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Ship Logs Suggest Upcoming Polar Reversal
Nyerp writes "Researchers are using naval logs dating back as far as 1590 to arrive at better estimates of the decline of Earth's magnetic field. The results suggest that there may be a reversal of earth's magnetic field in about 2000 years." Also worth noting, our ancestors have lived through a number of polar reversals, and we're still here, so no need to fret!
Our ancestors may have lived through this several times before but wont it affect us more as we are highly dependent on electricity and satalites etc?
Yes, except that's what you tell your descendents, a few generations after the compass becomes useless.
While the flips may occur quickly on a geological timeframe, they take much longer than a human lifetime to occur and stabilize.
A compass is a handy thing to have at sea, since without landmarks its the easiest way to keep pointing in the same direction. But there are other ways to navigate - with and without technology. We (or rather, "they," since we'll long be dust) will just have to make do with them.
No. Neither of those will tell you which way you're pointing. Both of those tell you where you are (actually, the cellestial version will only tell you where you are with the aid of an accurate clock).
Not quite the same thing.
On land, it's easy to walk in a straight line. You pick a tree or a rock or a mountain, walk towards it, then check your GPS gizmo and it will tell you which direction you walked. But while you're walking, you simply walk in the direction of the landmark you've chosen.
At sea, this is impossible. You can't just steer towards a landmark, because there are none. The best you can do is steer towards a particular star (the sun counts), but you'll probably have to make corrections for its motion. A compass serves the same purpose as a distant tree or mountain on land -- keeps you pointing in the same direction over the course of the present to near future. You need to be able to do that reliably before position fixes can help get you where you want to be.
Position references can be finessed into giving you a bearing track, but that's like telling a day trader that because the stock went up yesterday it's going to go up again tomorrow - maybe, but maybe not. You need more data to be sure.