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If there are two "mental tools" I wish we could teach every person, they are exponential growth and statistical thinking. Neither is intuitive, but they would help people understand this whole situation (and many others) a lot better.



My high school math teacher introduced exponential growth by asking the class if we'd take $1M now or $0.01 doubled daily for a month. We, as most people do, wanted the $1M, but the penny turns into more than $5M.

Had to explain this to someone yesterday. They literally wouldn't believe me until I screenshotted an Excel spreadsheet of the daily doublings, despite a finance degree.


I think that's exactly the issue. People can't picture it. You can show them a curve on a graph, but that doesn't translate for people without a mathematical/scientific background into "a shitload of people will get ill very quickly." Our brains seem not to be very well wired to make the connection between mathematical abstractions and reality, and aside from the minority of people who seem to just "get it," people don't understand without a good explanation from a very good teacher.


We technology people don't just inherently "get it", but rather have experience traveling up and down in powers of two for things that are meaningful to us. A month has 30 days - that's easily recognizable as a giga (2^10 ~= 10^3). And a billion isn't even that large to us.


Very true. But it doesn't stop there. One of my pet peeves is that people who believe they understand exponential growth will extrapolate too far in the future. More often than not, processes working against the exponential growth, negligible small in the beginning, will grow even faster and will reduce the grow rate, even without external intervention. In the example of COVID, it's the chance of interaction of an infected with an uninfected, even without social distancing, just because so many people will be infected, or dead. This effect is completely negligible in the beginning, but dominates in the end. (Of course, all the people modelling the epidemic have this effect in.)


I remember how it was taught in high school math class. It was some variation on the "rice on the chessboard" story:

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


I think that's a good example because it shows individual objects instead of curves on a graph, which for many people doesn't translate to reality.


I like to think that every contact outside increases risks. And conversely, to keep my sanity, that every prevented contact helps reduce the risk a little bit


https://www.albartlett.org/presentations/arithmetic_populati...

"It's a great pleasure to be here, and to have a chance just to share with you some very simple ideas about the problems we're facing. Some of these problems are local, some are national, some are global.

They're all tied together. They're tied together by arithmetic, and the arithmetic isn't very difficult. What I hope to do is, I hope to be able to convince you that the greatest shortcoming of the human race is our inability to understand the exponential function."

Most people I try to explain the current problems are really not able to understand. I explain that the spread is exponential, and that the problem is that is grows so fast. I say look at the graph from China, look at the graph from Italy.

They answer "ah, the Chinese maybe hid some numbers."

I say, it just doesn't matter, only the shape of the curve matters, and it repeats in every land. Even if the Chinese hid half of the cases, that difference disappears in only three-four days in our locations, where it grows so fast, as it grew in China before they did their measures, much harder than ours.

They don't understand still. They think only "80000 in China is more than "50000 in Italy" and it stops there. That Italy will get from 50K to 100K in four days, that's what they don't understand until they'd see it happened, but it would still, sadly, not convince them in anything.

Whereas, not only it's just the shape of the curve that matters, we know exactly why the spread is exponential, and what has to be done to change the shape: manage to stop the people who have it to transmit the virus to the rest of the population. It's "just" people who spread it -- the virus is not a bacteria, it doesn't live or multiply by itself, it needs a host which will replicate it, and the only host spreading it among the humans is human. There's nothing else that we know to work than that.

The major danger is that 4 from 5 carriers of the virus won't feel so bad to think that they should really stay at home. Most of the carriers aren't aware what they do. They all have their lives where what they do at the moment is "urgent" and "must be done." As soon as the droplets they produce enter the lungs of other people, the virus is spread. The droplets are tiny enough to be normally invisible to us, of course.

It doesn't help at all that the most of the highest politicians, across many different countries, downplayed the seriousness of the situation for a long time. Even less that the scientific ignorance was promoted as a virtue for even longer times.




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