What were the major discoveries and inventions of mankind in the last century?
The airplane is one of the most important inventions in the early 20th century, and it is generally believed that it was invented by the Wright brothers in America. Their flight on 1903 17 February 17 was recognized by the International Aviation Federation (FAI) as "the first controlled sustained power flight of heavier-than-air aircraft", and in the same year they founded Wright Aircraft Company.
Since the invention of the airplane, it has become an indispensable means of transportation for modern civilization. It profoundly changed and influenced people's lives and opened the history of human conquest of the blue sky.
2. Computer
John von neumann, the inventor of the computer. Computer is one of the most advanced scientific and technological inventions in the 20th century, which has had an extremely important impact on human production and social activities, and has developed rapidly with strong vitality.
Its application field has expanded from the initial military scientific research application to all fields of society, forming a huge computer industry, promoting global technological progress and triggering profound social changes. Computers have spread all over ordinary schools, enterprises and institutions, entered the homes of ordinary people and become an indispensable tool in the information society.
3. penicillin
Before the 1940s, humans had not mastered a drug that could effectively treat bacterial infections with little side effects. At that time, if someone got tuberculosis, it meant that the person was going to die soon.
In order to change this situation, researchers have made a long-term exploration, but the breakthrough in this respect stems from an unexpected discovery. ?
In modern times, British bacteriologist Fleming first discovered the world's first antibiotic-penicillin in 1928, and alexander fleming discovered penicillin by a lucky mistake.
1928, British scientist Fleming discovered penicillin for the first time in experimental research. However, due to the lack of advanced technology and in-depth understanding at that time, Fleming did not isolate penicillin alone.
From 65438 to 0929, Fleming published his research results. Unfortunately, this paper has not been paid attention to by the scientific community since it was published.
When observing the Petri dish with a microscope, Fleming found that the staphylococcus colonies around the mold had dissolved. This means that some secretions of mold can inhibit staphylococcus.
Subsequent identification showed that the above mold was Penicillium punctatum, so Fleming called its antibacterial substance penicillin. But unfortunately, Fleming has not been able to find a way to extract high-purity penicillin.
So he cultured Penicillium strains for generations, and provided them to British pathologist Howard Walter Flory and biochemist Ernst Boris ernst boris chain in 1939. ?
1938, the German chemist Ernst Boris ernst boris chain saw Fleming's paper in an old book, and began to do purification experiments.
Flory and Ernst Boris ernst boris chain re-experimented with penicillin in 1940. They injected eight mice with a lethal dose of Streptococcus, and then only four of them were injected with penicillin. Within a few hours, only four mice treated with penicillin were still alive and well.
Since then, a series of clinical experiments have confirmed the efficacy of penicillin on streptococcus, diphtheria and other bacterial infections. Penicillin can kill bacteria without damaging human cells, because penicillamine contained in penicillin can hinder the synthesis of bacterial cell walls, leading to the dissolution and death of bacteria, while human and animal cells have no cell walls.
/kloc-in the winter of 0/940, Ernst Boris ernst boris chain extracted a little penicillin, which was a major breakthrough, but it was still far from clinical application.
194 1 year, the baton of penicillin purification was passed to Australian pathologist Walter Flory. With the assistance of the U.S. military, Flory isolated strains from the soil brought back by pilots from airports around the world when they went out to perform tasks, which increased the output of penicillin from 2 units per cubic centimeter to 40 units.
About 194 1 years ago, pathologist Howard Walter Florey Baron Florey and biochemist Ernst Boris ernst boris chain of Oxford University in England realized the separation and purification of penicillin and found its curative effect on infectious diseases. However, penicillin can cause allergic reactions in individuals, so skin tests must be carried out before application.
Most of the antibiotics used are extracted from microbial culture solution, and some are artificially synthesized. Because of the different chemical compositions of different kinds of antibiotics, their mechanisms of action on microorganisms are also very different, some inhibit the synthesis of protein, some inhibit the synthesis of nucleic acids, and some inhibit the synthesis of cell walls.
After a period of intense experiments, Flory and ernst boris chain finally extracted penicillin crystals by freeze-drying. Later, Flory discovered a mold that could extract penicillin from a melon in large quantities, and prepared the corresponding culture solution with corn flour. Driven by these research results, American pharmaceutical companies began to produce penicillin on a large scale on 1942.
By 1943, pharmaceutical companies had discovered the method of mass production of penicillin. At that time, Britain and the United States were at war with Nazi Germany. This new medicine is very effective in controlling wound infection.
1943 10, Flory signed the first batch of penicillin production contracts with the US military. Penicillin was born at the end of World War II, which quickly reversed the war situation of the Allies. After the war, penicillin was widely used, saving tens of millions of lives.
By 1944, the supply of medicine was enough to treat all allied soldiers who participated in the war during World War II. Because of this great invention, Fleming, Flory and Qian En won the 1945 Nobel Prize in Physiology or Medicine for "discovering penicillin and its clinical effects".
4. Satellite TV
The inventor of TV set is john baird, a British electronic engineer. In 1923, he applied for a patent for a device that can generate 8 lines of images. The first TV set was sold at the end of 1930.
1932, BBC broadcast the first standardized TV program in the world. Since then, mankind has begun to step into the television era. Today, people use satellites and other channels to spread TV signals to every corner of the earth.
Nowadays, the per capita possession of TV in the world is extremely high (one per 10 people on average), which started at 1927 and started in the hands of Americans.
5、DNA
1953DNA, on February 28th, the famous British geneticist francis crick announced that he had "discovered the secret of life".
Crick and his American colleague james watson devoted themselves to the research of life science for many years, and finally found the molecular structure of DNA double helix which determines the inheritance of life from the nucleus, and deciphered the genetic codes of human beings, plants and animals.
This discovery initially revealed the secret of life, promoted the research and treatment of various diseases, and also promoted human research on improving food structure. In the first 20 years of the next century, it is possible for human beings to eliminate gene defects through gene therapy, and then overcome fatal sexual dysfunction such as cancer, heart disease, hemophilia and diabetes.
Undoubtedly, the research results of DNA molecular structure have played a great role in studying life and treating diseases, but it also makes people face the moral crisis caused by it. For example, the development of cloning technology has given mankind a difficult problem.
Baidu Encyclopedia-Invention of the 20th Century