Into Unscientific Chapter 713

 At this moment.

 In the reception room.

Hearing Lu Guangda's words, Yang Zhenning's face showed clear astonishment for the first time:

“Guangda, what do you mean?”

At this time, Yang Zhenning's tone was so high that it even broke his guard.

After all, it would be okay if this was the first time he heard the word donkey, but now it was the second time that Yang Zhenning heard the word donkey mentioned.

 Could it be that in the years since he left his motherland, the donkey has also mutated and started to participate in scientific research projects?

Then Yang Zhenning bit the soft part of the inner wall of the lip cavity hard, using the pain to force his thoughts back to reality:

"Guangda, what exactly is the donkey you are talking about? How can it be related to gravitons? - To be honest, Lao Huang mentioned something similar to this on the way to Jinmen."

Lu Guangda also returned to normal from slapping his thighs at this time. He scratched his chin twice with his fingers and said something in his mouth:

“Zhen Ning, don't be impatient. You'll understand after I explain.”

“First of all, let's bring the topic back to the original point and talk about the device you designed.”

“If my prediction is correct, one of the principles used in the original gravitational wave detector you designed should be the Michelson-Morley experimental principle, right?”

Yang Zhenning nodded readily.

 Whether it is primordial gravitational waves or conventional gravitational waves, since they are waves, the best way to detect them is obviously an interferometer.

 Because waves can be superimposed.

 When two waves overlap and the amplitude of the resultant wave is greater than the amplitude of the component waves, it is called constructive interference or constructive interference.

 If at a certain moment.

The crest of one wave meets the crest (or trough and trough) of another wave at the same place - that is to say, the vibrations caused by the two waves are in the same phase here, so at this point the vibrations caused by the two waves are always mutually exclusive. Intensified, the amplitude of the particle is the largest.

This kind of interference is called completely constructive interference, or completely constructive interference.

same.

 When two waves overlap and the amplitude of the resultant wave is smaller than the amplitude of the component waves, it is called destructive interference or destructive interference.

 If at a certain moment.

 The crest of one wave meets the trough of another wave at the same place, that is, the vibrations caused by the two waves are in opposite phases, so the vibrations caused at this point will always weaken each other.

  If the amplitudes of the two waves are the same, the sum of the displacements of the particle is always equal to 0.

 The interference at this time is also called completely destructive interference, or completely destructive interference.

This principle is essentially the same as the Michelson-Morley experiment, but the concept is much more advanced and refined - its level of advancement is even greater than the interferometer Xu Yun built in the 1850 copy.

According to Yang Zhenning's idea, this set of equipment can be divided into two stages according to the exploration target:

 The first stage is to detect conventional gravitational waves, and the second stage is to detect primordial gravitational waves.

The latter is slightly more difficult than the former. For example, it is already difficult for you to find a Super Saiyan in the world of "Dragon Ball", but it is even more difficult to find a Super Saiyan who can freely use the Ultimate Skill.

 So the two have a progressive relationship. Corresponding to these two stages, Yang Zhenning also designed two sets of equipment.

 “Guangda, this is what I think.”

 Lu Guangda had prepared a blackboard in the living room in advance, so Yang Zhenning immediately pulled the blackboard and started drawing:

“The first set of equipment utilizes the principle of laser interference. A laser beam is emitted from the laser instrument, passes through a spectroscope tilted at 45°, and is divided into two laser beams with exactly the same phase, which propagate in two directions perpendicular to each other. "

“After the two beams of light reach the two reflectors at the same distance, they are reflected back along the original path and interfere.”

“If the light beams travel the same distance, their light waves will be perfectly staggered, completely destructive interference will occur, and no laser signal will be detected on the detector.”

Yang Zhenning paused as he spoke, then drew an arrow at a 45° angle on the blackboard, and continued:

“When a gravitational wave passes through a detector, it causes disturbances in the space around the detector.”

“This perturbation causes space itself to stretch in one direction and compress in another, creating a subtle difference in the distance traveled by the two laser beams.”

“When the phases are staggered, the intensity of light on the detector will change significantly, proving the existence of gravitational waves.”

“Of course, this idea sounds simple, but in fact the investment cost is very high.”

 Lu Guangda listened quietly and nodded in agreement.

really.

Theoretically, Yang Zhenning's idea is very simple and clear, and it seems that it will work if you have the skills, but it is very difficult to implement in practice.

Because mathematically, the change in detector distance caused by gravitational waves can be as small as 1/10,000 of the size of a proton—that is, 10 minus 23 meters, so the size of the detection equipment must be extremely large.

After all, the longer the arms of interferometers, the smaller the measurements they can make, the more sensitive the instruments, and the more powerful their detection of gravitational waves.

 Based on Yang Zhenning and Lu Guangda's own calculations.

The arm length of this conventional gravitational wave interferometer must be at least 3.5km, and the internal optical path must be reflected more than 300 times to ensure that the laser optical path length can exceed 1,000km.

This project can be considered a major project at any time.

Then Lu Guangda thought for a while and said to Yang Zhenning:

“Zhen Ning, what is your expected equipment investment cost?”

Yang Zhenning's mouth moved. He wanted to ask Lu Guangda when he could explain the donkey problem, but after hesitating for two seconds, he decided to follow Lu Guangda's rhythm:

"If the exchange rate does not change much in the future, it will probably be 36 million Huaxia coins today - this project can be invested in batches within 25 years, and the first phase will cost about 3 million."

 Lu Guangda nodded slightly.

Although he didn't know the specific ideas of Yang Zhenning and others when he left the base, he was told that these scholars who returned to China would basically have their own projects in place.

 So he and another donkey in the base asked roundaboutly about the future exchange rate, and got an answer like "In terms of scientific research costs, 1 yuan today is probably equal to 100 yuan in the future."

 Calculated as follows.

The more than 36 million Chinese coins Yang Zhenning needs will probably be more than 30 billion in the future.

 This is indeed a big deal.

 According to what the donkey said, in the future, the investment in many national projects will only be between a few billion and 10 billion, and only a few master plans like Luzhou Liangxin Laboratory will exceed 100 billion.

 At that time, the economic strength of the rabbits was many times ahead of what it is now.

 Fortunately, as Yang Zhenning said, this number is an amount that can be invested in installments. The rabbits do not need to come up with so much money immediately. The first installment of 3 million is enough.

 And this is within the funding limit approved by the organization for Yang Zhenning.

because

With the strong push of the donkey in the base, Yang Zhenning's funding after returning to China was also raised to a very astonishing figure:

  10 million Chinese coins.

 That's right.

  10 million Chinese coins.

 This number can almost be described as astronomical to the poor rabbits today.

To know.

Since three years ago, the rabbits' direct investment in researching the atomic bomb has only been 2.8 billion Chinese coins.

Yang Zhenning's scientific research funding alone is equivalent to about three thousandths of the total cost of atomic bomb research.

Of course.

Other scholars' quotas are also not low. For example, Li Jingjun, the father of genetics, has a project fund of up to 5 million Chinese coins.

At the beginning, in order to reasonably take the cooked Xu Yun away from Guide County, Lao Guo and the others made up a theory that Xu Yun was related to a 5,000 yuan theft case.

That number shocked a group of ordinary workers at that time, let alone today it is hundreds or tens of millions.

These figures are extremely inconsistent with the current level of domestic development. People who don't know why will probably think that the rabbits are crazy.

But who gave Base 221 a reason worthy of the rabbits' stud?

The courage, vision and decisive courage of the few college students in the capital are once again vividly demonstrated in this third batch of international students returning to China.

Looking back to reality.

Yang Zhenning was promised the 10 million yuan before returning to China, so he seemed quite calm when talking about the amount of investment.

He is confident that the detector will produce some visible results before spending all his funds, so as to ensure that the country will increase subsequent investment - to be honest, if he does not even have this confidence, then he will not return to the country. Bring the project.

Then Yang Zhenning took a deep breath and looked at Lu Guangda again:

“Guangda, I've almost finished what I have to say. Now it's time for you to explain why primordial gravitational waves are related to donkeys, right?”

Lu Guangda didn't show off this time. He laughed twice and pointed at the second part written by Yang Zhenning on the blackboard:

“Lao Yang, didn't you say that your detection steps are divided into two stages?”

“The first is conventional gravitational wave detection, and the second is primordial gravitational waves.”

“It is the second stage of primordial gravitational waves that uses donkeys—at the same time, donkeys are still the core link in this stage.”

Yang Zhenning raised his eyebrows:

"How to say?"

Lu Guangda thought for a while, stood up from his seat, walked to Yang Zhenning, took the pen, and wrote on the blackboard:

“As usual, we still start from the principle of the equipment. Conventional gravitational wave detection can be regarded as a large-scale precision interferometer, which requires a physical 'mechanical arm' several kilometers long.”

“Therefore, this kind of equipment can only be built on the ground. It is one of the precision equipment on the ground, which is the so-called ground engineering.”

“However, the detection of primary gravitational waves is different. It has to go up to the sky and is related to aerospace.”

Yang Zhenning put his hands behind his back and nodded slightly, expressing his agreement.

 Mentioned earlier.

Gravitational waves are difficult to detect because their frequency is too low and their wavelength is too long.

 Take the first measured gravitational wave numbered GW150914 as an example.

 Its frequency is only about 150Hz, and its propagation speed is the speed of light, which is 300,000 kilometers/second.

  So its wavelength is 2000 kilometers, equivalent to one-third of the Earth's radius.

In the future when Xu Yun traveled back in time, the most well-known project in gravitational waves was obviously LIGO.

LIGO's total cost is about $600 million, with an arm length of four kilometers and more than 400 internal refraction light paths.

However, even with an arm span of several kilometers, interferometers built on land such as LIGO can only detect those parts of the gravitational waves with the highest frequencies and the shortest wavelengths. This is why whenever future generations hear gravitational waves, they are almost bound to be related to the more extreme situation of black holes merging or black holes swallowing neutron stars.

 Because only such extreme events can release huge amounts of energy in a short period of time, thus producing such high-frequency gravitational waves.

During the black hole merger that produced GW150914, the peak radiation power it reached instantly was ten times the sum of the radiation power of all luminous materials in the observable universe.

Even so.

When it crossed a distance of 1.3 billion light-years and passed by the Earth in 2015, LIGO Livingston and LIGOhanford, which had an arm span of only 4 kilometers, successfully detected the signal, but the other GEO600, which had an arm span of only 0.6 kilometers, failed to detect it.

At the same time, such high-energy extreme events are not common in the universe. In the six months from April to October 2019 when LIGO-Virgo was fully operational, a total of only 39 were detected, an average of about 3 times every two weeks.

 Conventional gravitational waves are detected in this way, let alone primordial gravitational waves.

The theoretical frequency of original gravitational waves is below 10 Hz, and the wavelength is at least tens of thousands of kilometers. The wavelength of some low-frequency gravitational waves can even reach the order of light years, which is difficult to detect with the arm span of LIGO.

in this case.

Since the size of the interferometer on the ground is not enough, the easiest way to think of is.

 Erect a very large interferometer in space.

 “Lao Yang.”

Then Lu Guangda drew a triangle on the blackboard, and while drawing, he said to Yang Zhenning:

“According to your idea, you are going to launch three satellites into the sky to actively track the possible time in the universe.”

“However, these three satellites do not move around the earth, but follow the earth around the sun.”

Yang Zhenning nodded again.

His idea is actually very simple:

The universe is vast, so if laser transmission is performed in the universe, can't the “length” of the robotic arm be adjusted at will?

 According to his plan.

 The distance between these three satellites is about 3.8 million kilometers, which is almost 10 times the distance between the earth and the moon. It takes more than 12 seconds for the laser to go from one device to another.

 At present, the total number of satellites launched into the sky by all countries on the earth does not exceed 8. Yang Zhenning's idea shows how exaggerated it is.

However, Lu Guangda has often encountered the impact of someone's weird remarks in the past period, so at this time he can still communicate with Yang Zhenning calmly:

“Lao Yang, according to the model you designed, many satellite equipment cannot be connected through metal structures.”

“Connecting equipment, that is, the material responsible for splicing core materials, must have stronger pulling force, bending force and shearing force than ordinary high-temperature tape.”

“And this material, Lao Yang, to tell you the truth, comes from the local donkey we mentioned before.”

“The official name of this thing is donkey pulp film, and it is now a very high-density military resource in our country.”

 Hear this.

Even though Yang Zhenning was prepared for some shocking words that Lu Guangda would throw out, there was still obvious astonishment on his face.

 Core material splicing.

 This is indeed a theoretical technical difficulty for satellites, especially high-precision detection satellites.

 Firstly, after the satellite breaks away from the rocket and enters orbit, the splicing area will encounter huge shear force.

The existence of this shear force will deform conventional alloys and ordinary colloids, thereby affecting the splicing structure of the satellite.

If the satellite does not carry any precision instruments and its structure is stable, then it will be okay.

  But if there is a device with an accuracy of several decimal places placed on it, the impact of the colloid deformation will be great.

 So if there is such a high-strength material, it can indeed be regarded as one of the important or even core materials related to the implementation of Yang Zhenning's idea.

But when this thing is combined with a donkey, it looks a little weird.

Looking at the confused and confused Yang Zhenning, Lu Guangda's mouth couldn't help but curl up a little.

 After he discovered that Yang Zhenning had designed a space detector, he actually had a premonition of this happening.

after all

 Donkey pulp film is the strongest splicing capsule material today. Whether it is the German guy or the bear next door, they are doing related transactions with the rabbits.

The purpose of purchasing donkey pulp film by these two countries is to use it in the aviation field - the difference is that the former is a satellite and the latter is a space shuttle.

So if Yang Zhenning's plan is to be implemented, it must be inseparable from the help of local donkeys.

"etc!"

Just when Lu Guangda was looking at Yang Zhenning happily, Yang Zhenning suddenly frowned:

“Guangda, the local donkey material you mentioned has the property of resisting high-strength forces, which means you definitely have enough experimental data to prove this.”

“At the same time, the material used for splicing the core material must be in a colloid or film state. If it can be effective in situations such as space, it must also be able to be used normally in the atmosphere, right?”

 Speaking of which.

Yang Zhenning suddenly raised his head and stared at Lu Guangda with sharp eyes:

“Could it be that the reason why you were able to capture U2 was that this local donkey material also played an important role in it?”

“No wonder you said that the U2 reconnaissance plane was kicked down by a donkey. Is that what happened?”

 Lu Guangda's raised corners of his mouth suddenly froze when he heard this, and there was a hint of obvious shock in his eyes.

　　A long time passed.

Lu Guangda just calmed down his expression, shook his head with a wry smile, and said slowly:

“Lao Yang, Lao Yang, I haven't seen you for so many years, but your thinking is still so sharp.”

“Forget it, the superiors didn't intend to hide this from you anyway—yes, the reason why we were able to shoot down the U2 was because we had a missile platform that could stay at an altitude of 30,000 to 40,000 meters.”

“This platform consists of four missiles, and one of the core materials of the platform is the capsule material made of local donkey slurry.”

“Its official name is donkey pulp film. You can write this name down. You should come into contact with it frequently in your work in the future.”

 “The native donkey is a good thing.”

Yang Zhenning nodded clearly.

 Sure enough it is so

The shooting down of the U2 reconnaissance plane is no secret across the sea. Especially for Chen Ning Yang and other relatively mid-level and high-level talents studying in the United States, this matter cannot be suppressed in the industry.

It's just that before returning to China, neither Yang Zhenning nor Li Zhengdao believed the explanation promoted across the sea [the rabbits were helped by the bears], so they didn't delve too deeply into this matter.

Now after hearing what Lu Guangda said, Yang Zhenning just thought of U2.

Then Yang Zhenning seemed to think of something again. He slurred, took out the "Physical Review Letters" journal from his body, pointed to the first page and said:

“Guangda, what's up with the ChineseDonkey in this paper? Does it also refer to the native donkey?”

The clinker Lu Guangda gave him a subtle look, denying Yang Zhenning's guess:

“Zhen Ning, this matter has nothing to do with the local donkey—it actually refers to another donkey, known as Mr. Wo Donkey.”

 “If there is a chance in the future, you should have a chance to deal with him.”

Yang Zhenning:

 “Okay, okay.”

Seeing Yang Zhenning's expression of wanting to explore the reason, Lu Guangda couldn't help but patted his friend on the shoulder:

"This matter is very complicated to explain. Let's wait until you go to the capital to meet with the big leaders."

“There is only one thing I can tell you about this paper at the moment, and that is that the equipment we used for the experiment is the 80MeV tandem electrostatic accelerator from CERN.”

This time, the expression on Yang Zhenning's face was not so surprised, and his face just showed an expression that was indeed the case.

Although Yang Zhenning did not think of the origin of the accelerator the first time he saw the paper, he studied the paper across the sea for more than two months. No matter how slow his thinking was, he could not fail to make this guess.

After all, there is only one piece of equipment in the world that can do this. However, it caught fire and was damaged during transportation. It is normal for Yang Zhenning to think of it.

 In fact.

There are probably many top scholars who are aware of this, but Germany, Britain and France have never acknowledged this, insisting that the accelerator was burned down in Normandy.

 In addition, many people cannot logically explain why the Rabbits can ask countries from three different camps to provide guarantees, so this matter is destined to become only a fruitless speculation.

Now Lu Guangda has just confirmed this speculation, which will not cause much psychological fluctuations for people like Yang Zhenning who have long been confident.

"correct."

Then Lu Guangda turned his attention to the blackboard in front of the two of them, pointed at the three satellites above and said:

“Zhen Ning, in addition to core material splicing, is there another problem that has not been solved in your plan?”

Yang Zhenning nodded frankly:

“Yes, there is another problem—even a space interferometer of this level is still unable to reach the bottom of the gravitational wave frequency.”

“Unless I can think of another way.”

 Mentioned above.

The frequency of gravitational waves is ridiculously low, and the wavelength is ridiculously high.

The space interferometer designed by Yang Zhenning can detect gravitational waves at most 10-6 to 10-9Hz. No matter how low the frequency is, it cannot detect gravitational waves with a length of light years.

unless

Rabbits have the ability to set up an interferometer larger than the Kuiper Belt of the solar system.

 And this is obviously impossible to do in the short term. Let alone the 30 years that Yang Zhenning thought, 300 years is about the same.

 If these gravitational waves cannot be successfully captured, the possibility of detecting distant gravitational waves will be at least halved.

This is also the reason why Yang Zhenning and Li Tsung-dao regard primordial gravitational waves as a lifelong bet - they themselves do not have much confidence in finding primordial gravitational waves.

Think of this.

Yang Zhenning couldn't help but sigh.

 An interferometer larger than the Kuiper Belt is obviously beyond human reach.

But just when Yang Zhenning was feeling a little sad, Lu Guangda's voice suddenly sounded in his ears:

“Zhenning, maybe someone I know can help me figure this out. Are you willing to give it a try?”

"oh?"

Yang Zhenning looked at his friend with some surprise:

 “Who? Are you coming? Or is it Teacher Wang?”

Teacher Wang in Yang Zhenning's mouth is Wang Ganchang. When Wang Ganchang was in China, he personally trained Li Zhengdao, a Nobel Prize winner, and Yang Zhenning also took several classes under his name.

 Therefore, although the two of them did not have a master-disciple relationship according to their academic records, Yang Zhenning still called Wang Ganchang Teacher Wang.

However, Lu Guangda quickly shook his head and denied Yang Zhenning's statement:

"neither."

When Yang Zhenning heard this, the confusion on his face became more intense:

"Who is that?"

Lu Guangda was silent for a few seconds and pointed to the journal Yang Zhenning had read to him before:

 “Another donkey.”

Note:

  25 was discharged from the hospital, but it is estimated that he will be recuperating for at least a month.

Chapter end