Archimedes’ Principle

Archimedes principle is one of the most important laws in physics.

Archimedes’ Principle
Archimedes’ Principle


Archimedes’ Principle


Archimedes principle is one of the most important laws in physics. was one of the greatest scientists in the classical age. He was altogether a mathematician, engineer, inventor, astronomer, and physicist. Scientists of modern age still use his concepts, theories, and inventions. 

He lived on an island named Syracuse in Sicily. It was one of the most influential cities. 

In the world at that time. He studied astronomy and geometry in Alexandria. Later, he decided to settle down in Syracuse. He wanted to devote free thinking so that he could continue his research.   

Archimedes was a great scholar and the king of Syracuse, Hireon was his patron. The king inspired him to carry on to find out more discoveries. Archimedes' screw was an effective invention by him. The primary purpose of this device was to empty seawater from a ship's hull. We still use this method in our irrigation process. He is also the inventor of the ‘Liver Law.’ He was so confident of this theory that his famous quote “Give me a lever and a place to stand, and I’ll move the world” derived. It literally changed the world.    

He also upgraded the defense system of the Syracuse. But he was unaware of the Roman attack. Roman general, Marcellous captured Syracuse but he had a soft corner for Archimedes. He wanted to meet him personally. So, he sent soldiers to bring the think-tank to him. Archimedes was so engaged in solving a math equation that he never knew about the Roman invasion. When the troops went to bring him with them, he got irritated and ordered them to leave. One of the enraged soldiers killed him. Although Marcellous ordered his army to take him alive, they knocked him down. One reason may be that they did not know the nobleman. Another reason may be that they were aware of his identity as the big-brain behind Syracuse’s defense system causing death to a lot of Roman soldiers.           

His death deserves our pity. But the fact that he was so sunken in his work resulted in his death deserves our praise. He was not worried about death as he prioritizes his work more. This indicates how dedicated he was in thinking and finding a possible solution to the problem. Once he was engaged in thoughts, he forgot everything. That's why he ran out to the roads naked after discovering the ‘Law of Buoyancy’ shouting “Eureka! Eureka!” that means “I’ve found it!”


The Syrecuan King, Hireon once had a new golden crown made by a goldsmith. The king suspects that he has been deceived by him. He assigned Archimedes to find out if the crown was made of solid gold or not. The thoughtful intellect took the matter seriously. He started to question himself. Archimedes tried to crack the problem but failed. 


Then one day, he was about to take a bath. The bathtub was full to the brim. When he got inside, he noticed water was overflowing from the tub’s edge. He realized that his body displaces the water. He further realized that the weight of the water his body spilled over was equal to the weight of his body. He knew that gold is heavier than other metals. So, this discovery can be used to solve the ‘crown puzzle.’ He was so excited that he came down from the tub and ran to the palace naked shouting “Eureka! Eureka!” This is the story still in practice today.

Archimedes took a vessel full of water and placed a piece of gold (weighing the same as the crown). He then measured the displaced water. After that, he refilled the vessel and now he places a silver piece into it. The removed water by the silver piece was lighter than that of the golden piece. It proves that gold is heavier than silver. At the final stage of his experiment, he placed the golden crown. The crown shifts less water than that of the golden piece displaces. Thus, Archimedes proved that the crown was not pure.   

We do not know what happened to the goldsmith. But we know the law of buoyancy now. Buoyancy is a force by a fluid that pushes a body at rest upward. It works as an anti-force against gravitation. For this, the body is forced to float on for the time being or to sink rapidly. If a solid body completely submerged into a fluid, the volume of the fluid and the solid body is equal. If the body submerges partially, the volume of fluid is equal to the volume of the specific part that submerges.  

This law also shows why bodies sink or float on. When the replaced fluid’s weight is lighter than the weight of the body, it sinks. But the object floats if the displaced fluid’s weight is heavier. From the buoyant force, the volume or average density of the object can be determined. 

The above force also known as buoyancy is the first condition of equilibrium. Steven’s law is the second condition of the equilibrium. The later law depicts that the center of gravity of the floating body and its center of buoyancy must lie on the same vertical. But when the equilibrium is stable it helps a body to float at the surface. For this, the metacenter must be situated above its center of gravity.    







The Archimedes principle is used in many fields besides physics. Medical, engineering, entomology, engineering, geology- to name a few are some fields where this principle is being used. The law can measure the volume of different irregular objects with irregular size and shape. It also explains the behaviors of the objects placed in any fluid. As we understand this principle, it helps us to find answers to our questions. How ships float, submarines dive, hot air balloons fly and many more others are solved by Archimedes long ago when he discovered this law.       

Archimedes law clears the fact why a big ship floats on the water whereas a coin with fewer weight sinks. Ships float on water by following three basic rules. They are- displacement, buoyancy, and density. Water vessels and ships displace a lot of water. The ship where it is now is forced by the displaced water as it wants to come back to its earlier position. The water pushes the ship upwards for the buoyancy force. The stronger the force, the better the object floats. The average density of water also plays an important role in the floating of the ships. 

Submarines are also a kind of ship, but they are navigated underwater. While making these water engines, scientists follow the Archimedes principle. Before submerging them into the water, the makers rely on the law as submarines must maintain a constant depth. The design of them depends on the calculation of the mass, density, and volume of both the submarine and the displaced water. They make the accurate ballast tank to be filled with the determined amount of water and select the depth for the submarine’s dive. 

Sometimes we become astonished to see water-walking bugs. How they do it? Yes! The Archimedes laws. Scientists have already found out the strategies that enable them to walk on water. Soon they are going to invent biomimetic water-walking robots by using their theories derived from water walking bugs. 

Geology is using his principle to solve geological mysteries. Geologists use it typically to study sedimentation profiles. The generalized principle is used at a higher level. Denser particles floating on top of a light fluid is an example of this. 

Bone volumes and densities are important for their treatment. The medical and dentistry field and dentistry field use the Archimedes principle to determine the densities of bones and teeth. The density of bones indicates human aging. This principle is also used to osteoporosis, bone strength, stiffness, and elasticity studies. To determine the reproducibility, the Archimedes principle was used in several Oral Surgery, Oral Medicine, Oral Pathology, Oral Radiology. For measuring the volume of teeth, the principle was compared with using cone beam computed tomography (CBCT). Although Archimedes law failed here it gave competition to CTBT at least.