Art/Architecture The World

How High the Moon; How Wide the Wall

It’s revealing that, although I have heard Jerry tell this joke scores of times over a wide number of years, at this moment when I want to mark it down here, I can’t recall the details. The gist is:

A bootlegger was standing before a judge and something in his testimony gave rise to the judge questioning his veracity concerning his claim of having seen something at quite a distance.

“Are you sure you saw that?” the judge asked.


“But how far can you see?”

“How far is it to the moon, your honor?”

Amazing isn’t it that with our naked eye, we can see that shinning orb which hangs suspended nearly 239,000 miles away from the earth.

This morning’s news carries the story that new exploration reveals the Great Wall of China to actually extend further than thought in years past, greatwall1and already it had been marked as one of the wonders of the world. Some have said it is visible from the moon; others dispute that.

The Great Wall of China is even greater than once thought, after a two-year government mapping study uncovered new sections totalling about 180 miles, according to a report posted on the website of the country’s national mapping agency.

Using infrared range finders and GPS devices, experts discovered portions of the wall concealed by hills, trenches and rivers that stretch from Hu Shan mountain in northern Liaoning province to Jiayu Pass in western Gansu province, the official China Daily reported on Monday.


Wikipedia’s take on whether or not the Great Wall is visible from the moon.

The Great Wall is a maximum 9.1m (30 ft) wide and is about the same color 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, metres for large telescopes) an object of reasonable contrast to its surroundings some 70 miles in diameter (1 arc-minute) would be visible to the unaided eye from the moon, whose average distance from Earth is 384,393 km (238,857 miles). The Great Wall is of course not a disc but more like a thread—it can be seen from much further than would be possible if it were simply a 30 foot disc. Still, the apparent width of the Great Wall from the moon is the same as that of a human hair viewed from 2 miles away. To see the wall from the moon would require spatial resolution 17,000 times better than normal (20/20) vision.[16] Not surprisingly, no lunar astronaut has ever claimed seeing the Great Wall from the moon.

Incidentally, if it were possible to see the Great Wall from the moon, one ought to be able to see many of the world’s highways as well, given that many surpass the Great Wall in width and brightness.

Some say The Wall which extends more than 4500 miles across China is visible from space, though not from as far away as the moon; others say not so.

A few years ago my son Steve and his wife had the opportunity to walk a section of the Great Wall. “Amazing,” he told me. “An amazing sight.”


Edit: August 2010  I want to clarify that the image here is not mine, but is included in the quoted material attributed to AP and to Wikipedia.