Benjamin Franklin came up with the idea of ??inventing the lightning rod by chance:
Franklin's most famous discovery was the unification of sky and earth electricity, which broke people's superstition about lightning. During the discharge experiment using the Leyden jar, Franklin faced the flash and crackle of electric sparks and could not help but associate it with the thunder and lightning in the sky. He realized that the electric sparks in the Leyden jar might be a kind of small thunder and lightning. . To test this idea, lightning from the sky must be brought to the ground. On a thunderstorm day in July 1752, Franklin made a large kite out of silk. A thin iron wire was placed on the top of the kite, and the iron wires were connected to the ground with silk threads. A copper key was tied to the end of the silk thread. The key was inserted into another Leyden jar. Franklin put the kite into the sky, and a burst of lightning struck down, and all the hairs on the silk thread stood up. When he put his hand close to the copper key, electric sparks were emitted. Tiandian was finally captured. Franklin discovered that the Leyden jar storing electricity from the sky can produce all the phenomena that electricity from the earth can produce, which proves that electricity from the sky and electricity from the earth are the same. In 1747, Franklin discovered the phenomenon that tips are more likely to discharge from the Leyden jar experiment. After he discovered the unity of sky electricity and earth electricity, he immediately thought of using the tip discharge principle to introduce powerful lightning from the sky into the ground. To prevent buildings from being struck by lightning. In 1760, Franklin erected a lightning rod on a building in Philadelphia, and the effect was very significant.
Newton discovered the law of universal gravitation when he was killed by an apple.
Russian chemist Mendeleev (1834~1907) was born in Siberia. He has loved labor, nature and study diligently since he was a child.
When Mendeleev was considering writing plans for his book "Principles of Chemistry" in 1860, he was deeply troubled by the lack of systematicity in inorganic chemistry. Therefore, he began to collect information on the properties and related data of every known element, and collected all the results that his predecessors could find in practice. Humanity's long-term practice and understanding activities on elemental issues have provided him with rich materials. On the basis of studying the results of his predecessors, he discovered that some elements not only have unique properties, but also have unique properties. For example, the known halogen elements fluorine, chlorine, bromine, and iodine all have similar properties; the alkali metal elements lithium, sodium, and potassium are quickly oxidized when exposed to the air, so they can only be in the form of compounds. Exist in nature; some metals such as copper, silver, and gold can remain in the air for a long time without being corroded. Because of this, they are called precious metals.
So Mendeleev began to try to arrange these elements. He built each element onto a rectangular cardboard card. Write the element symbol, atomic weight, element properties and its compounds on each rectangular piece of cardboard. Then they were nailed to the laboratory wall in rows and rows. After a series of queues, he discovered the regularity of the chemical properties of elements.
Therefore, when some people regard Mendeleev's discovery of the periodic law of elements as very simple and easily say that he obtained this great discovery by playing poker, Mendeleev took it seriously. He replied that it took him about 20 years to finally publish the periodic law of elements in 1869, ever since he decided to engage in this exploration work. He sorted out the chemical elements from the chaotic maze into categories. In addition, because he has great courage and confidence, is not afraid of criticism or ridicule from celebrities, has the courage to practice and promote his own views, he has finally been widely recognized.
The periodic law of elements
The periodic law of elements reveals a very important and interesting law: the properties of elements change periodically as the atomic weight increases, but it is not simple. repeat. Based on this principle, Mendeleev not only corrected some incorrect atomic weights, but also predicted the existence of more than 15 unknown elements. As a result, three elements were discovered while Mendeleev was still alive. In 1875, the French chemist Bois-Baudran discovered the first element to be filled and named it gallium. All the properties of this element are the same as Mendeleev predicted, except that the proportion is inconsistent. Mendeleev wrote a letter to the Paris Academy of Sciences, pointing out that the specific gravity of gallium should be about 5.9, not 4.7. At that time, the gallium was still in the hands of Boisbodhran, and Mendeleev had not yet seen it.
This incident greatly surprised Boisbodran, so he tried to purify it and remeasure the specific gravity of gallium. The results confirmed Mendeleev's prediction that the specific gravity was indeed 5.94. This result has greatly improved people's understanding of the periodic law of elements. It also shows that many scientific theories are called truth, not when scientists create these theories, but when this theory is continuously confirmed by practice. When Mendeleev predicted new elements through the periodic table, some scientists said that he was arrogantly inventing elements that did not exist. Through practice, Mendeleev's theory has received more and more widespread attention.
Later, based on the periodic law theory, people arranged and classified the more than 100 elements that had been discovered, and listed today's periodic table of chemical elements, which was posted on the laboratory wall and arranged behind the dictionary. It is a lesson that every student must learn and master when learning chemistry.
Now, we know that in the vast universe where humans live, all matter is composed of more than 100 elements, including us humans.
But, what are chemical elements? Chemical elements are collective names for atoms of the same type. Therefore, people often say that atoms are the "basic bricks" that constitute the material world. In a certain sense, this is true. However, the periodic law of chemical elements shows that chemical elements do not exist in isolation and are unrelated to each other. These facts mean that element atoms must also have their own internal laws. Changes in the theory of material structure are already here.
Finally, at the end of the 19th century, new developments occurred in practice, and radioactive elements and electrons were discovered. This was an excellent opportunity to reveal the inside story of atoms. But Mendeleev was confused in the face of practice. On the one hand, he was afraid that these discoveries would "complicate things" and shake "the foundation of the entire world view"; on the other hand, he felt that this "will be a very interesting thing...the reasons for the periodic patterns may be revealed." But Mendeleev himself died in 1907 with this contradictory thought on the eve of revealing the nature of the periodic law.
Mendeleev did not see that it was precisely because of a series of great discoveries and practices at the end of the 19th century and the beginning of the 20th century that the essence of the periodic law of elements was revealed and the theory of Mendeleev's era was abandoned. The old idea that atoms are indivisible. While discarding its inaccurate parts, it fully affirms its reasonable connotation and historical status. The new theory of the periodic law of elements born on this basis is more truthful than Mendeleev's theory.
The Life of Mendeleev
On January 27, 1907, the wind was freezing in Petersburg, the capital of Russia, the sun was dim, and the mercury on the thermometer dropped to minus 20 Many times, lanterns covered with black gauze were lit everywhere on the street, giving a sad atmosphere. The funeral procession of tens of thousands of people moved slowly on the street. At the front of the procession, there was neither a wreath nor a portrait, but a large wooden sign carried by a dozen young students, with many squares drawn on it. Gerry writes element symbols such as "C", "O", "Fe", and "Zn".
It turns out that the deceased was the famous Russian chemist Mendeleev, and the table with many squares painted on the wooden sign is the periodic table of chemical elements - Mendeleev's main contribution to chemistry.
Mendeleev was born into a family of a middle school principal who had seventeen children. He was the fourteenth. Just a few months after he was born, his father suddenly lost his sight and then lost his position as principal. Unable to make ends meet with a meager pension, the family moved to a nearby village where his uncle ran a small glass factory. The scene of workers smelting and processing glass had a great influence on his future chemical research involving beakers and flasks. In the autumn of 1841, Mendeleev, who was less than seven years old, and his teenage brother were admitted to the city middle school together, causing a sensation in the local area. Misfortune always follows poor people. When Mendeleev was 13 years old, his father died, and when he was 14 years old, the factory was reduced to ashes by fire. His mother had to move again, marry off her adult daughters, and let her two sons work. In the spring of 1849, Mendeleev graduated from high school, and his mother sold her property and wanted her youngest son to go to college. With the help of a friend of his father, Mendeleev entered the physics department of the Petersburg Teachers College. After only one year, he became a top student. In addition to intense study, he also wrote scientific reviews and received a small amount of royalties. By this time he had lost any financial support: his uncle and mother had died. In 1854, he graduated from university and won the gold medal of the college. He became an associate professor at the age of 23 and a professor at the age of 31.
The book that brought him initial fame was "Organic Chemistry". To write this book, he did not leave his desk for almost two months. After reaching the age of seventy, he became ill due to overwork and became half-blind. I work from early morning to 5:30 pm every day, and continue working after lunch until late at night. He died at his desk, still holding a pen in his hand. The discovery of the periodic law of elements in 1869 made him famous, and many foreign academies of sciences appointed him as an honorary academician. Once, a reporter asked him how he came up with the periodic law. Mendeleev laughed: "I have been thinking about this problem for 20 years, but you think I am sitting still. Five kopecks per line." , 5 kopecks arranged in a row, suddenly successful?"
Indeed, we should always remember Mendeleev's motto: "What is a genius? If you work hard for a lifetime, you will become a genius!"< /p>
Edison (1847-1931)
The 19th century is known as the century of science, and it is also a century characterized by the technologicalization and socialization of science. Science began to become an important part of social life in this century. The turbulent great innovation transformed into the great power of technological science. Some of this century's technological giants continued to be active into the 20th century. Thomas Alva Edison is one of them. Among the 100 most influential people in the past 1,000 years recently selected by the American "Life" magazine, Edison ranked first.
Edison came from a humble background and lived in poverty. His "education" was that he had only attended elementary school for three months in his life. The teacher was always dumbfounded by his weird questions and even said something about him in front of his mother. He is a fool and will have no future. In anger, his mother asked him to drop out of school and let her educate him herself. At this time, Edison's talent was fully revealed. Under the guidance of his mother, he read a lot of books and built a small laboratory at home. In order to raise the necessary expenses for the laboratory, he had to go out to work as a newsboy and publish newspapers. Finally, he used the money he saved to build a small laboratory in the luggage compartment of the train and continued to conduct chemical experiments. Later, a chemical fire broke out and almost burned the carriage. The angry bellman threw Edison's experimental equipment out of the car and slapped him several times. It is said that Edison was deaf for life as a result.
Edison is the kind of legendary figure admired by the American nation - although he did not receive a good school education, he achieved great success through personal struggle and extraordinary talent. He is self-taught, and with perseverance, rare enthusiasm and energy, he stood up from thousands of failures, overcame countless difficulties, and became an American inventor and entrepreneur. In his early years, he developed duplex and four-way telegraph systems and invented the automatic telegraph motor. Invented the phonograph from 1877 to 1879; experimented and improved electric lights (incandescent lamps) and telephones. Later, a lighting system was developed and a lot of work was done to achieve centralized power supply. He proposed and adopted the DC three-wire system. The generator with the largest capacity at that time was made, and in 1882, the first large-scale power plant was built using this machine. At the same time, experiments were conducted on railway electrification. In 1883, the "Edison effect", the phenomenon of hot electron emission, was discovered. There are also many famous inventions in film technology, mining, construction, chemical industry, etc. From 1869 to 1901 alone, 1,328 invention patents were obtained. During his life, he invented a new invention every 15 days on average, so he was known as the "King of Inventions".
Edison devoted himself to science and was indifferent to fame and fortune. When developing electric lights, a reporter said to him: "If you can really make electric lights to replace gas lights, you will definitely make a lot of money." Edison replied: "If a person works just to save money, it will be difficult for him to get anything. Nothing else - not even money!" He has always been called the father of modern film, but at a grand banquet held by people in the film industry for his 77th birthday, he said: "As for the development of film, I He only made some technical efforts, and the rest is the credit of others."
Edison was open-minded and good at dealing with adversity. Regarding the inconvenience of his deafness, he said: "Walking among the crowds on Broadway, I can be as calm as a person living deep in the forest. Deafness has always been a blessing to me, and it has saved me a lot of distractions and mental pain." One night in 1914, Edison's film laboratory suddenly suffered a fire, causing huge losses. Edison comforted his extremely sad wife and said: "It doesn't matter, even though I am 67 years old, I am not old.
From tomorrow morning, everything will start again, and I believe that no one will be too old to start working again. "The next day, Edison not only began to build a new workshop, but also began to invent a new light - a portable searchlight to help firefighters move forward in the dark. The fire was like a small episode for Edison.
Edison benefited the public and was not afraid of hardships. In order to find filament, he tested thousands of materials; in order to try out a new battery, he failed eight thousand times. Therefore, Edison often said: "Genius." It’s one percent inspiration and ninety-nine percent hard work. "At the age of 80, he still maintained the spirit of an inventor and carried out invention and creation activities tenaciously. In 1927, he established the Edison Plant Research Company and devoted himself to a new research field to search for new chemical materials. He was 81 years old. Edison successfully extracted rubber from weeds, which was highly praised by people.
At 3:24 in the morning on October 18, 1931, Edison closed his eyes and died at the age of 84. Years old. On his deathbed, he said calmly: "I have done my best for the happiness of mankind; there is nothing to regret. ”
On the day of the funeral, the entire United States turned off the lights for one minute to express condolences. This is the most solemn way for people to express their infinite memory for Edison, and it is also the tribute that people dedicate to this great inventor. A silent hymn.
Albert Einstein was born in Germany in 1879. He made outstanding scientific research achievements, the most outstanding of which was his experimental confirmation of the existence of atoms. The famous German physicist Einstein made outstanding contributions to the development of modern physics throughout his life, and developed the quantum hypothesis proposed by Planck. His most outstanding achievement was his breakthrough in the framework of Newtonian classical physics.
Before Einstein, people had believed since ancient times that although matter existed in time and space, their motion was restricted by time and space. and space are not affected by the distribution and movement of matter. Therefore, time, space, matter, and movement are completely separated and isolated. The genius physicist Newton also believed in this view and proposed absolute time. , the concepts of absolute space and absolute motion. Einstein disagreed with Newton's view of absolute space and time and absolute motion. Starting from the limited speed of light, he proposed that the time simultaneity in the universe is relative and is relative to a certain reference system. , for example, the time of events on the moon is relative to the reference system of the earth. On the basis that simultaneity is relative, he denied Newton's concepts of absolute time, absolute space and absolute motion because the simultaneity of time is all. Relative to a certain reference system, they are all relative; and movement is closely connected with time, so movement is also relative. Looking at the earth in isolation, its movement does not exist; space and time are closely connected, so absolute space does not exist. Therefore, Einstein connected time and space that seemed to be unrelated to each other, making them a closely related unity of opposites, and founded the concept of space in 1905. Special Theory of Relativity.
In 1916, after another 10 years of exploration, Einstein further completed the creation of the general theory of relativity. General relativity is a new theory of gravity that is applicable to all reference systems. Law. It is different from the special theory of relativity, which is only applicable to physical processes without gravity. It studies the reference system of straight line and uniform relative motion; while the general theory of relativity studies the reference system of any motion, which is suitable for straight line and uniform speed. The reference frame of motion is also adapted to the reference frame of accelerated motion and rotational motion, so it is the second floor of the building of relativity. The general theory of relativity further shows that time and space are not isolated, and the distribution and motion of matter also determine time. and the structure of space. They also interact with each other and are a unity of opposites. Einstein's theory of relativity is the most significant achievement of modern science and technology in the fantasy century. It led to a complete revolution in ancient physics and completed physics. The third theoretical synthesis further laid the foundation for the development of modern physics