Zero, which was invented late in history, is special among numbers. New studies are uncovering how the brain creates something out of nothing. Introduction Around 2,500 years ago, Babylonian traders in Mesopotamia impressed two slanted wedges into clay tablets. The shapes represented a placeholder digit, squeezed between others, to distinguish numbers such as 50, 505 and 5,005. An elementary version of the concept of zero was born. Hundreds of years later, in seventh-century India, zero took on ...