At the beginning of the 20th century, almost no one could imagine that electromagnetic waves could travel any meaningful distance without any metal wires or cables as conductors. So how do radio signals travel along the surface of the earth? Of course, it can shoot straight out of the horizon. But Guillermo Marconi believes that radio waves can travel along the surface of the earth if some conditions are provided. In his birthplace of Italy, he introduced a radio in 1995. Six years later, that is, 190 1 12 years later, Marconi, who was only 27 years old, created a miracle. He tied the radio antenna firmly to a flying kite and sent a Morse code "S". It flew about 2000 miles across the Atlantic. This signal comes from Cornwall, England. Less than 1 sec, he arrived in St. John's, Newfoundland, and Marconi heard three faint ticks. This is the voice of the birth of communication and the first shock wave in the electronic age. This era includes radio broadcasting, television and mobile phones-so this is a discovery that will open our imagination.
1903 aircraft
In February 17, Orville Wright and wilbur wright flew their plane made of wood, wires and cloth for 59 seconds before sunset. However, few newspapers are willing to comment on this matter, because the idea that humans fly into the sky and become contemporary Daedalus and Icarus is ridiculous to most sober people. The development of this undertaking is extremely rapid. In fact, only after 15 years, all parts of modern aircraft have been manufactured, if not all, then at least ideas about them have been born.
1907 plastics
After learning about the invention of plastic, the happiest thing in the world is the elephant. For hundreds of years, everything from the handle to billiards has been made of ivory as the standard raw material. In 1980s, the gradual decrease of ivory supply and the rise of billiards triggered a crisis. Phelan and Cowland, the largest billiard makers in the United States, can't wait to offer a reward of $6,543,800+gold-a considerable sum.
Until 1907, the Belgian inventor Leo Baekeland, who had made huge profits by inventing photographic paper for taking fast-moving photos, accidentally invented the compound of phenol and formaldehyde. The first pure synthetic plastic, phenolic plastic, has the functions of heat protection, electricity protection and corrosion protection. It is not only beneficial to billiards games, but also benefits from its versatility, from telephones to toilets. Everything from ashtrays to airplane parts is made of plastic. By 1968, if young graduates want to find a job in a promising and successful industry, they must listen to one word-plastic.
1928 penicillin
People call penicillin the most contributing drug in this century. Its inventor is British bacteriologist alexander fleming. 1928. In a bacterial culture experiment, the inventor accidentally found that a mold later called penicillin was devouring the bacteria he had cultivated in a Petri dish. According to Fleming's research results, after ten years' efforts, researchers at Oxford University in England finally found a way to extract this mold. 1943, in order to treat soldiers injured in World War II, the Allies began to put penicillin into industrial production. For more than half a century, penicillin has saved countless lives, prompting people to pay attention to the research and development of antibiotic family.
1923 TV set
The inventor of television is john baird, a British electronic engineer. 1923, he applied for a patent for equipment that can produce 8 lines of images. At the end of 1930, the first TV set was sold. 1932, BBC broadcast the first standardized TV program in the world. Since then, mankind has entered the television era. Today, people use satellites and other means to transmit TV signals.
1942 nuclear weapons
The atomic age began at 1942. In order to defeat the Axis fascism, the highest authorities in the United States decided to launch the Manhattan Project aimed at developing atomic weapons. At the end of the year, as part of the Manhattan Project, the first nuclear reactor was built and put into operation under a sports facility of the University of Chicago. 1July, 945 16, the mushroom cloud rose from the atomic energy research center in Los Alamos, New Mexico, USA, and the world's first atomic bomb exploded successfully. 1On August 6th and 9th, 998, the United States dropped two atomic bombs named "Fat Man" and "Little Boy" on Hiroshima and Nagasaki, Japan. The Japanese emperor then announced his unconditional surrender. The atomic bomb seems to have made great contributions to winning World War II, but mankind has since lived in the shadow of terrible atomic weapons.
1943 computer
Computer is the foundation of human society entering the information age, but it was born because of war. In order to decipher the German code, British mathematician alan turing designed the first electromechanical computer named "Giant". Although it is only a virtual computer for decoding, it pioneered the development of computer technology. Since then, computer technology has developed with each passing day. 1947, transistor computer came out. 1959, the integrated circuit computer was born; 1970, computer produced large-scale integrated circuits; Since 1980s, a new generation of microcomputers have mushroomed. On this basis, mankind has ushered in a new network era.
1953DNA
1953 On February 28th, the famous British geneticist francis crick announced that "the secret of life has been discovered". 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 decoded the genetic codes of human beings, plants and animals. This discovery initially revealed the secret of life. It has promoted the research and treatment of various diseases, and also promoted the research on improving food structure. In the first 20 years of the next century, human beings may eliminate gene defects by using gene therapy, and then overcome fatal sexual dysfunction such as cancer, heart disease, hemophilia and diabetes. The research results of human DNA molecular structure are undoubtedly of great significance to human life research and disease treatment, but it also makes people face the moral crisis caused by it, such as the development of cloning technology.
1954, Contraceptives:
1954, American doctor gregory pincus invented the contraceptive pill, which is a mixture of two hormones that inhibit ovulation in women. Contraceptive pill is listed as one of the greatest scientific achievements in the 20th century because it liberates women from passive childbearing. From then on, women can control their own fertility, decide whether to have children according to their own wishes, and decide when to get pregnant according to their own situation. More importantly, it breaks the shackles that imprison women's sexual freedom, gives women the right to leave home and participate in social work, and finally expands women's influence in social politics, economy and culture.
1957 artificial satellite
1957, 10 On April 4th, the Soviet Union launched the first artificial earth satellite in human history to commemorate the 40th anniversary of the victory of the October Revolution, marking the beginning of the space age. On April 2, 2008, Soviet astronaut Gagarin went into space in a spaceship, becoming the first person to go into space. Two American astronauts landed on the moon in a spaceship. Satellites can transmit TV and radio signals, and also provide services for aviation, Hainan Airlines, weather forecast and scientific and technological information, thus greatly reducing the size of the earth .48666.668666666086 In order to further explore the mysteries of the universe, human beings have placed many detectors on the main planets of the solar system, and grand plans to build an international space station are also in the pipeline.
1967 organ transplantation
From 65438 to 0967, South African surgeon Christiaan Barnard successfully performed the first heart transplant. Since then, with the development of medicine and medical equipment, doctors have gradually solved the problem of organ infection and successfully transplanted limbs, liver, skin, retina and even testicles. The medical community believes that the next frontier technology of organ transplantation is brain cell transplantation, in order to cure medical ills such as Alzheimer's disease and Parkinson's disease.
1978 IVF:
Louise Joy Brown, a British girl, is the first test-tube baby in the world. Now she is 2 1 year old. That year, her mother's egg and her father's sperm successfully mated in a test tube and gave birth to her. Since then, in vitro pregnancy technology has been continuously developed and perfected, and 1984 embryo freezing technology has been successfully tested. 1990, the experiment of embryo transfer technology was successful. The successful cultivation of IVF gives great hope to infertile couples, but it also causes people's worries about a moral problem. For example, when a woman gives birth to a child through a test-tube baby in her fifties or even sixties, it is possible that the old man will die while the child is still underage. So who will raise the orphan?
Take it.