5 Historical Mysteries Science Still Hasn't Fully Solved

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Four tiny parchment samples were enough for a University of Arizona laboratory to date the Voynich manuscript’s vellum to between 1404 and 1438, with 95 percent probability. The result was announced in December 2009, and it settled one question while leaving almost every other one open.

That pattern runs through all five puzzles below. Modern tools such as radiocarbon dating, X-ray tomography and satellite surveys keep adding data, yet the central “why” or “how” still has no agreed answer. These cases are all documented and real, and no conspiracy theories are needed.

1. The Voynich Manuscript still hasn’t been deciphered

Dated to the early 15th century, this book is written in an unknown system, filled with strange illustrations of plants that don’t exist. Wilfrid Voynich acquired it in 1912, and today it is catalogued at Yale’s Beinecke Library as MS 408.

Linguists, cryptographers, and even AI have tried to crack it, without a definitive answer so far. A caution applies to the date: radiocarbon dates the parchment, not the writing, and the gap between the two is unknown. A claim made at the 2009 press conference, that the inks were applied right after the parchment was made, was later shown to be incorrect.

2. The Antikythera Mechanism was “impossible” technology for its time

Recovered from a Greek shipwreck, this bronze device with complex gears, over 2,000 years old, is considered one of the first “analog computers” in history, used to predict astronomical positions, technology that wouldn’t reappear for over a thousand years. Sponge divers recovered it in 1901, and a gear was noticed in the corroded lump in 1902. The wreck dates to roughly 70-60 BC, while estimates for the device itself range from the third to the first century BC.

It has at least 30 gears, and the largest, about 13 centimetres across, has 223 teeth, matching the 223-month Saros eclipse cycle. The mechanism tracked the Sun and Moon, lunar phases, eclipses, the Metonic calendar and a four-year cycle of athletic games. Comparable complexity did not return until the 14th-century astronomical clocks of Richard of Wallingford and Giovanni de’ Dondi.

3. No one fully agrees on the purpose of the Nazca Lines

In the Peruvian desert, enormous geometric and animal designs, visible only from above, were created over 1,500 years ago. The Nazca people made them between about 500 BC and 500 AD by removing dark, iron-coated pebbles to expose lighter ground beneath. All the lines together stretch over 1,300 kilometres, and the largest figures span almost 370 metres.

There are theories (rituals, an astronomical calendar, ceremonial paths), but none has full consensus among archaeologists. Paul Kosok and Maria Reiche argued for sighting lines to the Sun and stars; other researchers link the lines to water worship and pilgrimage routes.

4. How the Easter Island Moai were moved is still debated

The giant stone statues weigh tons and were moved from the quarry without modern technology. More than 900 moai are known, all but 53 carved from volcanic tuff at the Rano Raraku quarry, where 394 remain. Most were carved between about 1250 and 1500 CE; the average statue is about 4 metres tall and 12.5 tonnes, while the tallest erected one, Paro, weighed an estimated 82 tonnes.

There are experimentally tested theories (including “walking” the statues by rocking them), but the exact method used by the Rapa Nui people is still debated. Terry Hunt and Carl Lipo propose that teams with ropes rocked the statues upright, and broken “road moai” fit that idea. Because the island was largely deforested, many scholars doubt that timber rollers and sledges were practical, and replica tests using sledges on log rollers moved 9- to 10-tonne statues with crews of 25 to 60 people, but they relied on timber the island may not have had.

5. The “Baghdad Battery” has puzzled archaeologists for decades

An artifact found in Iraq, with a configuration resembling a primitive electrochemical cell, has sparked decades of debate over whether it actually functioned as a battery or served another purpose. It was found in 1936 at Khujut Rabu near Ctesiphon and dated to the Parthian or Sasanian period: a clay jar about 15 centimetres tall holding a copper cylinder and an iron rod, sealed with bitumen. Wilhelm König suggested in 1938 that it was a galvanic cell for electroplating.

Most archaeologists today reject that reading. No wire connection is evident, no matching electroplated objects are known, and the copper tube is not watertight. Many scholars think the jar held sacred scrolls. Replicas can produce a small current, but that shows only that the design could work, not that anyone used it that way.

How labs and satellites keep reshaping the questions

The Arizona team tested four folios of the Voynich manuscript, and quirks in the calibration curve left folio 68 with a possible range of about two centuries.

In 2005, a Cardiff-led team used X-ray tomography to read inscriptions inside the Antikythera fragments, with results published in Nature in 2006. In 2024, Yamagata University and IBM reported 303 new Nazca geoglyphs from a six-month campaign that combined AI with satellite, aerial and drone imagery, bringing the total in the Nazca Pampa to 733. Researchers say only about 30 percent of the area has been explored.

Why “ancient astronauts” never solved the Nazca question

When a monument looks too large or precise for its era, extraterrestrial explanations tend to follow. Erich von Däniken claimed the Nazca Lines were landing sites for visitors from space, an idea scholars rejected after reproductions showed they could be built with simple tools and basic surveying.

The same lesson applies here. Antikythera was not alien technology but advanced Greek astronomy whose knowledge was later lost, and the Baghdad jar is far more likely a ritual container than a power source. “Unexplained” usually means “missing evidence”, which is why new surveys keep mattering. Related reading: the Library of Alexandria, ancient Egypt and Egyptian mummies.

If you’re into this kind of trivia, you’ll probably also enjoy facts about the bermuda triangle and facts about shipwrecks.