1900: A physics genius wandering around Europe

Chapter 606: Quantum decoherence interpretation! Shocking everyone! Quantum Darwinism! Fantastic!

Faced with this incredible little cat, the bosses present tried every possible means and clashed with ideas, but still failed to achieve satisfactory results.

Micro and macro, life and death, quantum mechanics and classical theory.

The fourth mythical beast, Bruce's cat, is much more difficult than anyone could imagine.

Of course, geniuses like Heisenberg did not give up. They felt that the thinking time was too short.

After the meeting is over, I will go back and study in seclusion, and I will definitely make new discoveries.

But at this moment, everyone is looking forward to it.

"In such a short time, what theory will Professor Bruce come up with?"

“And he brought up two at once.”

Under the gaze of everyone, Li Qiwei said slowly:
"The theories proposed before can be simply divided into two categories."

"One is to acknowledge the collapse of the wave function and, on this basis, discuss the reasons that lead to the collapse of the wave function."

"The other is to simply deny the collapse of the wave function."

“Although wave function collapse is a theoretical hypothesis I proposed, it does not mean that it is necessarily correct.”

"At least the time when the wave function collapses has not been figured out yet."

"So, I also want to try to overthrow myself once!"

"Of the two answers I prepared, one acknowledges the collapse of the wave function, and the other does not acknowledge the collapse of the wave function."

Wow!
Everyone was shocked!

"Professor Bruce is really bold. He even denied the wave function collapse he proposed himself."

"If it were me, I would never be willing to overturn my own achievements."

Heisenberg admired her even more.

In order to perfect quantum mechanics, Professor Bruce does not care about any face or honor at all.

Li Qiwei suddenly joked:
"Of course, if future physicists can figure out the nature of wave function collapse, then I won't be wrong."

"Because I bet on both sides."

"Hahaha."

Everyone smiled knowingly.

Professor Bruce is still as humorous as ever.

Soon, Ridgway went on to formally articulate his theory.

"The first conjecture is what I call the quantum decoherence interpretation."

"The so-called decoherence means the elimination of interference and entanglement."

"The interpretation I proposed before focused more on the probability of a single event."

"After the measurement, the system collapses into a specific state."

"But I think a more comprehensive description should be used, covering the probability of multiple events and the relationship between them."

“The process that a quantum system goes through can be called [history].”

“A complete history consists of a series of events, each with a certain probability of occurring.”

"For example, these events could be the results of measurements of a particle's position, momentum, etc."

“If you want to calculate the probability of the entire history, you can do it by multiplying the probabilities of these different events together.”

“Different histories can interfere with and overlap each other, and this effect needs to be considered.”

Wow!
Everyone was completely confused and had no idea what it meant.

It is both history and an event.

Li Qiwei smiled and said:
"Next, I will give an example to illustrate the quantum decoherence interpretation."

"Take the single-electron double-slit interference experiment as an example."

"The electron passing through the left slit is a precise history, and the electron passing through the right slit is also a precise history."

"The two histories become entangled and interfere, resulting in the electron being in a superposition state of having passed through both the left slit and the right slit."

“If I were to describe it in a formula, that’s it.”

Li Qiwei wrote as he spoke.

"When an electron passes through a double slit, its wave function looks like this: |ψ|=（Aψ+Aψ）."

"The left side of the equation represents the wave function of an electron passing through a double slit."

"On the right side of the equation, Aψ represents the history of the electron passing through the left slit, and Aψ represents the history of the electron passing through the right slit."

“The history of the electron passing through the double slit is the result of the interference and superposition of these two histories.”

"This is a bit like the interference superposition of wave functions, but it's different."

"Now, if we expand the right side of the formula, it becomes the following form."

"|ψ|=|Aψ|+|Aψ|+2AAψψ."

"Among them, the latter term [2AAψψ] is called the interference term."

"It is precisely because of the existence of the interference term that the history of the electron passing through the left slit and the right slit interferes, resulting in a quantum superposition state."

"If the value of the interference term is 0, then there is no superposition state, and the two histories of the electron passing through the left slit and the right slit will not interfere with each other."

"The probability between them becomes simply A/A."

"And this is the classic probability statement, which means that the electron either goes through the left slit or the right slit, there is no third result."

Wow!
Everyone was shocked beyond words!
Professor Bruce actually demonstrated the principles of superposition and interference through theoretical calculations.

This is so cool!

"My God!"

“The quantum decoherence interpretation is truly astonishing!”

"It does not deny the collapse of the wave function, but finds an extremely novel angle to look at quantum processes in a new way."

"As expected of Professor Bruce, even his wild and unrealistic fantasies are still well-founded and logical."

Whether it is right or not, at least decoherence is countless times more reliable than the so-called collapse of consciousness.

Professor Bruce’s strength is so terrifying!
However, the theory doesn’t end there!

Ridgeway continued:
"What I just talked about was the microscopic quantum system of a single electron."

“But to explain Bruce’s cat, you have to expand to the macro level.”

“Let’s take the double-slit interference experiment as an example.”

"What would happen if we replaced the single electron with a glass marble?"

"There is no doubt that macroscopic objects such as marbles will never pass through both slits at the same time, but can only choose to pass through one slit at a time."

"The probability of passing through the two slits follows the classical probability distribution."

“So here comes the problem.”

"When a single microscopic particle like an electron passes through a double slit, it has a superposition state."

"Marbles are also made up of countless microscopic particles, so why does the superposition state disappear?"

"This can be explained very well using quantum decoherence theory."

"It's very simple."

“When we’re dealing with macroscopic matter like a marble, we can write down the wave function for each of the microscopic particles that make it up.”

"Every microscopic particle has its own history when it passes through the double slit."

"The history of the marble passing through the double slit is the sum of the histories of countless microscopic particles."

"Now, let's write out the wave function of the marble, just like we did before."

"Of course, the number of atoms that make up a marble is astronomical, and it's impossible to write them all down."

"But the interference term behind the formula must be calculated to be 0."

"Only then will the marble exhibit the classical behavior and only pass through the left or right slit."

"In short, when we describe a macroscopic object made up of a large number of quantum objects, we are not describing the exact history of each individual quantum object," he said. "Instead, we are giving a rough description of their history in total."

"As a result, a large number of quantum objects will undergo decoherence, causing the system to change from a quantum state to a classical state."

“That’s what the quantum decoherence interpretation is about.”

"With this interpretation, let's now look back at the kitten problem."

"A cat is made up of a lot of microscopic particles, and so is even a Geiger counter."

"When the box is closed and the Geiger counter starts detecting the decay of atoms, the whole system has already undergone quantum decoherence."

"The superposition state disappears directly, leaving only two definite histories: life and death."

"Replace the cat with a human, and the result will be the same."

"The quantum decoherence interpretation completely avoids the problem of consciousness. In this interpretation, consciousness has no meaning at all."

"Everything is the calculation of the interference term behind the wave function. It is a purely physical process."

quiet!
Deathly silence!

Everyone's eyes widened in disbelief.

Although they had previously thought that Professor Bruce would definitely not just predict a few theories casually.

But I never expected it to be so "hardcore".

It is so hardcore that most people even want to directly accept this theory!

"My God!"

"Professor Bruce is exaggerating!"

“You can come up with such a stunning interpretation!”

“I even think this might be the best answer in the end.”

There is no contradiction between the quantum decoherence interpretation and the Bruce interpretation, and they appear to be very complementary.

The former in particular is very smooth in explaining the changes from micro to macro.

Heisenberg, Dirac and others were all shocked!

Professor Bruce once again exceeded their imagination.

However, at this time, Pauli suddenly raised a question:
"Professor, a large number of quantum objects decoherently cause the interference term to be zero. I can understand that."

"This is because the quantum objects interact with each other, causing their own interference to vanish."

"But for a single electron, why is its interference term zero?"

Wow!
Everyone was shocked!
Pauli was indeed a man of great talent and courage. While everyone was still digesting the content of quantum decoherence theory, he had already begun to question it.

Li Qiwei heard this and smiled slightly, saying:

“That’s a very good question.”

"Logically speaking, after the wave functions of a single electron are superimposed, the subsequent interference term should not be zero."

"But, Pauli, you forgot one condition!"

"According to the experimental results, the electron's wave function collapses only when it is measured, and it only passes through a single slit."

“And measurement means interaction.”

"So the decoherence of a quantum system is the process by which its coherence disappears as a result of its interaction with the environment."

"An open quantum system will inevitably interact with the surrounding environment, causing the superposition to be destroyed and the quantum state to become a classical state."

"The evolutionary process is a bit like Darwinian evolution in biology."

“You might as well call it [Quantum Darwinism].”

“When a quantum system interacts with its environment, it is actually also a process of being selected by the environment, similar to natural selection.”

“The direction of evolution of a quantum system is related to the environment.”

"This corresponds exactly to Bruce's interpretation: [Using wave methods to detect quantum, quantum behaves as waves; using particle methods to detect quantum, quantum behaves as particles]."

“It’s just that quantum Darwinism is more complicated and involves detailed calculations.”

"Of course, quantum Darwinism is just my conjecture, a supplement to the interpretation of quantum decoherence, and it may not be correct."

hiss!
If the quantum decoherence just now was horrifying, then the current quantum Darwinism is simply confusing.

"Professor Bruce actually combined physics and biology?"

"This is simply like a fairy tale!"

"The key is that what he said was very reasonable and linked together, which made people believe it."

Pauli opened his mouth blankly.

He thought he had found a loophole in quantum decoherence, but he didn't expect that it would be easily solved by Professor Bruce.

Quantum Darwinism, in particular, made him feel a huge gap.

Although it is just a concept and conjecture, it is far less rich than the interpretation of quantum decoherence.

But its significance is extraordinary.

"Professor Bruce's ideas are too wild!"

"Nothing can hold him back."

"I never thought that quantum mechanics could be combined with Darwinian evolution."

“Is this the realm of the Ke Dao Grandmaster?”

"Physics, chemistry and biology, all integrated!"

"Every blade of grass and every tree is truth!"

The proud Pauli also lowered his noble head.

At this moment, everyone was shocked!

The quantum decoherence interpretation is logically self-consistent, and it perfectly explains the incredible thought experiment of Bruce's cat.

Even the strict Pauli could not find fault with it.

In real history, the theory of quantum decoherence was not proposed until the 20s.

At first, the physics community did not pay much attention to it, but soon, quantum decoherence attracted the attention of countless bigwigs.

Because it is significantly different from other interpretations of quantum mechanics in that it has rigorous mathematical and logical deductions.

Most importantly, it explains a variety of issues very well.

The quantum decoherence interpretation does not overturn any experimental results in quantum mechanics.

The theory may be wrong, but the experimental results are absolutely ironclad facts.

The bigwigs present knew very well that no matter who proposed any interpretation, they would ultimately have to explain the existing experimental results in quantum mechanics.

They are the touchstones!
Clearly, the quantum decoherence interpretation is real gold!
It not only explains Bruce's cat, but also the single-electron double-slit interference experiment.

Compared with the previous interpretations, it is countless times more brilliant!
It can even compete with Bruce’s interpretation!
The Bruce interpretation was proposed by Professor Bruce himself.

Everyone was filled with emotion:

"Sure enough, the only one who can defeat Professor Bruce is himself."

Li Qiwei looked at everyone's expressions and smiled slightly.

Although the quantum decoherence interpretation explains Bruce's cat, it is not without any problems.

It’s just that the big guys present couldn’t think of it for the time being.

However, Li Qiwei didn't care.

This interpretation is just a transition he used to inspire the wisdom of the big guys, which is not surprising.

However, his calm expression was the epitome of unfathomable in the eyes of everyone!
At this moment, everyone had only one thought in their minds.

"Professor Bruce's first interpretation is already so awesome."

“How amazing will the second interpretation be?”

(End of this chapter)