Made in the 4th century and now in the British Museum, the Lycurgus Cup looks jade green when light reflects off it and ruby red when lit from inside. The secret was only cracked in the late 20th century: the glass contains tiny particles of gold and silver, a few tens of nanometers across, that scatter and transmit light differently. Roman glassmakers achieved the effect without knowing anything about the physics behind it.
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.