
Coronavirus: China’s Hubei reports 14,840 new cases, 242 additional deaths - csomar
https://www.cnbc.com/2020/02/13/coronavirus-latest-updates-china-hubei.html
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DoctorOetker
I think we were all suspecting this, consider the graph at:

[https://www.worldometers.info/coronavirus/coronavirus-
cases/](https://www.worldometers.info/coronavirus/coronavirus-cases/)

Observe the "Daily New Cases" graph, that looks like a sawtooth. It's very
easy to mentally fit a straight line on the left edge, and another straight
line on the right edge.

Now pretend the actual detected cases simply continued on the original
straight line, then at ~Feb 11 it would reach about 6k per day, instead of
falling down to 2k per day.

So the missing triangle has a base of about 7 days, and a height of about (6k
- 2k) = 4k per day.

The missing people under the area is thus base * height / 2 = 7 days * 4k per
day / 2 = 14k people...

The reason we all knew the crooked graph had to be false was because if you
consider the time distributions from infected to infectious, from infectious
to encountering a new person etc... then these distributions convolve, so you
never get these simple instantaneous hard bends.

The new numbers tell us that the original trajectory is continuing roughly
unabated!

So was this deception to buy time? build hope? it doesn't make any sense.
Unless Xi is so desperate as to become an inside trader and manipulate the
worldwide markets?

~~~
bredren
I was also tracking this graph and had built my own projection based on it.

After a day or so of thinking about it and seeing my projection match what was
being reported, I concluded China chose this function because it shows a
concern but does not cause great alarm. A predictable upward linear growth.
Unsettling, but not terrifying.

I had considered how to get actual accurate death data, and figured it was
impossible. However, there was some new, somewhat reporting from cremation
facilities in Wuhan that, if true, paint a very dire picture.

[https://www.epochtimes.com/gb/20/2/5/n11845444.htm](https://www.epochtimes.com/gb/20/2/5/n11845444.htm)

I doubt this is about markets now, this is as it has always been, about
"stability." The emergence of a true threat to stability that can not be
controlled by the worlds most successful authoritarian state is so unexpected
that I suspect the Xi and the politburo have been caught completely off guard
and unable to change strategies to contain the threat.

If they had been truthful about the deaths from the beginning, demonstrations
might have occurred that would have made things worse for everyone.

I think that we are going to see continued sharp rises in reports of deaths
now that WHO officials are on-site and it becomes more difficult to hide the
scale of what is most likely a global catastrophe.

~~~
DoctorOetker
>After a day or so of thinking about it and seeing my projection match what
was being reported, I concluded China chose this function because it shows a
concern but does not cause great alarm. A predictable upward linear growth.
Unsettling, but not terrifying.

Initially the expansion was clearly exponential as evidenced by the clean
straight line in the log-linear plots.

Under high mixing conditions (like a high N-dimensional cube) this is to be
expected for the initial breakout.

Then quarantine and lock-down measures came, and experts expected the second
derivative of the cumulative infections to reach a constant, which
subsequently happened.

I witnessed a lot of people not understanding 1) why a simple quadratic? 2)
why is a quadratic any better??

When there social distance measures are in effect, the virus can only diffuse
on territory, and not "teleport" by public transport etc.

This means that it can only spread in 2 dimensions.

Consider the oversimplification of an epicenter, with a disklike area of
infection, then a constant radial ground speed through diffusion, would mean
the infected area would increase quadratically with radius. And the radius
would increase proportionally to time (effective ground speed, since 2 months
from now people will not be able to suddenly sneeze 2 times as far...).

So the cumulative number of infections would hence increase quadratically with
time.

If we knew the eventual infection percentage (which Gabriel Leung estimated as
potentially being 60%?), then we could calculate the effective radial ground
speed:

If P is the number of people per area A then rho = P / A is the population
density.

If only a susceptible fraction S can get infected and assuming a circular
disk, with A = pi R ^ 2 = pi v ^ 2 t^ 2

Then we can calculate the cumulative number of infected people N as N = rho *
A * S = rho * S * pi * v ^ 2 * t ^ 2

so the daily new cases would be

dN / dt = rho * S * pi * v ^ 2 * ( 2 * t )

and its slope X would be:

X = d ^ 2 N / dt ^ 2 = rho * S * pi * v ^2 * 2

(units: confirmations per day, per day or confirmations per day ^ 2)

solving for ground speed:

v = sqrt( X / ( rho * S * pi * 2 ) )

Sadly I can not read Chinese for your link, can you fluently read Chinese or
did you use something like google translate?

