Tsinghua talent feels that his IQ is high, so someone asks what Wheeler's delayed choice experiment is, trying to crack it. Pen ~ fun ~ pavilion www.biquge.info81Δ

The young man who claimed to know the concept explained to everyone: "Since everyone is not convinced, then I will sort out this concept and tell you that it is okay, listen carefully."

Wheeler's delayed choice experiment is a thought experiment conceived by a physicist named Wheeler to question the incompleteness of quantum mechanics, and Einstein also found quantum mechanics inconceivable and proposed some thought experiments.

Wheeler's idea is to make a mirror, half transparent, half silver-plated, and the effect is that when a photon hits the mirror, there will be a 5o% chance of transmission, and a 5o% chance of reflection, so that two completely different light paths are created.

Two optical paths can be converged with a fully reflective mirror at point C, and two devices to detect photons can be placed at point C, so that you can know whether the photons are taking route A or route B.

Everyone understands this, right? ”

Everyone nodded.

The young man continued: "Okay, then the next step, now before the photon reaches C, choose one, for example: A, and put a semi-reflective mirror, this mirror can be eliminated by adjusting the optical path so that the photons of the light path A interfere with themselves.

This is a very strange place in quantum mechanics, and you need to study it yourself to understand the self-coherence of photons, so I won't say much about it here. In short, in the wave function constraint of the photon, if the photon disappears here, it will definitely appear in another optical path.

This becomes that the photon is always detected on the B side, and on the A side, it is never detected. The undetectable is due to self-interference, which means that a photon has traveled two routes at the same time. As I have just said, these two routes are very distinct, if you think about it, one is transmitted and the other is reflected.

That is, in the case of only the first half-mirror, the photon will either go A or B, and there will be only one optical path, while in the case of the second half-mirror, the photon will go both A and B. Then, when we have confirmed that the photon has gone a in the first case, suddenly put down the second half-mirror, and the photon goes two ways at the same time.

At this point, the second mirror changes what was already happening, and this is Wheeler's choice to delay the experiment. To sum it up with a terrifying sentence, that is, in the theory of quantum mechanics, things that have been born in the past can also be changed! ”

Nani? No matter how clever the young talents present are, they have been confused by this thought experiment. The groom drank the wine, and he couldn't understand it, so he quickly pulled the bride into another table and stopped playing with these top students.

The sister-in-law was also about to walk away with them, but at this time, Yuan Bao, a student of the Conservatory of Music, actually came to intervene and opened up: "I have an explanation. The sister-in-law suddenly stopped and almost took a step.

Yuan Bao said: "This brother explained in simple terms just now, very good. Although this is the first time I have heard of this experiment, I also know about the self-interference of photons, because the weirdest thing about double-slit interference is that an electron can interfere with itself. And I've really thought deeply about time.

I think you can waste a few minutes, listen to me, I think the understanding of time is the key to understanding this experiment.

I'm also going to do a thought experiment, where I assume that a closed system scene has only one indivisible point particle, which has no electric charge, no color charge, no spin, and no other physical properties except mass.

This second, when the point particle moves from A to B, and the next second, it returns from B to A, I would like to ask you, apart from the chronological order, can you still find any difference between this system and two seconds ago? ”

Su Yinxue: "If this system only has such a property as mass, then there is really no difference, what does this mean?" ”

Yuan Bao: "This shows that the time we talk about every day, in the quantum world, in the infinite subdivision, to the lowest level, time does not exist, or in other words, time can be reversed.

Just like Einstein suddenly had an inspiration when he was in an elevator and figured out a little, in fact, gravity is the same as magnification, there is no difference. ”

Sure enough, it was a brain hole, and Su Yinxue fell into deep thought.

The young man named Huang Jiajun, who had just explained what the delayed choice experiment was, said, "Wait, time doesn't exist? What does it mean? ”

Yuan Bao: "There is no need to set up something called time, because it is an indirect physical concept, and time is originally a derivative, and it has no unshakable status. So don't think it's inconceivable to change the past, which never existed.

All the things of the past life have an impact on the present, but you can't see it, the past will never disappear, but you will go where your eyes can't see. There was no time in the world, only motion, and the so-called past was just an infinite quanta combined world that moved to another state.

Wheeler's experiment deceived scientists into thinking logically with people's inherent notions of time. A thought experiment is a thought experiment, and it is likely that the experimenter will never be able to confirm the optical path and then instantly notify the collaborator to add a second mirror, because the two states are incompatible.

We don't need to figure out the specific details, we can break it directly, the wave function of the photon is so determined, and the self-coherence does not mean that the photon has traveled twice in an instant, and its physical state determines that the b path is chosen.

As the technology unfolds, scientists will one day figure out why using a second half-mirror forces the photon to take path b. ”

Everyone present didn't understand what Yuan Bao was talking about, only Huang Jiajun and Su Yinxue understood Yuan Bao's redefinition of the concept of time.

Su Yinxue really wanted to talk to him again, but today was obviously not the time, her sister greeted her from a distance, so she had to say: "Let's talk back!" ”

Wang Dongyi came to help again, patted Yuan Bao on the shoulder, and said, "Good boy, you successfully fooled our second miss, a second miss who studied physics, haha!" ”

Other rivals in love also feel bad, it's just that this product is rich, and even quantum mechanics can break two sentences, it's really a big fool.

###

When Yuan Bao was triumphantly fooling people, Song Yu here had just come back from playing roller skating outside, it was not easy for such a big person to be as happy as a child.

He opened the door and heard the sound of running water in the house, so he shouted, "Eh, Ling'er, are you back so early today?" ”

didn't hear Xie Ling's response, so he went to the bathroom to take a look, and saw that in front of the dressing mirror, Xie Ling's eyes were red, and he was standing there blankly.

Song Yu was stunned: "What's wrong?" What are you crying about? Who bullied you? ”

Xie Ling: "I was criticized by the leader. ”

Song Yu: "Why? ”

Xie Ling: "He said that I don't pay attention to the overall situation of the company and don't want to entertain customers, so if it goes on like this, I'm afraid he can't give me a probationary period." ”

Song Yu: "...... Does he have bad intentions? ”

Xie Ling complained: "You just know! This old fellow is obsessed with lust and disgusting. ”

Song Yu: "He didn't do anything, did he?" I'll beat him! ”

Xie Ling: "It's not good, but he said that I don't have any work experience, and he hired him exceptionally, hoping that I will be spiritual and know what kind of talents the company needs." ”

Song Yu: "Then resign, why should you be bullied by this pervert?" ”

Xie Ling: "What you said is so light, you pay the rent?" Do you pay for the groceries yourself? ”

Song Yu sighed: "Alas, how come there are bad people everywhere in this world?" Song Die's boss is not a good person, your boss is not a good person, and I don't have a boss appreciation. What's wrong with this society? ”

Xie Ling: "Or Wang Ziwei is comfortable, she bought a Mercedes-Benz S-class, and she earns me a month's salary at every turn, it's so cool, if I can get 8o, I will also buy a good car for Xiao Zhang to take care of." ”

Song Yu: "To have so much money, put it in the banking industry to make a lot of money, now the interest is 7%, a year, there are 5 or 60,000 yuan, equivalent to a monthly salary of 5,000 yuan, you can do it without Xiao Zhang." ”

Xie Ling: "Now that I think about it, you used to drive a sports car and didn't make a penny, you are a fool." ”

Song Yu was embarrassed: "This ...... Don't open any pot and mention it. The problem now is, we don't really have 8o thousand. ”

Xie Ling: "Are you looking for a job?" ”

Song Yu: "It's still ...... No, there is one who enters the factory, but it is not in Jincheng, and I heard that it is very hard. ”

Xie Ling: "It's really hard for you, for me, you live such a hard life." ”

Song Yu didn't expect that his girlfriend not only didn't bury himself useless, but also said such considerate words, and his blood surged for a while, saying: "Don't worry, even if I work as a coolie, I have to find a job to stay in Jincheng." ”

Seeing his determination, Xie Ling was very moved, and the little couple hugged each other and comforted each other.

The next day, Song Yu went to the construction site to sign up in high spirits, looking at his little white face, and was ridiculed by the contractor, Song Yu insisted again and again, and the foreman opened a salary of 8oo.

“8oo？” Song Yu remembered that his sister still had a salary of 12oo from the "bad guy" boss, and it was easy for her to ...... It's too different.

"Don't do it, fellow, it's like this, it's not impossible to give you 1ooo if you're skilled." When I heard it, the foreman was slightly disdainful.

Whether he does it or not, he will never persuade his sister to leave the "wolf's den" of the bad guy boss again.

"I'll think about it." He's still not angry, why is he only 8oo? It's 5o% worse than my sister, which is too inauthentic, and I was looked down upon by my sister when I went back.

He didn't know that as soon as the front foot left, a small worker was dissatisfied with the foreman and said, "Boss, why? I was only 65o when I first came in? You're going to give that little white face 8oo? Are you going to introduce your sister to someone or how to drop? (To be continued.) )