A pair of experimental psychologists say the Mona Lisa may be the world's first 3-D image.
The mysteries of Leonardo da Vinci's Mona Lisa, arguably one of the most famous paintings in the world, are never-ending. Who was this woman? Is she smiling? Did she once have eyebrows? The latest theory on the 16th-century masterpiece purports that da Vinci--a prolific inventor, scientist, and artist--was even more ahead of his time than we thought. According to a pair of experimental psychologists in Germany, Mona Lisa could be the world's first 3-D image.