Such a device, like a compass, it did not exist would be if our planet had no magnetosphere. In this case, the compass would be useless, as would in anywhere or in any direction depending on the inclination of the dial. Not all planets possess a magnetosphere, which in some approximation can be equated to the ionosphere. The essence of the concept boils down to how much heavenly body able to deflect the solar wind flow.Earth as a heavenly body has a sufficiently powerful magnetic field, so that, e.g., protects people from the damaging effect of gamma-radiation of the Sun. But, if the Earth has a magnetic field, then the laws of physics had to be poles between which extend magnetic lines. And, of course, they are on the Ground.The vanishing point of the magnetic field lines of the Earth is the pole that points the arrow of a compass. That only raises the question: and North? Why all so? And the answer is simple: because people are so comfortable. In fact, the so-called "magnetic North pole" is the South pole. This follows, again, from the laws of physics. The arrow of the compass is strictly along the lines of, but its magnetized end will point to the South pole, since it is known that the same charges of a magnet repel. Thus, the place where shows the arrow of a compass, will actually be the South magnetic pole of the Earth, which people used to call North. It has very strange properties.First, it drifts. Ie it moves relative to the earth's axis pretty fast - approx. 10 km per year. For comparison, the speed of movement of tectonic plates is approx. 1 cm/10,000 years. Second, the previous 400 years was in the territory of Canada under the pack ice, then as it is now rapidly moving in the direction of Taimyr. The speed of its movement is much higher than normal and is 64 km/year. Thirdly, it is not symmetrical about the South pole and, moreover, their drift is not dependent on each other. What is the phenomenon of drift of magnetic poles is not known to science. But has been shown to be a clear conclusion: the arrow of the compass points to the magnetic South pole of the Earth.
You point the compass
Most of the so-called "progressive humanity" used to think that the arrow of the compass always points due North. But, unfortunately, not the one marked by the North Star. And even more – not geographic that marked the convergence of the meridians. Worse, the compass shows... the South pole of the Earth. But what?
Is the advice useful?
You point the compass