1900: A physics genius wandering around Europe

Chapter 460 The Secret of the Fourth Quantum Number! Finally Revealed! He who wears the crown must bear its weight!
Leiden University Library, The Netherlands.

Uhlenbeck and Gudsmit sat opposite each other.

On the table in front of them, there were manuscript papers scattered around with densely packed calculation formulas.

Although it looks complicated, it is actually not simple at all.

Uhlenbeck's face was full of smiles.

He recalled the process of how he and his teammates discovered the fourth quantum number some time ago.

It was a story full of drama.

At that time, in order to catch up with Pauli, Goudsmit spent almost every day in the library after class.

In order to save time, he sometimes even just eats some fruit for lunch.

It can be seen how badly Pauli criticized him, that he was forced to work so hard even when preparing for the Physics Olympiad.

It happened that Uhlenbeck also came that day.

He has been obsessed with the fourth quantum number recently.

He had almost memorized the contents of Li Qiwei's speech in Germany.

However, he still had no clue.

The two sat together, staring at each other, with helpless looks on their faces.

Gudsmith sighed.

"Will I, Gu, always be outshined by Pauli?"

“I really can’t accept this!”

"The fourth quantum number, you mysterious elf, where are you hiding?"

After a lot of complaints, he had no choice but to read the quantum theory papers obediently.

Hope to find some inspiration.

At this time, Goodsmith picked up the apple next to him.

He was just about to take a bite when he suddenly remembered that he couldn't eat in the library.

So, I just endured it.

Then, as if possessed by a magic spell, he began to turn the apple.

Although the apple is irregular in shape, it is relatively flat on the top and bottom and can be turned barely.

As Goudsmit looked at the apple, his mood improved and he even started to laugh.

At this time, Uhlenbeck on the opposite side was attracted by Gudsmit's laughter.

He raised his head and looked at the other person, then looked at the apple spinning beside him and smiled.

"Dagu has been tortured to such a boring point."

"Oh, if you can't think of anything else, I might as well just persuade him."

"Without the fourth quantum number, there are other important unsolved mysteries in physics."

"A gentleman's revenge is never too late."

However, when Uhlenbeck took one last look at the apple.

boom!
It was as if a huge thunder exploded in his ears!

Almost in an instant, he felt a flash of inspiration as if at the beginning of the universe.

It illuminated all the darkness in his eyes and allowed him to glimpse the light of heaven.

"Oh!"

"Oh!"

"Oh, God!"

"I see!"

"I know what the fourth quantum number is!"

Uhlenbeck's heart was screaming wildly.

A surge of blood rushed to the sky.

His face was even distorted with excitement.

"Ah~~~!"

He stood up suddenly and roared.

I want to vent the excitement in my heart.

Everyone in the library was shocked.

"Fuck, who is this lunatic?"

"There's something wrong with you!"

"What kind of quality!"

They immediately looked in the direction of Uhlenbeck, their faces filled with contempt.

Goodsmith was very embarrassed. He quickly pulled his friend to sit down and then apologized to everyone.

"Uhlenbeck, what's wrong with you?"

"Nothing wrong?"

"I will never compete with Pauli again. Let's both study hard."

At this moment, Uhlenbeck's mood finally calmed down.

He quickly apologized to everyone in the library in a very gentle tone.

However, he excitedly said to Gudsmit:

"I know what the fourth quantum number is!"

"I was inspired by the apple you played with."

Wow!
After hearing this, Goodsmith was shocked.

His eyes widened, his face full of disbelief.

"really?"

"Uhlenbeck, you didn't lie to me!"

"Oh my God! Tell me!"

"I can't wait!"

Goodsmith couldn't describe his feelings, he felt like his blood was about to boil.

The fourth quantum number was becoming his nightmare.

Uhlenbeck took a long breath and said:
"The Pauli-Bruce exclusion principle proves that electrons must have a binary property."

"The electron is like a point, moving around the nucleus."

"In three-dimensional space, up and down, left and right, front and back, these degrees of freedom have already described the movement of electrons."

"Those are the three quantum numbers of the electron."

"They are the quantum number of the number of orbitals, the quantum number of the shape of the orbitals, and the quantum number of the direction of the orbitals."

"But we focus on the electrons themselves."

“What if it’s no longer a point, but an apple?”

Hearing this, Gudsmith was puzzled.

Think of an electron as an apple?
What's the point?

If an electron is the size of an apple, then the nucleus would probably be the size of the earth.

Now it's just that the apple is moving around the earth.

There is essentially no difference.

So, he asked:

"What's the point of this?"

Seeing that Gudsmit hadn't reacted yet, Uhlenbeck smiled and said:

"How did you make the apple exercise just now?"

Gudsmith said without hesitation:

"Just make it spin, like a spinning top."

"Is there anything special about this?"

Uhlenbeck just smiled and said nothing, staring into Gudsmith's eyes.

suddenly!

The latter was suddenly startled.

"Turn?"

“The apple is spinning?”

"Oh!"

"Oh my god!"

“The electrons are spinning!”

"Yes, yes, this is the fourth quantum number."

“And it’s the nature of the electron itself.”

"Uhlenbeck, you are the greatest genius!"

At this moment, Goodsmith went completely crazy.

The electron spin gave him a sudden enlightenment, and he saw the light after the fog had cleared.

There is also a feeling of enlightenment.

“So clever, so magical!”

Compliments kept pouring out of his mouth.

Uhlenbeck smiled and said:

"Yes, I think the fourth quantum number is the electron spin."

"If you imagine an electron as a solid sphere, then it has the concept of rotation."

"The electron will spin around its central axis."

"Depending on the direction of rotation, it can be divided into counterclockwise rotation and clockwise rotation."

"This corresponds exactly to the binary nature of electrons."

"That is, the fourth quantum number has two values."

"In this way, not only the Pauli-Bruce exclusion principle can be explained."

"Even the anomalous Zeeman effect can be explained."

"Because electrons have spin, they produce spin magnetic moment."

"When it interacts with a magnetic field, the electrons with different spins end up in slightly different energy states," he said. "As a result, the spectral lines split further."

"That's why the anomalous Zeeman effect emerges."

boom!
Goodsmith was like listening to the music of nature.

This analysis made him feel addicted.

It’s so exquisite!

He said excitedly:

"Uhlenbeck, you are going to be famous in the physics world!"

"I have a hunch that electron spin must be the fourth quantum number that physics has been searching for."

"Oh my God! I didn't expect it to be that simple."

Indeed, when Goudsmit actually knew about the existence of the fourth quantum number, it seemed very simple.

Spin!
This is the most basic concept of mechanics.

Any physics undergraduate can calculate various spin formulas.

However, before it was discovered, no one, even among so many big names in the physics community, could have thought of this.

At this moment, Goodsmith felt the greatness of Professor Bruce.

It’s so difficult to go from 0 to 1!

Moreover, the fourth quantum number was born on such a solid foundation.

He said with emotion:

“It was not for Professor Bruce, Professor Bohr, and Yu Yin who discovered the anomalous Zeeman effect.”

"Well, add a Pauli."

"It is simply impossible to discover the fourth quantum number out of thin air."

“Original physics research, it really is a game for geniuses.”

After listening to Gudsmit's words, Uhlenbeck smiled and said:

"Da Gu, you just said something wrong."

"It's not that I want to be famous in the physics world."

"It's the two of us together, making our name known all over the world!"

"Without your help and inspiration, I would never have thought of electron spin on my own."

"This honor belongs to both of us."

Wow!
Goodsmith was so excited that he could hardly contain himself.

He grabbed Uhlenbeck's hand and said tremblingly:
"Brothers!"

Uhlenbeck smiled:

"There's only one part left, and that's determining the exact value of the spin quantum number."

"Da Gu, you are better at math than me, so you have to put in more effort in this part."

Gudsmith said ambitiously:
"Don't worry, leave it to me."

Snapped!
At this moment, Uhlenbeck was awakened by the sound and came back to his memories.

There was a faint smile on the corner of his mouth.

The duo's experience of discovering the fourth quantum number was full of fun.

Maybe it will become a beautiful story in the field of physics in the future.

And Goodsmith, who was sitting opposite him, had just put down his pen and stretched.

It was the sound of his pen that awakened Uhlenbeck's memories.

He said with relief:

"Oh, I finally figured it out."

After Uhlenbeck took the result from the other party, he started to look at it.

"According to the above calculations, we know that:"

"The values ​​of the electron spin quantum number are [+] and [-]."

He smiled and said:

"Da Gu, you are amazing."

"This completes our theory."

"± corresponds exactly to binary value."

At this moment, the calm and low-key Uhlenbeck finally felt relieved.

Gudsmith said with longing and confidence:

"Professor Bruce's quantum theory seminar, I can't wait for it to start."

"Pauli will definitely come too."

"When the time comes, I'll make him open his eyes to our theory."

"The fourth quantum number is no worse than his exclusion principle."

"Hehe, let's see if he dares to mock me for being a poor student again."

Uhlenbeck smiled helplessly.

"Pauli, Pauli, why did you want to provoke Daigu?"

In his opinion, this time, even a genius like Pauli would fail.

After all, the discovery of electron spin was definitely a major event that shocked the physics community.

It is a major event in the field of quantum theory.

Uhlenbeck could already imagine the shock on the faces of so many bigwigs present after hearing this concept.

Even Professor Bruce would be surprised.

He thought happily.

however.

How can the road of physics research be smooth sailing?

Uhlenbeck and Goudsmit will soon be silenced by one question.

There is a huge bug in their electron spin quantum number!

In real history, after Uhlenbeck and Goudsmit wrote the paper on electron spin.

They first submitted the paper to their supervisor, Ehrenfest.

The latter was shocked after seeing it.

Because the idea is so bold.

No one had ever considered that electrons could have spin.

Ehrenfest was a little unsure.

However, he cherished the students' hard work and did not want to bury their talents.

So he sent the paper to Professor Lorentz, who had already retired.

Although Lorentz has retired, he remains the spiritual leader of the Dutch physics community.

Many younger generations would ask him for guidance when they encountered problems.

"Go and invite Elder Lorenz!"

When Lorenz saw the paper for the first time, he was also shocked.

He felt that this paper was very important.

But as a master of classical physics, Lorentz was very familiar with the concept of spin.

If the electron is really spinning.

Then
After a series of calculations.

Wow!
Lorenz discovered a huge problem.

If electrons are to spin, they have to break some kind of boundary.

This boundary is supposedly impossible to break. (Guess what)
This is amazing.

When Lorenz gave the results back, Uhlenbeck and Goudsmit immediately panicked.

Because according to Lorentz's calculations, there was a fatal error in their paper.

This mistake is even common sense and embarrassing.

As Lorentz was the leader of the Dutch physics community, it was impossible for his calculations to be wrong.

This is awkward.

But Ehrenfest loved his disciple dearly.

So he waved his hand and comforted her:
"Don't be afraid, both of you."

“The paper will be published as usual.”

"As a young man, it's okay to make mistakes."

"Maybe it wasn't a mistake?"

Thus, Uhlenbeck and Goudsmit's paper on electron spin was published.

This immediately caused an uproar in the physics community.

The bigwigs had mixed reactions.

Both Einstein and Bohr believed that the errors in Lorentz's calculations were not real errors.

This can be explained using the concepts of quantum theory.

However, Pauli always firmly opposed it.

Because just before that, he had fiercely criticized Koronig's paper.

The content of the latter's paper is almost identical to that of Ugu and his colleague.

Of course, it was later proved that Pauli was indeed wrong that time.

But, this life.

At the upcoming quantum theory seminar, it will depend on whether Pauli can discover this problem.

Once Pauli found out, given his personality, Ugu and the other two would probably become autistic on the spot.

It would have been difficult for anyone present to convince Pauli that the mistake was not actually a mistake.

unless
Li Qiwei takes action!
At this moment, the low laughter of Uhlenbeck and Gudsmit could be heard in the library.

They will both soon learn what it means to wear the crown and bear its weight.

When a new theory of physics is born, it is bound to be questioned.

Only by crossing this step can you see the vast sea and sky.

(End of this chapter)