On March 26th of this lovely 2020, I offered a simple visually oriented discussion about exponential growth: "Glass Half Empty", in which I emphasized the dangerously deceptive "early growth" phase of any exponential process. If a glass takes a minute - exactly 60 seconds - to become half full of a magical liquid which was deposited in a small amount at the beginning of the process and DOUBLES IN VOLUME each second, you CAN'T SEE IT until less than 10 seconds before the glass is half full. Then, a second later, the glass is FULL. If you wait a few minutes, the house will be flooded, and possibly the neighborhood.
That's exponential growth.
Most humans lack opportunities to develop an intuitive feel for that kind of rapid increase. The wealthy are very profitably aware of the notion of COMPOUND INTEREST. That's exponential growth for you. Doubling rates are typically measured in YEARS, not days. But a wealthy family that invests wisely over multiple generations will rise to that top 1% of the World's Wealthiest Families simply by riding exponential growth.
As discussed on Facebook with a friend from grad school years, nuclear explosions also tend to be exponential processes, although those initial "quiet doubling periods" happen far to quickly to be perceived without very high-speed cameras. The Wikipedia page on exponential growth features a video of exponential (approximately) growth of a colony of bacteria. Again: things appear to start out slowly. At some time, the growth (viewed in real time - as opposed to charted on a log scale) appears explosive.
So: How did we get from 15 proven cases of COVID19 in early 2020 in the USA to well over 100,000 deaths today (July 24th, 2020), over 4 *million* positive tests, and over 600,000 dead worldwide? A year ago, nobody had even HEARD of this disease.
Pandemics spread exponentially. Stopping COVID19 is NOT trivial.
In April (the 13th, of the 2020 "Year of Covid") I shared some thoughts about face coverings: "Why bother wearing cloth masks?". Back in mid-April, I don't recall this having been a politically polarized or ideologically controversial issue. It was easy to focus on the obvious facts regarding what we knew - even in mid-April - about the transmission mechanism, and what was known about droplets exhaled by potential carriers and how fabric can stop MOST of those droplets.
Since then, it is absolutely mind-boggling to see how this issue has become a hill on which many science-denying humans are willing to fight a battle to the death - quite literally. As my brother mentioned in a Facebook post, "not wearing a mask might make you feel wonderfully free, but it's like the so-called freedom to drive at 60 miles an hour through a neighborhood. Sooner or later, somebody is going to get killed". Sorry, Kent, if I paraphrased that inaccurately.
In May, as news outlets began worrying about a "second wave" and many were skeptical about the need for further caution given that "we've passed our peak", I offered a discussion I called "Flatten Which Curve?". Main point: there are multiple curves we are monitoring: total infections in any given geographical region; total deaths attributed by healthworkers to COVID19; as well as NEW cases, NEW deaths, available hospital beds, number of people CURRENTLY hospitalized... One remark in the concluding section was "New infections could spike dozens of times if we continue to change our behavior." But now - because of exponential growth of impacted humans - we're rapidly approaching a million deaths worldwide, four million infections in the USA, and well over 100,000 deaths in the USA. Remember, four moths ago we were still below or near a hundred deaths. If this continues, it's not a linear process: we won't add another 100 thousand in four months. The math would say we'd add another thousand-fold. That would take us to a third of the US population, which we don't really expect to happen. But that's the math. Exponential, not linear!
In June, a fantastic chart was shared and discussed. It's a simplistic but suitably exponential model for the likelihood of catching COVID19 at a gathering. One axis shows the size of the gathering (how many people?). Thee other axis shows just how bad the pandemic is in a country (US, in this case). Sadly, once this particular post was made public, the US was deeply divided over strongly politicized interpretations of ANY fact related to the pandemic. George Floyd had died under a Minneapolis policeman's knee. Protests erupted all over the country AND the planet. And the clouds of tear gas faced by certain protesters are a great metaphor for the smoke that has confounded the public's ability to remain rational and reasonable about COVID19. Instead of addressing the disease and its spread, folks prefer to accuse their political opponents of not behaving properly regarding the required behavior for minimizing the spread of the disease.
We have over five months left in 2020.
Five months during which the pandemic could easily devastate countless millions of families, particularly in the most impoverished, vulnerable communities worldwide. Some of us fret and whine about being confined to our homes, or being required by authorities to wear a mask. Maybe we wash our hands. Maybe we maintain 2 meters of separation whenever and wherever possible from others.
For billions of humans, if a home exists in which to "shelter in place", it is shared with ten or more others. Water is not available. Savings or publicly provided resources for staying alive... also are lacking.
The virus isn't going to disappear. But my actions, and yours: they will determine how rapidly COVID19 continues to spread, and just who will be added to the grim total number of deaths caused by that particular coronavirus.
Stay safe. Stay healthy. Think critically.
