Heather Whipps in LiveScience.com:
Maybe she’s smiling because she found the secret to immortality.
Leonardo da Vinci’s “Mona Lisa,” widely considered the world’s most recognizable work of art, turns 500 this year. Maybe.
The sitter’s enigmatic smirk is just one of the mysteries that historians, scientists and conspiracy theorists have been debating since the artist touched his last brushstroke to the canvas.
Even the year it was painted is not known for sure. It is widely believed to have been finished in 1506, but experts say that’s no more than a good guess. Toting it with him his entire life, da Vinci likely touched it up in subsequent years.
The painting currently hangs in the Louvre Museum in Paris. It is set behind a wall of bulletproof glass and watched over by armed guards.
So what’s all the fuss about?
More here.