Behind the Mona Lisa: 5 Most Incredible Discoveries of the Week

A major shipwreck find makes this week's list:

• Beneath the Mona Lisa: Will the real Mona Lisa please stand up—or at least send us a signal from within the paint layers? The art world is buzzing over a French scientist's claims that he discovered a portrait lurking beneath the top layer of the world's most famous painting. After 10 years of research, here's how Pascal Cotte describes what is underneath the surface.

• The 'Holy Grail of Shipwrecks' Has Been Found: Off the coast of Colombia, the gold, silver, gems, and jewelry carried by the Spanish galleon—which was sunk by the British in 1708—are thought to be worth anywhere from $1.5 billion to $17 billion, making it one of the largest treasures ever lost at sea. Find out which Nobel-winning author documented the galleon in one of his books.

• Stonehenge May Have Been Erected in Another Country: Stonehenge may reside in England, but it "was a Welsh monument from its very beginning." So says Professor Mike Parker Pearson in reference to what is a big step forward in our understanding of Stonehenge. Here's what bluestones, burnt hazelnuts, and charcoal have to do with the new finding.

• Researchers Discover How Not to Be a Jerk While Texting: Researchers showed 126 undergraduates a bunch of texts featuring an invitation and a reply. Participants rated replies that featured this certain piece of punctuation as less sincere; on the flip side, researchers found that adding another type of punctuation to a text reply bestows a higher degree of perceived sincerity on the message.

• Archaeologists Find Remnants of Caesar-Led Massacre: Scientists say they've confirmed that Julius Caesar stepped on what is now Dutch soil, claiming they've uncovered the remnants of a battle fought in 55 BC in the southern part of the country. Two Germanic tribes reportedly came to Caesar seeking his protection, and he went well beyond denying their request.

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