Archimedes

One of the most famous physicists of ancient times, Archimedes is known as the "Father of experimental science".

Archimedes was born in ancient Greece in the year 287 BC. He is credited with finding the famous Archimedes Principle.

According to the Archimedes Principle, if we weigh an object in air and then weigh it again when submerged in a liquid, the object will lose weight equal to the weight of the liquid it displaces. In other words, if a 10 kg ball is dipped in a bucket full of water, and the bucket loses 1 litre (approximately equal to 1 kg) water, the weight of the ball in water is 9 kg (10 kg - 1 kg).

Archimedes also gave the laws of flotation of bodies and the principle of lever. In addition to these, he discovered the use of levers and pulleys and how to pump water uphill using a screw, which later came to be known as an Archimedean screw. The system is still used to irrigate fields in Egypt.

 
Fundu Fact

Once King Heron of Syracuse gave Archimedes a crown made of gold. He suspected that it was not pure but alloyed with silver. He asked Archimedes to test its purity without damaging it. This was a new problem for the great mathematician.

He took note of the issue and proceeded to take a bath. On entering his bathtub, Archimedes observed that his body displaced some water and the water level in the tub rose. He then jumped out and ran down the street, naked, shouting "Eureka! Eureka!' (I have found it!). He had found a way to solve the king's problem.

Archimedes filled a vessel with water and dipped the crown in it. The water displaced by it was measured.

Then he filled the vessel with water and dipped an equal mass of pure gold in it. The water displaced was again collected and measured.

The amount of water displaced in the two observations was different. From this experiment Archimedes came to the conclusion that the gold crown was impure (otherwise the water displaced by the crown would have been equal to the water displaced by pure gold of the same weight)!
Did you know?
Romans captured Syracuse in 212 BC. At that time Archimedes had become quite old. One day while he was drawing some geometrical figure on the sand, one of the Roman soldiers asked him to accompany him. When he refused, the soldier pulled out his sword and killed him. Thus the world lost a great mathematical genius.