We Live In Nanjing

  Chapter 82 It is 130,000 kilometers away

As soon as Wang Ning’s voice fell, the amateur radio station 725 on the coffee table began to radiate electromagnetic signals. It converted pictures into sound and hid the sound in radio waves that human ears could not catch. This is a whisper that humans cannot capture and understand. Whispering, but the magic is that it is actually an image—turning an image into sound may be unimaginable for ordinary people, but for people who have mastered information coding technology, information is information, and the carrier is the carrier, as long as It is not difficult to gain insight into the nature of information and to separate it from the carrier—from the time when humans carved murals in caves with chisels hundreds of thousands of years ago, images, as the carrier of visual information, developed from rock walls to clay slabs. After thousands of years of vicissitudes and vicissitudes, the relationship between the two seems to have remained unchanged until the industrial revolution ignited and information theory brought the world's innovation. People can finally transform image information from two dimensions. Grabbing it from the plane of the sky, stuffing it into the sound, stuffing it into the electric current, stuffing it into the light wave, from then on any information can be broken apart and shattered and stuffed into any carrier.

  Insight into the nature of information, in a sense, this is also the power of God.

  Mastering the information, human beings take another step in the direction of the gods.

  Bai Zhen is guarding the laptop screen. The photos are being scanned from top to bottom little by little. What does this feel like? It's like a lottery, scratching music, scraping down one by one, revealing the pictures behind it.

  In the beginning, the signal reception was not good, and only the green snowflake noise was scraped out. The white shock slightly adjusted the direction of the antenna to receive a clearer picture.

  "How is the situation?" Wang Ning asked.

   "It's okay." Bai Zhen replied, "It's just a bit slow."

A Ugandan chimpanzee... Bah, the half-length photo of a baboon is 15KB in size, and the transmission speed between 725 and 705 in the living room for the simulation experiment at this moment is only about 1000bps, which is 0.1KB per second. Ideally, this It takes 150 seconds, which is two and a half minutes, for a photo to be transmitted successfully.

   But how can the reality be so ideal?

  Radio is a radio after all, not a cable optical fiber. It is convenient to use radio waves to transmit signals, and simple is simple, but you can no longer expect it to be very efficient.

  Convenience, simplicity, and efficiency, you can only have two of them at the same time.

Therefore, the image transmitted by the amateur radio is unstable. Put it on the network project, that is, the packet loss is serious, the antenna is not right, and the scraped out is a green snowflake spotted band. If you want to successfully receive a complete and clear picture at a time, It can't be done.

In order to ensure that the signal can be transmitted completely, Wang Ning will transmit multiple redundant signals. His 725 will send pictures continuously in a cycle of one hundred and fifty seconds until Bai Zhen can receive a picture completely. So in Bai Zhen's eyes, the Lenovo computer in front of him was repeatedly scraping, and it was a big prize to be able to scrape out a complete picture of himself.

   "Wait... there is interference, where is the interference?" Bai shook his head and looked around, "Is it a switch? Pharaoh, wait, I'll try to pull the brakes."

  He immediately ran to turn off the switch, and when the switch was switched off, the room was suddenly dark.

  "Is the power out?" Mom came out of the bedroom holding her mobile phone and flashing a flashlight, "Why is it suddenly dark?"

   "Lao Bai has opened the gate." Wang Ning sat on the sofa with a fat face illuminated by the faint green light of the CRT monitor, "We are doing an image transmission experiment."

   "If you do the experiment, do the experiment, what gate should you use?" Mom asked.

   "There is interference." Wang Ning replied.

Annoying electromagnetic interference in modern society is everywhere, such as the tower crane next door, the security walkie-talkie at the gate of the community, the electric car downstairs, and many inconspicuous small appliances in daily life, such as the power switch in the house. It is everywhere. There is no way to avoid all-round stereo interference. Bai Zhen can only turn off the switch of his own house, not the neighbor’s house next door, let alone the Meihua Villa community. The electromagnetic environment in the city is so bad.

  Some old HAMs like field battles...Ah no, wild frames, they are charged in this clean and endless environment, and a good signal-to-noise ratio allows them to hear the sound of the fly on the radio waves rubbing their hands.

  After the power failure, Bai Zhen tried to receive the signal again.

  "Are there any better?" Wang Ning asked.

   "No!" Bai Zhen said, "a dick."

  "You go to find the main gate of the community." Wang Ning said, "cut off all the power in the community, so that the interference will be fine."

   "Then I shall not be swallowed up by the property?"

  "Hey, for special reasons and during special periods, I told them to urgently requisition electricity. The first machine used a positron cannon on the Purple Mountain to deal with the Fifth Apostle. If you don't give electricity to Aya Polly, you will die."

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Bai Yang is sitting in the dark wearing a sweater, the radio is connected to the battery, the lamp is turned on, and the warm light propels the night to form a small circle, enclosing the desk, pen holder, radio and the face of the teenager. He holds the microphone in one hand. , Holding a pen in one hand, concentrate and work hard at writing.

"Huh? It's okay, the lights are dark. My father, they pulled the gate." Bai Yang said while holding down the PTT, "They are doing an image transmission experiment, Miss, let's continue...Do you know Newton? Newton's law of universal gravitation , OVER."

  "Newton?" The other end was puzzled, "What is Newton?"

"It's an individual, an Englishman, a great physicist." Bai Yang explained, "The F=G·(mm/r) that your teacher wrote on the draft is the formula for the law of universal gravitation, where F is gravitation, and G is the constant of gravitation, two m is the mass of a celestial body, r is the distance. It means the gravitational force between two celestial bodies, which is proportional to the product of their masses and inversely proportional to the square of their distance, OVER."

"Oh…"

  The girl nodded seemingly understanding.

  The monk chanted her scriptures to ring the bell, and it didn’t matter if she didn’t understand, just nod her head anyway.

   "I infer that your teacher was studying the relationship between the black moon and the earth, so he wrote these numbers and formulas on the draft paper." Bai Yang said, "It's just that you didn't understand it at the time, OVER."

   "I can't understand it now."

   "It doesn't matter if you don't understand, I can understand!" Bai Yang was very confident.

   There is a reason for Bai Yang’s self-confidence and confidence. He is a senior high school student who is about to face the college entrance examination.

  At this moment, he is at the stage where he has the broadest knowledge, strongest thinking ability, omniscience of astronomy and geography, and knowledge of history and politics in his life.

  "Let’s sort out these data, Miss, believe it or not, can I infer the whole picture of the black moon with the data of 1200 kilometers?" Bai Yang said, "OVER."

  The girl was taken aback, "Really?"

   "Really." Bai Yang nodded, "Miss, let's look at 1,200 kilometers first. This number written by the teacher on the draft of "Journey to the West", we think it is the diameter of the black moon, right?"

  Banxia nodded.

There are two numbers and two circles on the draft paper of "Journey to the West" on this page. The numbers are 1200 and 3476 respectively. The two numbers are marked beside the two circles. Pinellia and Baiyang reached a consensus when interpreting this draft. , Think that these two circles are the white moon and the black moon, 3476 is the diameter of the white moon, and 1200 should be the diameter of the black moon.

  "In your eyes, the black moon is the same size as the white moon?" Bai Yang then asked, "Miss, is that true? OVER."

   "Yes, they look the same size." Banxia nodded.

   "Then I can know how far Black Moon is from you..."

  Poplar opened the calculator and quickly typed drafts on the paper.

  He has never been so diligent in his life. He was still doing math and physics even after the power went out. My mother said that if he had the enthusiasm for studying at ordinary times, he would not have to kowtow all the way from Zijin Mountain to Xuanwu Lake if he wanted to enter Nanjing University.

  "The radius of the moon is 1,737 kilometers."

  "The distance between the earth and the moon is 380,000 kilometers."

  "The tangent should be 0.0045718..."

  Half a minute later, Bai Yang got the answer.

  "Miss, Black Moon is about 131,239 kilometers away from you, OVER."

   Banxia was taken aback.

"How did you know?"

"Ran, eldest lady, it’s a simple calculation. The white moon and the black moon are the same size in your eyes, so when you look at them, the radian angle is the same." Bai Yang explained, "The white moon is 380,000 kilometers away from you. With a diameter of 3476 kilometers, then the black moon has a diameter of 1,200 kilometers. Using trigonometric calculations, it should be 130,000 kilometers away from you, OVER."

"impressive."

   Although Banxia doesn’t understand, she thinks it’s amazing.

"We will continue to calculate next. Now that we know the distance between the black moon and the surface, we can calculate the cycle of the black moon, and the cycle of its revolving around the earth." Bai Yang was quite proud, and was praised by the beautiful girl for being as powerful as a bald physics teacher. The commendation of is much more useful. He listed the formula on the draft paper and counted down in a hurry, "Adding the radius of the earth, r should be 137,610 kilometers, and G is the gravitational constant. We take 6.67×10^(-11) Nm/kg...The formula T=√(4πr/GM), then T should be..."

  Bai Yang held his hand in the microphone and muttered words while counting. The room was silent late at night, and only the girl twenty years later listened.

  Numbers and formulas flowed from under the nib of the boy, and flowed into small rivers on the white paper.

  Poplar lived for eighteen years and studied physics for five years. For the first time, those dragon-slaying techniques that could be used for nine days to capture the moon and the oceans to catch turtles came into practical use.

After really using it, Bai Yang realized that he had mastered such a powerful tool. This is the law of the universe's operation and the underlying code of the universe online. Every high school student has built a magnificent building of classic physics in his mind, but it is just a few. Someone really uses it, letting it weather and collapse in time.

   "16 days!"

  "Miss, the black moon's cycle is 16 days. It revolves around the earth every 16 days, OVER."

   "Unbelievable! It's amazing, BG4MXH, how did this happen?"

  Banxia is unbelievable, she thinks BG4MXH is turning magic.

  He has never seen a black moon, why can he know how long the black moon turns around?

"I didn't do it myself. Behind me stood Newton, Kepler and all the physicists in human history." Bai Yang said, "and my physics teacher, he put all the most geniuses in history in their minds. The top wisdom contained has been taught to me."

   "Then your physics teacher is so amazing!"

"I thank you on behalf of our physics teacher, Miss, your teacher must have calculated these things at the time." Bai Yang said, "We continue to push down. Now we already know that the black moon is 130,000 kilometers away from us, but I can’t understand, why does it have to orbit 130,000 kilometers from the earth?"

  Banxia was startled, she didn't know what this question meant.

  Why do we need to orbit at a distance of 130,000 kilometers from the earth?

  Black Moon is willing to stay in that place, is that its freedom?

  How could she know why?

"Miss, the big eyes came from the black moon, right? Then why doesn't the black moon come closer so that the big eyes can come?" Bai Yang asked a question that Banxia had never thought of, "130,000 kilometers, this The distance is not close, it takes a long time to fly, why doesn't it get closer? OVER."

   "Hmm...what could be the special reason?"

  The girl thought for a while.

"There are reasons behind any phenomenon." Bai Yang said, "Miss, we might as well imagine that it can't get closer because it can't get closer. The reason why it has to stay on the orbit 130,000 kilometers away. It’s because it can only stay on an orbit of 130,000 kilometers recently, OVER."

   "Why?" Banxia asked, "Why can it only stay there?"

  "Because power is restricting it." Bai Yang replied, "There is an irresistible force restricting it, OVER."

   "What power?"

"Gravity, Miss, is universal gravitation." Bai Yang said, "This is the only force in the universe that cannot be unified and cannot be controlled. It restricts the black moon. If the black moon gets too close, it will be torn apart by the huge gravity of the earth. , 130,000 kilometers is its safety range. It cannot cross this red line. If it crosses the thunder pond, it will break its body... the name of this red line is Roche Limit, OVER."

"Assuming that 130,000 kilometers is the Roche limit of the earth and the black moon, then we can deduce the density of the black moon... Let me find the formula for the Roche limit! There are fluid Roche limit and rigid Roche limit..." Bai Yang Turning on the phone and rushing to Baidu, turned out a blank draft paper, "I found it! I found it! Let me do the math, the formula is d=2.423R(ρ/ρ)^(1/3), the average density of the earth It is 5507.85kg/m...then the average density of the black moon under the fluid Roche limit is 7.83kg/m, and the average density under the rigid Roche limit is 1.09kg/m."

  "Miss, the average density of Black Moon is between 1.09kg/m and 7.83kg/m."

  Banxia is a bit dazed, do not understand what this is a number.

  What is the concept of density?

  The density of air we breathe in daily life is 1.3kg/m. The density of nitrogen is 1.26kg/m, the density of oxygen is 1.46kg/m, and the densest gas radon is 9.73kg/m, which means that the maximum density of the black moon is not as large as radon.

  "What does this mean?" Banxia asked.

  "This shows that either Black Moon is a gaseous satellite, it is actually a mass of gas." Bai Yang paused, "Either it has a huge cavity inside, it is hollow."

  (End of this chapter)