I Just Want to Be a Quiet Top Student

Chapter 177 Different systems

Optics is an important branch of general objects, and holography is a booming branch of optics, which uses coherent light interference to obtain all the information of objects.

The holographic photosensitive film is placed on the xy plane with z=0. The photosensitive film receives the reference light and the spherical wave emitted from the object point at the same time, and is developed into a holographic film.

A proof is needed here. The ±1st-order diffracted light behind the hologram forms a virtual image and a real image of the object point, and the positions of the two image points are obtained.

Shen Qi considered the complex amplitude of the spherical wave in the z=0 plane. Under the paraxial condition, that is, the center of the sphere is far enough from the xy plane.

An approximate relationship can be obtained here:

[(X-x0)^2+(y-y0)^2+z0^2]≈∣z0∣+(x-x0)^2+(y-y0)^2/2z0

When illuminating the above-mentioned hologram with the original reference light, a round of mathematical processing is required to obtain the complex amplitude after the hologram.

……=βA^2Bexp{ik/2d0[(x-x0)^2+(y-y0)^2]}+……

This took Shen Qi a certain amount of time.

The truth is about to emerge. The first term on the right of the equal sign is the so-called “halo light” that basically propagates in the direction of the illuminating light. The second term represents a divergent spherical wave, and the third term is another order of diffracted light.

The key is the third term, which can be rewritten using u=sinθ/λ and k=2π/λ, the factor exp(-i4πux).

Finally, Shen Qi completed the proof and got the coordinates of the convergence point, that is, the real image point as (x0-2d0sinθ, y0, d0)

Arrived 10 minutes late to enter the venue and finished the optical paper in 45 minutes. Shen Qi checked it and handed in the paper.

Under the gaze of a group of sophomore seniors and sisters in Wuyuan, Shen Qi did not stop too much, and hurriedly left after handing in the papers.

In fact, Shen Qi was not the first person to hand in the paper. A boy handed in the paper earlier than him, about a few minutes earlier.

Shen Qi walked out of the classroom and found the first boy to hand in the paper standing by the window in the corridor.

The boy wears glasses, is quite tall, close to 1.9 meters, black clothes, black trousers and black leather shoes, with his hands in his trouser pockets, standing upright, looking at the sky that is not blue.

“This look, this temperament, at first glance, is a scholarly tyrant, like a fellow.” Shen Qi made a preliminary judgment on the boys.

Suddenly, the boy turned his head and glanced at Shen Qi, and said, “I haven’t seen you before.”

Shen Qi: “My name is Shen Qi.”

The boy nodded as if he had said hello, and then continued to observe the smog-raging sky.

Shen Qi walked to the window, next to the boy in Wuyuan, and watched the sky with the boy. The visibility was very low.

The two stood there, silent, 3 minutes passed.

Shen Qi finally couldn’t help it: “Brother, what do you see?”

The boy said: “Jupiter and Saturn are normal, but the trajectory of Uranus is unusual.”

Are you looking at the stars in broad daylight? Shen Qi replied calmly: “Uranus does not follow a precise ellipse. This can be explained as a dark force attracting it.”

Boy: “No matter what, Newton’s law is absolutely correct within the solar system.”

Shen Qi: “I agree with you, so Neptune was discovered.”

A conversation between two Yan University students actually relived a classic case in the history of astronomy.

It is discovered that Uranus does not move along an elliptical orbit, so the law of gravity is in danger of being overthrown.

A physicist named Le Verrier boldly predicted that there must be a dark and invisible planet that is attracting Uranus.

Soon after, the planet was observed by the Berlin Observatory.

It is pale blue and very beautiful. The people on earth named this blue planet after the Roman name of Neptune Poseidon.

This is how Neptune was discovered.

Shen Qi is not good at astrophysics, but his teacher in the high school physical competition team is very good. Mu Rong’s undergraduate degree is astronomy, and he was upgraded to astrophysics during his master’s and doctoral studies.

“Everything is consistent with Newton’s law. The elliptical plane is not on the’sky plane’.” The boy said again.

“For longer distances, the law of gravity is also correct.” Shen Qi said.

“Yes, we can not only understand the nebula, but also get some inspiration for the origin of stars based on the law of gravity,” the boy said.

“What do you call the brother?” Shen Qi can’t take it anymore. This person is so good at pretending to be B. In the branch of astrophysics, I can’t say that he must be my doctor of physics senior sister.

“Yang Dingtian, major in astronomy.” The boy introduced himself briefly.

“Yangding Tianyang Hierarch?”

“Yang Liwei’s Yang, man can conquer the sky.”

“Brother Dingtian is a sophomore, right?”

“Sophomore.”

“It’s better to meet by chance. It’s almost time for dinner. Why don’t we go for a drink? I believe you are a man with a story, and I have wine.” Shen Qi guessed, this style, this way of pretending to be B Yang Dingtian has a place in the ranking of the kings of Wuyuan.

Yang Dingtian: “No, please go back.”

Shen Qi is not upset: “Alright, then I will go back to the academy first, and I will come to ask for advice another day.”

“You are from a hospital?” Yang Dingtian’s calm face finally revealed a hint of surprise.

“A freshman in the Department of Mathematics.” Shen Qi discovered that his popularity in the Academy of Things was not as high as expected, at least this Senior Brother Yang did not know him.

“I want to test optics across majors in my freshman year?” Yang Dingtian asked.

“I have received a bachelor’s degree in mathematics, and I am studying for a second degree in physics.” Shen Qi told the truth.

“It seems that you are also a man with a story.” Yang Dingtian couldn’t help looking at Shen Qi a few more times, “I invite you to this wine today.”

The two walked together and walked towards the small restaurant outside the school.

“My past was very ordinary. I like mathematics and physics, and I came to Yanda University.” Shen Qi filled Yang Dingtian with a cup of snowflakes and rushed to the world, and then filled it with himself.

“IMO? Or IPhO?” Yang Dingtian drank a glass of Chinese wine is a bold man.

“IMO, how about you?” Shen Qi asked.

“My past is also very ordinary, IPhO.” Yang Dingtian finished a drink and poured a glass, and added: “I have participated in two sessions of IPhO.”

He was twice selected for the six-man roster of the national sports competition team. This is very sad. Shen Qijing and Yang Dingtian had a glass and finished his glass of wine in one sip: “Why did you choose astronomy?”

“Truth exists in the universe, and most human beings are lost in oil, salt, sauce and vinegar.” Yang Dingtian looked out the window and looked up at the sky, his eyes deep and firm.

“Senior brother’s pattern is really magnificent.” Shen Qixin said, why don’t you go to heaven, and he added wine to himself: “Let’s talk about some grounded topics. Which course is the most difficult for undergraduate physics?”

“Fortunately, it’s not very difficult.” Yang Dingtian said, “The physical difficulty is not the technique, but the Tao. The Tao is natural, and it is invariably changeable.”

“Brother Dingtian, tell me the truth, what is your average score in the physics major?” In the constant exchanges and discussions, mankind has made progress. Shen Qi discovered from Yang Dingtian that the B system of the Academy of Things is different from that of the Academy of Sciences.