posted Jan 1, 2015, 8:36 PM by ranmini@charliesresearch.com
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updated by Upali Salpadoru
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Archimedes 287BC to 212 BC
Archimedes of Syracuse 287bc - 212 bc. “Eureka! Eureka!” reverberated in the streets of Syracuse , 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? 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.
Syracuse
During the 1st Century BC, 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 Eratosthenes, He was most concerned about his theoretical work in mathematics.
He had an idea of ‘centre of gravity; (Centre of mass) of an object.
He did not use the word ‘moments; but he determined that a force acting at a distance from the pivotwould 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:
Archimedes was not the first one to use a lever but he is the one that explained the theory.
" මට ඉන්න තැනක් තිබේනම් ලෝකයම එසවිය හැකිය් " “Give me a place to stand. I’ll move the Earth”
The King had ordered a 4200 ton ship to be built. 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.
So he became one of the first to use the pulley systems to achieve a very high mechanical advantage.
The first written record of pulleys dates to the Sumerians of Mesopotamia in 1500 BCE,
Archimede's screw This invention has outlived almost all other inventions of the past. 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.
Archimedes pumps are used to pump water in USA. ඇමෙරිකාවේ භාවිතා වන ආකිමිඪියන් පොම්ප ක්රමයක්.
He got shining metal shields to act as mirrors to focus the sunlight on the enemy ships. The heat produced was able to ignite the wooden ships. 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. 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...
