Re: xkcd: Tukey

Lynn McGuire <lynnmcguire5@gmail.com> schrieb:

xkcd: Tukey
    https://www.xkcd.com/3104/

That one is really good, and reminds me of Mark Twain's
quote about the length of the Missisippi.

So true, so true.  I can always tell who is a new user of simulation
software, they expect to get 9 (ppb, parts per billion) or 12 (ppt,
parts per trillion) digits of precision out of our software.  I will go
through my explanation of how simulation software is based on
experimental data of 2 or 3 digits of precision and watch their faces
change when they start to understand.

You could also try explaining about the analytics.  If they hand
you an analysis which is accurate to 9 ppb in one of the main
components (not a trace component where 9 ppb which, for xome
reason, can be found at that level and where the 9 ppb is a large
fraction of what is in there), and prove that it's accurate even
when two different labs analyze it, several times, and the labs
don't know they are analyzing the same sample,

Or the number of theoretical stages in a column - that is a
model based on a false assumption, but (AFAIK) everybody
lumps mass transfer and equilibrium together; the HTU/NTU
method that I also learned at university is not really used,
and you cannot use a fractional number of theoretical stages.

But if they are asking for REPRODUCIBILITY, that is a very
much different matter, and can be quite justified.  (The value
converged to should be the same up to a certain accuracy for
different reasonable starting conditions).  They might want to use
a gradient-based optimization, which requires numerical derivatives,
for example.