"I am not short of money, I have money, money is not brought in life and death, and what is spent is considered money......"

Walking out of the nuclear fusion laboratory, Lu Yi kept muttering that he signed a financial expenditure form that Xu Ying had just taken, and then $3 billion was spent.

These money are all loans from Tomorrow Group and the bank, although everyone has a good relationship and the bank will not pursue the "bad business" of these money, but there is no doubt that Tomorrow Group is now in negative equity of more than 20 billion US dollars.

If it weren't for the support of the cancer suppressant drug that was about to go on the market, if it weren't for the continuous income dividends brought by superconducting graphene wires and controlled nuclear fusion, then he would not be the richest scientist in the world, but the most negative scientist.

If these billions of dollars are spent to buy back a hen that lays golden eggs, it is distressing but acceptable to spend it, just like the mold of superconducting graphene wire.

But now what I spent and bought back is a pile of metallic hydrogen, which is only enough for a small nuclear fusion reactor and a spacecraft space engine.

In this way, even he felt a sincere waste, and he even saw Xu Ying look at the boss when he signed, and the boss you are stupid and have a lot of money.

"The cost of such a small fusion reactor and space engine will reach 3.2 billion US dollars, and the entire cost of the entire spacecraft will be as high as 6 billion US dollars, including the design and production of other equipment and instruments of the spacecraft.

This is still relatively familiar with the country, and many technologies and equipment and instruments in the aerospace industry are good for the sake of discounting prices. ”

Lu Yi roughly calculated the account, and said with some smacking his tongue and pain: "Sure enough, gravitational waves can't be played by non-local tyrant players, this is just a carrier of equipment and instruments, and the cost of laser interferometer has not been calculated, the maintenance cost of the spacecraft during the period when the equipment is sent to the sky many times, and the cost of cooperating with the country or further improving the spacecraft to carry people into space for laser interferometer assembly."

If the research fails, almost $10 billion in funding will be wasted. ”

When he and Zhang Qing were preparing to study space gravitational waves, they didn't think about ground research, so that they could spend hundreds of millions of dollars to look decent.

However, after reviewing a large number of literatures, it is determined that the difficulty of studying on the ground is exponentially higher due to the interference of environmental noise, and it is necessary to study the finer frequency fluctuations and deeper information of gravitational waves.

It's the same as when you can't hear the whispers of people 10 meters away in a night with DJ music.

Compared to the relatively quiet environment of space, the ambient noise on the ground is too noisy.

"Hopefully there will be good news for the Ligo project tomorrow."

In anticipation, Lu Yi took out his notebook to check the data obtained from Tianqin's plan to fight the autumn wind.

He and Zhang Qing are both new to the study of space gravitational waves, even if they have systematic assistance, but in the absence of relevant equipment and instruments, the progress is not satisfactory.

This is why Zhang Qing was so happy to hear that the NSF agreed to provide the relevant parameter data of the ligo observatory and the complete data of the last time ligo discovered gravitational waves.

There are too many conjectures and ideas in my heart, which need to be verified by actual experimental data to be determined.

......

"Ambient noise comes from the environment, and it can come from a subtle fluctuation of the earth's seismic wave beneath your feet, a fluctuation from the sun or other planets, or even from the equipment itself.

From this point of view, the problem of environmental noise is unavoidable.

We would like to ask how we should identify which test data are useful and which are noise-induced interference data when we encounter interference from external environmental noise? What is the solution to this problem? ”

In the video conference with the Ligo project team the next day, Zhang Qing asked for help from Principal Luo of the Tianqin Project, and this question also bothered Lu Yi.

The essence of gravity is the bending of space-time, and the essence of gravitational waves is the ripples of space-time.

Although there is gravity when there is matter, there will be ripples when gravity is generated, just like the ripples of the water on the surface of the lake caused by throwing a stone in the calm lake.

But gravitational waves are so small that they are beyond the detection limits of conventional human means, and as small as the fluctuations of the equipment itself can cause serious interference, and even small enough to exceed the imagination limits of ordinary people.

Gravitational wave intensity = (40 * gravitational constant * moment of inertia * square of frequency * ellipticity) / (fourth power of the speed of light * distance)

where the gravitational constant unit symbol is G, G=0.0000000000667.

The speed of light is measured in meters in this formula, which is c=3000000000.

From this formula, from the operation process of multiplying G first and dividing the speed of light c to the fourth power, everyone can clearly feel how small the gravitational wave is.

Take the famous Crab Nebula neutron star in astronomy as an example, it is 6,500 light years away from us, rotates 30.3 times per second, and we feel the intensity of its gravitational waves change from 1e to 23 meters on Earth.

What is this concept?

The radius of the smallest atomic hydrogen atom: 1e-10 meters.

This means that if we want to see the gravitational waves of neutron stars in the Crab Nebula, we need to keep our eyes open and see the change of a hydrogen atom 1 billion kilometers away.

What high-precision machine tools, what nanometers, what monoatomic layers, are scum in front of gravitational waves.

One can imagine the shock and excitement of those who understand this concept when they learn that gravitational waves have been successfully detected.

The miracles created by human beings have exceeded their imagination!

"When it comes to noise, it's a matter of precision."

Hearing Zhang Qing's question, the scientists of the Ligo project team thought for a moment and said: "On the one hand, we need to increase the noise of the external environment as much as possible to improve the stability of the instrument, and at the same time, we can also use another method.

We place high-precision instruments around the space of the gravitational-wave observatory, and external noise is first felt by these high-precision instruments before it affects the detection.

By calculating the attenuation of these noises, we can get the change in the data that affects the doping into the actual detection, and finally when the detection test is completed, we cancel out and discard this part of the noise data in the collected test data. ”

"We can't be 100 percent sure that the offset and discarded data is completely noisy data, which will result in the loss of some valid data."

Zhang Qing immediately realized the flaw of this method, and asked a rhetorical question while recording it in a notebook.

"There's no way around it, and the benefits outweigh the disadvantages of letting the ambient noise actually interfere."

The scientists of the Ligo project team shook their heads helplessly and said: "Of course, we also need to improve the stability and precision of the instrument as much as possible, and reduce the environmental noise, which is the best way to solve the root problem."

In addition, we need to arrange multiple gravitational-wave observatories at different spatial positions and spatial distances, and through the data detected by two or more observatories, we can further solve this problem by mutual verification and more certain accuracy of the data. ”

"I heard that you are planning to set up a large laser interferometer gravitational-wave observatory in space, and we can actually cooperate in this regard."

At this time, another scientist from the LIGO project team spoke, and said with some anticipation in his eyes: "One is on the ground and the other is in space, and everyone's detection data verifies each other, which is more conducive to the development of gravitational wave research." ”

It is the dream of every gravitational wave researcher to send a large gravitational-wave observatory into space, but due to limited funding and various technical reasons, few people can realize this dream.

"This matter will be discussed later, after all, our spacecraft are all on the drawings, and our laser interference observatory is still in the factory."

In the face of this request, Lu Yi, who had just been using the system to help understand the test data sent by Ligo, unveiled the topic with a smile, and then used his laptop to mark out a few lines of data display in the video screen, and asked:

"I was just looking at your probing test data when I noticed a few unusual rows of fluctuating data, which were fleeting and incomplete.

I see in your notes that you marked this piece of data as device noise, and I want to determine how often this kind of data occurs? How is the tracking of this data going? ”