In 265 BC King Hieron of Syracuse, had commissioned a
goldsmith to make a gold crown.
Later he heard that the goldsmith may have mixed in some
silver, keeping back some of the gold for himself.
King Hieron asked Archimedes to find out if the crown was
made of pure gold without damage it.
That night Archimedes thought that he would weight out some
gold of the same weight as the crown.
If the volumes were different, then he would have uncovered
a fraud.
But, how to determine the volume of the irregular-shaped
crown?
Archimedes thought long and
hard……
He decided to take a hot bath to help
his mind relax and find a solution to this problem.
As he stepped into a bathtub filled
to the brim with water, the water overflowed, which got Archimedes to thinking about
possibilities.
Archimedes realized that his body caused an equal volume of
water to overflow when he got into the tub.
He had his method for measuring the volume of the crown!
Forgetting that he was undressed, he went running
naked down the streets from his home to the king’s palace yelling “Eureka”. Which in greek means “I
have found it”.
Archimedes uses water
displacement to compare the crown to an equal mass of gold. They should each
displace the same amount of water if the crown was pure gold.
The crown displaced
more water than an equal mass of gold. Therefore the crown was not pure gold.
The dishonest
goldsmith was executed for cheating the King.
This is the story of how the Archimedes principle discovered.
Archimedes principle is very important in helping to
measure the volume and density of irregular-shaped objects.
Also, it is very important for calculating the buoyancy force
in ship building industry.
