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[Phys-L] On Exponential Growth and Forecasts from Extrapolating Model Data.

Suppose there are presently 200 confirmed cases of Covid-19
Suppose this number doubles every three days.
Say that 20% of the US population has natural immunity.

How long to ripple though the susceptible population:
??why, 200 X 2^(3days) = 0.8 x 327 million, of course!
20.31 x 3 days = 61 days plus 14 days recovery time
for the last wave - grand total 75 days and June 1
sees us home and dry.
Then there's the mortality rate - let's call it just 1%
??not the 3% that people are suggesting.
Hmmmm....2.6 million deaths. So not just a shortage of
test strips - but a shortage of coffins and crematoria slots!

And that demonstrates the features of an exponential series
the weakness of extrapolating time series on current data!

Brian W