Compass chips

I once flew a track in the eastern arctic that magnetic error was briefly exactly -90 degrees. (Straight east of the magnetic pole) I was close enough to the magnetic pole that the magnetic error changed >1 degree / hour in a PBY.

w..

My father worked for a mining company called Cominco. At one point in the late 1970s they were developing a lead-zinc mine on Little Cornwallis Island, which is about 100 miles north of the magnetic pole, so the compass variation would have been 180 degrees!

He used to joke about renaming it "Palm Island" to improve recruiting. ;)

Cheers

Phil Hobbs

The truly heavy elements are, indeed, distributed almost uniformly. That's what makes them so bloody hard to mine for.

This is, among other things, the reason why it use to make sense to base currencies on gold: the occasional gold rush set aside, gold is actually distributed quite thinly, yet evenly all over the place. This means that to dig up a certain amount of gold takes essentially the same amount of work, no matter where in the world you do it. This meant the value of gold stayed relatively fixed over time --- until industrialized mining blew up that concept.

Another example are the so-called "rare earths" (chemically: lanthanides), which are currently mined almost exclusively in one place in China --- with some nasty political consequences to boot. Yet it doesn't really matter much where you open such a mining operation: the yield will be pretty similar basically everywhere.

So why is there almost no other mine which might give the Chinese some competition? Well, that's because to get useful amounts of these ores involves going through incredibly large amounts of dirt, and using some seriously dangerous physical and chemical processing to first isolate the extremely diluted rare-earth ores from the rest of the dirt, then to separate individual ores them from each other. So you can mine for rare earths wherever you want, but you'll get serious amounts of pollution coming from some fricking _huge_, ugly holes in the ground if you do. This eventually got this kind of mining choked off by environmental protection rules, or flat-out closed by the government, almost everywhere.

afaiui the Chinese helped it along by dumping to price until most other mines closed knowing that reopening a dirty mining operation like that in the more environmental cautious places of the world is near impossible

-Lasse

Riiiight.... the other current production is in India, Malaysia and Brazil, all famous for their environmental stewardship.

Best regards, Spehro Pefhany