Volume 1 Chaos Comes Chapter 20 Small World
When I returned to the laboratory building again, the Labor Day holiday had just ended. I didn't go out to play during that holiday. I was reading papers as usual.
One day after normal classes, I went to the science building to take an elective course. I passed by the corridor outside the clean room and saw Ai Bishui concentrating on making samples for our experiment.
She was covered entirely in spotless white clean work clothes, and only her eyes could be vaguely seen through the goose-yellow light.
These bright eyes are very recognizable to me. Under the goose yellow light, they are staring intently at the samples in the centrifuge.
In fact, according to regulations, undergraduates are unlikely to enter the clean room, but if it was her... it wouldn't be so strange. It seems that she has already designed the sample to simulate the brain. I stood outside the double-layer glass and stared at the various instruments for a long time, until the girl inside turned around and saw me, tilted her head slightly and waved to me.
A few days later she asked me to meet her, but the location was at the entrance of the basement of the science building.
"Ah, you're finally here, come on, let's move this together."
The girl in front of me had her hair tied up and was wearing a loose round-neck pinstripe shirt and skinny jeans.
This outfit mixed with her scent made me feel that summer was really here.
We pushed open the heavy fire door and walked in. I saw her walking towards a stainless steel Dewar tank that was half a person's height. Next to the tank were metal hoses of varying thicknesses.
"This is a tank of liquid nitrogen that I just applied for from the department. It's used for cooling." She took off the white coat hanging on the wall and put it on. She put on heat-insulating gloves and goggles and said, "Just get it on this car. We can get it to the lab together."
As soon as she finished speaking, she conjured up a two-wheeled cart with foot brakes from the corner. I had not noticed its existence just now. I dressed neatly like her and followed the operating procedures to transfer the cans to the chassis and then secure them firmly with ropes.
According to safety regulations, liquid nitrogen must be transported to other places by two people.
"I'm telling you, I once secretly filled half a thermos with the remaining liquid nitrogen and brought it back to the dormitory. I wanted to try making ice cream, and it was quite successful. But don't tell anyone else about this..."
This violates every safety regulation I can think of involving cold liquids.
But it was still very happy that she shared secrets with me, although it seemed that everyone liked to share secrets with me. However, we were still very strict when we were actually doing the experiment, after all, the millions of instruments would not play tricks on you.
"Will the experiment we are going to do generate a lot of heat? I remember that ferromagnetic samples should be conductors, right? Or is the liquid nitrogen used to provide low temperature conditions?"
The conductor cannot withstand much voltage, so it will not generate much heat.
"Yes, although this material itself is a conductor, calculations show that after special etching, its equivalent resistance will be very large, so the voltage required to activate it will also be very large... Complex systems are energy-consuming monsters."
The same is true for the human brain, which accounts for 2% of the human body mass but 20% of the metabolic load. Some studies have shown that this is due to the astonishing consumption of nerve signal transmission and neurotransmitter transfer.
We chatted for a while and then arrived at the laboratory on the 3rd floor. Ai Bishui cleared a clean area from the debris on the floor and set up the cooling tank.
This crowded little room was just as messy as before, and it seemed like some new things had been added. I noticed a thick pack of CDs on the table. Does anyone still watch CDs these days? Even DVD players are rare.
"That was given by our instructor to Senior Brother Kou's child. He said it seemed to be...something about his brother's CD? Maybe he forgot to bring it back after finishing his experiment."
He should be talking about "Haier Brothers"... Hey, this is also my childhood.
Ai Bishui turned around and looked at me strangely, as if we were not from the same generation.
"Is that so? What kind of story does it tell that such a large number of them were filmed?" She walked to the box, picked up a disc, took off her goggles and looked at it carefully, and I followed her.
"This is a very old popular science animation. The story is about two artificial humans created by a wise old man. They work with humans to overcome various disasters."
"Are you talking about intelligent creatures created by humans? It seems like a classic science fiction theme. But why should androids help humans? Because the setting says that they must abide by the Three Laws of Robotics?"
"Well, this... is just a popular science animation for children. It probably doesn't need to be so rigorous."
In fact, many famous hard science fictions do not need to be too rigorous. However, questioning the rigor of others or even one's own rigor is an occupational disease for physics students.
"Knowledge is the magic weapon to overcome disasters..." This is the line I remembered at that time.
By the time I came to my senses from my childhood memories, Ai Bishui had already returned to the microscope.
"Oh, it's getting late. Let me introduce you to the device I made." She adjusted the magnification of the microscope, and the image on the screen gradually zoomed out until the entire etched sample could be seen.
Unlike the long strip samples engraved in the center of the large electrode, the device in front of us is more like a "chocolate chip cookie" shape, with clumps dotted in the sparse background. Only through careful observation under a microscope can it be found that the nodes inside the clumps are densely packed with micro bridges built by thin .
"The neural network of the human brain is not a neatly arranged grid as assumed in machine learning, but an irregular pattern with local centers. The number of connections contained in these central neural clusters is far greater than that of other cells throughout the brain."
The teacher mentioned this model in passing during class, but did not explain it in detail. I was painfully searching for his words in my memory.
"You've had preserved egg and lean meat porridge, right? You should have it in your place."
"This is probably... available all over the country." Although it seems to have originated in Guangdong.
"Don't you think this structure is a bit like preserved egg and lean meat porridge? Most of it is sparse liquid, and the small clumps are floating preserved eggs or meat strips. Its density is much greater than the surrounding area."
She likes to use food-related concepts when making analogies, and now I have gradually picked up this habit.
"Thinking along this scenario, we can reach most places in the bowl from the meat strips because it has dense connections. But from the liquid, we can only reach a few points." As she spoke, she slowly moved her vision from one lump, and the connections gradually became sparse, and then gradually became denser when approaching another lump.
I recall that this structure is called "small world network", which is also a kind of complex system, and scientists have discovered that the human brain actually follows this structure.
"When we control it, we can't really affect each unit, after all, the scale of electrons is very, very small. The micro-nodes on this device are still huge macroscopic objects relative to the spins. We indirectly affect a large number of electron spins by adjusting them."
It's like saying that we can't command every pigeon, but we can indirectly influence the behavior of the entire group by inputting specific signals.
"In each node of this small-world network that can be seen under a microscope, there is an even more subtle network nested inside, where the real microcurrent is generated. This is actually also a fractal structure."
"Uh, so how do we make it nest..."
"Isn't this something we discussed before? I remember you were still on the train at that time."
I made a look of sudden enlightenment and pretended that I had fully understood it.
"But there is also a problem. We... or the entire human knowledge system does not have enough information about biological neural networks, so there is no experience to refer to on how to adjust the overall input and output."
As she spoke, she picked up a bunch of BNC cables connected to the sample, four of which were connected to the voltage source.
"So the only way now is to exhaustively select four from all external ports in order, and then record their performance under different voltages one by one. I have already sent the specific input signal instructions to your phone."
It was a thick PDF file, with dozens of pages.
"This... should take a long time."
I felt secretly delighted at the thought that this would give me more opportunities to be alone with her.
"Yes, so let's do the experiment separately. Wouldn't that be more efficient?"
After that day, we agreed on the time to come to the laboratory separately, and then all that was left was long, repetitive work.
