Archimedes. 287bc - 212 bc.

“Eureka! Eureka!” reverberated in the streets of Syracus (Sarausa [ a historic city on the Italian island of Sicily.  The cry came from a bearded man running across the city without a stitch on him.  What do the words mean? 

It means “I’ve found it!”           

What has he found?

Fig.1 Arcchimedes of Syracuse 287BC to 212 BC

  This was the man now considered as one of the top ten mathematicians that ever lived.  Out of all the pre-Christian scholars, Archimedes happened to be the most popular. Most    of what we know about him had come down the ages as anecdotes. Running away naked, hurling  away 500 pound loads on to enemy ships, focusing sun light to ignite them, up to the words uttered to his executioner as, “Do not disturb my circles” have been scrolled by the Greek historians only a few centuries after his death.

  During the 1st Century BC, when the Roman Empire was expanding, Syracuse was a Greek State in Sicily which was ruled by a King named Hiero II. His astronomer Phidias, brought up a gifted lad, probably his son, by the name Archimedes. The young man who has had some training at the renowned cultural citadel at the time, Alexandria, became the Kings adviser on military matters.

  Although what he conceived, designed and built brought him an immense popularity, all around the Mediterranean he does not seem to have considered them as really great achievements. From what he had been sending to his contemporaries in Alexandria such as Erastothenes, (who introduced latitudes and longitudes and calculated the circumference and the tilt of the world), it becomes clear that he was most concerned about his theoretical work in mathematics.

  So it would be most appropriate for us to consider his theoretical achievements to begin with.

         Discoveries About the Sphere                    

1. The surface area of a sphere is 4 times the area of a circle that will pass through its centre.  2 .A sphere embedded in a cylinder has a volume equal to 2/3rd the volume of the cylinder.  3. Circumference of a circle  ÷  diameter  =   A constant       (This constant is pi. π  and its value was estimated to be 22/7) Circle, sphere and cylinder had been his obsession throughout his life.

        .

Fig. Archimedes had requested a friend to erect a sphere inside a cylinder over his tomb.

Law of Moments

  He did not use the word ‘moments; but he determined the ‘centre of graviy; (Centre of mass) of plane surfaces and showed that a force acting at a distance from the pivot  would have a greater turning effect than a similar force acting closer to the pivot. This may be stated as the the Lever law.

Effort X Effort arm = Load X Load arm.

       Based on this discovery he is supposed to have said:-

                                   “Give me a place to stand. I’ll move the Earth”

   Using the lever principle they could extend a giant claw like feature and topple large ships.

Use of Compound pulley and complex machines

 Compound pulley

The King had ordered a gigantic ship, 4200 tons to be built. Once it was completed no amount of strong human beings could move it an inch. When it was entrusted to Archimedes, using a couple of pulleys and levers the effort of a few people could easily launch her.  

Discovery 5.

So he became the first man to use the pulley systems to achieve a very high mechanical advantage...

Other Inventions

Discovery 6:- Death Ray.

He got shining metal shields to act as mirrors to focus the sunlight on the enemy ships. The heat produced was able to reduce the wooden ships to ignite.

Discovery 7:- Missiles

He had machines to throw huge stones at ships in the sea. Details of design of these machines are not available but it has been written that he was able to repel several attacks by hurling heavy loads at the invading ships.

Discovery 8:- Archimedes screw is one of his inventions that have outlived almost all other inventions of the past.

Now the hydraulic engineers have shown that the Archimedes screw may, in reverse, even be used to generate power. This method seems to have many advantages over the conventional turbines used now.

  The tragic end

  In spite of all the sophisticated weaponry, a Roman General by the name Marcus Marcellus captured Syracuse and ordered his men to capture Archimedes alive. Unfortunately the soldier who met him did not identify the man. The soldier ordered the man to visit Marcellus but as he was buried in his problems rudely said, "Do not disturb my circles”. 

The soldier did not hesitate to run the sword severing one of the best brains that ever existed... 

Archimedes Principal.Physics terms A-L.