Around 1750 BCE, in the Mesopotamian city of Ur, a man named Nanni sent an angry clay tablet to the merchant Ea-nasir. He complained about poor-quality copper ingots and about the contempt with which his messengers had been sent back empty-handed. From now on, he warned, he would accept only copper of fine quality. The tablet belongs to the British Museum's collection, and online Ea-nasir has become known as history's worst trader.
Around 2300 BCE, Enheduanna, daughter of King Sargon of Akkad, became high priestess of the Moon god at Ur. She composed hymns to the goddess Inanna and put her name to them. She is the oldest person identified as the author of a literary work, about 1,500 years before Homer.
Squeeze Earth's 4.5 billion years into a single 24-hour day. Homo sapiens shows up around 11:59:54 p.m., roughly six seconds before midnight. All of written history, from Sumerian tablets to today, fits into the final tenth of a second. A cosmic blink.