Thread by @TheRealDoctorT

I know my niche here on Twitter is narrative threads, but I wanted to take a moment to discuss something that’s very difficult for us to truly grasp.

Something firefighters grasp intuitively, but many of us struggle with.

The idea of exponential growth. 1/

Let me start with a hypothetical question.

I’ll give you the answer later.

Monday: 541
Tuesday: 704
Wednesday: 938
Thursday: 1,195
3/27: 1,589+.

These are total US COVID-19 fatalities, growing by ~30% per day.

How many by the end of April, assuming the same % growth? 2/

We’ve all heard of the idea of exponential growth, even if it wasn’t called that.

Here in the US, a bear teaches us about exponential growth as kids in school.

His name is Smokey.

He teaches us that one small match can start a raging forest fire. 3/

Firefighters understand how quickly dangerous that smoldering match can be.

Why? Because a fire doesn’t go from one twig, to one other twig, to one other twig, and onwards slowly.

Each flame ignites many other flames, rapidly.

It’s why a forest fire is so deadly, so fast. 4/

Exponential growth is the idea of accelerating growth.

Instead of a straight line, it curves upwards faster and faster. See the graphs below.

We live linear lives, for the most part. Cause and effect. Ticking time.

Exponential growth is sort of... alien to our experience. 5/

Alright, remember that question I asked earlier? Assuming a constant 30% growth in fatalities, how many deaths would result from COVID-19 in the US by the end of April?

Around 12 million, conservatively (feel free to correct my back-of-the-napkin math).

Were you close? 6/

I cheated when I asked you for your guess.

I showed you numbers, but no visuals.

Below is the graph. Now would your initial guess have been different if you saw this?

When you see raw data in reports, understand that you’re not “seeing” the data.

(From @COVID19Tracking) 7/

Before I go any further, let me make something VERY clear.

I DO NOT think the final death toll from COVID-19 in America will be anywhere close to that number.

The point of that exercise was to show you how exponential growth can blindside you.

Now for point number two. 8/

Let’s say you reduced that cumulative growth rate in half to 15%.

We all socially distanced. We all washed our hands.

What does the total number of deaths look like at the end of April now?

About 200,000.

A MASSIVE difference, because the reduction is ALSO exponential. 9/

Our difficulty in comprehending exponential growth leads to two errors of underestimation.

1) We underestimate the rapidity and the scope of the problem.

2) We underestimate our potential impact on the outcome.

Both of these are vital to understand. 10/

If you understand, truly fundamentally understand, these numbers, then you know why the absolute worst thing we could do is stop social distancing too soon.

The economic toll of a shutdown is devastating, but the potential toll in lives of not shutting down is unfathomable. 11/

Before I’m accused of fear-mongering and inciting panic, let me state again, I’m NOT making predictions.

There are MANY reasons to be optimistic with regards to novel testing and therapies.

I vastly oversimplified to illustrate.

I’m NOT an ID specialist or epidemiologist. 12/

Just remember, every little thing you do, every choice you make, has the potential to shape things in ways beyond how we normally see the world.

Stay home.

Stay safe.

Look out for each other.

Sending prayers and positive vibes to all of you, and helping those I can #OnCall

CC: @ETSshow @medicalaxioms @Lexialex @WajahatAli @chadinabhan

A thread on a message you all (and many many others) have been spreading. Thanks for carrying the torch.