It’s actually an urban myth that the great wall of China is “visible from the moon” or visible from orbit with the naked eye unless we’re accepting that using Google earth amounts to the same. The claim the Great Wall is visible has been debunked many times but is still ingrained in popular culture.
The wall is a maximum 9.1 m (30 ft) wide, and is about the same colour as the soil surrounding it. Based on the optics of resolving power (distance versus the width of the iris: a few millimetres for the human eye, meters for large telescopes) only an object of reasonable contrast to its surroundings which is 70 mi (110 km) or more in diameter would be visible to the unaided eye from the moon, whose average distance from Earth is 384,393 km.
The apparent width of the Great Wall from the moon is the same as that of a human hair viewed from 2 miles (3.2 km) away. To see the wall from the moon would require spatial resolution 17,000 times better than normal (20/20) vision. Unsurprisingly, no lunar astronaut has ever claimed to have seen the Great Wall from the moon.
A more controversial question is whether the Wall is visible from low earth orbit, an altitude of as little as 100 miles (160 km). NASA claims that it is barely visible, and only under nearly perfect conditions; it is no more conspicuous than many other man-made objects. Other authors have argued that due to limitations of the optics of the eye and the spacing of photoreceptors on the retina, it is impossible to see the wall with the naked eye, even from low orbit, and would require visual acuity of 20/3 (7.7 times better than normal).
In 2001, Neil Armstrong stated about the view from Apollo 11:
I do not believe that, at least with my eyes, there would be any man-made object that I could see. I have not yet found somebody who has told me they’ve seen the Wall of China from Earth orbit. I’ve asked various people, particularly Shuttle guys, that have been many orbits around China in the daytime, and the ones I’ve talked to didn’t see it.
In October 2003, Chinese astronaut Yang Liwei stated that he had not been able to see the Great Wall of China. In response, the European Space Agency (ESA) issued a press release reporting that from an orbit between 160 and 320 km, the Great Wall is visible to the naked eye. In an attempt to further clarify things, the ESA published a picture of a part of the “Great Wall” photographed from Space. However, in a press release a week later (no longer available in the ESA’s website), they acknowledged that the “Great Wall” in the picture was actually a river…
History suggests that the great wall’s first origins can be traced as far back as the fifth or even eighth century B.C. It was during the Ming dynasty that the wall as we’ve come to recognise as a phenomena begins to be constructed..they’re a patient culture in China, but absolutely resolute to a cause and course once set.
China’s official reserves slipped to $3.18 trillion in the final quarter of 2011. The People’s Bank of China published data on Friday showing a $20.6 billion, or 0.6 percent, fall in reserves in the final three months of the year, although Beijing’s horde of foreign wealth is still by far the world’s largest. Reserves dropped in November and December, the first consecutive monthly fall since the first quarter of 2009, perhaps a sign of the impact that a falling trade surplus and an outflow of speculative funds is having on China’s capital flows.
The drop in China’s reserves may start to appease some critics who say they are a product of an economy reliant on an under-valued yuan for export-driven growth. The median forecast by economists was for China’s foreign exchange reserves to have held steady at the end of December from the end of the third quarter.
China reserves are the largest in the world, largely due to the central bank’s sterilisation of dollar inflows into the country’s closed capital account. But some analysts noted that increasing use of the yuan in trade settlements would also help slow China’s future build-up of foreign currencies.
In the third quarter of 2011, foreign exchange reserves rose just $4.2 billion to a record of $3.2 trillion. The pace was markedly slower than a $152.8 billion rise in the second quarter. ($1 = 6.3178 Chinese yuan)
And while the quarterly fall does not signal massive capital flight from China, analysts say it does argue for Beijing to further lower the amount of cash it makes banks hold as reserves to ensure sufficient market liquidity.
Foreign governments hold about 46 percent of all U.S. debt held by the public, more than $4.5 trillion. The largest foreign holder of U.S. debt is China, which owns more about $1.2 trillion in bills, notes and bonds, according to the Treasury.
Figures available in 2010 suggest China owns about 8 percent of publicly held U.S. debt. Of all the holders of U.S. debt China is the third-largest, behind only the Social Security Trust Fund’s holdings of nearly $3 trillion and the Federal Reserve’s nearly $2 trillion holdings in Treasury investments, purchased as part of its quantitative easing program to boost the economy.
To put China’s ownership of U.S. debt in perspective, it’s holding of $1.2 trillion is even larger than the amount owned by American households. U.S. citizens hold only about $959 billion in U.S. debt, according to the Federal Reserve.
Other large foreign holders of U.S. debt include Japan, which owns $912 billion; the United Kingdom, which owns $347 billion; Brazil, which holds $211 billion; Taiwan, which holds $153 billion; and Hong Kong, which owns $122 billion.