“Eureka”: how Archimedes made his famous discovery and what does gold have to do with it?

“Eureka”: how Archimedes made his famous discovery and what does gold have to do with it?



Average reading time — 3 minutes


“Eureka!” — Archimedes exclaimed, quickly jumping out of the bathtub in a public bath and running down the street. This word, which has become commonly used, is translated from ancient Greek as “I found it.” What made the great Hellenic scientist do this? And what role did gold play in this story? Let’s find out.



In the photo: Archimedes gave the world a number of scientific discoveries and (according to legend) even a joyful exclamation that accompanies any great insight.


The story of the golden crown

In the treatise of the scientist Vitruvius “De architectura” there is a retelling of the story of how the king of Syracuse, Hiero II, suspected his jeweler of fraud. He was sure that he had appropriated part of the gold given to him and made the ordered crown from a less valuable alloy. But it was difficult to prove these suspicions — methods of chemical analysis did not exist at that time, and many metals were similar in weight. The king instructed Archimedes to expose the jeweler.


In the photo: a copper coin with the profile of Hiero II, ruler of Syracuse and patron of Archimedes.


The scientist decided to solve the task. He quickly determined that gold and silver had different densities — gold has almost twice the density of silver. However, to rely on this indicator, one needs to know not only the weight, but also the volume of the crown. There were no instruments to measure it at that time. In addition, the crown itself was of a very complex shape. The scientist thought day and night about it, but no solution was found.

And then one day, while being in a public bath, Archimedes took the bath and noticed how the water splashed onto the floor under the weight of his body. It was at this moment that the scientist had an insight. Archimedes uttered the famous phrase and ran out into the street: he wanted to immediately test his discovery in action.


In the photo: a body of any complex shape immersed in a liquid displaces a volume of liquid (ΔV) equal to the volume of this body.


The method he discovered was ingenious and simple at the same time. Archimedes put the crown in a container of water and measured the volume of liquid displaced, and then did the same with a gold bar of the same weight. The difference turned out to be significant, and the dishonest jeweler was exposed.


Thus, gold contributed to yet another important scientific discovery. By the way, a great variety of similar interesting cases related to this precious metal can be found in history, which once again proves the great value of gold for humanity.


In the photo: the puzzled Hiero II of Syracuse (right) delves into the explanations of the father of hydrostatics, Archimedes (left), (fragment of a linocut by R. Yakhnin).


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