We all know what a magnet, the magnetic needle and compass. But not everyone knows that the magnetic needle never shows just to the north. It is everywhere on the globe “leaning” on the direction of north at a certain angle to east or west. Hence the old has gone firmly entrenched the name of this corner: the “magnetic declination”. But the self-magnetic declination is not strictly constant but continuously .Poetomu say exactly what magnetic declination is in what ever place in the world at some point, as impossible as predicting what will happen in this place and at the same time, such as temperature vozduha.Prognoz temperature air to make even easier. The air temperature along with random fluctuations is clearly expressed diurnal and annual variations, and if you change from year to year, it has almost no secular izmeneniy. annual temperature in any point of the globe varies little over the centuries and even millennia. Earth’s magnetism is, by contrast, is subject to significant secular changes. They are several times daily and annual changes and surpass even the most powerful “magnetic storms”, where the magnetic needle is rotated to different sides of the considerable evidence ugol.Lyubopytnym secular changes of magnetic declination are two ancient churches in the city Biysk.
During the construction of churches must follow the rules, to the altar was turned to the east. To do this a long time often resorted to “king of stones” – the magnetic iron ore, has a “magic bullet” property to attract the iron and point to the north, if a piece of this ore to put on a plate, floating on the water. This “king of stones” paid homage royal honors: wore it even in the purple robe (wrapped in crimson velvet). This matter, among other things, preserved until now used to paint the middle part of the horseshoe magnets definitely red. More ancient of the two Biysk churches was built in accordance with the “North”, which have a piece of magnetic ore in its tab. When it began construction of another church (150-200 years), the “north” was in another .Stroiteli it will probably have decided that their predecessors simply mistaken. As a result of these two churches are located near each other, looking entrance doors in different directions (at an angle in degrees 20). They are real monuments of the magnetic declination in different epohi.Hotya exact value of the magnetic declination, as we have said, and it is impossible to predict, nevertheless know the average of its value to the place and certain time is very important. For example, it necessary for navigation and blind during flight on airplanes. Many may have heard also of magnetic anomalies – areas where the declination or other magnetic elements differ markedly from their normal values for the area. Determination of magnetic anomalies is of great practical importance, because they usually indicate the presence of iron ore, as well as some other minerals. Scientists have long studied the phenomenon “Magnetic declination” and came to the conclusion that the secular magnetic changes have the same period (about 540-580 years old) around the globe.