Wen Long walked to the lake, he used his two paws to hold some lake water and wash his face, when he washed, Wen Long unconsciously looked at the bottom of the lake, and found that the water of this underground lake is very deep, according to common sense, it should be bottomless and can only see a piece of darkness. But Wen Long found that the bottom of the underground lake was a little different, because in the dark and deep water, there was something that was emitting a faint blue light.

"There's something glowing at the bottom of this lake! Meow! At this moment, Wen Long couldn't help but shout.

Hearing Wen Long's call, the others naturally rushed over immediately.

"Mr. Cat, what's wrong?" The first to come was Catherine, who asked as soon as she arrived.

"You see, there's something at the bottom of the lake that glows pale blue...... Maybe this thing has something to do with the Star Dragon, meow! Wen Long pointed to the deep bottom of the lake and said to Catherine.

"Mr. Cat, where are ...... Is there light? Catherine looked in the direction that Wen Long was pointing, but saw only a dark patch, and found no light.

"How could it not be? Obviously, there is! It's not the crystal light from the top of the cave shining on the surface of the lake, it's the deeper, a little bit of light from the bottom of the lake, meow! Wenlong emphasized again.

"But, Mr. Cat, I really don't see the light......"

"Mr. Cat, do you mean that there is a pale blue glow at the bottom of the lake? Begonias didn't see ...... either."

This time, not only Catherine, but even Begonia, who came over, said the same.

Only then did the dragon suddenly react.

"Oh, yes, I see...... Meow. ”

Only then did Wen Long remember that the lake was very deep, so the light blue light coming from the bottom of the lake seemed to be very weak, and it was probably difficult for ordinary people to notice. However, Wenlong is an Ailu cat after all, and he can have good eyesight even in the dark night, so this faint pale blue light is for Wenlong to discover.

Therefore, Wenlong didn't ask Catherine and Begonia for their opinions, but instead asked about Montenegro, who was also Ailu's cat. And as Wenlong thought, Montenegro's reply was completely different from that of Catherine and Begonia.

"Yes, Chief. There's a faint pale blue glow there, meow! ”

"Yes, Uncle Ben is really right! Meow! Wen Long said happily.

"But what does this have to do with the Star Dragon?" Montenegro asked puzzledly, "There are crystals everywhere in this cave that can emit a light blue shimmer, and the glimmer at the bottom of the lake is probably only emitted by the crystals that sink at the bottom of the lake......

"Maybe you're right, but I think it's a different possibility now...... Meow! Wen Long touched his beard and said.

"Another possibility?" The people around naturally wanted to hear what Wen Long said about the other possibility.

"Hmm......" Wen Long first looked around as he spoke, and then said slowly as if he had confirmed something, "These crystals may not really glow......

"I don't understand it at all. Mr. Cat ...... "Hearing Wen Long say this, Catherine didn't understand either.

In fact, not only Catherine, but the others were also in a dazed state, so no one spoke more, just quietly waiting for Wenlong to solve the mystery.

"Then before I ask you, do you know why the moon shines? Meow? However, Wen Long did not directly say the answer, but asked the others first.

"Why does the moon shine? Doesn't the moon shine all the time? Is there any reason for this? Catherine shook her head, indicating that she didn't know.

"The moon itself doesn't shine. The reason why we are able to see that the moon shines is because the moon reflects the sun's rays...... Meow. ”

"The moon is actually the reflection of the sun's rays?"

Hearing what Wen Long said, almost all of them showed surprised expressions. Only Begonia said thoughtfully: "The moonlight is actually the sunlight reflected by the moon...... Begonia seems to have heard a bachelor Wang Li, who often observes the night sky with a telescope...... I didn't expect you to even know about such a thing, Mr. Cat......"

"Oh......" Hearing Haitang's confirmation, the others were more convinced of Wenlong.

"Ahem, ahem...... In short, the crystals in this cave are actually similar to the moon, the crystals themselves do not emit light, but need to reflect other light to become brighter, and don't you notice that this pale blue light is actually the same as the starlight at night? Meow? ”

"But Lord Chief. It's daytime, there are no stars, where is the starlight? "Montenegro of this inquiry.

"Stupid! The stars were still in the sky in broad daylight, and they had not disappeared, only because the sun's rays were too strong. So the starlight is hidden, meow! ”

"Ah, yes...... Is that so? Montenegro scratched his head embarrassedly, "I don't read much, Lord Chief, don't lie to me, meow." ”

"I'm not lying to you, this is the truth, these crystals are actually a substance that filters out sunlight and leaves only light blue starlight, so the light we see from the crystals is light blue......"

Wen Long went on to explain: "Although the underground caves of Esther Lake are complex and vast, there are many entrances and exits to the ground, and the usual sunlight can shine through the caves that serve as entrances and exits, and then be absorbed by these crystals...... And only the pure starlight of pale blue is left! Meow! ”

"But......" Montenegro wanted to ask something, but was quickly interrupted by Wen Long.

"No need, Uncle Ben I know what you want to ask, what you want to ask is, since crystals rely on reflected light to glow, then why do they still glow in the depths of this cave, where the sun can't shine at all?"

"Ah...... That's true...... Meow. Montenegro nodded and said.

"You can see this by looking at the scattered crystals," Wen Long continued, "and the crystals scattered throughout the cave may seem to be haphazard, but in fact they are arranged very carefully. If you look closely, you can see that none of these crystals exist alone, which means that all crystals are connected, as long as any crystal shines, it must shine on another nearby crystal, so that the reflected light can be continuously transmitted between crystals......"

"Therefore, the starlight shining in from the entrances of several caves will be reflected through the crystals at the entrances, and then passed through the crystals along the way step by step, and eventually all the starlight will converge in the ......"

"This is it!! Meow! As he spoke, Wen Long pointed to the top of this huge karst cave, and also above the underground lake in front of him, and there, there was the largest light blue crystal in Lake Esther that Wen Long and the others had ever seen! (To be continued.) )