Chinese puzzle: The Great Wall of China is often cited as being the only non-natural object visible from space. For an object to be visible when viewed from above, the eye must be able to resolve it in two dimensions.
The Great Wall of China is immensely long but very narrow. If the eye is able to resolve its width from space, many other objects such as the Great Pyramid of Cheops should be large enough to be seen in two dimensions, despite having a much smaller total area.
Is the ability of the eye to resolve objects in the smaller of the two dimensions affected by the magnitude of the larger (and if so why) or is the claim made for the Great Wall of China incorrect?
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