On the Seasonality of the Virus

What are the odds that the coronavirus will recede on its own during the spring because of warmer temperatures or a higher ultraviolet (UV) index? This has been a question from the beginning.

There has been some research in support of the idea that the warmer season would force the virus to retreat. And there has been other research that concluded that the virus would retreat but not disappear, that it would survive in the southern hemisphere and that it could then stage a comeback in the northern hemisphere in the fall when cooler temperatures return.

Single Variables

Looking at the United States state by state, we find little correlation between the number of deaths per capita and the UV index. For example, Wisconsin with a UV index of 4 in March has so far suffered 25 deaths per million inhabitants, but Rhode Island also with a UV index of 4 saw as many as 60 deaths per million. At one extreme, New York, New Jersey, Michigan, Connecticut and Massachusetts, all with a March UV index of 4, had over 100 deaths per million. At the other extreme, South Dakota also with a March UV index of 4 had only 7 deaths per million. (All deaths figures are as of 12th April 2020 per Worldometer). Read more

A Few Certainties About Covid-19

There is plenty that we do not know about the coronavirus. But let us take stock of the things that we do know for sure, and of some other things that we will soon know.Screen Shot 2020-01-27 at 2.29.15 PM

Real-world Exponentiality

By now, a child understands exponential growth. If you start with one apple on March 1st and double every three days, you will have a thousand apples on March 31st and a million on April 30th.

But in the real world, not the abstract world of math, there are constraints on that growth. Doubling your apples every three days is feasible for a month or so because you can probably find a thousand apples and also find a place to store them. But it would be more difficult to find, transport and store a million apples, unless you are willing to pack a six car garage with apples from floor to ceiling (accurate math). If you did, most of them would rot and your neighbors would call for psychiatric help, two other constraints on unbridled exponentiality. Read more