Archimedes, an ancient Greek mathematician and mechanic, was the founder of statics and hydrostatics. He was born in Syria, Sicily, about 287 BC.

Gula died in the same place in 2 12 BC. Alexander studied with Euclid's students in the cultural center at that time in his early years, and later followed Alexander's scholars.

Close contact, so he is a member of the Alexandria school. Later generations spoke highly of Archimedes, and often listed him as history with I Newton and C F Gauss.

Three mathematicians who have made the greatest contribution since then.

His life is not recorded in detail, but many stories about him are widely circulated.

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It is said that after establishing the lever law of mechanics, he once boldly said, "Here it is!" "

I have a foothold, I can shake the earth! "

Shiloh, king of Syracuse, asked the goldsmith to make a pure gold crown because he was suspicious.

The surface was mixed with silver, so Archimedes was invited to identify it. When he entered the bathtub to take a bath.

At that time, the water overflowed the basin, so I realized that objects made of different materials, although in weight,

The same, but because of the different volumes, the discharged water will not be equal. According to this truth.

, you can judge whether the crown is adulterated. Archimedes jumped up with joy, naked.

He rushed home and shouted, "Found it! Eureka! " (Greek meaning

I found it. He put the basic principle of hydrostatics, that is, objects.

The reduced weight in the liquid is equal to the weight of the discharged liquid, which is summarized in his name.

In his book about floating bodies, he later became famous for Archimedes' principle.

During the Second Punic War, the Roman army besieged Syracuse, and Archimedes devoted all his intelligence to serving the motherland. Legend has it that he caught the enemy with a crane.

Ship, smashed; Invent wonderful machines and fire big stones and fireballs. There are also some books that record that he used a huge fire mirror to reflect sunlight and burn enemy ships, probably

In a word, he tried his best to deal a heavy blow to the enemy. Finally, Syracuse Gui was betrayed by spies and ran out of food. Archimedes was unfortunate.

Died at the hands of Roman soldiers

Archimedes' handed down works mainly include the following:

On the Ball and the Cylinder is his masterpiece, which contains many great achievements. Starting from several definitions and axioms, he deduced the areas and volumes of spheres and cylinders.

Wait for more than 50 propositions.

The balance of plane figure or its center of gravity, based on several basic assumptions, demonstrates the mechanical principle with strict geometric methods, and finds out the centers of gravity of several plane figures.

The sand counter designs a method that can represent any large number, which corrects some people's idea that sand is uncountable, and even if it can be counted, it can't be represented by arithmetic symbols.

Show the wrong point of view.

On the floating body, the buoyancy of the object is discussed and the stability of the rotating projectile in the fluid is studied. Archimedes also put forward a "flock problem", including eight.

Unknown. Finally, it comes down to a quadratic indefinite equation. The number of its solutions is amazing, * * * more than 200,000 digits! It is worth remembering whether Archimedes solved it at that time.

Doubt.

Archimedes method mainly focuses on the method of finding problems according to mechanical principles. He regards an area or volume as something with weight and divides it into many parts.

Small strips or sheets, then balance these "elements" with the known area or volume, find the center of gravity and fulcrum, and the required area or volume can be leveraged.

Law to calculate. He regards this method as a tentative work before strict proof, and will prove it by reducing to absurdity after getting the result. He used this method.

France has made many brilliant achievements. Archimedes' method has the idea of modern integral theory. However, he did not say whether this "element" is finite or infinite.

Many of them have not got rid of their dependence on geometry, let alone used the limit method. Nevertheless, his thought is epoch-making and worth learning from modern integral calculus.

Pioneer. He has many other inventions. No ancient scientist combined skillful calculation skills with strict proof like Archimedes.

The theory of image is closely combined with the concrete application of engineering technology.

Qian Xuesen (19 1 1-), born in Hangzhou, Zhejiang Province, is an aerodynamist, an academician of China Academy of Sciences and an academician of China Academy of Engineering. 1934 graduated from Shanghai jiaotong university, 1935 went to MIT to study abroad, got a master's degree the following year, and then entered California institute of technology. 1939 after receiving his doctorate in aviation and mathematics, he stayed in school to teach, engaged in applied mechanics and rocket and missile research. 1955 After returning to China, he served as director of the Institute of Mechanics of Chinese Academy of Sciences, vice president and dean of the Fifth Research Institute of the Ministry of National Defense, deputy director of the Seventh Machinery Department, deputy director of the Science and Technology Committee of the Commission of Science, Technology and Industry for National Defense, chairman of the third China Association for Science and Technology, vice chairman of the sixth to eighth CPPCC, and alternate member of the ninth to 12 Central Committee. He is currently a senior consultant of the Science and Technology Committee of the General Armament Department of China People's Liberation Army and honorary chairman of China Association for Science and Technology.

1956 put forward "opinions on establishing China's national defense aviation industry", and put forward an extremely important implementation plan for developing rocket and missile technology in China for the first time. Assist Nie in establishing the Fifth Research Institute of the Ministry of National Defense, which is a rocket and missile research institution. 1June, 1956, director of the institute. Since then, he has served as the technical director of the development of rockets, missiles and spacecraft in China for a long time, and has made outstanding contributions to the establishment and development of rockets, missiles and spacecraft in China with his rich knowledge in general, power, guidance, aerodynamics, structure, materials, computers, quality control and scientific and technological management. 1957 won the first prize of natural science of China Academy of Sciences, 1979 won the Outstanding Alumni Award of California Institute of Technology, and 1985 won the special prize of National Science and Technology Progress Award. 1989 was awarded the Rockville Medal and the title of world-class science and engineering celebrity; 199 1 was awarded the honorary title of "National Outstanding Contribution Scientist" and the first-class English Model Medal by the State Council and the Central Military Commission in.

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The king asked the goldsmith to make a new pure gold crown. But he suspected that the goldsmith had adulterated the gold crown. However, from the point of view of weight and appearance, there is nothing wrong with the finished crown. The king handed this difficult problem to Archimedes.

Archimedes thought about this problem day and night. One day, he went to the bathhouse to take a bath. When he sat down in the bathhouse slowly, the water overflowed from the basin. He looked at the overflowing water and suddenly shouted, "I know!" " "I ran home naked. It turned out that he had come up with a way.

Archimedes put the golden crown in a jar full of water, and some water overflowed. He picked up the crown, filled it with water, put a piece of gold as heavy as the crown into the water, and some water overflowed. He compared two kinds of water and found that the first one overflowed more than the second one. So he decided to mix the gold crown with silver. After the experiment, he worked out the weight of silver. The goldsmith was stunned when he announced his discovery.

The significance of this experiment is far greater than finding out that the goldsmith cheated the king. Archimedes discovered the principle that the weight of an object in a liquid is equal to the weight of the liquid he discharged. This principle is named after Archimedes. Until modern times, people are still using this principle to measure the ship's load.

In Watt's hometown of Greenock, every family makes a fire to boil water and cook. Who cares about such a common thing? Watt left his heart. Is there a Huai? He watched his grandmother cooking in the kitchen. There is a pot of boiling water on the stove. The boiling water is boiling. The lid of the pot smacked and kept jumping up. Watt observed it for a long time and felt very strange. He wanted to know what the reason was, so he asked his grandmother. What makes the lid jump? "

Grandma replied, "The water is boiling, that's all."

Watt asked discontentedly, "Why does the water jump as soon as the lid is opened?" ? Is something pushing it? "

Maybe grandma was too busy to answer him correctly, so she said impatiently, "I don't know." What is the significance of children asking these questions? "

Instead of finding the answer with grandma, Watt was unfairly criticized. He was very uncomfortable, but he didn't lose heart.

For several days in a row, whenever cooking, he squatted by the fire and observed carefully. At first, the lid was very stable. After a while, the water will boil and make a loud noise. On the ground, the steam in the pot came out and pushed the lid to jump. The steam kept rising, and the lid kept beating, as if a magician was hiding inside, doing tricks. Watt almost cried out for joy. He opened the lid, closed it again and again, and verified it again and again. He also covered the cup and spoon that sprayed steam. Watt finally figured out that steam pushed the lid to jump, and the power of this steam was not small.

Just as Watt was in high spirits and ecstatic, grandma spoke again: "You child, you are ungrateful. What's so funny about the kettle? Go away! " She said casually.

His grandmother is too impatient and subjective, and if she neglects it casually, it will almost dampen Watt's self-esteem and enthusiasm for exploring scientific knowledge. Old man, you don't understand Watt's heart at all, do you? What a revelation water vapor is to Watt! Isn't the physical phenomenon that water vapor pushes the lid of the kettle to jump off the water bottle the source of Watt's understanding of inventing the steam engine?

1769, watt changed the steam engine into a single-acting engine with great power. Later, after many studies, the trial production of the new steam engine was completed in 1782. With the linkage device on the machine, the simple motion turned into rotary motion, and the perfect steam engine was successfully invented.

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