For some of us, the oldest mysteries, the ones before our time, are the most compelling. Sometimes, we stumble upon an answer like a happy accident. Other times, someone just won't let go until he or she finds the solution.

10. The 20-Year Search For A Missing Opera

Enrique Granados, a renowned Spanish composer, wrote an unpublished opera called Maria del Carmen in 1898. The story of a love triangle in Murcia, the opera was so celebrated when it opened in Madrid that the Queen of Spain gave Granados the distinguished Charles III Cross for his music. Even so, the original version of the opera was never performed again.

When the New York Metropolitan Opera performed another of the composer's works in 1916, Granados and his wife sailed to America with the only copy of Maria del Carmen. Granados hoped to persuade the Met to perform his masterpiece. When they didn't agree, the Granados set sail to Spain via England, but a German submarine torpedoed their boat in the English Channel.

The couple drowned, but the three-volume opera survived, as did their six children whom they'd left in Barcelona. Two decades later, a son who needed money sold the opera to an American musician against the wishes of other family members. For the next few decades, the music's ownership was litigated. Before the issue was settled, the opera was supposedly destroyed in a New York warehouse fire in 1970.

A couple of decades later, Walter Clark, a graduate student writing a dissertation on music, learned of the missing masterpiece. For the next 20 years, he couldn't shake his doubts about its fate. “I wondered if it was really destroyed,” Clark said. “No one had done a proper inventory after the fire. When I was researching my [2006 biography of Granados], I contacted the grandson of the man who had purchased Maria, and he kept looking.” Finally, in 2009, the opera was found, although it had been damaged by smoke and water. Thanks to the music professor who played detective, Maria del Carmen has been restored and subsequently published by the company, Trito. For the first time since 1899, the opera will also be performed in Spain in 2015.

9. The Moroccan Village Built On A Rock Pile

At about 3,900 meters (13,000 ft) above sea level, the village of Arroumd sits perilously atop a huge pile of rocks in the High Atlas Mountains of Morocco. For over 130 years, the origin of that rock pile has mystified scientists. Most assumed the movement of a glacier deposited the rocks, but modern dating techniques point to seismic activity 4,500 years ago as the culprit. The village is located near a major tectonic fault that sits below the face of a cliff.

Although a glacier probably eroded the face of the cliff, making it vulnerable to collapse, the avalanche occurred approximately 7,000 years after the glacier melted. So the glacier may have made the cliff more likely to collapse, but an earthquake was probably the actual trigger of the avalanche of rocks. Even beyond the huge pile of rocks, Arroumd is a mysterious place. “Several incidents occurred at the site, including some accidents—minor, thankfully–and mystery ailments to those who went there,” said lead researcher Philip Hughes. “I always joke about the ‘curse' of the Arroumd landform. This year, we encountered severe whirlwinds when entering the valley . . . We were unable to stand on our feet, which is rather unusual for this part of the world, where climate is often hot and calm.”

8. How Mary Ingalls Really Went Blind

In the Little House on the Prairie children's book series, author Laura Ingalls Wilder wrote that her real-life sister, Mary, was blinded by scarlet fever at age 14. The event was also dramatized on a television series based on the books. But pediatricians say the explanation for Mary's blindness doesn't make sense.

Dr. Beth Tarini was surprised by that discovery even as a medical student. "I was in my pediatrics rotation," said Tarini. "We were talking about scarlet fever, and I said, 'Oh, scarlet fever makes you go blind. Mary Ingalls went blind from it.' " Her professor disagreed, which propelled Tarini on a detective mission to find out what really happened to Mary.

Tarini and her team researched the issue for 10 years. They found that Mary had scarlet fever as a young child, but her illness at 14 was referred to as "brain fever." There was also no reference to her having the distinctive rash of scarlet fever as a teenager. While scarlet fever had a mortality rate for children of up to 30 percent in the 1800s, most cases of blindness from the disease were temporary.

As the team continued to investigate, they discovered that Laura wrote a letter to her daughter, Rose, in 1937 describing Mary's illness. Laura sent the letter right before the publication of her book By the Shores of Silver Lake, which described Mary's blindness as being caused by scarlet fever. However, an excerpt from the letter stated: "Mary had some sort of spinal sickness. I am not sure if the Dr. named it. We learned later when Pa took her from De Smet, South Dakota to Chicago, Illinois to a specialist that the nerves of her eyes were paralyzed and there was no hope."

After poring over historical records, including the Ingalls' town newspaper that reported that Mary had suffered from severe headaches and partial paralysis on one side of her face, the researchers now believe that Mary contracted viral meningoencephalitis, which inflames the brain and spinal cord. By inflaming the optic nerve, it can also lead to blindness.

7. Gospel Of The Lots Of Mary

Recently translated by Princeton University religion professor Anne Marie Luijendijk, the 1,500-year-old "Gospel of the Lots of Mary" is not a gospel describing the life and death of Jesus Christ, as everyone had assumed. Instead, it's a sort of Magic 8 Ball to predict the future and help people solve their problems.

This Christian oracle book was written in the Egyptian Coptic language, which uses the Greek alphabet. The book opens like this: “The Gospel of the lots of Mary, the mother of the Lord Jesus Christ, she to whom Gabriel the Archangel brought the good news. He who will go forward with his whole heart will obtain what he seeks. Only do not be of two minds.”

That opening led Luijendijk to believe the book contained a standard type of gospel. However, she found that the heavily used book was made up of 37 oracles, which rarely mentioned Jesus. If a person needed help with a problem, he would ask a question of the book's owner. Then they would select an oracle at random to solve the problem. The book's owner would interpret the oracle's answer.

Each oracle is written so vaguely that it could be used for many situations. An example would be: “Stop being of two minds, o human, whether this thing will happen or not. Yes, it will happen! Be brave and do not be of two minds. Because it will remain with you a long time and you will receive joy and happiness.”

Ancient "lot books" were consulted to predict people's futures. Overall, this book takes a positive view of what lies ahead. However, Luijendijk had never known of another lot book that was referred to as a “gospel,” which translates as "good news." That leads Luijendijk to believe that gospels may have been viewed differently in ancient times, perhaps not solely as texts about the life and death of Jesus.

In 1984, the text was donated to Harvard University by the daughter-in-law of an antiquities trader. However, no one knows how or when the family acquired the book.

6. Why Palmyra Was Located In The Syrian Desert

Palmyra was an important trading hub in the Roman Empire around 2,000 years ago. But historians could never understand how Palmyra's 100,000 residents were able to thrive in the middle of the Syrian desert—or why they would live there in the first place.

However, a team of Norwegian and Syrian researchers has finally solved the mystery. Palmyra and over three dozen surrounding (but forgotten) ancient Roman farming villages used a network of water reservoirs to make their arid steppe green. By collecting and channeling the yearly rainfall of 12–15 centimeters (5–6 in) from seasonal storms into these reservoirs, the ancient inhabitants farmed the land with a variety of crops. This gave Palmyra a stable source of food, even during droughts, making it a grand oasis of avenues, arches, and columns in a vibrant desert marketplace.

The city also prospered as a major trading hub linking Eastern civilizations with Western ones. Although the Persians and Parthians controlled the East and the Romans dominated the West, there were small independent kingdoms located between the two. Each of their rulers demanded payments from travelers to use their water routes—along parts of the Euphrates and Nile Rivers, for example.

Rather than pay all those exorbitant river taxes to take the direct routes, tradesmen would cut through the desert and stop at Palmyra. There, they could purchase the items and services they needed to safely complete their journeys. This greatly contributed to Palmyra's prosperity in ancient times.

注：本文转载自前十网，译者：Freya然