Archimedes - Who detected impurity in the golden Crown without breaking?

Brave and religious king Hieron wanted to offer some presents to the Gods. For that he wanted to get a crown of gold. A specific quantity of gold was given to the goldsmith who fabricated the crown and delivered on the scheduled day. The king became suspicious that the goldsmith has mixed silver with gold. The crown was built so beautifully that the king did not want to break it in order to confirm his suspicion. King called Archimedes, the famous scientist to test the crown without damaging it.

Archimedes spent his time thinking a way to solve the problem. One day when he got into the bath tub, he noticed that his body displaced some water making the water level in the bath tub rise. Then he jumped out and ran to the palace naked, saying "Eureka, Eureka" meaning "I have found it".

To check the purity of the crown he filled a vessel with water and dipped the crown in it. The water and displaced by it was measured. In the same way an equal mass of pure gold was dipped and displaced water was measured to find there was a difference which proved the impurity of the Crown. On the basis of this discovery, finding out the relative density of substances was established.

Archimedes formulated the law of flotation of bodies, evolved the principle of levers. With lever and pulleys he was able to lift a loaded ship on to a bank. He was a gifted mathematician. He calculated the value of pi(II)=22/7 which is used even today by student. He found the formula to find the circumference and area of a circle. He made several types of war machines and these machines worked by means of levers and pulleys.

Archimedes was born in Syracuse on 287 BC. This city was captured by Romans. Later one day when Archimedes was making some geometrical figures on the ground a Roman soldier entered his house. So he has asked the soldier not to spoil his diagrams. Proud soldier got composed and killed Archimedes in 212 BC.