawing doesn't involve much shopping around). We used the cardboard from the shipping boxes the fans came in. The shroud is very important. Square corners disturb the airflow and can drop the unit's efficiency by about a third. A normal sized classroom for 30 to 40 students probably needs two units. Keep them away from walls, doors, and openable windows. The filters will probably last the school year if you turn them off when people aren't in the room. Most of the classrooms are showing readings under 600 ppm with these and the school's HVAC system fans all on high. The boxes make a big difference. Commercial air cleaners with good filters probably make more sense in offices and schools if they want to go long term, but 600 cfpm MERV-13 filters are about $500 and in short supply these days. Like carbon dioxide meters I suspect we'll see some movement on air filter and fan design.
Some learnings:
Duct tape is frustrating!
Schools have mountains of duct tape.
Eighth graders are the perfect people to enlist if you want to build a lot of them. Eighth grade girls if you want them to be semi-presentable.
_________
1 These are rule of thumb numbers based on empirical evidence. But it's complex with many confounding factors.
2 A closed car can be spectacularly high. I sat in my car for fifteen minutes with one other person and recorded 3800 ppm! You can drop this by opening the windows. Opening them diagonally makes a lot of sense for creating airflow. Airliners have good general circulation, but a given row can be bad. A flight is probably much safer than a half hour Uber ride if the driver has the windows up.
3 People are already taking measurements in gyms, restaurants, etc and putting them online with locations and business names. It's ad hoc and not very standardized, but there are over 100 locations in NYC the last time I checked. It makes much more sense for a business to do their air handling homework and post numbers in their establishment as well as their website. Hopefully at some point a respectable aggregator will step in.
breadth and depth
His parents were Danish, hers Swedish. By some measures it was a mixed marriage with any number of small cultural differences. He noted and took delight in these small differences and ambiguities. Rather than hunting, fishing or bowling he'd hike in the Summer and take long walks the rest of the year. He liked to walk by himself and I suspect thinking about the stories he'd tell to friends and family about once a week. He said storytelling was in his family and he had a great voice for it. We'd sit in his yard and listen. Some were short, some took a half hour. They were imaginative with emotional moments coming in unsuspecting places. They weren't the polished work of a writer, but left you wondering how he made those connections. Only years later did I learn what an amazingly varied background he had and continually sought out.
My sister is a visual storyteller. It took her half a lifetime to come to a place where she realized a single frame made of many images could be a short story that left you with questions and an open invitation to wonder. She's extremely creative. The stories come to her quickly, but require a week or two to realize. I suspect my Dad was a big influence. He believed the best answers were incomplete and led to deeper questions. He believed breadth was required to see simple answers weren't simple. Corinne went for breadth, unfortunately I started down a path that was deeper than broad.
A trigger for this post was a recent newsletter from David Epstein (The Sports Gene, Range). He begins by talking about Emma Raducanu at the US Open:
Earlier this month, 18-year-old British tennis player Emma Raducanu won her first Grand Slam title. It was a shock; she entered the tournament with 400-to-1 odds. One of my favorite sportswriters, the Guardian’s Sean Ingle, asked Raducanu’s former coach about the factors that helped her talent blossom. Here’s what the coach said:
“From my perspective one of the best things with Emma is that she was exposed to a lot of sports from a young age, and didn’t go too specific into tennis straight away. I see that on court. When she’s learning a new skill, or trying something a little bit different, she has the ability and coordination to pick things up very quickly, even if it’s quite a big technical change.”
Raducanu added this:
“I was initially in ballet, then my dad hijacked me from ballet and threw me into every sport you could imagine. I was doing horse riding, swimming, tap dancing, basketball, skiing, golf and, from the age of five to eight, I was go-karting…From the age of nine I started motocross in a forest somewhere for a year. This was all alongside tennis.”
Although there are a few athletic geniuses like Tiger Woods who focus early, most elite athletes follow a very different path building a broad set of varied skills before specializing. Epstein goes into depth in both of his books. Outside of athletics, the generalists he focuses on in Range have richly diverse backgrounds. Something very different that the experience many have in trade school and college programs. These people have built the tools they need to think creatively. They're often better than narrow experts when confronted with a novel challenge.
I'm sometimes asked to speak on the importance of STEM education at a local school and am doing it again. I tell them STEM ok, but overemphasized in K12. I think a broader liberal arts education leads to flexibility and creativity later on in life. Unfortunately that isn't reflected in many (most?) hiring practices. The lack of intellectual flexibility and diversity has lead to serous problems in some companies (tech in particular). One can always add breadth later, but that can be inefficient once you're out of school.
I don't mean to disrespect STEM subjects. Assuming the curriculum allows, they can be made relevant and exciting to those who won't use them in their work. They add to breadth and can be a starting point for depth. There are wonderful math and science books and teaching approaches that unlock wonder without getting bogged down in minutia. Enough information and wonder that perhaps students will become citizens who can make informed choices.
Over the decades I've slowly broadened muself by talking to people and getting involved with their ideas and projects. Many of you have your own diverse lists. My short and incomplete list includes human powered airplanes, done strange things with sound, learned a little about animated film making, been around story tellers, learned a bit of anthropology and sociology, done art history research, learned about fashion and how clothes are made, learned a bit about diabetes, been involved in sandbending, the mental side of elite sport, and even know a bit about the fluid dynamics of balls used in sports. Many of my guides and friends see this blog and I need to say thank you! It amazes me how some of this triggers a thought in something I'm working on later. You find yourself becoming more creative with age. Who would have thought that the math for thinking about boundary layer separation on an almost non-spinning beach volleyball would help thinking about neutron star atmospheres. Or the linkage between animation and fabric design, or... the list goes on and on...
Depth is great, but you need breadth to be creative.
Posted at 10:20 AM in art, book recommendation, building insight, critical thinking, education, general comments, story time | Permalink | Comments (0)
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