Ancient cultures have produced amazing works, such as the Moai, Pyramids, and Hanging Gardens. Since we don’t know for sure how they managed this, there are some who use this uncertainty for negative evidence that aliens did it. At the other end of the spectrum are those who interpret seeming anachronisms as evidence of innovation among long-ago peoples.

In 1961 a trio of California rock hounds found a specimen whose innards contained a heavily-encrusted metallic object. The discoverers pronounced it to be a spark plug encased in a geode. The inner object was said to be 500,000 years old, which would drastically alter automotive history’s timeline. This mystery find was dubbed the Coso Artifact.

Investigation showed it to indeed be a spark plug, but the geode portion is where the claim fell apart. The website rocksandminerals4u describes a geode as the Tootsie Roll Pop of the geology world. They are hollowed rocks, in the middle of which awaits a surprise, usually quartz. Geodes have thin shells on the outside and crystals on the inside, distinctions nowhere to be found in the Coso Artifact.

Investigators Pierre Tromberg and Paul Heinrich determined that the object became encased in a concretion  of iron, which was caused by the rusting of the spark plug. Still, Tromberg and Heinrich did verify an outstanding claim, confirming that there is something called the Spark Club Collectors of America. These enthusiasts of electric current delivery systems found the plug to be a 1920s Champion version that was used in Model T engines.

Overexcitement led to this archeological misfire, whereas our next object was more a result of pareidolia. Klerksdorp spheres are small objects who believers think could only have been manufactured by intelligent beings. They are buried deep enough under Earth that their creators would had to have lived millions of years ago.

Indeed, the spheres appear manufactured and symmetrical, and even include nearly-perfect grooves that would seem to suggest coming from a factory.  However, they are the result of the normal sedimentary process. Klerksdorp spheres began as concretions that formed in volcanic sediment or ash, and this formation also caused the grooves to form. This is because the concretion is harder than the material it forms around, so that when softer material erodes, the imprint remains.

From possibly genuine, albeit amateur mistakes, we move to outright fraud. Ica Stones vary in size from a pebble to a boulder, but are usually about the size of an arrowhead. They have been superficially scratched to show images of spaceships, humans walking with dinosaurs, and advanced surgery techniques.

Like most manufactured mysteries, the precise beginnings of the Ica Stones is unknown, but we do know when they became objects of mass curiosity. They had been presented as merely pieces of artwork until Dr. Javier Darquea received one for his birthday. He sought more, and Peruvian street merchants were happy to have a wealthy new customer. He collected as many as he could and created a museum based around them, cataloging the Stones and touting them as a window to an ancient enlightened culture. He made no attempt to verify their origin or the artist’s intent. The Stones were not carved, but only had a surface layer of oxidation scraped off, showing the creations were not ancient. What the images lacked in authenticity, they made up for in suppleness, appealing to believers in ancient astronauts, creationism, and Atlantis.

Long before it became a perpetual war zone, Baghdad was home to a wealth of archeological and cultural artifacts. Many of these were housed in the National Museum of Iraq, where Wilhelm Konig worked. He was a painter, not a scientist, which partly explains how he deduced that a ceramic pot housing a copper tube and an iron bar was a battery, about 2,000 years before these were known to exist. While no one knows for sure, this object was likely a clay jar that stored papyrus scrolls. Even if it was something else, there’s no reason to think it was a Mesopotamian alkaline. For the copper tube is insulated from both the iron bar and the outside, meaning no circuit is being made.

In all these instances, the anomalous nature of a highly-advanced technology coming from an otherwise unknown culture speaks to its improbability. The sudden leap in knowledge is another giveaway. In the first three examples, we aren’t even told who these people were. They made a lone, highly innovative contribution, then disappeared. They left us no burial mounds, archeological evidence, artwork, memorials, monuments, maps, written histories, or other sign of their existence. They managed medical, transportation, or manufacturing abilities that would not otherwise be seen for a thousand or a million years. Yet they were incapable of documenting any of this, save for one culture that managed to archive it by mastering  the art of doodling on a pebble.