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-----Original Message-----
From: Phys-l [mailto:phys-l-bounces@mail.phys-l.org] On Behalf Of John
Denker via Phys-l
Sent: Tuesday, March 14, 2017 9:33 AM
To: Forum for Physics Educators <Phys-L@Phys-L.org>
Cc: John Denker <jsd@av8n.com>
Subject: [Phys-L] depicting uncertainty on maps
Hi --
Here is a timely example of uncertainty handled in an intelligent way.
Note the contrast:
++ For a point forecast, the National Weather Service routinely expresses
the uncertainty in the amount of snowfall by quoting a range, e.g. 12
to 18 inches. In physics it might be more conventional to write that
as 15±3 inches, but quoting the range is perfectly reasonable also.
-- On a map, the contours and color-coding don't lend themselves to
representing a range.
++ You can do a lot better by putting out *three* maps: lower limit,
nominal, and upper limit. The NWS has an experimental page that
does just that. Here is a screen grab:
https://www.av8n.com/physics/img48/snowfall-map-brackets.png
By way of contrast, note that as usual in the real world, the uncertainty is
neither calculated nor communicated using sig figs or anything like that.
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