"Is it possible that there is some technology that can implant dreams into others?" Bai Song looked at Sun Jie.

If Professor Ye’s blog is true, generally speaking, there are two possibilities. One is that Professor Ye was frightened and his mind automatically made up some things, resulting in a dream; the second is that someone influenced his dream.

These two situations are unlikely. The first is mainly because Professor Ye probably doesn't know the tour guide. How can he know something he doesn't know in a dream? The second is naturally because of this technology...

Therefore, the biggest possibility is that the above assumption is violated, that is, the blog posted by Professor Ye is fake.

Then if Professor Ye’s blog is fake, it is unlikely to be suicide.

"I think it might be that Professor Ye was hypnotized," Sun Jie said. "It is indeed a bit too difficult to implant dreams. This requires implanting memories from the inside. If humans had this mature technology, memorizing words would be too easy in the future. But hypnosis is possible. The subconscious of a hypnotized person can be influenced and controlled by others."

"How much do you know about hypnosis?" Bai Song asked, "If this is the case, will there be any difference when Professor Ye's brain is dissected after he commits suicide?"

"This..." Sun Jie shook his head: "Forensic doctors don't have this business..."

"Okay..." Bai Song did not continue to embarrass Sun Jie. Things like hypnosis are really hard to say.

It stands to reason that people like Professor Ye are not easy to be hypnotized, but this is just "not easy" and does not mean "impossible". If Professor Ye was really frightened by that "adventure", it would be much easier for him to be hypnotized again.

"The key to the problem is not actually this," Wang Huadong frowned.

As an on-site investigator, the scene where the tour guide died was too simple for him. He could figure out the clues in no time. But this scene was clearly suicide no matter how he looked at it.

To put it bluntly, if this was not Professor Ye's death, but just another case encountered in daily life, he could have concluded that this person committed suicide.

"My opinion is still suicide," Wang Huadong said, "This is the consensus, but our focus should not be here. We need to know what happened to the little girl. This is the most important thing."

"Huadong is right," Sun Jie said, "Did you make any progress with the professors you approached?"

"They are all professors of mechanics and the like," Bai Song said, "I feel like the field is not right. I mentioned this to President Ren a few hours ago. A professor of optics is on his way here and will be here soon. I feel like there will be new breakthroughs."

"Optics?" Wang Huadong seemed to understand Bai Song's analysis: "Yeah, I see."

…

One hour later.

Every profession has its own specialties, and you have to accept this.

The deeper you go into physics, the more specialized you become. Except for a few professors who have a wide range of interests, most people only focus on one field. The professor who came this time is an optics professor at Nanjiang University. His surname is Xu and he is well-known in the field.

Ren Hao has taken Bai Song's words very seriously, and the person he invited this time is indeed a big shot.

"Let me take a look at the transcript first," Professor Xu made this request after watching the video and photos.

"See the transcript?" It was the first time that Bai Song heard that the professor also wanted to see the transcript.

"Well, the two groups that saw this girl only had descriptions but no video footage," Professor Xu said, "It depends on your ability to record things in writing."

Bai Song and others brought the transcripts, and Professor Xu carefully considered it for a while, then looked at the video and photos.

"I have an idea, you can listen to it," said Professor Xu.

"You go ahead!" Bai Song sat more dignified.

"Pepper's Ghost," the professor said, "This is the only way to fake something according to the current level of science."

"What is this?" Bai Song was the first to ask.

"It's actually very common. It's just fake holographic projection technology," the professor said. "It's often used in stage magic."

"Can you explain the principle to me?" Bai Song asked, "How could you deceive Professor Ye so closely?"

"That's impossible. We can't fool Professor Ye in that situation. It's too close." The professor said, "We don't have the technology. But I can tell you about this Pepper's Ghost."

Speaking of which, this is not a difficult technique and it is used on many stages.

"Pepper's Ghost uses a transparent film made of glass or other materials. The refractive index of this film is completely different from that of air, and the refractive index of light in it is also different, so there is a chance for it to form an image. Do you understand?" said the professor.

"?" Bai Song asked, "Can you tell me in detail?"

"Due to the different refractive indices, when light reaches the interface of the materials, part of it will be reflected and part of it will be transmitted. The amount of light can be controlled by the Fresnel equation. Simply put, it is about the relationship between the electric vector and the incident electric vector during reflection and refraction. The specific expression is..." The professor began to talk non-stop for more than ten minutes: "Do you understand?"

Bai Song clapped his hands immediately, and when the other people saw Bai Song doing this, they also followed suit and clapped.

"Um, do you understand?" Professor Xu asked.

Bai Song was a little embarrassed: "Professor, this...can you give us a demonstration?"

"Well, I have the courseware here, you can take a look."

Then, Bai Song saw an experimental setup.

One image, two rooms (one of which is out of the viewer's sight), and a glass wall between the viewer and the two rooms.

The light from the image will be refracted when it enters and leaves the glass. The audience can see the image on the glass, but cannot see the glass at all. The glass seems to be in mid-air, so the image appears in mid-air like a ghost.

After watching the demonstration video, Bai Song was still shocked. This is the power of science... After thinking for a while, Bai Song said, "So, this is consistent with the records of the two groups of people other than Professor Ye, and even consistent with the content in the video and photos. But Professor Ye was so close to it, how could he not see it clearly?"

"This is not within the scope of our optical research." Professor Xu looked at Bai Song and said, "Officer, I feel that you may have a misunderstanding. That is... how should I put it... let me ask you, are all the people in your police force good people?"

After listening to Professor Xu's words, Bai Song suddenly understood!

The problem is solved. Professor Ye was acting and lying from the beginning to the end! Professor Ye is not a good person at all!

This can solve many problems, but it cannot explain why Professor Ye died. Of course, this is not Professor Xu's responsibility. This big guy has completed his job perfectly.