Googling "mysterious ancient discoveries" or "unexplained ancient inventions" leads to dozens of sites listing artifacts supposedly so baffling the only possible answer could be aliens, time travel, the paranormal, the Iluminati, or aliens. Wait - did we already mention aliens? Sorry: they're a go-to explanation for anything apparently too sophisticated, weird, or "out-of-place" for "humans figured it out, okay?" to be a satisfying explanation.
It's a disheartening discovery, because once you separate the hoaxes and nonsense from the finds of actual archeological interest, there are still cool mysteries to explore. The list below features mysterious ancient inventions, unexplained ancient discoveries, and some slightly more recent finds still baffling to scientists in the 21st century - but not because they're a sign of alien tech. Give ancient humanity a little more credit, y'know?
It's not like anyone is aching for napalm to make a comeback, but scientists and historians are nonetheless very curious about 7th-century "Greek Fire," a deadly proto-napalm fired from ships that "would cling to flesh and was impossible to extinguish with water."
The Byzantine Empire wielded it with aplomb, but, like Coca-Cola Classic and Bush's Baked Beans, the recipe for Greek Fire was a protected family secret. National Geographic pulled a Mythbusters and took a guess at the ingredients in 2002, using a "bronze pump" and a "mixture of light crude oil and pine resin." The results? It wiped out a ship "in minutes."
Returning from the Crusades, a lot of perplexed Europeans started talking about swords wielded by Islamic warriors "that could slice through a floating handkerchief, bend 90 degrees and flex back with no damage." Fast-forward to the 21st century and the recipe for so-called "Damascus steel" is still a mystery.
The best guess is that the blades consisted of "crucible steel," which is created by melting iron with plant matter. Still, no one knows the specific type of crucible steel used to yield such a blade.
If you haven't heard of the Voynich Manuscript, you're in for a treat. Researchers say the hand-written and hand-drawn manuscript, featuring text in an indecipherable language and hundreds of illustrations including "a myriad of drawings of miniature female forms, most with swelled abdomens, immersed or wading in fluids and oddly interacting with interconnecting tubes and capsules," was created by someone sometime during the 15th century in Central Europe. A Polish-American antiquarian bookseller named Wilfrid M. Voynich acquired it in 1912. Other than that, it is a total mystery.
Recently, an electrical engineer and his sons who studied the artifact theorized that the manuscript used a phonetic transcription of a Turkish dialect. A British researcher would also publish a paper on his findings, claiming the dialect was an ancient "proto-Romance" language. Currently, both theories are still unproven.
Unlike the Roman dodecahedra, scientists have a pretty good idea what the so-called Antikythera Mechanism is all about. Discovered at the bottom of the sea in 1901, the intricate device was likely constructed around the end of the second century BC. It “calculated and displayed celestial information, particularly cycles such as the phases of the moon and a luni-solar calendar,” according to research compiled in Nature.
But we still don’t know who built it, who used it, and what they used it for, exactly. It’s also still unclear why it is “technically more complex than any known device for at least a millennium afterwards,” to quote the Nature abstract, which prompted a many “ancient aliens” and “TIME TRAVEL IS REAL!!” blog posts after it was published in 2006.
But history, as Brian Dunning of Skeptoid notes, tells us similar gear-based technology was around two and a half millennia prior, and Occam’s Razor tells us any “siblings” of the Antikythera Mechanism, like most commonplace bronze objects of the period, were likely “recycled” into other objects. It’s still mysterious, just for less reasons than some might think.