How Did Archimedes Test the King’s Crown?
The crown had the right weight — but was it really pure gold?
The Puzzle
The king suspected that a goldsmith had mixed cheaper silver into his crown. Archimedes had to test it without cutting, melting, or damaging it.
The Big Idea
Gold is denser than silver. Two objects can have the same weight but different volumes. So a crown mixed with silver would occupy more space than the same weight of pure gold.
Water Provides the Clue
Submerge an object in water and it displaces an amount of water related to its volume. Compare the crown with pure gold of the same weight: if the crown displaces more water, its density is lower.
And “Eureka!”?
The famous bath story comes from Vitruvius, writing roughly two centuries after Archimedes. We cannot know whether every detail happened exactly that way — but the physics of volume and density is real.
Try It Yourself
Compare objects made from different materials. Can objects of equal weight occupy different volumes? Water lets you explore the same relationship.
From Voices of the Past: Origins
The world is full of clues. Discovery begins when someone notices them.