The invention of the historical compass

The invention of the compass recorded in history that the earth itself is a huge magnet, and there is current and convection in the outer core of the earth composed of molten iron and nickel, thus generating a magnetic field.

Like a simple magnetic stripe, the earth's magnetic field has two poles-the North Pole and the South Pole. Put a magnetic stripe on the paper covered with iron filings, and the iron filings will be distributed along the magnetic lines radiated by the magnetic poles.

A magnetized object, such as a magnet and a compass pointer, will also adjust its direction like iron filings to keep it consistent with the direction of the magnetic field lines. In the 1 century, people in China used magnets in a device called "Sina", which was mainly used to see geomantic omen.

In this device, the magnet is carved into the shape of a spoon and placed on a polished chassis, which points itself to the north-south axis. The chassis is usually engraved with azimuth (east, west, south and north), constellation distribution and symbols for divination.

In 83 AD, China philosopher Wang Chong recorded this device, but did not mention its application in navigation. In the 8th century, China people used magnetized iron needles to replace the magnets in Sina.

This kind of magnetic needle is obtained by magnetizing an iron needle along the magnetic axis of a magnet with excellent magnetism. 1086, Shen Kuo, a scientist from China, explicitly mentioned a magnetic compass specially used for navigation in his Meng Qian Bi Tan.

Up to117017065438, Zhou Pingke Tan written by Zhu He in the Northern Song Dynasty described the use of the compass at sea. However, it was not until the beginning of the European exploration era that the compass was made into a complex navigation device.

In view of a large number of innovations in the Far East, the compass is likely to be spread to the West. Before that, European travelers used the sun or Polaris to tell the north-south direction.

Although they can get more accurate positioning through this astronomical method, it can only be done when the weather is clear-the bad weather that appears from time to time often seriously affects navigation activities and leads to disastrous consequences. In 1 1 century, vikings may have used compasses to sail on the coast of northern Europe, but the first record of magnetic compasses came from Alexander, a British scholar and priest. Written by Nickmann and published in 1 180.

The early European compass inserted a magnetized pointer vertically into a straw, and then let the straw float vertically in a plate filled with water. Such equipment can indicate the accurate direction to a certain extent, but it is extremely inconvenient to carry when traveling.

At 1250, the pointer is mounted on a pivot, and above it is a circular card marked with the main direction, which can rotate with the pointer. 1269, French scientist Petrus? Perigrinas first explained how magnets (and compasses) work.

He described the magnetic pole and invented the compass, so that the pointer could indicate the direction in degrees. Further improvements to the compass include putting the pointer and dial in a box.

Early boxes were made of materials such as wood or ivory, which did not interfere with the magnetic force exerted on the pointer. The later use of brass was also based on this consideration.

/kloc-in the 6th century, the ship's compass was installed on a self-correcting shaft or bracket to ensure that the compass could always remain horizontal on a bumpy ship. The compass soon became an indispensable tool.

1594, British philosopher Francis? Bacon called the invention of the compass pointer one of the three most important advances in civilized society (the other two are gunpowder and printing). Every year, thousands of sailors entrust their lives to a trembling piece of iron and operate according to its instructions during the voyage.

Later, sailors gradually realized that the pointer was not always accurate, and it would be disturbed by nearby objects, especially iron products. Navigation compasses will also be influenced by the mainland. When sailing in the east-west direction, navigators know that proper azimuth compensation must be carried out to offset the influence of a phenomenon called "magnetic deviation".

Who invented the compass in history? Who invented the compass in history?

Patience ~ the ancestor of compass-the ancestor of Sina compass appeared in the Warring States Period. It is made of natural magnets.

It looks like a spoon with a round bottom, which can be balanced on a smooth "field" and can rotate freely. When it is at rest, the handle of the spoon will point to the south.

The ancients called it "Sina", and in the book Han Feizi at that time, there was: "Wang Li Sina took the time first." "Sooner or later" means square, east.

Guiguzi recorded the application of Sina, and Zheng people took Sina with them when picking jade to make sure they didn't get lost. In the Spring and Autumn Period, nephrite and jadeite with hardness of 5-7 degrees can be polished into various shapes, so natural magnets with hardness of only 5.5-6.5 degrees can also be used to make SiNa.

In the book Lun Heng, Wang Chong of the Eastern Han Dynasty made a clear record of the shape and usage of Sina. Sina is made of a whole natural magnet after pondering. The handle of the spoon is guided by the pole, so that the center of gravity of the whole spoon falls right in the middle of the bottom of the spoon. The spoon is placed in a smooth field, surrounded by a four-dimensional stem and branches, which synthesize 24 directions.

This design was completed through long-term research after the ancients carefully observed many phenomena related to magnetism in nature and accumulated a lot of knowledge and experience. The appearance of Sina is the practical application of people's understanding of the polarity of magnet fingers.

However, Sina also has many defects. Natural magnets are hard to find, and they are easy to lose their magnetism when they are impacted and heated during processing. Therefore, Sina's magnetism is relatively weak, and the contact with the site should be very smooth, otherwise it will be difficult to rotate because of the great friction resistance, and the expected guiding effect will not be achieved.

Moreover, Sina has a certain volume and weight, which is inconvenient to carry, which may be the main reason why Sina has not been widely used for a long time. Sina consists of a bronze disc and a magnetic spoon made of a natural magnet. The bronze disc is engraved with 24 directions, and the magnetic spoon is placed on the central circular surface of the disc. When it is at rest, the tail of the spoon points to the south.

The invention of the compass In ancient times, people often cut thin iron leaves into the shape of fish. The belly of a fish is slightly concave, like a boat. Float on the water surface after magnetization, which can refer to north and south. It was used as a game at that time.

Cui Bao of the Eastern Jin Dynasty once mentioned this kind of "guiding blind fish" in Notes on Ancient and Modern Times. Ceng Gongliang in the Northern Song Dynasty recorded the method of making and using the fish guide in the General Introduction to the Five Classics: "Cut it with thin iron leaves, two inches long and five points wide, with the head and tail as sharp as a fish's tip, and burn it with charcoal. Hou Tongchi, with iron wok and iron pot fish as the initial fire, the tail is straight, dipped in the basin and sealed.

When in use, the water bowl is placed flat in a windless place, the fish is on the water surface, so that it floats, and the head is always in the afternoon. "This is an artificial magnetization method, using the earth's magnetic field to magnetize the iron sheet.

That is, put the red-hot iron sheet in the meridian direction. The molecules inside the hot iron sheet are in a relatively active state, which makes the iron molecules arrange along the direction of the earth's magnetic field to achieve the purpose of magnetization.

This arrangement can be quickly fixed by immersing it in water, and the degree of magnetization can be increased by tilting the fish tail slightly downward. The invention of artificial magnetization has played a great role in the application and development of compass.

This is also a great event in the history of the development of magnetism and geomagnetism. Shen Kuo in the Northern Song Dynasty mentioned another method of artificial magnetization in Meng Qian Bi Tan: "Fang Jia can be guided by a magnet."

According to Shen Kuo, technicians at that time rubbed sewing needles with magnets to make them magnetic. From now on, this is a method to make the arrangement of magnetic domains in the steel needle tend to a certain direction by using the magnetic field of natural magnets, thus making the steel needle appear magnetic.

This method is simpler than geomagnetic method, and the magnetization effect is better than geomagnetic method. The invention of friction method is not only the earliest in the world, but also creates conditions for the emergence of practical magnetic direction finder. Shen Kuo also talked about various phenomena in the process of friction magnetization in Meng Qian's Notes: "If a magnet is used for tit-for-tat, it will be sharp and always guided. Some people point to the north and are not afraid of stones ... On the contrary, there should be differences between the north and the south, which has not been studied in depth."

That is to say, after rubbing the sewing needle with a magnet, it sometimes points to the north in a tit-for-tat manner. From now on, all magnets have two poles, N and S, and the direction of the sewing needle is different when magnetized, so the direction after magnetization is also different.

But Shen Kuo didn't know this truth. He truly recorded this phenomenon and frankly admitted that he didn't think deeply. I hope future generations can explore further.

Regarding the installation method of magnetic needle, Shen Kuo introduced four methods: 1. Shui Piao method-Put some rushes on the magnetic needle to float on the water, which can indicate the direction. 2. Bowl lip rotation method-put the magnetic needle on the edge of the bowl mouth, and the magnetic needle can rotate to indicate the direction.

3. nail rotation method-put the magnetic needle on the nail. Because the nail surface is smooth, the magnetic needle can rotate freely to indicate the direction. 4. Twilight hanging method-coat some wax in the middle of the magnetic needle, stick a silk on it, and hang it in a windless place to indicate the direction.

Shen Kuo also compared four methods. He pointed out that the biggest disadvantage of water flotation is that the water surface is easy to shake, which affects the measurement results. Bowl lip rotation and nail rotation are flexible because of low friction, but they are easy to fall off.

Shen Kuo emphasized the hanging method, which he thought was an ideal and practical method. In fact, the four methods pointed out by Shen Kuo have summarized the two systems of compass devices so far-water needle and dry needle.

Meng Qian Bi Tan is a book about ancient science and technology in China written by Shen Kuo (1031-1095), which talks about some problems of magnetism and compass. In the Southern Song Dynasty, Chen introduced another method of making fish and turtle guides in Guang Ji.

This fingerless fish is different from that recorded in the General Theory of Wu Jing. Carve the finger-sized wood into the shape of a fish. Put a natural magnet in the belly of the wooden fish, and the S pole of the magnet points to the head of the fish. After sealing with wax, insert a needle from the fish's mouth and it becomes a fingerless fish. Floating it on the water, a fish head guide, is also a kind of water needle.

The guide turtle was a popular new device at that time. Place a natural magnet in the abdomen of the wooden turtle, dig a smooth hole under the abdomen of the wooden turtle, align it and put it on the pointed bamboo nail standing upright on the board, so that the wooden turtle is placed in a fixed and accessible place.