"Your Majesty, Madam, if you listen carefully, you will find that this telegraph machine can actually emit two sounds. One is such a short sound. The person on the other side can record this signal as a point when receiving it. It is pronounced as "dip", and there is also a long sound that can last for a certain period of time. When the person on the other side receives this mark, he can mark it as a horizontal line, which is pronounced as "dah". Your Majesty and your empress can listen carefully. Listen!"
Zuifengxuan.
In order to explain the message transmission mechanism of the telegraph to Li Er and Chang Sun, Li Zexuan explained the principle while personally operating the telegraph. In fact, the principle is very simple. It is nothing more than the length of time the key is closed. The control telegraph machine sends two different signals.
"Well, that's true, but just relying on these alone, I'm afraid it can't convey the message, right?"
When Li Er saw Li Zexuan's demonstration, he was amazed at the magic of the telegraph machine and asked doubtfully.
"Your Majesty, these two monotonous signals alone cannot fully express what both parties want to express. This telegraph machine also needs to be used in conjunction with the code book."
Li Zexuan explained with a smile.
"What is a codebook? You kid can't finish the sentence in one go?"
Li Er frowned and said displeasedly. He dared to deliberately try to make a bridge in front of him. This kid is really brave~!
"Well, back to Your Majesty, I just said that the two signals sent by the telegraph machine can be recorded as dots and horizontal lines. I later combined these dots and horizontal lines with each other. Each combination represents a number, such as Say one dot and four horizontal lines represent the number "1", and so on for the rest of the numbers. There are ten numbers in total. Then the transmitter can combine the four numbers with each other to represent a word. In this way, there are ten thousand ways. The combination method, that is to say, through this method, ten thousand different words can be expressed! And the words corresponding to each combination are the code books that Xiaochen mentioned!"
Li Zexuan stood with his hands behind his back and talked a little pretentiously. What this guy is thinking is that it is a rare opportunity to show off in front of Li Er. If he doesn't pretend, it will be in vain.
In fact, what he just mentioned is the famous Morse code in the modern history of the world. In 1832, Russian diplomat Schilling built a machine that used the deflection of the galvanometer pointer to receive information. Later, in 1835, after three years of study, the American painter Morse successfully used the "on and off" and "length" of electric current to replace human words for transmission.
Morse code is an early form of digital communication, but it is different from modern binary codes that only use two states: zero and one. Its code includes five types: dots, dashes, pauses between dots and dashes, and pauses between dots and dashes. Short pauses between characters (between dots and dashes), medium pauses between each word, and long pauses between sentences. Then using different combinations of dots and dashes to represent twenty-six English letters and ten Arabic numerals, communication can be perfectly achieved.
Later, Morse code was introduced to China and went through some improvements. It is almost like what Li Zexuan just said, but it is based on the original with some more combinations.
Li Er was frowning and thinking, but he didn't notice Li Zexuan's look of needing a beating, otherwise he would have to give them two big feet. Empress Changsun accidentally caught a glimpse of Li Zexuan's expression, and she couldn't help but want to laugh.
"I see! This idea of yours is really good! But according to what you said, the so-called code book can be changed at will?"
Li Er himself is a man of great wisdom. Putting aside the electromagnetic knowledge that does not belong to this era, he can still understand the principles of these code combinations.
"Your Majesty is really discerning! As His Majesty said, this codebook can be changed at will according to needs. As long as both parties sending the message use the same codebook, there will be no problem! Officially due to the ever-changing characteristics of telegraph codes, only It ensures the security of the messages that two people send to each other, so that even if the message is intercepted by others, others will not know what the messages mean when they look at the dots and dashes!"
Li Zexuan's eyes lit up when he heard Li Er's question. He secretly thought that the ancients were not fools either. What he had more than them was just some knowledge.
"Ha~! Stop flattering me, kid! Oh, based on what you just said, can the message sent by this telegraph machine be intercepted by others?"
Li Er felt secretly happy in his heart, but he smiled and cursed on his face, but he was a little puzzled. When he thought about it, the message sent by the telegraph machine was silent and invisible during the transmission. How could it be intercepted
"Your Majesty, the telegraph machine transmits information, which is actually equivalent to the military messenger transmitting military information through text. There is a possibility of being intercepted! All you need is a high-power telegraph receiver, and then adjust the receiving frequency of the telegraph receiver to With the corresponding waveband, you can capture the telegram information sent by others. Of course, this is only a theoretical possibility of being intercepted, because Xiao Chen is the only one in the world who is proficient in the production principles of telegraph machines!"
Nothing can be invincible. Although the electromagnetic waves emitted by telegraph machines are invisible and silent, they can still be captured with the right methods. In some Anti-Japanese War TV series, plots about underground parties intercepting and deciphering enemy telegrams often appear. !
"In the army~~"
Li Er's heart moved and he murmured to himself. Although he didn't know what "power", "frequency" and "band" were, it did not prevent him from obtaining other key information. At this time, he looked at it again. He checked the telegraph machine on the table, and his eyes slowly became more and more intense. This is the artifact of the country! With the telegraph machine, wouldn't Datang be invincible in wars in the future
He had been fighting for a lifetime, and he immediately thought of what a huge role this telegraph machine would play if it were used in the army.
"You just said that you are the only one in the world who is proficient in the manufacturing principles of telegraph machines?"
Li Er squinted his eyes, looked at Li Zexuan and said.
Well, Li Zexuan's heart tightened. He felt a hint of danger. Could it be that he had just gone too far in showing off
"Your Majesty, it should...should be like this!"
Li Zexuan couldn't tell anything was wrong from Li Er's tone, so he could only answer bravely.
"Can this telegraph machine be mass-produced? Can it be used to transmit intelligence in the military?"
Li Er didn't have any special expression on his face, but there was a trace of hope in his heart.
"this... ."
Li Zexuan felt like scolding his mother. As expected, Lao Li wanted every good thing he saw! What a robber!
"Your Majesty, the telegraph machine is currently only in the experimental stage. Its transmission distance and working time are not stable. It is okay for me to use it to chat with Yu Xi, but if it is used to transmit intelligence in the military, it must first be used Solve its power supply problem, and then there is the problem of its signal transmission distance... "
"Chat? Are you planning to use this telegraph machine to chat?"
Before Li Zexuan finished speaking, Li Er couldn't help but interrupt. He saw his eyes staring with an expression that he wanted to eat people. If the eldest grandson hadn't been beside him, he would have drawn his sword and chopped Li Zexuan into pieces and fed it to the dogs. !
"Uh, Your Majesty... Your Majesty!"
Li Zexuan secretly cried out that something was going to happen, and in his haste, he spilled the beans, "This is a pill!" The robber is going to eat people!
... ... ... ... ... ... ... ... .
(End of chapter)