Find stories about Archimedes

Two thousand one hundred and ninety years ago, a great physicist appeared in Syracuse, Sicily, ancient Greece. His name was Archimedes (287-212 BC). Archimedes was diligent and studious throughout his life, dedicated himself to science, and was loyal to his motherland. He was respected and praised by people. Archimedes discovered the law of the lever and Archimedes' law is named after him. And used these laws to design a variety of machinery to serve the people and the motherland. Details of his life cannot be verified. But the stories about his inventions and defense of the motherland have been passed down to this day.

The establishment of the law of leverage

People have been using leverage since ancient times and know how to use it skillfully. When the pyramids were being built in Egypt, slaves used levers to lift heavy stones. Shipbuilders used levers to erect masts on ships. People used water booms to get water from wells, etc. But why does leverage do this? Before Archimedes discovered the law of the lever, no one could explain it. At that time, when some philosophers talked about this issue, they insisted that it was "demonic nature". Archimedes did not admit that there was any "demon nature". He understands that various phenomena in nature always have natural reasons to explain them. Leverage had its natural causes, too, and he was determined to explain them. After repeated observations, experiments and calculations, Archimedes finally established the law of balance of levers. That is, "the moment arm is inversely proportional to the force (weight)." In other words, the small weight is one-thousandth of the large weight, and the long moment arm should be several times as long as the short moment arm. After Archimedes established the law of the lever, he deduced that as long as the appropriate lever length could be obtained, any weight could be lifted with very little force. It is said that he once said such heroic words:

"Give me a fulcrum, and I can lift the earth!"

After hearing this, the King of Syracuse said to Archimedes Said: "By Zeus (Zeus is the king of gods in Greek mythology, in charge of sky, thunder, lightning and rain), what you said is really weird, Archimedes!" Archimedes explained to the king After understanding the characteristics of the lever, the king said: "Where can I find a fulcrum to lift the earth?"

"There is no such fulcrum." Archimedes replied.

"Then it is impossible to make people believe in the power of mechanics?" said the king.

"No, no, you misunderstood, Your Majesty, I can give you other examples." Archimedes said.

The king said: "You are too bragging! You can push a heavy thing for me and see what you say." At that time, the king had a difficult problem, that is, he built a heavy object for the king of Egypt. A very big ship. After the ship was built, the entire city of Syracuse was mobilized, but they could not push it into the water. Archimedes said: "Okay, let me push this boat for you."

After Archimedes left the king, he used the principles of levers and pulleys to design and manufacture An ingenious piece of machinery. After everything was ready, Archimedes invited the king to watch the launch of the ship. He handed the end of a thick rope to the king and asked him to pull gently. Suddenly, the big ship slowly moved and slid into the water smoothly. The king and ministers were amazed to see such a miracle, as if they were watching a magic trick! So the king convinced Archimedes and issued a proclamation to the whole country: "From now on, no matter what Archimedes says, you must believe him..."

The problem of weighing the crown

In the eyes of ordinary people, Archimedes is a "weird". In the words of the Roman historian Plutarch: "He seemed to be a man bewitched and didn't care about food or his own body." Sometimes, when rice was placed on the table and he was asked to eat, he seemed to He didn't hear it and continued to draw his geometric figures in the ashes of the brazier. His wife must watch over him at all times. For example, when he was rubbing his body with oil, he would just sit there and draw patterns on his body with the oil, forgetting what he was doing. His wife was even more afraid of sending him to the bathhouse to take a bath. This joke was caused by a new crown of the king.

Not long ago, the king asked a craftsman to make a gold crown for him.

The king gave the craftsman as much gold as he needed. The craftsman's skills are very skillful, and the crown made is exquisite and unique, and it weighs as much as the gold given by the king. However, someone reported to the king: "When the craftsmen were making the crown, they secretly swallowed part of the gold and mixed the same weight of silver into it." After hearing this, the king also became suspicious, so he called Archimedes and asked him for ideas. Determine whether the gold crown is mixed with silver, and whether the craftsman has embezzled the gold. This time, Archimedes was stumped. He returned home and thought hard for a long time, but could not come up with a solution. He couldn't eat well every day, couldn't sleep well, and didn't take a shower, as if he was possessed.

One day, the king sent someone to urge him to report to the palace. His wife saw that he was too dirty and forced him to take a bath. When he was taking a bath in the bathhouse, he was still thinking about the problem of weighing the crown. Suddenly, he noticed that as his body sank in the tub, some of the water overflowed from the edge of the tub. At the same time, he felt that the deeper he went into the water, the lighter his body became. So he immediately jumped out of the tub, forgot to put on his clothes, and ran into the street where the crowd was. While running, he shouted: "I figured it out, I figured it out, the solution to the crown has been found!"

After he entered the palace, he said to the king: "Please allow me to do an experiment first. Only then can I report the results to you." The king agreed. Archimedes placed a piece of gold, a piece of silver, and the crown, which were as heavy as the crown, in a basin one by one. He saw that the amount of water discharged by the gold piece was less than that of the silver piece, and that the amount of water discharged by the crown was less than that of the gold piece. A lot of water.

Archimedes said to the king: "The crown is mixed with silver!" The king saw the experiment and didn't understand it, so he asked Archimedes to explain it. Archimedes said: "Comparing one kilogram of wood with one kilogram of iron, the volume of wood is larger. If they are put into water respectively, the amount of water displaced by the larger wood will be greater than that of the smaller iron. I Apply this principle to gold, silver and crowns. Because gold has a high density and silver has a low density, the volume of gold and silver must be greater than the volume of gold and silver. If the block is put into water, then the amount of water discharged by the gold block is less than that of the silver block. The experiment just showed that the crown discharges more water than the gold block, which means that the density of the crown is smaller than that of the gold block, which proves that the crown is not used. Made of pure gold." Archimedes told the story in a logical manner, which convinced the king. The results of the experiment proved that the craftsman had embezzled the gold.

This experiment of Archimedes is the embryo of "hydrostatics". But he did not stop at this point and continued to study the problem of floating bodies in depth. The result was the discovery of an important principle in natural science - Archimedes' law. That is: when an object is immersed in a liquid, the volume of liquid displaced is equal to the volume of the object immersed; the buoyancy of the floating body is maintained equal to the weight of the liquid displaced by the floating body.

A wonder in the history of war

In 213 BC, the Roman army led by Marchelu invaded Syracuse, the country of Archimedes. At this time, Archimedes, who was seventy-five years old, immediately used all his talents to help his motherland and fight against the enemy.

The Roman commander Marche became even more arrogant after capturing two cities in Syracuse. He believed that with only five days of preparation time, the ancient city of Syracuse, the capital of the country, could be captured. But he did not expect that all his plans would be shattered just because of a white-haired old man named Archimedes who loved his motherland.

This battle that took place 2,190 years ago is called by historians: a spectacle in the history of war!

Marcaeus led the fleet to attack Syracuse from the water. The soldiers on each of his battleships were equipped with bows, arrows, slings and darts. They wanted to drive the defenders of Syracuse down the city, and then use the siege engines mounted on the battleships to let the soldiers rush into Syracuse. antiquity. However, Archimedes was well prepared. When the enemy fleet approached, Archimedes launched the huge long-range projection machines he built. The long-range projection machine can project more than 200 kilograms of stones more than a thousand meters away (equivalent to the range of an 18th-century cannon).

These huge stones hit the battleship like hailstones, causing Marche to panic. The ship sank and the soldiers died in panic. Marchelu had no choice but to evacuate the remaining warships in a hurry.

Markailu decided to attack again at night. He thought that Archimedes couldn't see far at night, and his huge long-range projection machines would be useless when the fleet arrived at the city. However, when Marche Road attacked at night, they were in bad luck again. Archimedes' short-range machines were activated, and these machines continued to throw darts and stones, causing the Roman army to suffer another heavy blow, and even Marche was almost killed.

Marcae was unwilling to give up his attempt to capture Syracuse. He still urged the army and the engineers who forced him to continue the contest with Archimedes. In the end, it was all in vain. Sometimes, Rome rushed warships with siege engines to the city of Syracuse, and the defenders would start a machine with a "long mouth", and stones would fall down from the "long mouth". Not only did they smash the siege machines to pieces, but they also smashed the battleships to pieces, putting the Roman soldiers in a desperate situation. Sometimes, a kind of iron hook was lowered from the city. This kind of iron hook was very flexible with machine control. The iron hook could hook the bow of a Roman warship, and then pull the warship up, causing the warship to overturn to one side and flood the water. inside.

Marcailu tried all kinds of offensive methods, but they were all broken by Archimedes' invention. The Roman army became as timid as mice. When they saw a rope sticking out from the top of the wall, they ran away desperately and shouted: "Archimedes has used another machine to play tricks on us!"

In the end, Marche Road had no choice but to surround the ancient city of Syracuse in an attempt to trap the people in the city to death. This method of his made Archimedes helpless. The Roman army besieged the city for eight months. Finally, taking advantage of the fact that the Syracusans were celebrating a festival and neglecting to take precautions, they sneaked in from a remote city gate and captured Syracuse.

When the Roman army rushed into the city, Marchelu had ordered not to kill the great physicist. But at that time, Archimedes was drawing his figures in his laboratory. As the soldiers rushed in, he was startled by the sound of footsteps. This disturbance made him wake up and shouted angrily: "Hey! You ruined my picture, run away!" As a result, his anger angered the Roman soldiers, and Archimedes died by the sword. .

Although the great physicist Archimedes died, his contribution to mankind in science is immeasurable!