"If it is only a explanation of the principle, the quantum operator cryptography technology should be relatively easy to explain. Pen Fun Pavilion wWw. ｂiquge。 The abbreviated name for info technology should be 'quantum passwords', which is the method used by the system to verify the identity of the user. Clearing his throat, Ge Yiwei retrieved the information he had saved in the individual combat unit, "Uh...... Doctor, do you know about John Wheeler's delayed experiment?"

“…… I think I should be able to guess what it is. However," the conversation changed, and Bayi Yonglin stretched out his finger and tapped on the table, "There is a difference between the earth and us in terms of scientific terms, and the experimental prototype may also be different, so you should introduce it in detail." ”

"Hah, let me think about it...... I should be able to memorize it. When I was taking the exam...... "Knocking on the head, Ge Yiwei struggled to recall everything related to this experiment, "First of all, we should already be very familiar with the basics of the electron double-slit interference experiment: electron beam, double slit, when we don't find out which slit the electron has passed, the interference, when we explore, the interference fringe disappears. Wheeler's basic experimental idea is to replace the double slit with a half-silver-coated mirror, and the electron beam is also replaced with a photon, and the incident path of the mirror and the photon is placed at a 45-degree angle, at which point a quantum random process occurs, and the photon is half likely to fly straight and half of the probability is reflected. Then we cleverly arranged some total mirrors to intersect these two separate forks and then look at them at the end so that we could determine which path the photons flew from – the reflected path A or the transmitted path B. ”

"Go on. Your prototype experiments are indeed different from ours. Picking up the teacup, Bayi Yonglin said, "I'm a little curious about how you're going to explain this experiment to me with your verbal and logical skills. ”

"Aha...... That's not a good thing for me. Shrugging his shoulders, Ge Yiwei continued, "However, if we insert a semi-silver-plated mirror at an angle of 45 degrees at the end and carefully arrange the phase, it is completely possible to achieve the photon from the two paths AB in one direction to appear inverted and completely canceled out, without the photon, the other direction is strengthened, that is, the photon interferes with itself at this time, and for this it must come along both paths at the same time - this fact is equivalent to the interference fringe of the electron means that it passes through the double slit at the same time... …”

"There's something wrong with your narrative. It is never possible for a single electron to pass through a double slit at the same time. Frowning, Bayi Yonglin retorted, "What changes is not the number of paths that individual electrons pass, but their position wave function." Here you should say that if you don't add a semi-silver-plated mirror, then a large number of photons should form a simple superimposed image similar to a machine-gun bullet passing through a double slit, while if you add a semi-silver-plated mirror, it is an interference image of a classical wave, and the probability waves of photons on two paths interfere with each other. ”

“…… Ahhh Indeed, atomicity, atomicity is very important...... bowing his head and sincerely apologizing, Ge Yiwei said, "Then let's put it this way, if there is no half-mirror at the end, then there is no interference term for photons on both paths, and if there is, there is an interference term." But the problem is that the decision on whether to insert a mirror can only be made when the photons have passed through the first half of the mirror and are almost at the end point. In other words, whether a large number of photons have an interference term in two paths can be determined after they have already traveled through those paths. As Bohr said, 'Any fundamental quantum phenomenon is a phenomenon only after it has been recorded', in this experiment we cannot change the fact that it happened in the past, but we can delay deciding how it 'should' happen in the past. ”

Whew, I'm so tired. Taking a slight breath and seeing that Bayi Yonglin was waiting for his words, Ge Yiwei hurriedly took a sip of tea and continued: "Then, the quantum operator encryption technology is based on the facts revealed by this experiment. In the actual design of the password verification system, we make the question of whether the verified end meets the identity equivalent to whether the verified end has a 'half-lens', and when designing the photon path, we can make the two paths intersect at point A first, and then intersect at the end point B at the verified endpoint. In this way, if there is a half-lens at the verified end, then what we see at point A should also be an interference image of the classical wave, and if not, we can only get an image of the density distribution of the bullet fired by the machine gun, so that the system can complete the authentication of the external terminal. ”

"It sounds like a lot of work, but it doesn't seem to have much real value. What's the use of going to the trouble of making something like this?"

"Of course it works, doctor. In this encrypted password system, the system itself does not accept any external input of information, but only actively sends information to the verified party. This means that it is impossible for the verified party to use brute force or virus programs to crack it. It's like a lock that is absolutely impossible to pick open or break, only that key can open it. ”

"But it's dangerous over there. If it is just a semi-reflector, it can be said that it is too easy to imitate. ”

"But in the top-level encryption, the semi-reflector that acts as the key seems to be replaced by a small mechanism designed by quantum state matter, and its uniqueness is guaranteed by the principle of quantum unclonability, and the only downside is that you can never have two keys at the same time. ”

"And the key has to be broken once if you open the lock once, and you have to make another one every time. Speaking of this, Bayi Yonglin raised his head and met Ge Yiwei's puzzled gaze, "I guess." After all, if the principle of quantum unclonability is to come in handy, this unique quantum state must be probed – and then destroyed. The wave function graph is also used to encrypt it, right? The photons emitted by the system are definitely not casual......"

"Ah, your instincts are so powerful. "It is said that Gensokyo's captain certification follows this procedure. In other words, the reversal of time has not broken the principle of quantum unclonability, and now, the quantum state that exists in the boss's body out of nowhere and is used as a captain's proof is absolutely different from Miss Reimu. Nodding, Ge Yiwei went through the conclusions of yesterday in his heart, "So...... Doctor, what is magic ......?"

"Mass-energy conversion system. ”

Because Bayi Yonglin's words were too simple, Ge Yiwei was even a little stunned at first. When he reacted and waited for the other party's next words, the white-haired woman in the doctor's robe began to close her eyes in the chair, and seemed unwilling to reveal too much. Seeing this scene, Ge Yiwei twitched the corners of his mouth: "Doctor, you only say such a sentence, I can't understand it at all......

"If you don't understand, just ask, and I'll try my best to answer your questions. When he opened his eyes and saw Ge Yiwei's confused appearance, Bayi Yonglin sighed, "Forget it, I'll guide you." Mass-energy transformation system, you understand the biological meaning of the word system, right?"

"Ah, of course. At the level of individual life, cells, tissues, organs, systems, and individuals follow this level. Slightly understanding the other party's train of thought, Ge Yiwei replied, "If the word system is strictly defined by science, it means that it is as ...... as the urinary system, respiratory system, digestive system, circulatory system, immune system, etc."

"That's it. Magic is a biological phenomenon that is regulated by a system within a living individual. It's so complicated that you can't explain the principles of all magical phenomena in such a short period of time, just as you can't map a person's genes in a matter of hours. As a simple example, kappa have the ability to control water, they have a biological enzyme in their body that synthesizes special organic matter, and the synthetic organic matter is hydrophilic at one end and hydrophobic at the other, and the purpose of water control is achieved through the precise control of this substance. Another example is the Magician's lightning spell, which spreads low-resistance matter in the air in a stepwise manner to form an electric current that travels to the target. The special substances required for magical phenomena are obtained by regulating the expression of genes to adjust the synthesis of biological enzymes, and then indirectly adjust metabolism. Don't say that these controls are too delicate to do, in fact, doing these controls is the same as moving your fingers flexibly, and it may seem difficult to analyze carefully, but it is a piece of cake for our brains. Pointing to his head with his finger, Bayi Yonglin looked over again, "Regarding these things, these two examples are enough, if you let me say it in detail, be prepared to stay here for more than ten years." What else don't you understand?"

"Ah, there is!" Although he was slow for a while in order to comprehend the large number of words spoken on the other side as quickly as possible, Ge Yiwei still asked the key question he had found in time, "Is mass energy transformation the energy source of the system? What is this? than binding energy? It can't make me believe that there is a fission reactor or fusion reactor in the body of magic." Where do you get the ingredients? I haven't seen it...... Miss Reimu, they are going to replenish uranium-235 or deuterium tritium. ”

"Hawking radiation. That's what you should call it. Coupled with a process similar to the conversion of radiant energy from photosynthesis, this is the principle. ”

"No, it's true that Hawking radiation is released by black holes by reducing mass, and even if there is a phenomenon of mass energy transformation, I can also believe that photosynthesis converts radiation energy, but you tell me that every magical person has a black hole in their body, which is even more unbelievable than having a reactor in their body......"

"Have you solved the problem of the gravitational field of a particle at a very small scale?" that is, the problem of how to determine the gravitational field of a particle......

"Hey, doctor, please don't force people to make it difficult, this problem has been going on for so long, the tug-of-war between relativity and quantum mechanics has been going on for so long, I can't solve it if I want to solve it, right? In that case, I'm sure I'm going to win the Nobel Prize." ”

“…… It's a pity that you haven't solved it yet. Then I can't tell you anything more. ”

“…… This sounds really hurtful. Hanging his head helplessly, Ge Yiwei glanced at Bayi Yonglin, who still looked indifferent, "Can't you use a more euphemistic expression?" Forget it, why are you tangled in this...... Can you give me an answer to Miss Yakumo's question?"

"But it's not too early. Looking at the sky outside the window, Bayi Yonglin frowned and replied, "If you let the Hakuri witch outside wait like this, I'm worried that you will have a lot of trouble later." Moreover, the inter-gap thing must involve macroscopic quantum superposition, negative energy and dark energy, and if you go deeper, you have to talk about the 'gradual degeneration effect' and ......"

"Oh my God. Macroscopic quantum superposition?Do you mean, cat-like particles?" Immediately covering his head, Ge Yiwei's voice sounded very painful, "Negative energy and dark energy are involved, this is really ......"

"To correct a point, cat form and macro stacking are two different things...... Ah, that's going to be more detailed. I don't know much about these things. There are really not many, only shallow principles. Since you are studying physics, you should also know how much difference there is between having a mass-energy conversion equation and building a nuclear bomb. ”

“…… The mass-energy conversion equation only needs a Lorentz transform to modify the classical theory, and if you want to build a nuclear bomb, you must follow the atomic microstructure. I always feel that these should be two fields that not only have a gap in development level but also have unrelated content. Shaking his head with a wry smile, Ge Yiwei said, "It's really not like your style to give such an example. ”

"Because I know that many people don't have the correct understanding that the mass-energy conversion equation is the basis of nuclear bombs, I use it. But the fact is that as you said, the simple derivation of the mass-energy conversion equation only requires the Lorentz change to correct the classical mechanics. Nodding, Bayi Yonglin moved his neck slightly, "So I guess I can't tell you the relevant content of the gap today." Come back next time...... Ah, but there's one thing I'd like to ask. ”

“…… What's the matter? ”

"Until then, since you've just shown your sincerity, I should do the same. Looking down at the teacups on the table, Bayi Yonglin smiled softly, "The time machine is now in the hands of the Nazis. Before, this thing was kept by the moon capital, so I can still receive the corresponding message. That's it. ”

Ge Yiwei felt his heart stop beating a few beats.

Why did she tell herself about it? Was she a time traveler exposed? No, it shouldn't. According to the available information, Bayi Yonglin can at most deduce that he belongs to the knowers of Gensokyo's hidden secrets...... So this is a temptation? What does she want to test me? And even if it does, what can it be?

Careless, absolutely careless. This person should have a source of information that he did not understand. Ah, by the way, could it be that Miss Yakumo took the initiative to reveal it? If that's the case......

"What are you referring to? How can such a thing as a time machine exist?" After a moment of thought, Ge Yiwei immediately came to a conclusion. In any case, on the surface, it is necessary to deny, at least to reveal to the other party that you do not want your identity to be revealed, "So, ...... is your question?"

"Ah, I'm just a little interested in you as a person. Nodding noncommittally, Bayi Yonglin didn't ask too much, "What are you going to do next......?"

Speaking of which, she stretched out her thumb and pointed to the ground: "The general direction of the plan." ”

“…… Actually, Miss Yakumo and I both think that there are some things that are not in a position right now. So," he gestured to understand that the other party was asking about his handling of Gensokyo, and Ge Yiwei replied respectfully, "In order to avoid the danger that is coming, it is necessary to let that thing move." What do you think?"

"Oh. Where are you going to go?"

"It's not decided yet. That is...... Light years or so. ”

————————————————— Dividing Line———————————————————

"Can you tell me what you're thinking?"

Hearing a familiar voice behind him, Bayi Yonglin, who had just sent Ge Yiwei away, turned around. The sun had set in the west, and the shadows of the two people on the ground were dragged long: "...... Sorry, princess. There are some things that I really have to do alone. ”

"But some of your actions really baffle me. I had long known that this would be the answer, Penglai Shan Kaguya sighed and shook his head, "For example, this time." Didn't you already know the principle of quantum operator cryptography?"

"I'm sorry, I'm really sorry. He didn't do any superfluous movements, and Bayi Yonglin still lowered his head. In fact, she couldn't think of anything else she could do, "I'm really sorry." ”

“…… I just don't want you to do everything by yourself. The tone softened, Penglai Mountain Huiye looked at the great sage of the moon capital in front of him, and smiled helplessly, "I understand that I can't help you with anything." …… Alright, I'm going to eat. Ah~~Ah~~Ah~~What will today's dinner be......"

The princess is still the same as ever. It's just great.

Standing alone in the setting sun, Bayi Yonglin looked at the back of Kaguya slowly walking into the house, and then turned to look in the direction of Ge Yiwei's departure, and finally quietly looked at his lonely shadow on the ground.