Unsolved Mysteries - Solved at Last? Quiz

Answer: sliding on ice that had formed underneath them

Large rocks appear to have glided along the once-lake floor with "drag marks" of their path. In 2006, scientist Ralph Lorenz found that when Death Valley temperatures drop, enough water and ice forms under the rocks to cause them to "float" or "sail" across the river. Time-lapsed video in August 2004 reportedly has confirmed the activity.

Answer: first analogue computer

Advanced MRI scanning machines has determined that the Antikythera Mechanism was a calendaring device used to analyze planet orbits, predict eclipses, and date Olympic games. What remains a mystery is why it took over a thousand years for this technology to be developed further, given that devices of similar complexity apparently do not appear again until the 14th century.

Answer: weapons or implements of early man

Early theories claimed "thunderstones" were thrown down to earth by gods of thunder during battle. In the 1580s, a Vatican City official named Michele Mercati realized that these "thunderstones" were not godly or otherworldly but were actually arrowheads created by humans during the Stone Age.

His theory was not accepted then, because the estimate for the start of human existence on earth at that time was incorrect (i.e., did not go far back enough).

Answer: myth used to cover up violence by European settlers

European settlers claimed that the Susquehannocks murdered and ate their neighboring tribes. April Beisaw, an anthropologist at Vassar College, believed the reputation was unfair. Beisaw and her team studied artifacts from the tribe and the remains of neighboring people. Finding no evidence of cannibalism or extreme violence from the tribe, Beisaw attributed the cannibalism legend to European settlers who likely used the myth as a cover for their own violent actions in the area.

Answer: human body fat

Spontaneous human combustion allegedly involves someone burning to death from flames that do not have an obvious external source. This phenomenon was first described in the 1600s and generally results in the head and torso being burned to ash. Some investigations have shown that a likely explanation is that the clothing of these victims were set on fire from a small source, like a candle or cigarette.

The wick effect suggests that the body is kept aflame by its own fats after being ignited.

Answer: icequakes

The Bloop was detected by the U.S. National Oceanic and Atmospheric Administration in 1997. Stories attributed it to underwater monsters or creatures or even H.P. Lovecraft's Cthulhu. The fantastical fun may be over, because scientists have declared the "bloop" sounds come from icequakes (when icebergs crack and fracture).

The "bloop" can be heard more frequently between the Ross Sea and Bransfield Straits.

Answer: sand termites

The "fairy circles" of the Namib desert are distinctive grass-like circles appearing randomly in the sand. Norbert Jurgens, of the University of Hamburg, discovered that the "fairies" were actually a species of sand termite (Psammotermes allocerus). The circles were created when the termites ate the grass roots, causing the retention of rain water beneath the area.

When the termites came to the surface, rainwater leached into the sand, creating the "fairy circles" of grass around the perimeter.

Answer: Nikumaroro

The U.S. report concluded that Earhart and her navigator Fred Noonan ran out of fuel and crashed while looking for their intended destination on Howland Island. The International Group for Historic Aircraft Recovery (TIGHAR) developed its theory after discovering a piece of aluminum debris. TIGHAR concluded it was sheet metal from Earhart's twin-engine Lockheed Electra, because it matched a replacement part installed for a navigational window.

A photo published in "The Miami Herald" led TIGHAR to claim that the debris "matched" the replacement part shown in the photo.

Answer: internally near the jaw

Fossils of the Helicoprion showed a teeth spiral similar to a circular saw. What scientists could not figure out was where it was originally located on the animal. CT scanning led scientists to determine that the spiral was actually positioned internally, acting like a "tooth factory," new teeth pushing the old teeth into a "whorl." The Helicoprion's closest living relative is the chimaera or "ghost shark."

Answer: Trajan

The "Bosham Head" is believed to date back to 122 AD. Although it was in bad shape, scientists used modern technology to identify it as the head from a large sculpture of Trajan.