In the early 2th century, few people could imagine that an electromagnetic wave could travel any meaningful distance without any metal wire or cable as conductor. So how can a radio signal travel along the surface of the earth? Of course, it can shoot off the horizon in a straight line. But Guglielmo Marconi believes that radio waves can travel along the surface of the earth if some conditions are provided. In 1895, in his birthplace of Italy, he sent a radio signal and traveled 15 miles. Six years later, on December 12, 191, Marconi, who was only 27 years old, created a miracle. He tied the radio antenna firmly to a flying kite and launched a Morse code "S". It traveled about 2 miles across the Atlantic Ocean. This signal was sent from Huzhen, Polder, Cornwall, England, and reached St. John's in Newfoundland in less than one second. Marconi heard three faint ticks. This is the voice of the birth of the communication industry and the first shock wave of the arrival of the electronic age. This era includes radio broadcasting, television and cellular phones-so this is a discovery that will open our imagination.
The plane in 193
On December 17th, 193, Orville Wright and Wilbur Wright had been able to fly their plane made of wood, wires and cloth for 59 seconds before the sun went down. However, few newspapers are willing to comment on this matter, because the idea that human beings fly into the sky to become contemporary Daedalus and Icarus is considered ridiculous by most sober people. But once successful, the development of this cause is extremely rapid. In fact, only 15 years later, if not all the components of all modern aircraft have been made, then at least the idea about them has been born.
Plastics in p>197
After learning about the invention of plastics, the happiest thing in the world is the elephant. For hundreds of years, everything from the handle of a knife to billiards has been made of ivory. In the 198s, the gradual decrease of ivory supply and the rise of billiards triggered a crisis. Phelan and Cowland, the largest billiards producers in the United States, can't wait to offer a reward of $1, worth of gold-a considerable reward-to recruit any "invention genius" who can provide synthetic products instead of ivory.
Until 197, Leo Baekeland, a Belgian inventor who had made huge profits by inventing photographic paper for taking fast-moving photos, accidentally invented the compound of phenol and formaldehyde. This innovative pure synthetic plastic, phenolic plastic, has the functions of heat protection, electricity protection and corrosion protection. Not only does it benefit billiards, but one of the great benefits of plastic lies in its versatility. From telephones to toilets, from ashtrays to airplane parts, everything uses plastic. By 1968, if young graduates want to find a job in a promising and successful industry, they must listen to one word-plastic.
Penicillin in p>1928
People said that penicillin was the most contribution medicine in this century, and its inventor was British bacteriologist alexander fleming. In 1928, the inventor accidentally discovered in a bacterial culture experiment that a mold later called penicillin was devouring the bacteria he had cultivated in a Petri dish. According to the results of Fleming's research, researchers at Oxford University in England have finally found a way to refine this mold after ten years of hard work, and put it into medical treatment experiments. In 1943, in order to treat soldiers wounded in World War II, the Allies began to put penicillin into industrial production. In more than half a century, penicillin has saved countless lives and prompted people to pay attention to the research and development of antibiotic family.
in 1923, the inventor of the TV set
was john baird, a British electronic engineer. In 1923, he applied for a patent for his own device that could produce 8-line images. The first TV set was sold at the end of 193. In 1932, the BBC broadcast the world's first standardized TV program. From then on, mankind began to step into the television era. Today, people use satellites and other channels to spread TV signals to every corner of the earth.
the atomic age of nuclear weapons in 1942
began in 1942. In order to defeat the Axis fascism, the highest authorities in the United States decided to start the Manhattan Project aimed at developing atomic weapons. At the end of the year, as part of "Manhattan Project", the first nuclear reactor was built and put into operation under a sports facility of the University of Chicago. On July 16th, 1945, a mushroom cloud rose from the Los Alamos Atomic Energy Research Center in New Mexico, USA, and the world's first atomic bomb exploded successfully. On August 6th and 9th of that year, the United States dropped two atomic bombs named "Fat Man" and "Little Boy" on Hiroshima and Nagasaki in Japan. The Japanese emperor then announced his unconditional surrender. The atomic bomb seemed to have made great contributions to the victory of World War II, but mankind has since lived in the shadow of terrible atomic weapons.
Computers in p>1943
Computers were the foundation for human society to enter the information age, but they were born because of the war. In 1943, in order to decipher the German code, the British mathematician alan turing designed the first electromechanical computer named "Giant". Although it was only an imaginary computer for decoding, it pioneered the development of computer technology, and the development of computer technology changed with each passing day. In 1947, the transistor computer came out; In 1959, the integrated circuit computer was born; In 197, large-scale integrated circuits were produced by computers; Since the 198s, a new generation of microcomputers has sprung up. On this basis, mankind has ushered in a new era of network.
1953 DNA
On February 28th, 1953, the famous British geneticist francis crick announced that he had "discovered the secret of life". Crick and his American colleague, james watson, have been devoted 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 2 years of the next century, it is possible for human beings to eliminate genetic defects by gene therapy, and then overcome cancer, heart disease, hemophilia, diabetes and other fatal dysfunction. Undoubtedly, the achievements of human research on the molecular structure of DNA play a great role in human research on life and treatment of diseases, but it also makes people face the moral crisis caused by it. For example, the development of cloning technology has given human beings a difficult problem.
In 1954, the contraceptive pill:
In 1954, American doctor gregory pincus invented the contraceptive pill, which is a mixture of two hormones that inhibit ovulation in women. The reason why the contraceptive pill is listed as one of the greatest scientific achievements in the 2th century is that it liberates women from passive fertility. From then on, women can control their fertility independently, 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 them the right to go out of the family to participate in social work, and finally expands women's influence in social politics, economy and culture.
artificial satellite in 1957
On October 4, 1957, the Soviet Union launched the first artificial earth satellite in human history to commemorate the 4th anniversary of the victory of the October Revolution, marking the beginning of the space age. On April 2, 1961, Soviet astronaut Gagarin went into space by spaceship and became the first person to go into space. On July 2, 1969, two American astronauts landed on the moon in a spaceship. Satellites can transmit TV and radio program signals, and also provide services for aviation, Hainan Airlines, weather forecast and scientific and technological information, thus greatly "shrinking" the earth. In order to further explore the mysteries of the universe, humans have put many probes on the main planets of the solar system, and a grand plan to establish an international space station is also in the pipeline.
organ transplantation in 1967
In 1967, Christian Barnard, a South African surgeon, successfully performed the first heart transplant. Since then, with the more and more advanced medicine and medical equipment, medical scientists have gradually solved the problems such as infection of transplanted organs and successfully transplanted limbs, liver, skin, retina and even testis. The medical community believes that the next frontier technology of organ transplantation is brain cell transplantation, which can cure medical stubborn diseases such as Alzheimer's disease and Parkinson's disease. In the next century, medical scientists will devote themselves to solving the problem of xenotransplantation and transplanting organs from other animals into human bodies.
1978 IVF:
British girl Louise Brown was the first IVF in the world, and now she is 21 years old. At that time, her mother's egg and her father's sperm were successfully mated in a test tube, which gave birth to her. Since then, the technology of in vitro pregnancy has been continuously developed and perfected. In 1984, the experiment of embryo freezing technology was successful. In 199, the experiment of embryo transfer technology was successful. The successful cultivation of IVF has given great hope to infertile couples, but it has also aroused people's worries about a moral issue. For example, if a woman gives birth to a child through IVF in her fifties or even sixties, the old man may die while the child is still underage. So who will raise the orphan?