China Wall

The Great China Wall's History

China's ancient wall is known as the Great Wall of China. Cement, rocks, bricks, and ground powder are used to build the wall. It was constructed to fend off enemy attacks on the northern region of the Chinese Empire. It is the longest building ever constructed by humans. Its dimensions are approximately 9.1 meters (30 feet) wide, 15 meters (50 feet) high, and 21,196 kilometers (13,171 miles) long. The wall's earlier portions are composed of stone and compacted dirt. In the later Ming dynasty, bricks were utilized. There are seven thousand watch towers, block houses for the soldiers, and smoke signaling beacons.

China wall history

The "Great Wall of China", also known as Nineteen Walls, has been constructed. The first one dates back to the seventh century BC. 

During the Qin Dynasty, the first Emperor of imperial China, Qin Shai Hong, constructed the most well-known wall between 226 and 200 BC. Due to theft, not much of this wall is still standing. Compared to the current wall, it was much further north. The current wall was constructed in the Ming Dynasty.             

The Qin Dynasty was established by the First Emperor of China. His enemies were the northern Chinese Xiongnu tribes. Since some areas of China are easily traversed, Qin Shi Huang began 

    

construction of the Great Wall to increase the difficulty of a Xiongnu invasion.Other Chinese dynasties had extended and improved the wall.

The "Great Wall" was renovated, rebuilt, or extended under the Han, Sui, Jin, and Northern dynasties. There was significant reconstruction work done during the Ming Dynasty. Some parts of the wall were constructed using stone and brick rather than earth.

The Great Wall was built and rebuilt using locally available materials. The wall was composed in part of twigs, straw, and mud. Numerous factors contributed to the deaths of thousands of laborers, including fatigue, disease, animal attacks, and starvation. It is a myth that the deceased workers were interred within and beneath the Great Wall  Perceptibility from orbit

There is no scientific evidence to support the rumors that astronauts can see the Great Wall from the moon. Radar images from space have revealed the Great Wall. However, scientists are certain that astronauts cannot see the wall with their unaided eyes. Neil Armstrong was one astronaut who talked about being able to see the Great Wall from space. He claimed that it was evident that the wall was invisible on the moon. But only with binoculars and a lot of practice was astronaut William Pogue able to see the wall from a Low Earth Orbit distance (300–530 km height). 

 The collective name for a series of fortification systems that were primarily constructed across China's historical northern borders to defend and unite Chinese states' and empires' territories against various steppe nomadic groups and their polities is the Great Wall of China (Chinese: WànlŐ Chángchéng).

Ancient Chinese states began constructing walls as early as the 7th century BC. Later, Qin Shi Huang (220–206 BC), the first Emperor of China, connected certain regions. The Qin wall is mostly gone. Later, numerous succeeding dynasties constructed and preserved long sections of border walls. The wall's most famous portions were constructed during the Ming dynasty (1368–1644).

In addition to defense, the Great Wall served other functions such as regulating or promoting trade, controlling immigration and emigration, allowing duties to be imposed on goods shipped along the Silk Road, and controlling border controls. In addition, the building of watchtowers, troop barracks, garrison stations, and signaling abilities using fire or smoke, as well as the fact that the Great Wall's route functioned as a corridor for transportation .There are several courses in the frontier walls constructed by various dynasties. Together, they form an arc that roughly marks the border of the Mongolian steppe, extending from Liaodong in the east to Lop Lake in the west and from the Sino-Russian region in the north to the Taohe River in the south. Utilizing cutting-edge technologies, an extensive archaeological survey has determined that the Ming dynasty's walls span 8,850 km (5,500 mi). This is composed of 2,232 km (1,387 mi) of naturally occurring defensive barriers like hills and rivers, 359 km (223 mi) of trenches, and 6,259 km (3,889 mi) of actual wall sections. The total length of the wall, including all of its branches, was determined by another archaeological survey to be 21,196 km (13,171 mi). Now,Most people agree that the Great Wall's defensive system is one of the most amazing architectural achievements in history.

The Great Wall of China is the collective name for a series of fortifications that have historically gone by several names in Chinese and English.

In Chinese history, the phrase "Long Rampart(s)" (changcheng) first appears in Sima Qian's Records of the Grand Historian, where it refers to the First Emperor's more cohesive construction as well as the distinct great walls erected between and to the north of the Warring states.The "earth" radical is a phono-semantic compound that is used to represent the city or fortress in the Chinese character.

phonetic, with the pronunciation of Old Chinese reconstructed as *deŋ. Originally used to refer to the rampart that surrounded traditional Chinese cities and, subsequently, to the walls surrounding these states, it is now much more frequently the Chinese word for city 

The walls were not named as such, but Sima Qian's description of it in the Records gave rise to the longer Chinese name "Ten-Thousand Mile Long Wall" (Wanli Changcheng). Although the term "the long wall of 10,000 miles" is more closely associated with the modern form, the frontier general Tan Daoji is quoted in the advertisement 493 Book of Song as referring to something similar. The traditional Chinese mile was a frequently erratic measure that varied depending on the terrain and was meant to depict the length of a typical village. It was typically standardized at lengths of about 540 meters, or one-third of an English mile. Following China's metrication in 1930, it has consistently equaled 500 meters or 1,600 feet, so the wall's name would seem to describe a five thousand kilometers (3,100 miles). However, this usage of "ten-thousand" (wàn) simply means "innumerable" or "immeasurable" and is figurative, much like the Greek and English myriad. Owing to the wall's connotation with the First Emperor's purported despotism, Chinese dynasties that followed Qin tended to refrain from calling their own wall extensions the "Long Wall".Rather, a number of terms such as "frontier(s)" (sāi), "rampart(s)" (yuán), "barrier(s)" (zhàng), "the outer fortresses" (wàibŏo), and "the border wall(s)" (biānqiáng) were used in medieval records. Some poetic and colloquial terms for the wall were "the Earth Dragon" (Tǔlóng) and "the Purple Frontier" (Zɐsāi).Similar to the English "Great Wall," the term "Long Wall" was only used during the king period to refer to all of the border walls, regardless of where they were located or which dynasty they originated from.

Early modern European traveler accounts of "the Chinese wall" led to the evolution of the current English name. By the 1800s, "The Great Wall of China" had evolved into a standard in English and French, while it is still referred to as "the Chinese wall" in other European languages like German.

Features

The Great Wall was mostly constructed out of rammed earth, stones, and wood before bricks were used. However, bricks and other building materials like stone, lime, and tiles were extensively utilized in many sections of the wall during the Ming. Building progressed more quickly because bricks were lighter and easier to work with than dirt and stone due to their size and weight. Bricks could also withstand more weight and last longer than rammed earth. While stone is more difficult to work with, it can support its own weight more effectively than brick. As such, the wall's foundation, inner and outer brims, and gateways were all constructed from stones that had been cut into rectangular shapes. Most of the wall's uppermost section is lined with battlements. It was crucial to have the capacity to alert garrisons to enemy movements and summon reinforcements. For better visibility, signal towers were erected atop hillsides and other prominent locations along the wall. Wooden gates have the potential to be used as a trap for people passing through. In close proximity to the inner wall were constructed armories, stables, and barracks.

The Wall is in poor condition in many places, but it has been preserved and even extensively renovated in areas north of Beijing and close to tourist destinations. On occasion, the wall served as a source of stones for constructing homes and roadways. Graffiti and vandalism are also common in some areas of the Wall, and inscriptions on bricks have been stolen and sold for as much as 50 renminbi. Some have been destroyed to make room for mining or building. a 2012 National Cultural Heritage report.

According to the administration, 1,961 km (1,219 mi) of the Ming Great Wall have vanished, or 22% of the wall. In the next 20 years, erosion from Gansu Province's wall could cause more than 60 km (37 mi) to disappear. In certain locations, the wall's height has decreased from over 5 meters (16 feet 5 inches) to under 2 meters (6 feet 7 inches). Many of the square lookout towers that are depicted in the most well-known pictures of the wall have vanished. large portions of the wall in the west are more prone to erosion because they are made of mud rather than brick and stone. 2014 saw the concrete repair of a section of the wall close to the Liaoning and Hebei provincial borders. The piece has received a lot of criticism.

Perceptibility from orbit

from the lunar surface                       

There is a well-known but improbable myth that the Wall can be seen from the moon (385,000 km, 239,000 miles).

In a 1754 letter, English antiquary William Studeley mentions the myth that the Great Wall can be seen from the Moon, which is among the earliest references to the legend. Stukeley said, "This mighty wall [Hadrian's wall] of four score miles [130 km] in length is only exceeded by the Chinese Wall, which makes a considerable figure upon the terrestrial globe, and may be discerned at the Moon." Henry Norman made a similar claim in 1895, saying, "Besides its age it enjoys the reputation of being the only work of human hands on the globe visible from the Moon." The matter of "canals" on Mars gained prominence in the late 1800s and could have contributed to the the idea that long, thin objects could be seen in space. The Ripley's Believe it or not strip from 1932 also makes reference to the Great Wall's visibility from space.

The idea that the Great Wall can be seen from the moon has been refuted numerous times (the Great Wall's apparent width from the moon is equivalent to the width of a human hair when viewed from a distance of 3 km/2 mi), but the idea persists in popular culture.

from an asteroid belt

Whether the Wall can be seen from low Earth orbit—as low as 160 km (100 mi)—is a more contentious question. According to NASA, it is only really visible in almost ideal circumstances and is not particularly noticeable compared to many other man-made objects.

"The Great Wall of China is, indeed, visible to the naked eye at Earth orbit of 100 to 200 miles [160 to 320 km] high," said veteran American astronaut Gene Cernan. It's less visible than a lot of other objects, says Ed Lu, the International Space Station's Expedition 7 Science Officer. Furthermore, you must know where to look."

Chinese astronaut Yang Liwei claimed in October 2003 that he had failed to see the Great Wall of China. In response, a press release was released by the European Space Agency (ESA) stating that the Great Wall can be seen with the unaided eye from an orbit ranging from 160 to 320 km (100 to 200 mi). 

Chinese-American astronaut Leroy Chiao captured this image of the wall from the International Space Station. The photographer was unsure if he had really caught it because it was so faint. The Great Wall can be seen from "space" with the unaided eye under ideal viewing conditions—that is, if one knows exactly where to look—according to a report published in the China Daily based on the photograph.