50: Learning Magnifier

A new week arrived, and Li Baoyu, Zhao Zixuan, and Fang Mu gathered again at Xu Bai's Card Shop to learn from him.

After several days of practice, the three of them could already create simple transparent sheets.

Today, Xu Bai was going to teach them how to make a Magnifying Glass.

"The core principle of a Magnifying Glass is the refraction of light. When light passes from one medium into another, its direction changes due to a change in speed.

The material of the lens is a crucial factor determining the performance of a Magnifying Glass. You can currently make simple lenses, and you can continuously optimize them later.

First, I'll explain refraction to you. You might not fully understand it just by listening, so I'll do a small experiment for you.

This experiment is very simple. I'll demonstrate it with a cup of water and a chopstick. Watch."

Xu Bai took out a chopstick and a glass cup he had prepared earlier, poured about half a cup of clear water into the glass, and then, holding the chopstick in his right hand, inserted it into the transparent glass cup filled with water.

The originally straight bamboo chopstick had barely touched the water's surface when, at the water's boundary, it suddenly appeared to be 'broken' by an invisible hand.

The part in the water looked bent upwards, and the chopstick's edge seemed as if it had been ironed by a Magnifying Glass, its outline swollen and thickened, with even the chopstick's texture 'stretched' to be clearly visible.

"Light 'bends' when it enters water from the air. When our eyes follow the light, we perceive the chopstick as broken at that point.

In reality, the human eye sees a virtual image of the chopstick by looking against the refracted light."

Xu Bai explained while drawing the path of the light.

Li Baoyu, Zhao Zixuan, and Fang Mu looked at the chopstick in the cup, then at the light's path diagram, and fell into contemplation.

Li Baoyu leaned forward, his nose almost touching the rim of the cup, his gaze scanning back and forth at the intersection of the water and the chopstick.

Fang Mu pulled the chopstick out of the cup, confirmed it was an ordinary chopstick, and then reinserted it into the water.

This principle seemed relatively simple, but it was not easy to summarize it and demonstrate it through an experiment.

Fang Mu suddenly recalled that when he was a child, he would often miss the fish when trying to spear them, even though he aimed directly at them. This might have been the reason.

"Next, you can observe the appearance of a Magnifying Glass. Then you can try to make one."

Xu Bai inserted the Magnifying Glass cards he had made last night into the cards Reader, took out three Magnifying Glasses, and handed them to the three people in front of him.

The three took them and began to observe.

On the mat nearby, Xu Le also held a small, miniature Magnifying Glass in his hand, using it to observe Fugui.

Fugui was a little alarmed by this; after all, observation is relative, and seeing his little master's eyes suddenly magnified, he felt a bit like escaping.

However, Xu Le's body was mostly sprawled over Fugui, so Fugui could only close his dog eyes, believing that what the eye doesn't see, the heart doesn't grieve over.

For those who didn't understand, a Magnifying Glass enlarging other objects was indeed very novel, and Xu Le was very satisfied with his new toy.

After they had observed for a while, Zhao Zixuan thought that the study of the Magnifying Glass was over, and now it was time to start making one himself.

Unexpectedly, Xu Bai pulled out another chopstick and a cup, repeating the experiment from earlier.

Just as Li Baoyu, Zhao Zixuan, and Fang Mu were puzzled, Xu Bai took out a small packet of salt, tore it open, poured it into the water, and stirred it with the chopstick.

After waiting a minute, the salt dissolved, and the water's surface became calm. Xu Bai then inserted the chopstick into the glass cup, which was half-filled with water.

"What differences do you see between these two?"