23: transparent

In the afternoon, after Xu Bai woke up, he took out the cards-making tools he had brought from home that morning and sat directly by the cabinet to start making cardss, preparing the learning materials for the afternoon.

Unknowingly, time passed quickly, and by the end of the second class, Zhao Zixuan and his two companions came out of the academy.

Xu Bai tapped the transparent cabinet, "Do you know what this is?"

"It's a star energy stone." Fang Mu answered, then thought for a moment and added, "It's a used star energy stone."

"What's the use of this? We can't use cardss to make star energy stones. Are we supposed to use this to make a Magnifying Glass by hand?" Zhao Zixuan blurted out the idea that popped into his head.

Xu Bai's head was covered in black lines. He rolled up the paper in his hand and lightly tapped Zhao Zixuan's head.

"What is your little head thinking? Just because you can do it doesn't mean you can use cardss to make it. Also, do you know how expensive a star energy stone is? Just because you have money doesn't mean I do."

Touching the spot on his head where he was tapped, Zhao Zixuan chuckled. Li Baoyu and Fang Mu, sitting nearby, also covered their mouths, secretly laughing.

Xu Bai clapped his hands, drawing the attention of the three back to him.

"Alright, let's get back to the main topic. Look at what this used star energy stone and a Magnifying Glass have in common."

"They can both see things on the other side." Li Baoyu quickly answered.

Hearing this answer, Xu Bai nodded with satisfaction.

"Yes, they can both see things on the other side. In other words, both items are transparent.

For an object, transparency refers to its ability to allow light to pass through and see the other side, just like this star energy stone, and water, which we encounter daily, are all transparent.

As for wood, stone, and the cards in my hand, they are all opaque because they cannot let light pass through.

This principle is still very simple. Do you understand?"

Listening to Xu Bai's simple and clear description, the three nodded.

The top student, Fang Mu, summarized, "In other words, we need to make something transparent, and this object needs to serve as the lens for a Magnifying Glass. That way, we can make a Magnifying Glass."

Xu Bai agreed:

"You're half right. We do need to make a transparent object. Let me first explain the principle of transparency to you!

The principle of transparency is divided into two perspectives: the material structure perspective and the optical perspective.

From the material structure perspective, it can be explained this way: the aggregated state structure of matter is divided into isotropic and anisotropic.

When the aggregated state structure of matter is isotropic, light can pass through completely without being fully reflected or absorbed, thus appearing transparent; conversely, when the aggregated state structure of matter is anisotropic, light cannot pass through completely, leading to reflection or absorption, and the object appears opaque.

From the optical perspective, it can be explained this way: there are three types of interaction between light and matter: light is reflected, light is absorbed by matter, and light passes through matter. The necessary condition for forming a transparent body is that it does not absorb or reflect all visible light.

Alright, please understand what I just said. Next, let's try to make transparent things. Everyone, take out your cards-making tools and give it a try."

Fang Mu and the other two nodded.

Transparent... light-transmitting... trans... This was Brother Xu's unique insight. They had never seen this explanation in books or heard anyone else mention it.

The three's ideas about transparency became increasingly clear in their minds.