Chapter 8 Section 8

The cup holding the instant coffee was still not cleaned, but Kusanagi thought to himself, since he still has to deal with this person, he should learn to bear it first. "Having said that, I still didn't expect it to be a laser." He sighed as he set the glass down on the table. "To be precise, it is a carbon dioxide laser." Tang Chuan nodded and said. "Huh? Are there many types of lasers?" "Yeah, the typical ones are carbon dioxide laser, YAG laser and glass laser." "We often hear the word laser, but we don't think that it actually exists around us."

"It's also used in CD players. If the laser can be powerful enough to burn people, maybe that scene is like a lens in a science fiction movie." "There is a laser gun, but this gun is not used in the factory, but a substitute for it is used." The laser device in the Tokita processing station is a box-shaped machine as big as a tractor. It is said that the factory manager here bought it at a low price from the company he used to work for. It is mainly used for cutting and welding steel plates. . "In order to be able to produce a laser with a higher output power, the laser beam including carbon dioxide gas must be output at a high speed, and the high-voltage discharge must be guaranteed to be carried out smoothly, so the size of the required device is naturally large. Like A laser device the size of a tractor can cut steel plates only a few millimeters thick."

"In the novel, James Bond cuts through the body of an armored vehicle with a laser gun the size of a pistol." "I don't think it will come true even if it takes another hundred years." Tang Chuan said flatly. "Then—" Kusanagi folded his arms and stared at his old badminton opponent and asked, "When did you notice it?" "What did you observe?" "Lasers. Didn't you know that a long time ago?" "Ah..." Tang Chuan said with his mouth half-opened, "As soon as I heard that the burning started from the back of the young man's head, I guessed it might be related to the laser. But I'm really sure it's because of the red line."

"I've always wanted to ask, what is that red line?" "No mystery, it's a 'nitrogen-neon' laser." Hearing Yukawa's answer, Kusanagi looked very disappointed. "It's a laser again!" "Don't make such an impatient expression. You should be familiar with it. Singers often use lasers in concerts. It works on the same principle." "Then why did it take that route?" For laser devices, it is very important to adjust the laser line, otherwise the required power will not be output.At first, I didn't know how the laser was emitted from which direction, but in the actual adjustment, it is particularly dangerous to use a high-output laser beam. Therefore, only harmless lasers can be used when adjusting the direction, that is, nitrogen- Neon laser. "

"That is to say, this way you can see the red line?" "According to my reasoning, the criminal may have tried to emit a nitrogen-neon laser in advance in order to adjust the emission route of the carbon dioxide laser. I guess there must be a device capable of emitting lasers nearby, so I went to look for it. I found that factory by accident. In the room I saw, there was no laser equipment, but on the shelf tray, there was a part that could only be cut by laser. In fact, in the part On the cross section, fine textures can be seen, and in that room are also kept the carbon dioxide, hydrogen and nitrogen gas cylinders necessary to generate the laser beam. So I immediately realized that there must be CO2 lasers in other rooms device."

From the T-junction where the accident happened, walk about one district away, then turn left, and the factory is at the end of the road.When the second incident happened, the police arrived and found the window was open and the laser device was directly opposite the window. "Didn't it say that laser light travels in a straight line?" "So use a mirror. If the laser is shot directly from the factory, it may hit the utility pole or other objects at the first corner. If a special mirror with gold plating is placed there to adjust the position, the laser is You can hit a T-junction because gold reflects laser light almost 100 percent of the time."

"Isn't it necessary to use a nitrogen-neon laser for adjustment?" "you are right." "Then why sometimes you can see it and sometimes you can't?" "Generally speaking, a laser cannot be seen with the naked eye, but once it hits something, we can see its reflected light. For example, when a nitrogen-neon laser encounters flying dust, it will There is a red line. When the girl sees the red line, it is likely that there is dust or other substances flying around." "Oh!" Kusanagi scratched his head, a strange feeling of vague understanding arose spontaneously.

"However, it was beyond my expectation that the other mechanic was the criminal. I guessed that the young man named Maeshima must be the criminal, because I heard from you that he lived near the scene of the accident." "The other mechanic also lives in this apartment." This person is Ryuo Kanemori.Kusanagi regretted why he didn't ask the two of them where they worked. "Fortunately, Maejima told Kanemori what he heard from Yukawa's mouth, so that the trap we set up was successful. If one step is wrong, then this carefully planned game will be meaningless."

"However, I still have one thing that I can't understand." Tang Chuan said. Seeing this, Kusanagi smiled suddenly, and asked, "I want to ask why those two people switched rooms?" "That's right. Didn't Jinsen live on the first floor and Maejima lived on the second floor? But the fact turned out to be the opposite." "It's like this..." When Kusanagi questioned where Maejima was when the incident happened, Maejima pointed to the bed, Kusanagi interpreted it as he was staying in the house.In fact, what Maeshima wanted to say was that he was in the downstairs room.

"Why is this? Is it because the scene of the accident where the crime took place can be seen from the second floor, so on the day of the crime, Jin Sen used some reasonable reason to borrow Maejima's room?" "No, that's not the case. These two people used to change rooms frequently." "why?" "Well, this is the criminal motive of this case." Kusanagi sipped his coffee slowly on purpose.He thought, sometimes in order to make people anxious, it's not bad to sell about. "The reason is that Jinsen participated in volunteer activities, and the content of the job was to read books borrowed from the library, record them on tapes, and then give them to people with vision problems. This is not a job that anyone can do. , requires special training. Jinsen went to school to study for half a year before officially doing recording work."

"Kimson's younger sister is a blind woman, and maybe that's why he wanted to do the job. But even with professional training, it's not an easy job to do. Surprisingly, there is no Special-purpose machines can be used for recording, and it is said that most of them use ordinary recorders prepared by the recorders themselves, but the microphone must be a special special-purpose product. Therefore, Jinsen himself just bought a special-purpose microphone.” "Only use Mike...ah! That's how it is." Tang Chuan nodded his head with an expression of sudden realization. "Yes, Kanemori would borrow Maeshima's speakers every day when he was recording, so whenever he was recording, Kanemori would stay in Maejima's house. Even if he was watching TV in Kanemori's room, Maeshima would Headphones would be plugged in to prevent any other noise from getting into the tape that might be interfering." "In addition, there is another advantage of Kanemori borrowing Maeshima's room, that is, there are a lot of books in his room. In fact, most of the books that Kanemori has recorded so far are Maeshima's. On the night when the incident happened, he was reading The book The Martian Chronicles. That's how it happened." "For volunteer work doing sound, this room couldn't be more ideal." After listening to Yukawa's thoughts, Kusanagi nodded. "This was before those guys on motorcycles showed up." "Those guys..." Tang Chuan frowned unhappily. Kimson says he has been unable to record seriously lately at all because of the noise made by the youths on motorcycles.Sometimes it was hard to record, but the sound of the engine came at a critical moment. "He was so angry that he even wanted to kill?" "No, he said he didn't want to kill people, he just wanted to frighten them by lighting the gasoline in the plastic bucket." "But unfortunately, there was a person standing in front of it, and the laser just hit the back of his head, which led to such a tragedy." "I'm afraid this is why Yamashita Ryosuke died on the spot." Kusanagi repeated the doctor's words. "After Ryosuke Yamashita fell to the ground, the laser ignited the plastic barrel as expected. Is this true?" Yu Chuan gently pushed down his glasses, "Did Kanemori control the laser device remotely?" "It is said to use a phone! I heard that the laser device can already be controlled by a computer. The sound of the phone's keystrokes is transmitted to the computer connected to it in some form, and the computer's program will be activated." Kusanagi looked at the work log and read out this confession.Although he read it himself.But he still didn't fully understand what it meant.There is an extension for the wireless phone in Maeshima's room because he doesn't have a phone.For Maeshima, who can't speak at all, the phone is just a nuisance. " "So for Jinsen, it is impossible to operate flexibly and accurately. Perhaps when he knows that someone is standing in the optical axis, it is already too late." "He is so unfortunate!" Kusanagi said with emotion, "Before, it was impossible to record seriously because of the noise. After the murder, he was disturbed and his voice trembled, so he couldn't record well." "I can feel it." "When I took him to the police station, he said he had something to ask me. Guess what?" "what?" "Give him a fairy tale book and let him record. He said that now he feels that he can record well again." "Oh, record fairy tales!" The two were silent for a while, then Tang Chuan stretched and stood up, "How about another cup of instant coffee?" "Have a drink!" Kusanagi pointed to the cup sadly.