Is Great Wall the only manmade object visible from the moon by naked eyes?
The answer is simply “NO”. But the following sentence is found in the Wikipedia.
One of the earliest known references to this myth appears in a letter written in 1754 by the English antiquary William Stukeley. Stukeley wrote that, “This mighty wall of four score miles in length (Hadrian’s Wall) is only exceeded by the Chinese Wall, which makes a considerable figure upon the terrestrial globe, and may be discerned at the moon.” The claim was also mentioned by Henry Norman in 1895 where he states “besides its age it enjoys the reputation of being the only work of human hands on the globe visible from the moon.”
Basically it is impossible to pin point a narrow object with no more than 9 meter width located a few hundreds kilometers away regardless of its length. This is like locating one piece of hair from 100 meters away. Moreover, if the color of the object is not starkly different from the surrounding, it is not hard to imagine identifying Great Wall from the moon is impossible. Even from the low orbit at ~160 km (or 100 miles) above ground, Grate Wall cannot be identified without an instrument. Neil Armstrong stated as follow (Wikipedia).
“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.
However, this myth has extended its life throughout the centuries and descended until today. I personally saw a few kid’s books that stated this myth as if it is the truth. Why this kind of misinformation survives despite the relentless corrections made by various experts?
How misinformation are born and survive
Following are my two cents on misinformation.
- Human beings tend to be impressed by brain-stimulating short information. If the information appears unconventional and sounds impressive, it has higher chances to be casted in the brain. I have seen some of smartest people devoted a part of their life to pyramid scheme only to find the chance of success is little more than winning a lottery unless themselves are the very early starters of the scheme.
- Many misinformation are caused by complexities. If there are 10 different factors affecting the result, e.g. effluent quality of activated sludge process, it is extremely difficult to understand the interactions among the 10 factors. Even if the absolute theory exists, it is usually not possible to describe it to make everyone understood easily. In this case, only the simple explanations that can impress people become outstanding.
- A good portion of misinformation is tricky to be even defined as misinformation because they are very hard or nearly impossible to be either proven or disproven. For example, it is very hard to prove UF membranes are less prone to fouling than MF membrane in water treatment, but there are notions like this.
- One very important ingredient of long lasting misinformation is simplicity. It must be simple to be engraved in human brain so that it is not lost easily.
- A new forms of misinformation are generated ironically due to the flood of information as the number of journals sharply increases in recent decades. According to the following figure, total number of published papers has more than doubled in the period of 1990 – 2009. This is perhaps influenced by the ever increasing pressure schools and institutes are putting on their staffs to generate more outcomes in the wake of global competitions. Meanwhile, researchers in corporate world are also getting pressure by the profit driven corporate cultures. Once misinformation is generated, it can be cited by people who are not familiar with the topic or can be misused by people who seek anything that supports their theories. The drawback of having too much information has been discussed by Bauerlein et al. (2012).
Fig. 1. Total number of articles per year in PubMed Database (Stanford U).
© Seong Hoon Yoon