1900: A physics genius wandering around Europe

Chapter 586 If you don't look at the moon, it doesn't exist! What is measurement! The essence of the world! Li Ai's dispute!
In real history, the Copenhagen interpretation is the orthodox explanation of the nature of the world by quantum mechanics.

It has almost become synonymous with quantum mechanics, and the Copenhagen interpretation is equal to quantum mechanics.

In this life, the Copenhagen interpretation developed by Born, Heisenberg, Bohr and others was proposed by Ridgway alone.

The original Copenhagen interpretation has also become the Bruce interpretation!

Bruce's interpretation represents the orthodoxy of quantum mechanics!

It contains three core concepts: probability wave, uncertainty principle, and complementarity principle (the superposition principle and wave function collapse are its corollaries).

The three major concepts overturn three "common sense" in classical physics.

The probability wave denies causality, the uncertainty principle denies determinism, and the complementarity principle denies objective existence.

At this moment, many bigwigs on the field couldn't help but discuss with each other.

Bruce's interpretation brought them such a huge shock!
This already involves a discussion about the nature of the world.

According to the principle of complementarity, electrons are nothing until they are measured.

Strictly speaking, an electron is neither a probability wave nor a particle; these are just one side of it.

There is a concept in Buddhism called "Buddha has a thousand faces but one heart."

This one mind is the essence of the electron, and it is indescribable.

The thousand faces refer to the wave or particle properties exhibited by electrons.

The state of an electron can only be described by the wave function ψ, but ψ itself is a complex number, has no physical meaning, and does not represent any physical reality.

Only |ψ| has physical meaning and represents the probability of an electron appearing at a certain position.

The wave function ψ follows the Schrödinger equation as it evolves in time and space.

Therefore, [before measurement], the electron will always exist in the form of wave function ψ.

In this state, you can't say that the electron is a probability wave, nor can you say that the electron is a particle.

You also can't say that an electron is both a probability wave and a particle.

You can't even say that an electron is neither a probability wave nor a particle.

As long as you try to describe the picture of the electron, it will be wrong.

You can only say: [Electrons are nothing]!
It means nothing, like a ghostly apparition.

Electrons only exhibit certain properties [when you measure them].

It's really incredible.

Planck murmured:
"I have a feeling that the outcome of today's meeting will completely overturn the entirety of physics!"

Even with the extraordinary wisdom of many bigwigs present, they were confused by the principle of complementarity.

However, Einstein frowned slightly.

He has always been skeptical about quantum mechanics.

He believes that the reason why quantum mechanics seems incredible is actually because hidden variables have not been discovered.

He could barely accept probability waves and the uncertainty principle.

Although he had previously stated in his debate with Ridgway that "God does not play dice."

However, phenomena such as atomic decay and electron transition that exist in reality do prove the existence of probability.

Therefore, Einstein was not particularly resistant.

However, he could not accept the last point Bruce raised today.

“Without observation, there is no objective existence?”

"How can this be!"

In Einstein's view, objective reality must be independent of the observer.

Even if humans suddenly disappear, the earth will still exist and the universe will still exist.

It is impossible that everything in the world would cease to exist due to the absence of human observation.

The complementarity principle's denial of objective existence made Einstein dare not accept it no matter what.

He glanced at Schrödinger and felt disappointed.

"It's over. Xiao Xue is almost stunned."

"It seems that I can only rely on myself to fight alone!"

Soon, Lorenz, the host, was the first to react.

Although there was still shock on his face, he still had to preside over the meeting.

"Now, please start asking questions regarding Professor Bruce's theory."

The venue began to get restless.

Young people, you look at me, I look at you, want to stand up, but don’t know how to start.

The older generation, on the other hand, remained calm and said to themselves: "We must not expose facts that we do not understand."

At this moment, Einstein took a deep breath.

He looked around and asked the classic question:

"Bruce, if we don't look at the moon, does that mean it doesn't exist?"

Wow!
Everyone was shocked!

The message contained in this sentence is really chilling!
Thinking hard!
According to the principle of complementarity, when the moon is not observed, it is in a superposition of various states.

The moon at this time is not the moon that humans know.

It could be an apple, a beautiful woman, or nothing at all.

Only when you observe it will the moon collapse from the superposition state into the [moon's eigenstate].

The moon at this moment is the moon we have always seen and known.

But this statement is really too scary!
If we take it one step further, we can come up with an incredible proposition:

“If there were no humans, would everything in the universe still exist?”

In response to Einstein's questioning, Li Qiwei smiled slightly.

"Einstein, that depends on how you understand the concept of [objective existence]."

“I want to use a vivid example to illustrate this problem.”

"All our current descriptions of the world are based on human senses."

"The wavelength that the human eye can see is between 400nm and 760nm."

"In this wavelength band, the world we see is rich and colorful, full of various colors."

“Apples are red, bananas are yellow, and watermelons are green.”

"I've been reading some biology papers lately."

"Some studies have shown that cats and dogs can see a much narrower wavelength range than humans, about 450nm-550nm."

"So, in the eyes of cats and dogs, the world is not colorful, but black and white."

“They see the world as if they were watching a black-and-white movie.”

“Apples are no longer red, bananas are no longer yellow, and watermelons are no longer green.”

"Now, if there is a hypothetical alien life form, they can only see beyond the infrared wavelengths."

"Then the world will be even more bizarre in the eyes of these aliens."

"But it's easy for us to admit that fact."

“No matter what color an apple is in the eyes of humans, cats, dogs, or aliens, [an apple] is an objective existence.”

"Red is just a color property measured by the human eye."

"If you look at it with alien eyes, you'll get another color property."

“Back to the question of the moon.”

"When the moon is not observed, it does conform to the wave-particle duality and is nothing."

"But the moon is still there, just in a state that we cannot know."

"The reason why the moon appears to be matter is because we use particle methods to measure the moon, so it appears to be particle-like."

"If there are strange creatures, they rely on sensory fluctuations to observe the world."

"Then in the eyes of this creature, the moon exists in the form of a probability wave." "Although according to the calculation of matter wave theory, the de Broglie wavelength of the moon is too short, far smaller than the observable range."

"But in theory, it is possible."

"Whether it is the real moon in the eyes of humans or the fluctuating moon in the eyes of strange creatures, they are just one aspect of the objective existence of the moon."

“That’s the core idea of ​​the principle of complementarity.”

hiss!
Everyone was stunned with shock!

This explanation is so scary!

"The debate between Professor Bruce and Professor Einstein concerns the nature of the world!"

While everyone was amazed, Einstein looked solemn.

He firmly believed that even without measurement, the moon must exist in a certain [definite form].

It is not the case that if you measure something using wave methods, it is a wave, and if you measure something using particle methods, it is a particle.

Objective existence is objective existence and is not subject to anyone's will.

In later generations, the vast majority of people shared the same view as Einstein.

They cannot believe that objective existence depends on the behavior of the observer.

But that's the magic of quantum mechanics.

So far, there have been no experimental results that violate Bruce's interpretation.

This is enough to prove the correctness of quantum mechanics.

So if you accept the Bruce interpretation, then you understand quantum mechanics.

Otherwise, you can only choose to reject Bruce's interpretation and continue to look for new theories to explain the nature of the world.

Obviously, Einstein chose the latter.

Moreover, he keenly discovered a problem.

"Bruce, you said that measurement will affect objective existence, causing its wave function to collapse and exhibit a certain property."

"So what kind of behavior is considered to be [measured] in the true sense?"

“Does seeing with the human eye count as a measurement?”

“Does looking through a cat’s eye count as a measurement?”

Wow!
Everyone was shocked again!

Professor Einstein is indeed sharp!
In the principle of complementarity, the most difficult concept to understand accurately is [measurement].

In quantum mechanics, what counts as a measurement?

Li Qiwei smiled calmly and replied:
“The instrument’s measurements are well understood.”

"Using a ruler to measure length and a balance to measure mass are both measurements."

"In the microscopic quantum field, we use photons or electrons to impact the substance to be tested. By analyzing the conditions of the photons and electrons after the collision, we can analyze the information of the substance to be tested."

“That’s also measurement.”

"Of course, seeing with the human eye also counts as measurement."

“Take the example of looking at apples.”

"When the light in the space hits the surface of the apple, it is reflected and scattered."

"This reflected and scattered light is received by the cones in the human eye."

"Then our brain interprets and fits the information from the light."

"Eventually, it appears to our eyes as [an apple]."

“The process of measuring with the human eye is very similar to that of measuring with an instrument.”

"The light in space is the photons or electrons emitted by the instrument."

"The light reflected by the apple is the new state of the photons and electrons after they interact with the substance being tested."

“So, of course, human vision is also measurement.”

"In the same way, seeing with a cat's eye or a dog's eye is also a measurement."

“When we talk about observers, we don’t mean [humans who see with their eyes].”

"It means the process above!"

"Take the moon question that Professor Einstein just raised as an example."

"Even if all humans disappeared at this moment, or even if all life in the universe disappeared, there would still be observers."

"Because as long as a beam of light shines on the moon, or a meteorite hits the moon, it is a measurement for the moon!"

"This measurement process is the observer! Or the observer effect!"

“The observer is not a person or a cat or a stone, it is a measuring process!”

"It's just that the measurement results cannot be analyzed because there is no participation of intelligent creatures."

"But for the moon itself, once it is measured, it will collapse from the superposition state to the eigenstate."

"Whether the result of the measurement is a particle moon or a wave moon depends only on the measurement method."

Wow!
Everyone was shocked!

Most people have already started to feel dizzy after listening to it.

"Oh my God! Professor Bruce's theory is so hard to understand!"

"Is this still the quantum mechanics I'm familiar with?"

At this moment, Bohr looked excited and trembling all over.

"Hahaha, I understand!"

"The root of the disagreement between Professor Bruce and Professor Einstein is [the current state of quantum]."

“Take the electron, for example.”

"Professor Bruce believes that [the electron is in a superposition state and is nothing], and you have to measure it in some way to determine whether it is a particle or a wave."

"Professor Einstein rejected this view, but he did not give his own explanation. He could not describe [the state of the electron at this moment]."

Bohr's analysis made everyone's eyes light up.

They seemed to understand what was going on.

And at a glance, the difference is obvious!

After all, Professor Bruce came up with an explanatory model, while Professor Einstein did not!
However, people did not look down on Einstein because of this.

Are you kidding? They themselves cannot come up with a reasonable theory that can consistently explain the wave-particle duality of electrons.

Although Professor Bruce's theory is shocking, it does make sense if you think about it carefully.

As long as you acknowledge the concepts such as the superposition state of electrons and that measurement will cause the collapse of the wave function, the wave-particle duality is not difficult to understand.

At this time, Schrödinger suddenly thought about a question.

"Humans, cats, dogs, and instruments are all measurements. What's the difference between them?"

“Could it be human consciousness?”

"hiss!"

Just when Schrödinger seemed to be grasping something.

Li Qiwei's momentum suddenly changed!
Everyone immediately felt a domineering aura!

God is as powerful as hell!

Horror!
Ridgeway said enthusiastically:

“More than two hundred years ago, Newton wrote in the opening chapter of Mathematical Principles of Natural Philosophy: I will now demonstrate the framework of the world system.”

"Today, more than two hundred years later, I, Bruce Lee, want to follow the example of the ancient sages, carry on their unique knowledge, and create a new world for physics."

"Now, I want to use experiments to reveal the nature of the world!"

Come out!
Single electron double slit experiment!
boom!
The whole audience was shocked!

"Is Professor Bruce going to prove the principle of complementarity with an experiment right here and now?"

"So scary!"

(End of this chapter)