"Dr. Li, how much do you know about parallel universes?"

Ge Wei held a goblet, leisurely shook the red wine, and asked his question.

Dr. Li was a little surprised, but he didn't expect this kind of problem. He thought it would be an academic issue, at least related to his academic research.

What is the understanding of parallel universes? How to put it, this question ...... Unbounded, whimsical, or ...... The other party asks such a question, what other factors are in it?

However, since I asked him, of course, I can't help but answer. Thankfully, for this ...... Well, let's call it a topic for the time being, and he also has some research or interest in this topic.

Dr. Lee's academic research at the University is related to quantum disciplines. But he has a wide range of interests, and he is also a man who likes to be whimsical - Dr. Li characterizes Ge Wei as a boss who loves science and likes to think wildly. On weekdays, Dr. Li also does some theoretical research and discusses with people with similar interests. Regarding the theory of parallel universes, Dr. Li has his own unique opinion.

Dr. Li pondered deeply and fell into thought, preparing language, trying to explain these esoteric theories to a layman in the simplest language. Yes, he has another definition of Ge Wei, although this big boss loves science, which is a great thing, but after all, it is a hobby, and even his half-baked students may not be as good, it is better to use the most superficial language.

Ge Wei smiled silently, did not urge, and silently tasted the best red wine from the world's first-class winery in the glass. He was also looking forward to hearing what Dr. Lee had to say.

After a while, Dr. Li looked up and asked a question instead of answering the question first.

Dr. Li asked Ge Wei, "Hmm...... Have you ever heard of Schrödinger's cat?"

"Schrödinger's cat?" Ge Wei was slightly stunned. The wine glass stopped in mid-air, his eyes thought thoughtfully, and he nodded, "I've heard a little." However, I would like Dr. Li to explain in detail. ”

Dr. Li nodded silently, pondered the language again, and then began his first speech in front of Ge Wei. And in Ge Wei's opinion. This is the second time.

"Although quantum theory was born, a century has passed, and its glory has been at its peak and it has also flourished for half a century. However, the confusion that quantum theory once caused, to this day, still puzzles us......"

If Dr. Li has magic in him, the initial obstacle to communicating with Ge Wei has gradually subsided. The signs of crampedness and uneasiness faded away. When returning to the realm of his familiarity. Dr. Lee seemed to change his personality immediately. The brilliance in Dr. Li's eyes at this moment was the same as when Ge Wei saw that Dr. Li at the Plane Ruler Summit that day.

As Bohr famously said: Whoever is not confused when he first hears quantum theory must not have understood it. Schrödinger's cat is the most representative of many quantum puzzles. It's about a cat, sealed in a secret room with food and poison. There is a hammer on the poison bottle, which is controlled by an electronic switch. Electronic switches, in turn, are controlled by radioactive atoms. If the nucleus decays, alpha particles are released. Touch the electronic switch, the hammer falls, smashes the poison bottle, releases the cyanide gas inside, and the cat will definitely die......"

Ge Wei continued to sip the red wine and listened carefully. Schrödinger's cat. He didn't know much, except that it was proposed by an Austrian scientist named Schrödinger. The reason why Ge Wei cares is because the theories described in it are closely related to his current situation.

He had to figure out the theory completely. He had one thing to finalize.

Dr. Lee went on to explain, "The decay of the nucleus is a random event, and we know for sure. It's just half-life - half the time it takes for the nucleus to decay.

"If the half-life of a radioactive element is one day, then after one day, there is half less of that element, and another day, there is less of the remaining half. However, physicists have no way of knowing when it decays, in the morning or in the afternoon. Of course, physicists know the chance that it decays in the morning or afternoon -- that is, the chance that the cat will die in the morning or afternoon.

"If we don't lift the lid of the chamber, based on our experience in everyday life, we can assume that cats are either dead or alive. These are its two eigenstates. However, if we describe the Schrödinger cat in terms of the Schrödinger equation, we can only say that it is in a superposition of living and inactive. We can only know for sure whether a cat is dead or alive the moment the lid is lifted. At this point, the wave function of the cat immediately shrinks from the superposition state to a certain eigenstate. Quantum theory holds that if the lid is not lifted and the observation is not made, we will never know whether the cat is dead or alive, and it will always be in a half-dead superposition. ”

Ge Wei nodded: "In other words, before the observation, it must be uncertain?"

"Yes. Dr. Lee affirmed: "Quantum theory describes the uncertainty of the world, and cats can be dead or alive. Whether it is dead or alive, there are two possibilities, and there are two outcomes. By inference, when one outcome is determined, the other disappears? That's what I'm going to say next, which is the question you asked, do parallel universes exist?"

Ge Wei smiled slightly, of course parallel universes exist, not only there are, but there are many.

He didn't talk nonsense, but quietly continued to listen to Dr. Lee's explanation.

"For a long time, the Copenhagen interpretation became the 'orthodox', 'standard' interpretation. But the cat, which never died or lived, always made physicists uneasy like a nightmare. In "The Cat in Search of Schrödinger," Glibin wants to tell us where the Copenhagen interpretation has failed, and what interpretation can replace it?"

Dr. Lee's eyes twinkled: "In 1957, Everett proposed the 'many-world interpretation', which seemed to be a boon to the world, but because it was so bizarre, few people would take it seriously at that time. But Glibin argues that there are many advantages to a multi-world interpretation, and that it can be used as an alternative to the Copenhagen interpretation. Glibin wrote in his book: 'Everett...... Point out that both cats are real. There is a live cat and there is a dead cat, but they are in different worlds. The question is not whether the radioactive atom in the box decays, but whether it decays and does not! When we look into the box, the world splits into two versions of itself. Both versions are identical in all other respects. The only difference is that in one of the versions, the atom decayed. The cat is dead, and in another version, the atom is not decaying, and the cat is still alive!"

Dr. Lee was visibly excited: "In other words, the two worlds of 'the atom decays and the cat is dead, and the atom does not decay and the cat is alive' will evolve completely independently of each other! So he went on to say, 'It sounds like science fiction, and yet...... It is based on impeccable mathematical equations, based on the simple, self-consistent, and logical results of quantum mechanics. ''In the quantum manyworld, we choose our own path by participating. In this world we live in, there are no hidden variables, God does not roll the dice, everything is real. According to Gleebin, if Einstein had been alive, he would probably have agreed and greatly praised this 'there are no hidden variables.' God doesn't roll dice' theory. Einstein believed in God, but Einstein did not believe that God would roll the dice. ”

Dr. Lee abruptly stood up from the couch and paced back and forth: "The advantage of this interpretation is that the Schrödinger equation always holds true, and the wave function never collapses, thus simplifying the basic theory. But the problem is that the assumptions are too bizarre, and the price comes is that these parallel worlds are all equally real. It's no wonder some people say. In the history of science, the many-world interpretation is undoubtedly the boldest and most ambitious theory ever proposed. The question is—" Dr. Lee looked at Ge Wei.

"There is no evidence. Ge Wei smiled.

"Yes. Dr. Lee nodded deeply: "Any kind of theory." There needs to be evidence to prove it. The theory of many worlds seems absurd, but it really has no theory, can it prove it? The answer is still no. The evidence, with the progress of modern science, is already available. ”

"Oh?"

"I remember it very well. In May 1996, it was big news for the entire world scientific community. Dr. Lee recalled, "The National Institute of Standards and Technology in Boulder, Colorado, USA, was a well-known research institution. Those genius lunatics. I made a "Schrödinger's cat" out of a single beryllium ion, and took a snapshot and found that the beryllium ion was spinning up in the first space position, and at the same time spinning down in the second space, and the two states were 80 nanometers apart! That's a huge distance at the atomic scale. Imagine that this beryllium ion is a psychic master, who appeared in New York at the same time as the Himalayas, one of whom was parachuting from the top of a skyscraper, and the other who was climbing to the top of a snowy mountain! This 'incarnate doctor' characteristic of quantum is called 'quantum coherence' in physics. In the early Young's double-slit experiment, a single light particle delicately passed through two slits at the same time with beautiful wave-particle duality, creating a beautiful chiaroscuro coherent stripe on the observation screen. ”

"What does that mean?" asked Ge Wei.

"Imagine that in a closed box, there is a live cat and a bottle of poison. When decay occurs, the vial is broken and the cat will be poisoned. According to common sense, cats may or may not be alive. But quantum mechanics tells us that there is an intermediate state where cats are neither dead nor alive until they make observations and see what happens. Quantum theory tells us that nothing is real unless an observation is made. ”

Ge Wei frowned: "Everything is ...... No...... Real?"

Dr. Lee smiled clearly, and at this moment he was completely less cramped when he came in. He smiled and said, "There was a widely circulated argument in the quantum school that 'the moon doesn't exist when we don't observe.'" This is of course a departure from the original intention, to be precise, because the moon is also made up of indeterminate particles, so if we turn our head away from the moon, a large number of particles start to disperse according to the wave function. As a result, the edge of the moon begins to appear blurry and uncertain, and it gradually 'melts' into a probability wave that spreads into the surrounding space. Of course, the probability of such a large moon completely melting into space is a long, long time, but the essence of the problem is that if you don't observe the moon, it will go from a definite state to an infinite number of indefinite superimpositions. Without observing it, a deterministic, objective moon does not exist. But as soon as he turned around, a bright moon hung high in the air again, as if nothing had happened. But in fact, the laws of quantum mechanics limit the wave function of a massive object like the moon to a very small area, so even if the moon disperses, the degree of dispersion is not visible to the human eye. ”

Speaking of this, Ge Wei was relieved, and both of them laughed.

Dr. Li stroked his palms and smiled: "I can't help but admit it, this sounds like a very strong subjective idealism. Although it is actually a certain difference from the philosophical theory we usually understand, many people will naturally think of the famous saying "Esse.Est.Percipi", "to be is to be perceived", and if this sentence were slightly changed to "to exist is to be measured", it would be similar to what Copenhagen meant. This is what a Bishop of Berkeley said in history, and his place in the history of philosophy is undoubtedly important, although people are usually happy to criticize him, but does our Copenhagen doctrine go further than him? And quantum theory?'Your Majesty, I don't need the assumption of God.'" ”

Dr. Lee laughed. Ge Wei couldn't cry or laugh while holding the red wine.

Ge Wei remembered that he once chatted with Yi Chen about wine in his spare time, and Yi Chen mentioned that there was a master named Wang Yangming in their Kunlun Immortal Realm. This person also said a similar sentence in the Kunlun Immortal Realm: "When you don't look at this flower, this flower and you will die together, and when you come to see this flower, the color of this flower will be understood for a while......

What Ge Wei wants to say is that if Wang Yang knew quantum theory, he would probably say: "When you don't observe this flower, this flower does not really exist, and it will die according to the wave function, and when you come to observe this flower, the wave function of this flower will collapse, and its color will become clear and real for a while......

Measurement is reason, and measurement is unreasonable.

Ge Wei's smile gradually narrowed, and he felt that he seemed to understand a lot of things at once. There were many inferences about Qingdao Chufu, and he felt that he was right. (To be continued......)