1900: A physics genius wandering around Europe

Chapter 596: Improved experiment! Spin at a distance! Quantum mechanics is in danger again! How diff

Chapter 596: Improved experiment! Spin at a distance! Quantum mechanics is in danger again! How difficult is this! Li Qiwei takes action!

The third afternoon of the meeting.

The second thought experiment proposed by Einstein shocked everyone.

According to his experiment, if the uncertainty principle is to be used at any scale, a superluminal interaction must occur.

This is what is called action at a distance.

But according to special relativity, this cannot happen.

Therefore, there is a contradiction between quantum mechanics and relativity.

In real history, the thought experiment proposed by Einstein is the famous "EPR paradox".

After the failure of the Sixth Solvay Conference, Einstein still did not give up his doubts about quantum mechanics.

By then, he had moved to the United States and chose to spend the rest of his life at Princeton University.

With the vigorous development of quantum mechanics and nuclear physics, relativity has lost its former glory.

Einstein was also regarded as an old-fashioned person who did not understand quantum mechanics.

But his fame is so great that there are always many people willing to follow him.

If Einstein was not really good at teaching students, there would probably be more people wanting to curry favor with him.

Rosen and Podolsky were two of those little fans, and they became Einstein's assistants.

In 1935, Einstein suddenly told the two that he had figured out how to prove the incompleteness of quantum mechanics.

He orally explained his general ideas, then Rosen was responsible for calculating the formulas and Podolsky was responsible for writing the article.

At the end of May, a paper co-authored by the three was published titled "Can the physical reality described by quantum mechanics be considered complete?"

This paper, which was only 4 pages long, shocked the entire physics community once it was published!
Various newspapers reported the event extensively.

“Einstein is still as good as ever!”

"Shock! Quantum mechanics has suffered a fatal blow!"

No one dares to underestimate Einstein's research on the nature of quantum mechanics.

Although he is an old antique, the strength of an old antique is really strong.

Because the paper is so famous, the paradox described in the article is also called the "EPR paradox."

E, P, and R are the initials of Einstein, Podolsky, and Rosen respectively.

And in this life, under the powerful pressure from Li Qiwei, Einstein's inspiration burst out and his strength exploded.

He thought of the EPR paradox ahead of time and calculated it himself, shocking everyone!
Some people even began to support his thought experiment.

At this moment, Goudsmit stepped forward.

It would be a lie to say he wasn't nervous in front of so many big guys.

Although he had attended Bruce meetings before, he was not treated as well as he is today.

Stand shoulder to shoulder with Professor Einstein and question Professor Bruce.

If it were me a few years ago, I would have been scared to death.

However, he was the one who discovered electron spin after all. After several years of training, he gradually developed the demeanor of a big boss.

Gudsmith paused, nodded to everyone, and said calmly:
“I wanted to improve on Professor Einstein’s thought experiment and make it more concise.”

“The specific process is as follows.”

"There is a system consisting of two particles of spin 1/2, particle A and particle B."

"And the total spin of this system is 0, so particle A and particle B spin in opposite directions at the same moment."

"Now, place these two particles one light year apart to prevent any information from being transferred between them."

"According to the Bruce interpretation, before particle A is measured, its spin state is in a superposition state, which means it can be either up or down."

"Similarly, particle B is also in a superposition state of spin up and spin down."

"When particle A is measured, it causes the wave function to collapse, and the spin of particle A instantly changes to an eigenstate, either up or down."

"Then, in order to keep the spin of the entire system at 1, particle B, which is one light-year away, must also collapse its wave function instantly, and its spin direction must be opposite to that of particle A."

"That is to say, even if the distance is one light year, the measurement process of particle A will instantly affect the spin state of particle B."

"Obviously, this violates the principle that the speed of light cannot be exceeded."

boom!
The whole audience was shocked!

Goudsmit's experiment is indeed easier to understand than Einstein's.

He used the spin state of electrons as an example, which made everyone understand immediately.

"My God!"

"This is incredible!"

"Particles A and B are one light year apart. How can they change state instantly?"

“There’s definitely something wrong with quantum mechanics.”

At this moment, many people began to waver.

Because the above situation is absolutely impossible to happen.

At this time, amid the shock of everyone, Gudsmith continued:

"According to Professor Einstein's explanation, particle A and particle B actually have a definite spin state at the moment they separate."

"For example, particle A has spin up, and particle B has spin down."

"Even if we don't measure them, they still spin like this."

"When we determine through measurement that particle A's spin is upward, it actually has no effect on particle B."

"Because the state of particle B was determined before it was separated, it was spin-down."

"Right now, we are just getting specific information through measurement."

"So, Professor Einstein believed that there is no so-called superposition state, and there can be no action at a distance."

"Everything is determined the moment particle A and particle B are separated."

“The essence of the world remains certain.”

Wow!
Everyone was shocked!

We even had an illusion:
"Goudsmit speaks better than Professor Einstein!"

Many people lamented:
"Even an average physicist can understand what he means."

"It's really a hero out of a boy!"

"The brilliance of geniuses like Heisenberg and Pauli overshadowed Goudsmit's talent."

"But today, the other party blossomed to his full potential and made a stunning debut!"

Einstein was also shocked.

This old friend’s students are truly amazing.

Not only did he deeply understand his own thought experiment, but he was also able to draw inferences about other situations from his own experience, which is very rare.

He couldn't help but said:

"Thank you for your complement, Dr. Goodsmith."

"Your improvement fully expresses my thoughts."

Then he smiled at Ehrenfest and Lorenz:

"Old Ai, your ability to train students is much better than mine."

"Fortunately, I rejected Professor Lorentz's invitation to teach, otherwise I would have become a sinner in the Dutch scientific community."

Lorenz and Ehrenfest both smiled knowingly.

They were deeply moved.

Who would have thought that Einstein could even defeat Professor Bruce.

Yes, they think there are indeed problems with quantum mechanics.

Maybe Bruce really lost this game.

Ehrenfest smiled:
"I want to know how Bruce is going to solve this problem now."

After saying that, he looked somewhere.

There, Bruce sat in the middle, with Bohr on the left and Heisenberg on the right.

But at this moment everyone's eyes were focused on Einstein.

Goodsmith smiled excitedly when he heard the compliment.

But he dare not be proud, because he is just standing on the shoulders of giants.

Today's meeting was an eye-opener for him!

Masters compete with each other, and each move is fatal!
He finally understood why his mentor, Professor Ehrenfest, had always taught them not to ignore any details. Because in the eyes of the big guys, any seemingly insignificant problem would eventually lead to the failure of the theory.

There is no "almost" in science, only "yes" and "no"!
"Professor Einstein, I think your theory is perhaps the most pressing problem in quantum mechanics."

"If quantum mechanics is truly local, perhaps there is still room for improvement."

Einstein nodded.

"Yes."

“I question quantum mechanics not to overthrow it, but to prove its flaws.”

Everyone nodded when they heard this.

As the two were bragging about their business, Schrödinger suddenly laughed and said:
"Following what Goudsmit said, we can actually give a more vivid example."

"Suppose there is a pair of shoes, one for each foot."

“They were then randomly packed into two boxes, one to Amsterdam and one to Brussels.”

"Until the boxes are opened, no one knows which box contains the left shoe and which box contains the right shoe."

"But we know very well that [the shoe in a box is the left shoe] is a certain thing and will not change because of anything."

“If the box is opened in Goudsmit in Amsterdam and there is a left shoe inside, then the one in Brussels is the right shoe.”

"At this point, we knew that whether Goudsmit opened the box or not, the left shoe must be inside."

"Because the left and right sides of the shoes are determined the moment they are placed in the box, they will not be affected by any observation behavior."

“The so-called measurement process is just knowing the established facts.”

"Of course, if we insist that the left and right sides of the shoe are affected by the measurement, then it can only be within a certain spatial range."

"If the two boxes were one light year apart, they would obviously not be affected."

Wow!
After Ai Guxue and the other two spoke in unison, everyone completely understood this thought experiment and understood Einstein's point of view.

It can be said that Einstein's thought experiment attacked the foundation of quantum mechanics, making all theories based on it no longer reliable.

Probability waves, uncertainty principle, complementarity principle, wave function collapse, etc., all have problems.

Quantum mechanics has irreconcilable flaws.

Danger again!

Pauli felt a burning pain on his face, which was caused by the beating from Gudsmith.

After Dagu's improvements, this thought experiment became even more deadly.

This leaves no room for quantum mechanics.

"Damn! I underestimated that guy. He does have some strength."

Pauli laughed instead, without feeling the slightest bit of shame at being slapped in the face.

"As long as I'm thick-skinned enough, no one can penetrate it."

Although he has a sharp tongue, he absolutely respects strength.

And Goodsmith's ability was recognized by someone he was dating.

Now it was Pauli's turn to have a headache. He was a staunch supporter of quantum mechanics, so he had to solve this paradox.

The speed of light cannot be exceeded and the paradox of quantum mechanics.

Heisenberg's expression became even uglier.

He thought that Schrödinger's smile was just for him.

"What's with the left shoe and the right shoe? It's just to mock me for being as low as a shoe."

"Damn it!"

Schrödinger certainly had no such idea.

If he desperately opposes quantum mechanics, wouldn't he be opposing his own wave mechanics as well?

He just thinks there are problems with the existing explanations.

Heisenberg had no words to express his pain.

Because he couldn't give any counterattack.

When it comes to scientific discussions, it’s not about who has the loudest voice, but about who has the strongest strength and the most powerful logic.

Although he hated to admit it, Einstein's experiment was indeed flawless.

"What went wrong?"

"My intuition tells me that there must be something illogical about Einstein's paradox."

"Quantum mechanics is such a perfect theory, it can't possibly be wrong!"

"Absolutely impossible!"

Heisenberg was caught in a dilemma.

Bohr remained calm.

The additions made by Goudsmit and Schrödinger did not make the problem more complicated; the core was still Einstein's experiment.

With his intelligence, he could easily understand it even without Gu Xue and the others’ vivid explanation.

But like Heisenberg and Pauli, he was helpless.

This thought experiment is really unsolvable.

"Sure enough, there is still a big gap between me and the teacher."

"If you put yourself in his shoes, how would you explain this problem?"

At this moment, not only the Li faction and others were thinking hard, but everyone was extremely interested.

Everyone was communicating.

Some people agree, some people doubt.

Born tried to refute it from the perspective of mathematical rationality.

But Einstein then gave the mathematical derivation of the theory, and Born had to give up.

Yu Yin questioned:
"It is impossible to separate two particles by a distance of one light year in an instant. There must be some additional compensation in this process."

Everyone's eyes lit up.

Just like in thermodynamics, it is impossible to transfer heat from a low-temperature object to a high-temperature object unless additional work is done.

Perhaps the same is true of quantum mechanics.

But Schrödinger immediately retorted:

"This process is different from thermodynamics and cannot be confused with it."

“Because no one knows what the compensation is.”

According to the razor principle, we can only assume that it does not exist.

Otherwise, any theory can be questioned from an implicit point of view.

People were coming and going, it was very lively.

But after a period of time, no useful conclusions were reached.

suddenly!

Everyone's eyes turned in the same direction.

The direction of that man!
"My God!"

"Professor Bruce is actually meditating with his eyes closed!"