Name: Archimedes
Country or region: Greece
Discipline: Mathematicians and Engineers
Invention: Founder of Theoretical Mechanics
Brief Calendar
Archimedes, Greek mathematician and engineer. Born about 287 BC in Syracuse, Sicily; He died in Syracuse in about 212 BC. Archimedes, the son of an astronomer, was a great scientist and mathematician in ancient times. It was not until Newton appeared two thousand years later that he could be compared with him. Archimedes studied in Alexandria, where his teacher Kang Nong was a student of Euclid. Archimedes decided not to stay in Alexandria, but to return to his hometown, which was an unusual move at that time. This may be because he was related to Herod II, the ancient king of Syracuse. Archimedes was a noble and independent man, and he did not ask the Egyptian royal family to support his research work. Archimedes has the most stories about ancient scientists, and even Thales can't compare with them. All these stories are so beautiful that if someone asks whether the stories are true or not, it seems to make people feel cruel. For example, even the story of Archimedes' forgetfulness is celebrated everywhere. It is said that when he concentrates on thinking, he can't even remember whether he has eaten (there are similar stories about more modern mathematicians, such as Newton and Wiener *). Legend has it that King Hiro once asked his clever relative Archimedes to measure the crown just made by the goldsmith to see if it was pure gold or a mixture of silver, as the craftsman said. And warned Archimedes severely in advance not to destroy the crown during the determination. At first Archimedes was at a loss. Until one day when he was bathing in a basin full of water, he noticed that the water overflowed. Suddenly a flash of thought reminded him that the volume of spilled water was equal to the volume of his body immersed in water. Then, if the crown is immersed in water, he can tell the volume of the crown according to the rising of the water surface. He compared the volume of the crown with the volume of equal weight gold, and if the two volumes are equal, it proves that the crown is pure gold; If the crown is mixed with silver, the crown will be larger. When Archimedes discovered this principle of buoyancy, his excitement was indescribable. He suddenly jumped out of the bathtub, ran naked into the street of Syracuse, and ran straight to the imperial army, shouting: "Eureka! Eureka!” (I found it! I found it! ) From then on, this sentence has become an appropriate expression when announcing a discovery. The end of the story is that the crown was indeed mixed with some silver, and the goldsmith was sentenced to death. ) Archimedes also discovered the lever principle. Although strato had already used this principle, it was Archimedes who developed the complete mathematical relationship of this principle. He pointed out that a small object at the far end of the fulcrum will be in balance with a large object at the near end of the fulcrum, and that the weight of the object is inversely proportional to the distance from the fulcrum. From this, he established "statics" and put forward the concept of center of gravity for scientific observation, which shows that he was two thousand years ahead of his time. In fact, it was not until his works were translated into Latin in 1544 that scientists like Steven and Galileo were inspired to make new explorations in his direction. ) The lever principle explains why a large stone can be pried up with an iron bar. Because the force at the far end of the iron bar (just a lever) is balanced with the force of the weight at the near end of the iron bar. Archimedes famously said, "As long as I have a foothold, I can move the earth." Of course, if he has a lever with enough length and rigidity, it can be done! Legend has it that Hiro once questioned him about this sentence and asked him if he dared to move something surprisingly big, even if it was not as big as the whole earth. So Archimedes hooked a set of levers in the form of pulleys with hooks, but he sat comfortably and pulled a full ship from the port to the shore without any effort (according to legend). Archimedes opposed Plato's widely publicized traditional idea of art for art's sake. He devoted himself to the study of very practical content. It is said that he invented a hollow full spiral cylinder, which can be used as a water pump when it rotates. Now it is still called "Archimedes spiral" (although it is certain that Egyptians had this kind of thing long before Archimedes). Others believe that Archimedes designed a planetarium in which the motion of celestial bodies can be simulated. However, it seems that Archimedes is not really proud of his victory in mechanics. Perhaps he thinks that these are not the job of a philosopher. So he only published his mathematical works. In the field of mathematics, he calculated the value (the ratio of circumference to its diameter), which exceeded the results obtained in the field of classical mathematics. He pointed out that the value was between 223/71 and 22/7. In order to find this value, he used the method of calculating the perimeter and diameter of the inscribed and circumscribed polygons of a circle. The more sides of a polygon, the closer it is to a circle in shape and area, the longer the perimeter of the inscribed polygon and the shorter the perimeter of the circumscribed polygon, and the closer it is to both. This is very similar to some methods used in calculus after a long time. It is often said that Archimedes would have discovered calculus two thousand years earlier than Newton if he could use a set of suitable mathematical symbols at that time. Archimedes is also famous for a paper in which he calculated the number of gravel needed to fill the whole universe (the size of the universe has been imagined here). The main purpose of his doing this is to show that there is nothing too big to measure in the world. To illustrate this point, he used a set of symbols equivalent to our index today to represent large numbers. However, Archimedes did not spend his old age in peace. As a warrior, he won the greatest reputation. In Archimedes' later years, Rome fought Carthage for the second time. The leader of the Carthaginians is Hannibal, one of the greatest generals in history. He invaded Italy in 218 BC and began to build his great cause. Herod II made a covenant with Rome, and remained faithful to it, and finally died, and his grandson Heronemes continued to rule. The Romans suffered a terrible defeat in Keni, and it once seemed that they would both perish. Heronim, eager to maintain victory, fell to the Carthaginian side. However, the Romans were not completely defeated. Under the leadership of General Maceiras, they sent a fleet against Syracuse, and from then on began a three-year strange war between the Roman fleet and Archimedes. According to legend, if there were no clever tools invented by this great scientist to deal with the Roman fleet, the Romans would quickly capture the city. Legend has it that Archimedes made a large lens to set the fleet on fire and lifted the ship with a jack; Turn the boat upside down, and so on. Legend has it that in the end, the Romans were afraid to go near the city wall. As long as a rope appeared above them, they would be scared away, because they believed that the terrible Archimedes must be using some novel monster to make them die. There is no doubt that a considerable part of this legend is exaggerated, because the Greeks (like Plutarch, the main source of this legend) were eager to describe how the Greeks used their intelligence to resist the strong physique of the Romans, but failed to describe it truthfully, so they were exaggerated. However, the siege lasted for a long time until 212 BC when Syracuse was defeated. (In 22 BC, Rome won the most in the war with Carthage.