"Civilization without people, meaningless." This is a line from The Wandering Earth 2. On January 22, New Year's Day, the movie was released as scheduled. Three days ago, Dr. Cui Yuanhao, one of the scientific advisers of the film, had already watched the special screening of scientists in advance. He graduated from Beijing Post with a Ph.D. in communications, and participated in conceptual design and refining the worldview of the film.
Figure | The first from the right is Choi Won-ho (Source: Choi Won-ho)
The film mainly has three groups of characters: technical supporters (scientists) mainly composed of Tu Hengyu, Tu Yaya and Ma Zhao, practical operators (astronauts) dominated by Liu Peiqiang and Zhang Peng, and high-level decision-makers (diplomats) dominated by Zhou Zhezhi and Hao Xiaoxi. This article will start with the part of the scientist.
Figure | A corner of the set (Source: Infographic)
Tu Hengyu: A supporter of technology to save the earth
One of the most touching parts of the film is quantum scientist Tu Hengyu, the digital life created for his daughter Tuya, who died in a car accident. Tu Hengyu's research direction is digital life and digital world, that is, exploring whether digital life can be realized. Therefore, he is precisely positioned as an architect of the digital world.
His Beijing Digital Life Research Institute designs the 550 series quantum computers. The initial version was the 550A, which was iterated to 550C and 550W when the space crisis came. Later, when the UEG (United Earth Government) Joint Government Ethics Committee banned the Digital Life Project, Tu Hengyu and his leader Ma Zhao began to turn and focus entirely on designing 550W.
And Tu Hengyu's biggest private wish is to make a real digital life. Later, he did make his daughter Tuya the first person to have a digital life, she has consciousness and can interact with the real world, of course, Tu Hengyu was also imprisoned for a while.
Specifically, he uploaded Tuya's thinking to the digital life carrier and gave Tuya two minutes of life through a computing power of 550A. Why only two minutes? Because the computing power of 550A is limited. The limitation here is that digital life itself requires environmental perception, as well as cognition of historical memory, and cognition produces emotions, and emotions perceive human behavior.
Therefore, when Tu Hengyu "makes" life, he must not only consider the historical memory of Tuya, but also consider the current environmental state. At the beginning, due to the lack of computing power of 550A, it was impossible to generate a perfect digital world, which would bring about the collapse of the digital world, which would cause problems with Tuya's consciousness, so her first reaction at that time was that it was dark around, in fact, this is the manifestation of digital life entering a state of self-preservation.
When the computing power becomes stronger, the digital world will be more realistic and stable. At this time, Tuya's digital life can communicate with the outside world more stably, and its life span can be extended to 70 years.
Figure | A corner of the set (Source: Infographic)
With the help of Tuya's digital life, Tuhengyu was able to start the Internet root server at a critical moment. In the movie, humans must restart the global engine at the same time, so a time-synchronized system is needed. But time was of the essence, so the most likely synchronization system at that time was to use a synchronous private network for engines that had already been designed. In fact, this is also Tuhengyu's plan to rely on the original Internet architecture.
When using a synchronous network to restart the engine, it is necessary to restart the global Internet at the same time. As a private network, the synchronous network is built on the Internet, similar to the financial private network in the real world, by making high-density slices of the Internet to ensure that the engine can operate normally on the Internet in a high-density manner.
The Internet root server in the chip is a collection of real-world Internet root servers plus a core router. It's not exactly the same as the root server we know it. In reality, even if we restart a server, it is technically impossible to completely restart the Internet. But for the film, the crew had to simplify the concept, so the two functions were combined into one.
Restarting the root server is a crucial step in restarting the Internet, so why do you need to restart three root servers?
Cui Yuanhao said: "Considering that there was a lot of concurrency in the network at that time, a redundant backup was needed. Restart three can fight against the restart storm when the Internet resumes to start, you must know that there will be many people connected to the network at that time, which will bring a large number of simultaneous requests to the server, in fact, this is similar to a DDOS attack, so you need to restart three to ensure that a restart can successfully restart the global Internet. ”
But in real life, the Internet adopts a distributed deployment method and does not have an absolute center. When the concepts of root server and core router come together, it amounts to a global Internet hub.
In the existing DNS system of mankind, there is an economic recovery scheme itself. National Internet agencies have elected seven representatives around the world, each holding the Internet's DNS chips and keys. When the Internet's domain name system suffers a crisis, it only takes five people together to restore the normal operation of the global Internet with the help of the key.
But in order to simplify the plot, Tu Hengyu in the movie can restore the network alone. Theoretically, the Beijing Internet Center and root server in the film, which are equipped with DNS technology, have an important impact on the global Internet. However, in real life, only the combination of root servers and backbone routers can restore the global Internet to operation, otherwise root servers can only restore DNS-related services. However, a 173-minute film simply can't cover everything, so some concepts have to be simplified and discarded.
From a plot point of view, the necessity of the role of Tu Hengyu's leader, Ma Zhao, is that the screenwriter cannot let a narrator explain these scientific concepts, and then a real character is needed. Deep down, Ma Zhao is actually a "digital person", and he drew a Mobius ring on his suicide note, which shows that he is a strong supporter of digital life. To some extent, Ma Zhao's role mission is to guide Tu Hengyu to make MOSS. In fact, the Möbius ring is also a clear hint that he should also know about the existence of future versions of MOSS.
The film also introduces 550W in turn as MOSS, and 550W comes from the 550 series project. Therefore, it is very likely that some behavior of Tu Hengyu led to the birth of such a strong artificial intelligence as MOSS.
Figure | Tu Hengyu looks at MOSS (Source: Infographic)
As mentioned earlier, digital life is a continuous iterative process, and the MOSS itself in the film is the life of weak artificial intelligence, although it can communicate with humans, but does not have the same emotions and consciousness as humans.
Cui Yuanhao said: "Professor Wang Yuanzhuo of the Institute of Computing of the Chinese Academy of Sciences (the leader of the scientific consultant artificial intelligence group) proposed the idea of people in the loop to enrich the plot, of course, this is also a relatively large research direction in the field of artificial intelligence, that is, the introduction of human decision-making in the process of machine decision-making, which can improve the accuracy of the algorithm and make artificial intelligence more intelligent." ”
When designing the concept of the script, the scientific advisory group believed that the introduction of human circuits could transform Tuya's digital life from weak artificial intelligence to strong artificial intelligence.
Later, when Liu Peiqiang asked MOSS, MOSS said: "This is MOSS's answer." Obviously this is a very strong artificial intelligence - it is conscious. And its core transformation comes from the concept of human circuit, that is, the intervention of Tuya.
In fact, strong artificial intelligence is the late state of MOSS, when it can detonate the moon, do comprehensive surveillance of humans, etc. "But because of the length, we can't show more, but we did think like this, and I guess some viewers can guess it." Cui Yuanhao said.
Figure | A corner of the set (Source: Infographic)
Liu Peiqiang: A concrete practitioner of saving the earth
In the film, the plot of the space elevator is Liu Peiqiang's key scene. However, the concept of the space elevator is not new, and it can basically be understood as a variant of the Tower of Babel in the Bible thousands of years ago, that is, using power to reach the sky.
When large numbers of people enter space, they need to resort to space elevators, or other cheaper ways of gravity. In reality, most astronauts go into space by rocket or space shuttle, and 90% of them use fuel.
In this case, it makes no economic sense for humans to use ways to break away from gravity. Although rockets can be recycled, thus reducing some costs, they are still too expensive to support large-scale human access to space.
In the movie, people want to advance the Ark plan, but it is unrealistic to build a large-scale space station on the ground, once it enters the gravitational range, the space station will be captured by gravity, and the energy required by such a massive creation when it is separated from gravity is an astronomical amount.
Therefore, the most appropriate way is to establish a synchronous space station in geostationary orbit, only in this way can it be more stable, so as to facilitate large-scale construction in orbit and lead humans out of the solar system after completion.
So, how to do large-scale construction on a stationary track? One possible and economical way is to take a space elevator.
"Why is the space elevator the core of the Ark program? Because without a space elevator, the Ark project would not work. If the space elevator really exists, such a giant building 7 times the diameter of the earth and 1/4 of the distance between the moon and the moon will be the most brilliant miracle in the history of human civilization. At that time, the earth was like a small circle, and it was constantly spinning with its big arms. Cui Yuanhao said.
In reality, we can't realize the idea of breaking out of the solar system without going into space very economically. Cui Yuanhao said: "Robert Heinlein, the 'father of modern American science fiction', believes that as long as you can reach a low-Earth orbit about 160 kilometers above the ground, your solar system journey is half complete. "Because when detached from gravity, human beings have to pay far more energy than interstellar navigation."
Figure | A corner of the set (Source: Infographic)
In Liu Peiqiang's scene, the Roche limit is also a term that appears many times. Chen Xuelei, a researcher at the National Astronomical Observatory of the Chinese Academy of Sciences, said that the Roche limit is a common concept in astrophysics. The Earth, the Moon, etc. are generally bound together by their own gravity, and if two celestial bodies are close to each other, the tidal force may be greater than the celestial body's own gravity, resulting in the collapse of the celestial body. In reality, people have observed the phenomenon of black holes causing the tidal disintegration of stars, and Jupiter has also seen the tidal collapse of comets.
However, back to the plot of the movie, because the Earth's gravity is much greater than the Moon's, the Earth will first cause the Moon to disintegrate, and a large amount of material after the collapse will fall to the Earth. According to the mass estimates of the Earth and the Moon, the Roche limit should be more than 5 times the radius of the Moon, that is, the distance between the center of mass of the Earth and the Moon is only more than 9,000 kilometers. Considering that the radius of the Earth is about 6400 kilometers and the radius of the Moon is about 1700 kilometers, the Earth and the lunar surface are already very close at this time.
Chen Xuelei said that the distance between the earth and the moon shown in the movie screen is not so close, which is a bug in the movie. Of course, long before the Earth and Moon reached the Roche limit, the tidal force was already very large, which was enough to produce huge tides on the ground, not only bringing ocean tides, but also the ground would no longer be stable.
So, why can all the nuclear weapons on Earth on Earth in the movie blow up the moon? How did lunar nuclear fusion occur?
Chen Xuelei said that in reality, all human nuclear weapons are far from enough to blow up the moon. The crew may also have taken it into account, so they designed a concept of a phased array of nuclear explosions: let nuclear weapons explode at a precisely controlled time, so that the explosion waves generated by each nuclear explosion can converge exactly in the center of the moon, thereby forming a huge temperature and pressure.
"The principle of destroying the moon seems to be that this huge temperature and pressure promote the center of the moon to achieve heavy nuclear fusion. This is actually a bit similar to the detonation of an ordinary nuclear bomb. Chen Xuelei said.
You may also know that the atomic bomb center uses nuclear fission materials such as uranium or plutonium, and special shapes of ordinary explosives are laid outside, and by precisely controlling the detonation time of ordinary explosives, a beam converges to the center, and the huge pressure generated by this instantly compresses uranium and plutonium to a very small volume, so as to achieve a critical mass of chain reaction, and finally detonate the atomic bomb. Hydrogen bombs, on the other hand, use the enormous temperature and pressure generated by atomic bomb detonation to detonate nuclear fusion of materials such as deuterium and tritium.
But the question is, what kind of fusion will happen at the center of the moon? You know, nuclear fusion at the center of the sun is a fusion of hydrogen nuclei, but the center of the moon is not hydrogen.
The Earth engine in the movie uses heavy nuclear fusion, that is, the use of silicon, oxygen and other heavier nuclei on Earth to achieve fusion, which requires a much higher temperature than the center of the sun, and in nature generally only the center of massive stars that evolve to the late stage.
"As a science fiction movie, it's just a possibility. In reality, just by exploding thousands of nuclear bombs on the lunar surface, even if the shock wave generated by the explosion reaches the lunar core at the same time through precise control, the temperature is not enough. Chen Xuelei said analytically.
But more importantly, the lunar core is actually unable to re-nuclear fusion at all. Because the principle of heavy nuclear fusion is that when two heavier nuclei fuse together to form a heavier nucleus, some energy is released. The reason why energy can be released is because the mass of the two nuclei together is greater than the mass of the formed nucleus. Then, this excess mass can be converted into energy according to Einstein's mass-energy formula.
The problem is that this energy release reaction can only proceed up to the iron core, because the iron nucleus is the most stable, and when it fuses with any other nucleus, it needs to absorb energy rather than release it. The center of the moon actually contains a lot of iron, so even if you add it to the high temperature, it will not cause it to undergo heavy nuclear fusion. So this plot is actually untenable.
"But in the movie, the moon is still a mess after that, which is also a bit confusing. Because if the moon does undergo nuclear fusion, it will be blown up, so it is still impossible to avoid a large number of debris hitting the earth. It would also be strange if it did not blow up, but turned into a star like the sun. Moreover, this does not free the moon from Earth, so this part of the story seems a bit unrounded. Chen Xuelei said.
Figure | Chen Xuelei (Source: Chen Xuelei)
But he also said: "Science fiction film is an art, it cannot be required to be completely in line with science, although strictly picky, some plots are indeed not completely in line with science, but the sense of realism of the picture is very strong." If you don't make specific calculations, it is more consistent with the psychological feelings of our general audience. I love this movie, and the excellent special effects in it are not inferior to foreign science fiction films. ”
In this regard, Cui Yuanhao said: "The scientific advisory group first determined the first big principle: the existing human nuclear weapons cannot completely blow up the moon, which is several orders of magnitude worse, so dropping a nuclear bomb in other science fiction films to blow it up is not valid in our opinion." "So how should it be blown up? In fact, there are many ways. An interesting method is to arrange a large number of explosive elements on the surface of the moon in an array in a phased array manner, that is, the nuclear bomb in the movie.
If arranged very precisely, an explosion superposition can occur at a point in the interior of the moon, such as the lunar mantle, that is, an energy superposition can be generated at a certain point. If the point itself is a confined space, or a relatively perfect space, then it is possible to produce a fusion reaction similar to the explosion of a hydrogen bomb. Theoretically, given that heavy nuclear fusion in the movie world has been established, if its energy is enough, the moon's interior may be able to sustain continuous nuclear fusion, causing it to explode on its own.
"This is equivalent to the crew opening a brain hole, which is likely to be unrealizable. But considering that the movie itself already assumes that heavy nuclear fusion is valid. So if human nuclear weapons can generate enough energy to trigger heavy nuclear fusion, then the moon can blow itself up. Cui Yuanhao said.
Figure | A corner of the set (Source: Choi Won-ho)
Zhou Zhezhi: A high-level player who saves the earth
Regarding the setting of the three groups of characters, Cui Yuanhao believes: "I have always felt that this is through three kinds of characters to reflect the different reactions of human beings at three levels when facing a crisis. Zhou Zhezhi and Hao Xiaoxi are among the top decision-makers. When mankind faces a crisis, there will definitely be a lot of games at the top, and then China will have to show its responsibility. ”
Figure | A corner of the set (Source: Infographic)
The line of Tu Hengyu and Ma Zhao is talking about the process of scientific and technological change; Liu Peiqiang and Zhang Peng are talking about how to deal with difficult problems when talking about specific operations.
At the same time, they also imply different emotions. Zhou Zhe directly alludes to the family and national conditions, Tu Hengyu focuses on family affection, and Liu Peiqiang highlights love and brotherhood with Zhang Peng. "When faced with problems, the three characters have a common intersection, allowing some stories to be interspersed between the three groups of characters, which is also the source of the epic sense of the film."
The three lines are also independent of each other, but they are not completely independent in the physical sense. Their closest junction point is that when Liu Peiqiang was interviewing, Tu Hengyu was opposite the glass. In addition, they passed by in the hallway.
And in the ending Easter egg, MOSS says that he is the culprit of the crisis, so what do you think of such a plot setting? And will there be a sequel to the movie?
Will there be The Wandering Earth 3?
Cui Yuanhao said: "On this issue, I can only ask you a few questions from the perspective of viewing. There are several coincidences in the plot: First, when Zhou Zhezhi made the femur declaration, it happened to be when Tuya was inserted into MOSS, so what does the birth of this civilization refer to? Second, it was Ma Zhao who before he drowned, and we know that he was a very digital-leaning man, or at least a staunch supporter of digital life, who said that civilization without humans is meaningless. And what kind of civilization is this civilization? Who are people? If from the perspective of MOSS, human arrogance is the original sin of mankind, then what does MOSS think is the best solution for mankind? Does it feel like a civilization? These can be left for everyone to think about. ”
Figure | The end of the film shows the name of the scientific advisory group including Choi Won-ho (Source: Choi Won-ho)
In addition, if you brush the second or third brush, you notice that Zhou Zhe is directly facing the camera in the conference room and has a long gaze. In the visual language, the camera itself is the perspective of MOSS, and he has been staring at the camera, obviously aware of the existence of MOSS and the possible actions of MOSS.
At the critical moment, Zhou Zhezhi repeated: "Our people will definitely be able to complete the task, regardless of reality or falsehood." "True or false" – these are his own words, indicating that he must know that MOSS exists, which is why he insists on restarting the root server.
At the end of the film, there is a flashback of Zhou Zhe when he was old - the bald Tu Hengyu is wearing a mecha. And Tu Hengyu's body is dead, so where is this scene? And Zhou Zhezhi was already old at that time, so the timeline is definitely not now, so this paragraph is very worth playing.
Figure | Group photo of the Scientific Advisory Group: The first from the right is Cui Yuanhao (Source: Cui Yuanhao)
In fact, the first movie is a very long version, a total of four hours, and the epic sense in this version will be stronger, and the four plans each take up about the same space. Later, it became a confrontation between reality and digital, so digital life and artificial intelligence accounted for a very large proportion.
(Source: Infographic)
"From the very beginning, the design, presentation, and related lines of the 550 series computers were the responsibility of my scientific advisory group, including the growth of digital life, the code scrolling on the screen, the artistry, and the presentation of the actors themselves." Cui Yuanhao said.
There is a scene in the movie where Tu Hengyu is working from home, and the wall is full of artificial intelligence formulas and calculation processes. As shown in the figure below, under the suggestion of scientific advisers such as Cui Yuanhao, the crew put the important formula in a prominent position.
Figure | Above: Tu Hengyu's room layout in the movie; Below: The crew is designing the room layout (Source: Cui Yuanhao)
When watching a movie, you may feel that Tu Hengyu has been writing code, and then he realized digital life. In this regard, Cui Yuanhao said: "Because the movie is already very long, it is unlikely to add anything. In fact, the scientific consultant did a lot of design, and we wrote more than 100,000 words together on the world view of the movie, and the final presentation was only the tip of the iceberg. ”
Figure | Part of the work documents of Cui Yuanhao when he participated in the scientific adviser (Source: Choi Yuanhao)
"As scientific advisers, we hope to insist on the authenticity of science, try to start from existing scientific knowledge, and do some reasoning as reasonable as possible." But the crew considered artistry and achievability, so they took the approach of discarding or simplifying the concept. Cui Yuanhao said.
(Source: Choi Won-ho)
In addition, Choi Won-ho believes that for foreigners, they rarely see collectivist films like "The Wandering Earth 2". The Wandering Earth 2 is very high-minded, discussing the relationship between civilization, the virtual and the real. As viewers, we can also define this civilization as the birth of a digital civilization, or the relationship between two civilizations. That is, everyone should give corresponding feedback at different social levels.
It is also reported that the film is adapted from Liu Cixin's novel of the same name, and the intention is also consistent with the spiritual core of the novel, and Liu Cixin himself is more inclined to describe macroscopic epic stories. This is also the difference between "The Wandering Earth 2" and foreign science fiction movies, and it has also received high scores on foreign film review websites.
Perhaps this is not only because the film is so well made, but also because it tells a story of solidarity with human beings. As Zhou Zhezhi said: "In the vast universe, the earth is just a small white dot, but this little white dot is our everything." ”
Support: Lu Yuqing interviewed the scientific advisor of "The Wandering Earth 2": How does the moon "blow itself up"?