Some scientific and technological inventions time

Telegraph 1838 Samuel Morse invented the telegraph receiver, which alternately turns on and off the current to generate different signals, namely dots, dashes and blanks. He used the combination of these three different signals to create a code expressing 26 letters and numbers, which is the Morse code that will be used all over the world in the future. Telephone 1876 Bell, an American youth, invented the first telephone that transmitted sound through a vibrating reed. He vibrates the reed with sound, and the electromagnet near the reed immediately turns the vibration into a current with different strengths. The current is transmitted to the receiver through the wire, and then the other reed is vibrated by an electromagnet to turn the electrical signal into sound again. From then on, human voice can be transmitted to distant places through wires. Edison, the great inventor of the electric light bulb, began to study the light produced by electricity in 1877. He found that the resistor would heat up and glow after heating, so he invented the electric light bulb. Radio Communication 1864 Mark Schweier, a scientist at Cambridge University, combined the knowledge of electricity and magnetism to prove the existence of radio waves in theory. 1894 Italian Marconi made the first radio transmitter. His design can send a series of radio waves into the air. Because there is no need to connect sending and receiving equipment with wires, this technology has become a famous radio communication. Invention of internal combustion engine with ore receiver In the second scientific and technological revolution, in addition to the development and application of electric power technology, another representative scientific and technological achievement was the invention of internal combustion engine. Internal combustion engine is a power machine in which fuel burns directly in the cylinder, and the piston or rotor is driven to do work by the high temperature and high pressure gas generated during combustion. It is widely used in trucks, tractors, buses, ships and locomotives, and has become the main driving force of transportation.