[conspire] (forw) Re: Correction

[Rick Moen]

Quoting Texx (texxgadget at gmail.com):

[pond puzzle:]

> Putting on sysadmin hat, the question should be asked WHY do they get this
> problem wrong?

The most common hypothesis is that people are so accustomed to _linear_
trends that they picture those even where you stress that this is
something dramatically different.

To elaborate on that, human intuition was shaped pretty well be natural
selection to avoid getting eaten on the savannah, but consistently
misleads people in a more-complex world.

Here's another puzzle to make the point:  In a pre-SARS-CoV-2 scenario,
you have a room where a random assortment of people gather.  How many
people must enter the room before there is a > 50% likelihood of at
least two of those people sharing the same birthday?  Take a guess based
on intuition, and then I'll be glad to explain why your intuition on
this puzzle (_and mine too, and everyone else's_) is wildly wrong.

For simplicity, and to avoid getting all wound up in (uninteresting!)
edge cases, assume 365 days in the year (e.g., let's not get hung up on
Frederic from 'Pirates of Penzance' having been born on Feb. 29 and
apprenticed to pirates until his 21st birthday), and let's assume rates
of human birth are randomly distributed around the days of the year.

If you want to cheat, look up 'Birthday Paradox' -- or, if you're a
tedious math wonk, you can just calculate the answer.  But doing either
of those does an end-run around my point, which is how very wrong
everyone's intuitive guess is, and why that happens.  (Which I'll
explain later.)

Hint for the math wonks:  The easy way to calculate the answer involves
inverting the question.


> If its doubling every day then going back a day its halving.
> That known, its quite easy to find 50% 25% 12.5% .625% etc.

Be careful:  Like the epidemial concept of R-zero, the basic
reproduction number, doubling rate is _completely_ context-dependent.
It is not an inherent, fixed property of a disease organism, but rather
a value observed specific to a time and place that depends on local
conditions (including population density, part of the reason NYC is in
such trouble).



> Everyone NEEDS a LOG!

I'm not sure it did much for Margaret Lanterman.
https://www.youtube.com/watch?v=BloTVTziM6c