We didn't say anything more, and the four of us immediately set off to check. Pen "Fun" Pavilion www.biquge.info because everyone knows that if one minute is late, Hotaru and Qixing will be in danger for one more minute. After all, they are girls, especially Hotaru, who has no power to fight, and if something happens to her, I don't know how to explain it to Amin.

We've inspected the walls of the cave and the underground, and we haven't found anything related to the mechanism. We rule out the first possibility for now. Then we immediately tested the second possibility. I just did the math, if the cave here does change, the time interval is about five or six minutes. But at this time, we just experimented, no, let's go back to the big lake. So we decided to try a few more time slots.

We tried three, seven, eight, nine, ten, twenty minutes, but we still saw the big lake when we went out. In the end, we also took out the climbing rope, Zhang Long and the wolf pulled in the cave, and Fei Bao and I took the climbing rope and walked outside and waited for a while, and walked back to the same place. The second possibility was also denied.

Finally all four of us stood in front of the mural, staring closely at the two red dragons. By this time, the dragon had reached its peak. The third possibility is hard to convince, but it's the only one that I can see. Did this dragon really climb on its own? Are there really ghosts here? Did Kaiseong and Hotaru get captured by a ghost? Was the gunshots we heard before we came in on purpose to draw us in? A lot of wild thoughts swirled around in my head.

"Ke Shao, do you think we are really hitting ghosts?" Fei Bao said.

"I don't want to hit a ghost either!" I thought with a frown.

"Sherlock Holmes said that once you have ruled out all the impossible facts, then what remains, no matter how incredible, is the truth of the facts." The wolf said.

"Did you tell that Sherlock Holmes how you can eliminate all the impossible facts!" Fei Bao said.

"How can you say such a thing!" The wolf said, "This needs to be analyzed on a case-by-case basis!" ”

"Isn't that nonsense if it's of no practical use?"

"You're! Shallow! ”

"I'm so low-educated, I'm so superficial! What do you think? Bite me! ”

"One of you two is one less sentence!" Zhang Long said, "This is the time to figure out a way, not the time to quarrel." ”

"Could it be that you're missing something?" I took my flashlight and looked around, and suddenly remembered that there was a place that really hadn't been checked.

At this time, the wolf next to me suddenly reacted and rushed to the mural. But strangely, instead of looking at the mural, he looked at the wall beneath it with wide eyes of surprise. He shone his flashlight on the wall and looked closely.

"Little white face, are you stupid?" Fei Bao said, "Is it that the dragon has reached the top of the cave, and there is nothing to do, but he wants to pretend to be forced, so he pretends to be like he has found something." ”

"Don't talk nonsense, you all come and see!" The wolf said, "Indeed, the dragon is going up!" ”

I was immediately surprised, and if this was said by the water blower of Fat Bao, I would have been skeptical. But these words came from the mouth of the little white face, and he gave me the feeling that he was a good boy, and people like him should not like to brag.

We walked over at once.

"The dragon is up there!" Fat Bao pointed to the mural dragon on the wall and said, "What are you looking at here?" ”

"There's some lines carved here, and the lines are painted on them. These pigments are so close to transparency that you can't see them without looking closely. The wolf said.

"What do you do with a layer of transparent paint on the lines for no reason?" Fei Bao said, "Did it hurt for the ancients to be idle? Are they stupid? ”

"You're the idiot!" The wolf said, "The lines are carved regularly, and the paint is used to show the colors!" ”

"Your boss, how do transparent paints show colors!"

I suddenly understood what the wolf was trying to say, and was surprised to say, "How can such a thing happen!" I looked at the two dragons overhead, "And how does it change color?" ”

"I've read in a book about ancient mechanism formations, and there are some special pigments in ancient times that can change over time!" The wolf said.

"What color change? What are you talking about? Fat Bao asked, "How did these two dragons climb up?"

"It's because of the change in color!" I said, "There are actually countless dragons painted on the walls, and as time goes on, the color of the dragon below fades, and the color of the dragon on top fades, so we look like the dragon is climbing up!" ”

"Are those paints so godly?" "It will change over time!" ”

"It varies depending on the temperature change over the course of the day." "Because there is a temperature difference between the top and bottom of the cave, and the temperature is different depending on the day, the pigment changes differently!" It's daytime, so the temperature in the upper layer of the cave will be higher than the temperature in the lower layer, and the pigment is estimated to be darker the higher the temperature. Got it? A sucker! ”

"Your boss, if you know a little bit, you're pretending to be forced here!" "You haven't explained how the pigment changes due to the change in temperature!" ”

"I don't understand such a profound question!"

"Cut!"

I touched the paint on the wall, there was some moisture on it, and when I wiped it off, I realized that the paint was actually solid, and it was crystalline. I took a closer look and said, "This is a thermally induced liquid crystal." ”

"You know again?" Fei Bao said.

"When I was in college, I did an experiment on thermally induced liquid crystals in an elective physics class, so I knew a little about it." I said, "Thermally induced liquid crystal molecules are very sensitive, distort with temperature, and aggregate at areas with high temperatures. This change in molecular structure affects the wavelength at which light is absorbed and reflected by a part of the liquid crystal, causing the hot part to change color significantly. For example, the two red dragons on the mural climb upwards, because of the daylight, the temperature of the upper part of the cave will gradually be higher than that of the lower part, so the thermally induced liquid crystal molecules will slowly rise along the lines on the wall. At the same time, due to the change in temperature, the liquid crystal molecules are slightly distorted in one direction, causing the liquid crystal to absorb more of the other colors in the visible light and reflect the red part. So at this time, the red dragon on the mural we were looking at was climbing up. At night, the outside temperature drops, so the lower part of the cave will be warmer than the upper part, and it is estimated that the mural will run down at that time. ”