In the early days of optics, the interpretation of color appeared particularly difficult. Before Newton, Europeans’ understanding of color was based on Aristotle’s view. Aristotle believed that color is not an objective property of objects, but people’s subjective feelings. The formation of all colors is the result of the proportional mixing of light and darkness, white and black.
In early 1666, Newton made a triangular glass prism and used it to study the color of light. To do this, he painted the room dark and made a small hole in the window to let in an appropriate amount of sunlight. He also placed the prism at the entrance of the light so that the refracted light could hit the opposite wall. Through this experiment, he got a colored light spot on the wall. The color arrangement was red, orange, yellow, green, blue, Indigo, purple. Newton called this color spot a spectrum.
Later generations called this experiment the dispersion experiment of light!
In 1830, Thomas Young, a British doctor and physicist, opened a small hole in a blind to let light pass through, and used a mirror to reflect the light that passed through. He then used a piece of paper about 1/30 inch thick to split the light into two beams down the middle. The result is seeing intersecting light and shadow.
This is the famous Young's double slit interference experiment, which shows that two beams of light can interfere with each other like waves. This experiment also played a crucial role in the creation of quantum science a century later.
Li Zexuan moved these two experiments to the Tang Dynasty to let the students in the academy understand that the sunlight they see every day is not as simple as it seems! Light is a very wonderful substance. Understanding its inner workings will lead to many amazing things!
At this moment, the curtains in the auditorium have been opened, but most people still haven't come back to their senses. They can't figure out why there are only two beams of light, but they seem to turn into many beams when they shine on the paper. Li Zexuan is How did you do it?
"Chief Shan, what was that just now..."
A student couldn't help but stood up and wanted to seek the truth, but halfway through the question, he couldn't continue because he felt that Li Zexuan would definitely prevaricate like before.
Sure enough, Li Zexuan waved his hand and said: "Let's put this aside first, and I will take you..."
"Let's play a little game!"
Before the last few words were uttered, all the teachers and students in the audience spoke for Li Zexuan in unison, and their voices were so loud and angry that Li Zexuan on the podium felt a strong sense of resentment coming towards his face. ah!
"Ahem! So you all know it!"
Li Zexuan was sweating on his forehead and said something awkward. Then he took out two iron boxes and shouted to the side: "Mo Zhong, Mo Yun, you two come here!"
The two brothers had already come down from the roof. When they heard that Li Zexuan was in trouble again, they had no choice but to run over again.
"You two each hold a box. Pay attention to the thread in the middle. Don't be too far away from each other, otherwise the thread will be broken and I won't be able to forgive you!"
"Yes, yes, Chief Shan!"
The two brothers quickly agreed and each took a box.
"Now you two go and stand over there!"
Li Zexuan pointed to the corner at the back of the auditorium and said.
The two brothers did as they were told and left.
Everyone was confused, but there were two exceptions, namely Li Tai and Cheng Chumo, because they had not only seen this thing before, but also played with it.
Li Zexuan took out two more iron boxes (one contained a voltaic battery and the other contained a telegraph machine). After connecting the wires, he raised his head and said, "The next little game will be more interesting. You guys Have you ever thought that one day, two people thousands of miles apart can send messages to each other?”
Sun Zifan: "Send the message!"
Wang Meng: "You can also fly pigeons to deliver messages!"
Li Zexuan shook his head and said: "A distance of thousands of miles, how long does it take to send a letter or a flying pigeon to send a message? The two things you saw today will enable you to instantly send messages thousands of miles apart in the future!"
"Wow~!"
"This...how is this possible?"
"Thousands of miles apart, sending messages instantly, isn't this a magical method?"
Everyone in the audience was in an uproar again. It is said that they were shocked more times today than in the past combined. Li Zexuan always said nothing to surprise him!
"Due to the limited space, let's do a ten-foot-spaced communication experiment first! The next time the box on my side makes a sound, the one on Mo Zhong's hand will also make a sound!"
Li Zexuan opened the iron box and began to send the "telegram".
"Didi! Di~! Di~! Di~!"
Two short and three long!
Almost at the same time, the iron box in Mo Zhong's hand also sounded "Didi! Di~! Di~! Di~" two short and three long sounds.
Although students and teachers find it very magical, most of them don't quite understand it yet.
"Chief, how can you send a message with just this beeping sound?"
one student asked, standing up.
"Haha, that's a good question! This classmate, please think carefully about the sound you just heard. Is it long or short?"
The student frowned, thought for a moment, and replied, "Yes, Chief!"
"Then think about it again, if I combine these long and short sounds with each other, and the different combinations correspond to a word, for example, the two short and three long sounds just correspond to the word "Li", then can I pass this message? What’s up?”
As soon as he finished speaking, there were exclamations everywhere!
"Wow, why didn't I think of that? Chief Shan's method is really brilliant!"
“I just don’t know how far this thing can travel!”
Li Zexuan added at this time: "According to my preliminary tests, this thing can be used to transmit messages to each other within thirty miles! If there is a slight improvement in the future, it is not a dream to transmit messages to each other thousands of miles apart!"
"Wow, more than thirty miles? That's amazing!"
"It's amazing! It's amazing! An iron box can send messages thousands of miles!"
The auditorium was boiling once again!
The older generation of academy gentlemen looked at each other in shock. At this moment, they really felt that they were old and could not keep up with the times!
"Okay, let's get this out of the way for now, there's going to be fun later! Mo Zhong, Mo Yun, please put these things away!"
Li Zexuan once again showed a charming smile and ordered.
It is impossible for him to explain the principles of the telegraph in detail now!
The students all showed expressions of "Sure enough," but now they were too lazy to complain, so they stayed silent and watched Li Zexuan's performance.
I saw Li Zexuan bring a basin of water from under the desk, and then took out a box and two tubes of colored glass. Then he looked at everyone and said with a smile: "The next step is to witness the miracle. You will see it." Truly something out of nothing~!”
………………………
