Monday, September 12, 2016

Finding True North for Dummies

Map of magnetic declination in the United States, circa 2005
Magnetic declination map of North America (2005)
We've heard it said (on many occasions) that "a little knowledge is a dangerous thing." OK, well, maybe not many occasions – except around the conference table at the Antisocial Network's weekly staff meeting. In the real world, a lack of knowledge is a dangerous thing, especially when one is pretending familiarity with the subject at hand. That's pretty much what's nailed all Dumbass of the Day winners so far. Today's candidate is a noob to our site, a onetime theater major by the name of Mark Keller.  We caught Mark as he was holding forth on geography in "How to Determine True North,"¹ now appearing at some Leaf Group niche called GoneOutdoors.com. Really...

We'd like to think that most people already know (or at least have been told) that
"Compasses point toward the magnetic north pole, located near Ellesmere island in northern Canada---but true north..."
...is someplace different. According to Keller,
"...true north is about 70 miles away."
     Besides the fact that true north isn't a place, it's a direction, the geographic north pole (which Mark has incorrectly called "true north") is a lot more than 70 miles² from the magnetic north pole, and – gasp! – the difference between the two changes constantly! With an opening like that, we weren't sure we could trust Keller's instructions, so we looked...

...and Mark sort of has the basics correct. He talks a great deal about how to find the declination, "the degree of error between true north and where your compass is pointing" using a website and/or "a declination map."

Mark, being unfamiliar with the use of maps -- he's probably a lot more familiar with stage directions than with compass directions -- omits the most common source of declination information, the declination arrow printed on maps such as USGS topo maps. To continue, however...

Keller found an excellent resource of declination information and, unlike so many of his fellow eHowians, reworded it relatively accurately. We strongly suggest, however, that you go to the source instead of depending on Mark's semi-accurate copy-reword-paste job, if only because he needs to be slapped around for that 70 miles bull. That, and his obvious unfamiliarity with the actual meaning of true north are all we needed to give him his Dumbass of the Day award. Being right for the wrong reason just isn't good enough: it's "a little knowledge," and it's a "dangerous thing"!
Oh yeah, and another thing: Keller says not one word about finding north using Polaris, the North Star. Nuff said? Nuff said.


¹ The original has been deleted by Leaf Group, but can still be accessed using the Wayback machine at archive.org. Its URL was   http://www.ehow.com/how_5818799_determine-true-north.html
² When Keller wrote his post, the difference was about 700 km, for what little that's worth
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