Printing is one of the four great inventions of Han working people in ancient China. Printing originated from Taoist woodcut printing and was active in Sui Dynasty woodcut printing. In the Song Renzong era, it was developed and perfected by Bi Sheng, resulting in movable type printing, which was spread to Europe by Mongols, so people later called Bi Sheng the ancestor of printing. China's printing is the pioneer of modern human civilization, which has created conditions for the wide spread and exchange of knowledge. Printing first spread to Korea, Japan, Central Asia, West Asia and Europe. The invention of movable type printing is a great technological revolution in the history of printing. The method of movable type printing is to make the positive and negative character patterns of single words first, then select the single words according to the original manuscript, arrange them in the font plate, ink them, and then remove the font after printing, so as to use them again in the next typesetting.
Gunpowder is said to have been invented by Ge Hong in Jin Dynasty. The study of gunpowder began with the ancient Taoist alchemy. The ancients refined Dan medicine to live forever. The purpose and motive of alchemy are ridiculous, but its experimental method still has some merits, which eventually led to the invention of gunpowder. Engles spoke highly of China's pioneering role in inventing gunpowder: "It has been proved beyond doubt that gunpowder was transmitted from China to Arabs through India, and Arabs were transmitted to Europe through Spain together with gunpowder weapons." The invention of gunpowder greatly promoted the process of historical development and was one of the important pillars of the European Renaissance. Although alchemists have mastered certain chemical methods, their direction is to seek the medicine of immortality, so the invention of gunpowder has certain contingency.
The invention of compass with physical direction indication consists of trilogy: Sina, magnetic needle and compass. All belong to China's invention.
Compass is one of the four great inventions in ancient China, and its invention has played an inestimable role in the development of human science and 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. 1 1 At the end of the century or at the beginning of the 2nd century, China ships began to use compasses for navigation. Zhou Ping can talk in the Northern Song Dynasty: "Sailors know geography, watch the stars at night, watch the sun by day, and watch the compass in the dark."
Atomic bomb (A-bomb) is an atomic bomb and a kind of nuclear weapon. It uses the photothermal radiation, shock wave and induced radioactivity of nuclear reaction to cause death and destruction, as well as to cause large-scale radioactive pollution and prevent the other side from taking military action to achieve strategic goals. It mainly includes fission weapons (first generation nuclear weapons, usually called atomic bombs) and fusion weapons (also called hydrogen bombs, which are divided into two levels and three levels). Some also put light elements with induced radiation into weapons to increase radiation intensity, expand pollution, or strengthen neutron radiation to kill people (such as neutron bombs). 1July, 945 16 in the early morning, the world's first atomic bomb exploded successfully in the desert area of Alama Dole Air Force Base, New Mexico, USA.
1936, a key project established in the German Penemende Rocket Research Center-Wernher wernher von braun, the pioneer of human missile technology, was named "Revenge Messenger" by Goebbels of the Third Reich Propaganda Department. As a leader, he led the implementation of the V-2 project. 1939, the world's first missile A- 1 was successfully launched from Germany, which opened a new era of human military weapons. 1942, V- 1 and V-2 missiles were successfully launched; 1944 From June to September, Germany launched V- 1 and V-2 missiles to London. In the late World War II, Germany also developed several surface-to-air missiles, such as Rhine's daughter, X-7 anti-tank missile and X-4 line guided air-to-air missile. These missiles were all developed by Wernher wernher von braun.
Satellites can be divided into earth satellites or satellites of other planets according to the planets around them. According to the source, earth satellites can be divided into natural satellites and artificial earth satellites.
natural satellite
A star orbiting a planet, such as the moon, a satellite of the earth.
artificial/man-made earth satellite
Sputnik is a prosperous family. According to the purpose, it can be divided into three categories: scientific satellites, technical experimental satellites and applied satellites. Scientific satellites are satellites used for scientific exploration and research, mainly including space physics exploration satellites and astronomical satellites, which are used to study the upper atmosphere, the earth's radiation belt, the earth's magnetosphere, cosmic rays and solar radiation. And can observe other stars.
19571On October 4th, the former Soviet Union successfully launched the world's first artificial earth satellite.
Subsequently, the United States, France and Japan successively launched artificial earth satellites.
1On April 24th, 970, the first artificial earth satellite "Dongfanghong-1" designed and manufactured by China was successfully launched by the Long March-1 carrier rocket. The orbit of the satellite is 439 kilometers from the nearest point of the earth and 2384 kilometers from the farthest point. The angle between the orbital plane and the equatorial plane of the earth is 68.5 degrees, and it takes 1 14 minutes to circle the earth. The satellite weighs 173 kg and plays the music of Dongfanghong at a frequency of 20009 megacycles.
(I hope to adopt it, thank you)