Re: xkcd: Tukey

Lynn McGuire wrote:

On 6/21/2025 3:09 PM, William Hyde wrote:

Lynn McGuire wrote:

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

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You get them to understand?
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Could you try with policy makers?
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Yes, yes, I know you're going to laugh again.  This time with ample justification!
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William Hyde

 The worst thing is getting the young inexperienced engineers to understand that even though we are first principles simulation software, they think that any simulation is good for making billion dollar decisions on.  They need to validate that simulation with a pilot plant and extreme laboratory data first.  Few do nowadays.

In terms of policy I was thinking of a bridge built up here across a cold saltwater strait.
It was clear (from previous work done) that the supports of the bridge were sturdy enough to resist sea ice, and far enough apart to prevent a dam of sea ice from building up.
Nonetheless a sea ice model was run to test the latter conclusion.  The problem was, that although it was a good model for predicting large scale changes in sea ice, it was utterly inappropriate for the current problem (a crowbar is a useful tool, but doesn't work so well as a needle).
The consulting firm got the model from some academics for nothing, and doubtless charged at least five figures for using it.
The bridge is fine, but the waste of time and money was unnecessary, and obviously so.
William Hyde