future library.

Chapter 77 Geometric Optics
People often like to use the big bang to describe the development of certain sciences.The big bang of information, the big bang of finance, the big bang of physics..., and later compiled the big bang of the universe and the big bang of life...

In fact, since the 18th century, people have been surprised by the continuous development of technology.

Even the scientists themselves.

In the previous thousands of years, scholars lived a leisurely life, and the development of science could also match the leisurely pace of life.For example, there are many things that Italian gentlemen treasured equations as martial arts secrets. After Gauss solved the problem of heptagons, he liked to mail his research results to friends instead of publishing them. Many of his achievements were dug out after his death, and Fermat also had the same hobby. The classic Fermat's last theorem comes from two sentences in the margins of a book. He himself declared "I have found a Wonderful proof, but unfortunately the blank space here is too small to write in——It’s a pity, it took three or four hundred years of hard work for later generations to solve this problem, if he can really use some kind of wonderful proof instead of With hundreds of pages of complex formulas, Euler, Gauss, Abel, Cauchy and others may beat him up in another world for one day, two days, or 400 years...

And in the 19th century, if any scientist dares to treasure his research content, his epitaph will be blank—no technology, theory, or discovery will wait for him for 10 years, if he is unlucky , a postal delay could land him in endless arguments.

The reason is the accumulation of knowledge. When enough knowledge of one type is accumulated, various branches will grow naturally, and the speed will become faster and faster. The situation that Cheng Jinzhou is now encountering is also the same .

The knowledge stored in his memory is the essence that has been tempered by the masters, at least it is the support of a certain system.Those branches that will be eliminated soon, or non-mainline branches, and transitional research will not exist in the textbooks Cheng Jinzhou studied, and it is very difficult for him to fully explain them.

In addition, the more he leaked a certain part of the content, the easier it is for the astrologers to research more advanced content, which is not a good thing for Xiao Cheng.

In this world, not the most valuable papers get the most citations—and not all valuable papers are instantly discovered by all scholars.Einstein's theory of relativity is a standard counterexample, and another Mr. Edison who loves home is another extreme.

In many ways, Edison did the work of a technician. For many years, he was known as an inventor, but at that time, he received more praise than Einstein in many cases.

In terms of reward and longevity, Cheng Jinzhou hopes to become Edison instead of Einstein. The latter's theory of relativity has not been widely cited until the 21st century, while the former's incandescent light bulb and phonograph have won many praises since their invention. .

As far as a child's identity is concerned, Cheng Jinzhou is definitely the representative of "Xin Ji Liu".

Sitting on a chair in the study room, Cheng Jinzhou made the face of the ring as big as a wall, and carefully read the few books he got, hoping to find some worthless, but can be exchanged for contribution points. minutiae.

He had already figured out the simple parts of Euclidean geometry and mechanical metrology. If he wanted to develop and branch out, Cheng Jinzhou could do it, but that would require him to actively mobilize his memory and re-calculate and derive. Not only was the process cumbersome and laborious, labor, and may not be recognized by the astromancers quickly - just like all research in the world, most research with world significance often does not receive world-class praise at the beginning. For these, it will inevitably When it comes to changing history or changing science, any scholar will be cautious in the early stages.

"Or, take the path of chemistry?" Cheng Jinzhou glanced at the paper with a long name from the library: "Synthesis and Catalysis of Pyrrocene Samarium Complexes", this standard branch of later research is now the It is definitely impossible to do, but the legendary periodic table of elements is something that middle school students can memorize thoroughly, and it is also commonly used in experiments.

Most importantly, chemistry is the easiest subject to verify and prove, and it is easy to produce evidence.

Thinking of this, Cheng Jinzhou wrote a few paragraphs on the properties of potassium, sodium, magnesium, and aluminum, and then blotted them out with ink, muttering to himself, "This is a discovery that will inevitably change the world, and it cannot be brought out now."

For a whole night, Dr. Cheng Da was immersed in the question of "what to plagiarize", which may be the simplest problem in the history of human scientific research.

There were very few people waiting in the house in the capital, and no one came to take a second look when he fell asleep at night.Cheng Jinzhou woke up from the cold once in the middle of the night, so he had to cover himself with a quilt and blow out the oil lamp - the servants in the family's villa were the most powerful, and you could tell which family lost power and gained power by looking at their attitude.

……

The morning sun shines on the quilt through the window screen, making people feel warm all over.Classes will be suspended for two days after the quiz, and the servants will not come to call for someone, so Cheng Jinzhou is allowed to sleep until noon.

If it was in the old house, there would have been servants shouting outside the door at this time: Good morning, third brother.

He must have shouted that he could answer "Good morning" before giving up.

But in the capital, Cheng Jinzhou could only open his eyes from the twilight, and then looked at the beams of light passing through the gap between the two screen windows in a daze.

Bright light beams form bright paths, and countless dust floats, rotates, and swims in them without any rules... At home, this kind of scene is often seen, but at this moment, the mind is full of science. In Cheng Jinzhou's eyes, such a light beam represents two important theories.

Both Tyndall phenomenon and Brownian motion can be represented by it.

Cheng Jinzhou exhaled, shook his head and laughed. Tyndall phenomenon is often used in colloids. Although Brownian motion appeared in the 19th century, it was just a curiosity in the early stage. The influence they can bring certainly does not have a cubic equation. many.Now it is okay to say that it is completely useless.

"The incident light is larger than the wavelength of the particle, and it will be scattered." Cheng Jinzhou memorized the power behind his back, and soon laughed to himself: "It's not bad for the great astrologists to understand what the incident light is, but they still scatter..."

He was talking to himself, and suddenly froze.

Geometric optics seems to be a very good branch - the content is simple and direct, easy to understand, easy to use, and it is quite familiar to me. When Cheng Jinzhou was a tutor for freshmen, he taught geometric optics no less than three or four times. .

This is definitely the simplest of all required courses in theoretical physics.It only needs elementary and middle-level mathematics to solve the problem, it is easy to extend it, and it is convenient to converge it...

Cheng Jinzhou got up quickly, and while putting on his clothes, he shouted: "Those outside, two people are coming in."

The servants naturally got up early. Hearing his call, a boy came in slowly and said, "Third Master, lunch is already ready."

"Come in and grind the ink for me." Cheng Jinzhou glared at this guy, his dissatisfaction was beyond words.

The servant didn't care and lazily rolled up his sleeves.Except for a few of the two or three surnamed Cheng in other courtyards in the capital, they were all slaves bought locally. The stewards above were sons of other clans. They treated the third brother of the Qingzi clan as if they were the same. He treats other bastards who come to Beijing to take the exam in the same way.For them, they have taken care of all the errands for so many years, and they don't think there is anything special about Cheng Jinzhou. Anyway, there are no requirements from above, so naturally they can worry less.

"One more person comes in." Cheng Jinzhou was excited and didn't want to waste energy on a servant.These people are all guys who have grown up in Beijing. There is no need to beat them. As long as they can gain a firm foothold, everything will go smoothly.

Another 25-year-old boy walked in, and after a non-standard salute, he said, "Third Master."

"My third brother." Cheng Jinzhou couldn't help but said, "Go and get some quills and cardboard."

Since geometric optics talks about geometry, it is about drawing pictures.

In fact, the so-called geometric optics has been learned by most people in physics in middle school, and the content is extremely simple. You only need to understand three laws to complete most of the work: light travels in a straight line, light will reflect, Light refracts...

And studying the relationship between them, when it happens, and the result after it happens is basically the whole content of geometric optics. As for why this kind of problem happens, it can usually be left to physical optics to deal with.

While writing down the main content, Cheng Jinzhou bit his pen, thinking about what content to derive.

Although the theory is the most important, but only the main content, waiting for others to add branches and leaves for you, who knows if it will wait until the end of time.In addition, pay attention to whether someone has already studied similar content-Cheng Jinzhou believes that the astrologists of this era will certainly not deal with optical problems in such a systematic way, but they must have some understanding in some aspects, at least in order to complete Astronomical measurements, they have been able to make decent telescopes out of crystals.

"What's your name?" Cheng Jinzhou wrote the three laws in simplified Chinese on the paper, and then asked the servant next to him who was polishing ink.

"Lu Dayong."

"Which house in the city delivers the fastest?"

"The Xue family has the biggest car and horse business?" Lu Dayong was happy that his master would find someone else to deliver the letter, so as not to trouble himself.

"Now go to the Xue family to get the letter from me. You want the fastest and safest one." In the cities of ancient China, there was a simple postal system, and the Great Xia Dynasty developed better in this respect. Perhaps it is because the centralized power is not strong enough and the transportation methods are more complicated, so that many official documents are delivered through some private individuals with government relations, but the degree of convenience has also improved. At least in a city of Xiajing's size, letters want two To arrive within three hours, most of them have to rely on professionals.

Cheng Jinzhou drove the two of them out, pulled a piece of paper, and began to write a letter to Xiang Xin. At the same time, he attached some results of geometric optics and asked her how much she knew. Since Xiang Xin wants to study geometry, he must know how deep the astrologists are in this area, so it is safest to ask her.

After finishing these, Cheng Jinzhou began to recall the content of his lectures back then, and then recorded them one by one, and only waited for Xiang Xin's reply before making deletions.

……

(End of this chapter)