"Eureka" is the Motto of the State of California and the name of a city in that state. It is a Greek word meaning, "I have found it." This phrase is appropriate for California and maybe even the city considering all those who have found a better life in California. Whether it is better economic opportunities, better climate, better health or better vistas, many arrivals to California have thought some variety of "I have found it!"
"Eureka" has a connection to the discovery of gold. The story dates backover 2000 years to Archimides of Syracuse. The King had purchased a new crown but now was worried he had been cheated by not being provided pure gold he had payed for. The King asked Archimides to learn if he had been cheated. Archimides was the foremost scientist in the world at that time but he didn't know how to prove its purity without destroying the crown. How was he to determine the purtiy without destroying the object?
Archimides thought about this problem all of the time no matter what he was doing. He could not think of an answer.
One day he noticed the water overflowed as he was getting into his bathtub. This gave Archimides an idea. The story goes that he was so excited about this idea that he ran down the street shouting, "Eureka," although he forgot to put on his clothes.
What he had found was the idea that an object immersed in water displaces or raises the level of the water. Archimides applyed the rule of logic that said no two objects could occupy the same space and concluded that an object displaces its volume of water and by measuring the water Archimides could determine the volume of the crown.
Archimedes immersed the crown in water and measured its volume. Then he weighed the crown. Dividing the weight of the crown by the volume provided the density of the crown. He did similar measures of what he knew to be pure gold and found the densities to be the same. The crown was pure gold.
This concept is one of the elements for understanding bouyancy and its discovery was a milestone in the progress of science.
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© HWS, 1998