Is the sun a natural compass?
The sun is a natural compass. Natural compasses include sun, moon, Polaris, tree rings, snow, moss, ant nests and so on. For example, according to The Sun, in the northern hemisphere except the tropic of cancer, sunlight always comes from the south. Compass, called Sina in ancient times, is mainly composed of magnetic needles installed on the shaft. Under the action of natural geomagnetic field, the magnetic needle can rotate freely and keep in the tangential direction of magnetic meridian. The south pole of the magnetic needle points to the geographical south pole (magnetic north pole), and the direction can be distinguished by using this property. Compass is the result of China ancient working people's understanding of magnet magnetism in long-term practice. As one of four great inventions of ancient china, its invention has played an inestimable role in the development of human science, technology and civilization. In ancient China, the compass was first used for rituals, etiquette, military affairs and divination, and to determine the orientation when looking at geomantic omen.
Natural compass
sun
There are many magical phenomena in nature. For example, the sun is the most famous natural compass in nature. Continents cannot be evenly distributed on the earth, and most of them are in the northern hemisphere, so the vast majority of human beings live in the northern hemisphere. Except for the area south of the Tropic of Cancer, the rays of the sun always come from the south, so the south is generally easy to confirm. As we all know, the sun rises in the east and sets in the west. In the morning, the sun rises in the east and sets in the west at night. At noon, the sun is in the south and the shadows of trees face north.
Polaris
Polaris is the best natural compass in nature. Polaris, also known as Beichen and Ziweixing, refers to a star closest to the north celestial pole, that is, a brighter star in the north pole direction of the earth. At night, as long as you find the north star, you can determine the direction. If you want to find the North Star, you must first find the Big Dipper, which looks like a water spoon. If you extend the two stars (Tian Xuan and Shu Tian) on the side of the water spoon by about five times, there will be a brighter star, which is the North Star.
moon
As the only natural satellite of the earth, the moon reflects sunlight and is also the most common compass in nature. Because of the different running directions, the receiving sphere often changes. At night, the moon rises in the east and sets in the west, and different images such as spheres, semicircles and meniscus are received on the spherical surface, which is called "moon phase". The change of the moon phase has certain rules in time and direction, so as long as we know the moon phase and time, we can find the direction. For example, the direction of the moon at night is: the first quarter moon, in the south at 6 pm, and in the west at 12 pm; The full moon (14- 18) is in the east at 6 pm, in the south at 12 pm, and in the west at 6 am the next day; First quarter moon, in the east at night 12, and in the south at 6 o'clock the next morning.
Tree rings
After the trees are cut down, many concentric rings can be seen on the stump, which are called rings in botany. People have realized that tree rings record the ever-changing traces of nature and are extremely precious scientific data. Tree rings, as the compass of nature, usually face south in width and north in density, and the south grows faster than the north with wider intervals. The tree rings on the south side are sparse, because sunlight and rain are richer than the shady side facing north, and more nutrients are obtained in the south direction, and the trees grow thicker, so the tree rings are sparse; Similarly, the north-facing side is blocked, the nutrient absorption in the south is insufficient, and the annual rings are denser.