According to the speculation of modern archaeologists, the natural magnetite ore is cut into a spoon-shaped thing and placed on a smooth board with directions engraved on it. The direction can be identified by the function of a magnet guide.
The earth is a big magnet. The poles of the earth are close to the geographical south pole and the geographical north pole respectively. When the magnets on the surface of the earth can rotate freely, they will indicate the north and south because of the nature that the magnets repel each other and attract each other-this truth was not understood by the ancients; But this phenomenon has been discovered by the ancients.
Modern people have made all kinds of electronic compasses. Smartphones generally have this software. Electronic compass, also known as digital compass, is a method to determine the North Pole by using geomagnetic field. When applied to a mobile phone, it is actually an electronic compass. An electronic compass generally consists of a magnetoresistive sensor and a fluxgate.
Extended data
Magnetic meridian changes with the seasons.
First, on the vernal equinox and autumnal equinox, magnetic meridian coincides with the meridian and meridian of the earth, and the compass points directly to the north and south poles of the earth, with an error of only 0.08 eccentricity of the earth's axis, which can be ignored.
Secondly, in summer solstice and winter solstice, the magnetic meridian and meridian do not coincide, and the magnetic declination is the largest, with the maximum deviation of plus or minus 23.26, that is to say, the magnetic declination near the earth's north and south poles is the largest. The circumference of the earth divided by the angle of 365 is plus or minus 23, which is equal to the distance between the magnetic deviation point and the north and south poles (plus or minus radian kilometers).
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