“The Gold Crush that helped to create one of the most sensational discoveries in history” — a popular scientific anecdote
Once upon a time there was a little boy named Archimedes who lived in ancient Greece around 300 B.C. Archimedes loved mathematics. He solved almost every single problem that was thrown at him with great enthusiasm and zest. People were bewildered by his ability to solve problems way beyond his own age group. Archimedes was a well built boy who grew into a fine young man with curly hair and curly beard.
King Hiero ruled Greece at that time and he loved Archimedes like a son and treated him like one too. One day, after winning a battle over his enemies, the king decided to offer a gold crown to God on a holy day. The day was approaching quickly but the crown was not yet made. So the king promised a reward of 500 guineas to anyone who quickly brought him a pure gold crown.
After a few weeks, a smith called Efliger came to the castle and brought a shining yellow gold crown. King Hiero was very happy and got ready to give him 500 guineas. But just as he was about to , Archimedes cried out “How do you know it’s real?”
After thinking about it, the king agreed with Archimedes, and said, "I have no way to check that this crown is made of pure gold!". Efliger, the poor smith, looked at the king with dismay and said, “BUT, MY LORD, we have to melt down the beautiful crown in order to find out if it is made of pure gold. If you find out that the crown is made of pure gold, you will ask me to remake the crown. I am SORRY, but there won't be sufficient time left to remake the crown before the holy day of offering."
Hearing this, the king became sad. He asked Archimedes if he could check the purity of the crown without melting it down. Archimedes thought about the problem from dusk to dawn. His body and mind got no rest until he became so tired that decided to take a bath to freshen himself up. He immersed himself into a bathtub full of water and unmindfully kept watching how the water spilled out of the tub.
Suddenly Archimedes realized that the more his body dipped into the water, the more volume of water was displaced. He realized the link between displaced volume of water and the volume of his body under water! Gold is heavier (and more dense) than silver. So a crown made by mixing gold and silver would displace more water than if it were made of pure gold. He jumped out of the tub and ran into the palace naked and screaming EUREKA! EUREKA!!!! In Greek, Eureka means "I found it".
From this came the famous “Archimedes’ Principle that says, "Any object, wholly or partly immersed in a fluid, is buoyed up by a force equal to the weight of the fluid displaced by the object." Archimdes' principle became useful to determine the volume and density of any irregular shaped object.
Reference+ Rorres, Chris. "The Golden Crown: Galileo's Balance". Drexel University. http://www.math.nyu.edu/~crorres/Archimedes/Crown/bilancetta.html. Retrieved on 2009-03-24.