What did humans invent in the 20th century and who invented it?

Marconi invented radio communications, Willis Carrier invented air conditioning, John Baird invented satellite television, Gregory Pincus invented the contraceptive pill, Alan Turing Invented the computer.

1. Radio communication

Radio communication refers to an electronic communication tool that can transmit information without wires. It was invented by Marconi in Italy and Popov in Russia. Like the telephone, wireless telegraphy was a communication tool invented after numerous early improvements.

At the end of the 19th century, three people made significant contributions to the development of wireless telegraphy technology. James Clerk Maxwell, a professor of experimental physics at the University of Cambridge in the United Kingdom, used mathematical methods to prove in 1864 that electric waves can produce effects at considerable distances (electrical signals are not limited to wire transmission).

Maxwell also predicted that this signal or electromagnetism would proceed at the speed of light. For the next 22 years, wireless communications remained theoretical. In 1888, German physicist Henrich Hertz's experiments proved that Maxwell's conclusion was correct.

He installed two conductors in the center of a parabolic metal mirror, separated by a gap, to form a so-called spark gap arrester. About five feet away, another coil was connected to a discharger at the focus of another parabolic collector, aimed at the first metal mirror.

Hertz found that when the first discharger fired a spark, it caused a smaller spark from another discharger in a coil five feet away. Hertz also proved that radio electromagnetic waves move in straight lines and can be reflected by thin metal sheets, just like light waves can be reflected by mirrors. Therefore, there is no doubt that wireless telegraphy is a feasible concept.

Building on this success, the Italian physicist Guglimo Marconi repeated Hertz's experiments at the Villa Graywind in his hometown of Pontegio, near Bologna. He went further than Hertz and obtained a spark from a second discharger 30 feet away that was consistent with the spark from the first discharger.

This is indeed a major scientific and technological achievement, but telegraphs still cannot be transmitted over such short distances. Marconi revised his design many times, gradually increasing the propagation distance to 300 yards and 2 miles, and finally crossed the English Channel in 1899. This is closer to what the early dreamers of wireless telegraphy were trying to achieve.

In 1901, Marconi used Morse code to send letters and signals across the Atlantic Ocean, proving the unlimited potential of radio waves. The signal was transmitted from Purdeaux, Cornwall, to St. John's, Newfoundland, Canada, using metal wires connected to kites as receiving antennas, a distance of nearly 2,000 miles. This marks that wireless telegraphy has practical application value.

2. Air conditioning

In late 1902, the first modern, electrically powered air conditioning system was invented by Willis Carrier (1876-1950). The difference between its design and Wolff's design is that it not only controls the temperature, but also controls the humidity of the air to improve the quality of the production process at a printing factory in Bucklin, New York.

This technology provides a low heat and humidity environment, making the paper area and ink arrangement more accurate. Later, Carrier's technology began to be used in the workplace to improve production efficiency, and the Carrier Engineering Company was established in 1915 to cope with the surge in demand.

With gradual development, air conditioning began to be used to improve the comfort in homes and cars. Sales of residential air conditioning systems didn't really take off until the 1950s.

Willis Carrier is known as the "Father of Air Conditioning" by future generations because of his great contribution to the air conditioning industry.

3. Satellite TV

The inventor of television was British electronic engineer John Baird. In 1923, he applied for a patent for his device that could produce 8-line images. .

The first television set was sold at the end of 1930. In 1932, the British Broadcasting Corporation broadcast the world's first regulated television program. Since then, mankind has entered the television era. Today, people use satellites and other means to spread television signals to every corner of the earth.

Television TV, which has a very high per capita ownership in the world (one for every 10 people on average), began in 1927 and was made by Americans.

4. Contraceptive pills

In 1954, American physician Gregory Pincus invented the contraceptive pill, which is a mixture of two hormones that inhibit female ovulation. The birth control pill ranks among the greatest scientific achievements of the twentieth century.

The reason is that it liberates women from passive reproduction. 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 circumstances.

More importantly, it breaks the shackles that restrict women’s sexual freedom, empowers them to go out of the family and participate in social work, and ultimately expands women’s influence in social politics, economy, culture and other aspects.

5. Computer

The computer is the foundation for human society to enter the information age, but it was born because of war.

In 1943, in order to decipher the German code, the British mathematician Alan Turing designed the first electromechanical computer called "Giant". Although this was only a hypothetical computer for decoding, it pioneered computer technology. The first of its kind, computer technology has developed rapidly since then.

In 1947, the transistor computer was born; in 1959, the integrated circuit computer was born; in 1970, the large-scale integrated circuit computer was produced; starting in the 1980s, a new generation of microcomputers emerged. On this basis, mankind has ushered in a new era of the Internet.

Baidu Encyclopedia - 20th Century Invention