When I had time for such pursuits, I taught myself Tibetan and became reasonably fluent. With no one to speak it with, the ability waned, but I may brush up again if I ever make it to Delingha, a village tucked in a basin below the Himalayan foothills. Outside Delingha rests Mount Baigong and, more specifically, the Baigong Pipes. The Pipes were touted as an Out of Place Artifact (Oopart), which are seemingly modern or even futuristic objects in ancient surroundings, anachronisms that, for a while anyway, evade attempts to explain them.
Inside the mountain are hollow rusty tubes, ranging in size from needle-like to a coconut’s circumference. They run from deep inside the mountain and snake their way to a lake about 10 school bus lengths away. Many are uniform in size and seem to have been placed there deliberately. They are deeply embedded into the mountain’s walls and floor, enough so that humans could not have constructed them that way.
Combine all this with imagination and desire, and some have concluded a species with advanced metallurgical skills came from beyond the solar system to build the Baigong Pipes. That was the conclusion of author Bai Yu following his 1996 visit to the site. He further deduced that the flat open terrain nearby would be ideal for an alien landing site. There was yet another tantalizing twist to the tale. The first scientists to examine the Pipes determined they were composed of eight percent unknown materials and into this information vacuum was plugged the notion of that this eight percent represented alien technology or minerals.
Then scientists from the China Seismological Bureau examined the Oopart using a technique to determine how long it’s been since a crystalline mineral was either heated or exposed to sunlight. The result showed that if these were indeed iron pipes that had been smelted, they were made 150,000 years ago. Humans traipsed into the region 120,000 years later, so this served as a kneejerk confirmation of the alien species sewer system speculation.
Ooparts will infrequently excite Young Earth Creationists, such as when a hammer embedded in Cretaceous lime rock was presented as proof the layer was millions of years younger than those gosh darn secular geologists thought. (More on that here: http://rationalwiki.org/wiki/London_Hammer). Mostly, however, Oopart enthusiasts are limited to fans of ancient aliens or long-lost advanced civilizations.
A more terrestrial hypothesis of the Pipes offered that they were fossilized tree root casts, with the roots transforming to soil and then to rock. Experiments confirmed that the pipes contained organic plant material and even microscopic tree rings. As to how they got inside a cave where trees would not grow, scientists concluded that the basin was once a vast lake and over many millennia, floods filled it with debris that included these fossils.
Brian Dunning at Skeptoid further explained, “Fissures could have been washed full of iron-rich sediment during floods. Combined with water and the presence of hydrogen sulfide gas, the sediment could have eventually hardened into the rusty metallic pipe-like structures of iron pyrite found today.”
So the Pipes were never part of an alien sewer, but rather the result of Earth Science in action. As usual, reality was intriguing enough. And It turns out that there is at least one other place on Earth with such distinctive pipes and they had been discovered earlier than those at Mount Baigong. They were first found by geologists, not E.T. enthusiasts, so there never was an alien angle ascribed to them.
Writing in the Journal of Sedimentary Research in the early 1990s, the researchers reported they had found fossilized tree casts in Louisiana soil. These cylindrical structures were dated to about 85,000 years ago and their chemical composition depended on where and when they formed. The results were metallic structures, almost identical to the Baigong Pipes. So that’s either the explanation or it’s proof the alien plumbers opened a second location.