Bell applied for a patent for the invention of the telephone.
Bell was born into a family of linguists. 1864, 17-year-old Bell began to study acoustics. From 65438 to 0869, Bell, 22, was employed by Boston University to teach phonetics. 1872, 25-year-old Bell started a school in Boston to train deaf-mute teachers and wrote a book "A Guide to Visual Language". From 65438 to 0873, 26-year-old Bell became a professor of vocal physiology at Boston University.
Once, when Bell was doing an experiment on "visual language" for the deaf-mute, he found that when the current passed and blocked, the spiral coil would make noise, just like the "tick" sound when the telegraph sent Morse code. Then, Bell thought that electricity might make a sound. As long as the intensity of current changes to simulate the sound wave changes when people speak, then the current can transmit the sound made by people.
Young Bell told his friends in the field of electricity, but most of them didn't think it was his fantasy. Only Henry, the master of electromagnetism, encouraged and supported him to continue his experiment. So Bell and his assistant Watson started the experiment. They made two prototypes, that is, covering the bottom of a cylinder with a film, connecting a carbon rod in the center of the film and inserting it into sulfuric acid solution. In this way, when people talk to it, the film vibrates, the contact resistance between carbon rod and sulfuric acid changes, and the current also changes; When receiving, due to the change of current, changing sound waves are generated. Therefore, sound transmission is realized.
However, there is still no communication between the two prototypes. One day, Bell frowned at the window and meditated. Suddenly, there was melodious guitar sound in the distance. This inspired him, so he added a speaker to the prototype to improve the sensitivity of the sound.
1On June 2nd, 875, Bell experimented on the prototype with a sound box. Watson is at the other end of the room. Suddenly, Bell accidentally spilled sulfuric acid on his leg during the operation. He couldn't help shouting, "Watson, come and help me!" " "
"Yes, yes!" Watson ran happily from the other end of the prototype and hugged Bell tightly without looking at his leg. Bell also forgot his leg injury and murmured, "it worked, it worked!" "
1876 February 14, Bell applied for the telephone patent right in the US Patent Office; 10 In March, Bell obtained a patent for telephone invention, announcing the arrival of a new era of mankind.
Bell, 29, invented the telephone. Two years later, on 1878, Bell established a telephone company, and realized the long-distance telephone test between Boston and new york, which are 300 kilometers apart. Since then, the telephone has spread rapidly in major cities in North America, and quickly swept the world.
Bell has made outstanding contributions in the fields of acoustics and electricity, and obtained more than 30 patents, half of which are telephones. His name "Zhong" was later used as a unit for measuring sound intensity level in acoustics, and it was also used in electricity to calculate the ratio of current or voltage and the ratio of output to input power.
Other inventors Gray and mutch.
However, Bell was not the only one who invented the telephone. A man named Gray once filed a lawsuit with Bell over the telephone patent right. They filed the patent on the same day, but Graybeal Bell was about two hours late and finally lost the case.
It is worth mentioning that Antonio mutch, the "inventor of the telephone" who changed his name in the 2nd/Kloc-0th century, fought a marathon lawsuit with Bell for the right to invent the telephone.
Mutch/Kloc-0 was born in Florence in April, 808, and/Kloc-0 moved to the United States in August, 845. In order to improve his living environment, he began to study electrophysiology, and he was very interested in it. Soon, he invented the method of treating diseases by electric shock. People don't know whether this informal treatment is really successful, but on 1849, when he prepared a set of equipment for his friend in another room, an unexpected miracle appeared. He clearly heard his friend's voice coming from the other room through the wire connecting the two rooms. At that time, he inserted a metal reed connected with a coil into a friend's mouth, and the coil was connected to a conductor in another room. In fact, the metal reed plays the role of a sensor here. It is because it is connected with the coil that its vibration is converted into current. Mutch immediately realized the unusual significance of this phenomenon, and immediately began to study what he called the "talking telegraph" device. At that time, his future competitor Bell was only 2 years old.
In 1854, mutch made the first prototype that worked like a telephone. He once described it like this: "This is a vibrating diaphragm, which changes the current on the electromagnet. This change in current, when it reaches the other end of the wire, will transfer the same vibration to the receiving diaphragm, and it will be restored to text. "
The following year, mutch's telephone was named "long-distance telephone". At the same time, the equipment is still being further improved: at first, the rough coil has been replaced by the combination of magnetic coil and diaphragm. In addition, mutch also envisages strengthening the signal multiplier along the route to avoid the gradual attenuation of long-distance transmission signals.
1860, mutch published an introduction about the telephone prototype in an Italian newspaper in new york, but he didn't apply for a patent for invention, because it cost 250 dollars to apply for a patent in the United States at that time, and mutch was poor and didn't know English, so he couldn't integrate into American society. /kloc-in 0/870, Qi Mu, who was over 60 years old, was seriously ill. In order to treat the disease, he had to sell his hard-made telephone equipment for 6 yuan. From 65438 to 0873, mutch lived in poverty and had to live on social welfare. 1874, mutch sent his telephone equipment to Western Union for sale, but the equipment was lost by Western Union. Later, Bell signed a contract with Western Union, and mutch went to court for a lawsuit, which dragged on for a long time because of insufficient evidence. 1889, just as there was a rumor that Mucci was going to win the right of telephone invention, poor him died. It was not until 1 13 that Mu Qi was approved by the US Congress for his invention right.
Telegraph American Morse invented the telegraph in the 1930s.
Tram German engineer von Siemens 188 1 laid the first tram track in the suburbs of Berlin, electrified by one rail and surrounded by another. But this kind of line is too dangerous for the traffic on the street, so Siemens solved the power supply and safety problems by raising the transmission line. 1884, American C. J. Vanderbilt tried to carry passengers by tram at the Toronto agricultural exhibition. The tram he tried was to transmit electricity by collecting poles with contact wheels and overhead contact lines, and the rail was used as another loop. 1888, spola, an American, used the above method to switch to electric tractors on several horse-drawn rail cars in Richmond, and improved the current collector, control system, motor suspension mode and driving mode of the vehicles, so modern trams appeared. As the leader of electric vehicles in China and the advocate of "green transportation", we independently designed and developed electric bicycles as early as 1996. In order to obtain the living space of the industry, we "noisy" from one city to another to promote these cities. ...
Electric light Edison, USA
John von neumann, the inventor of the computer.
Computer, commonly known as computer, is an electronic computer for high-speed calculation, which can be used for numerical calculation, logical calculation and memory storage. It is a modern intelligent electronic device that can run according to the program and automatically process massive data at high speed. It consists of hardware system and software system, and a computer without any software is called bare metal. It can be divided into five categories: supercomputer, industrial control computer, network computer, personal computer and embedded computer. More advanced computers include biological computers, photonic computers and quantum computers.
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.