1900: A physics genius wandering around Europe

Chapter 412: Paper published! The wave-particle duality of light is proven! A sensation in the physics community!
Wu Youxun is indeed a genius in Chinese physics.

Based directly on Ridgway's theory, he designed the Compton effect, which was originally discovered accidentally.

When he discussed the proposal with Compton after the paper was published, he said:
"Since we want to verify that light has momentum, we can just let it collide with matter."

"Then observe whether the momentum of the light changes after the collision."

"How do you measure the momentum of light?" Compton asked.

Wu Youxun smiled and said, "Isn't there a formula in Professor Bruce's paper?"

Compton suddenly realized, "You mean p=hv/c."

Wu Youxun nodded and said:

"If the momentum p changes, since h and c are both constants, that means the frequency v will change."

"For convenience, we use wavelength λ instead of v."

"According to the speed of light = wavelength × frequency, that is, c = λ × v."

"Substituting this in, we get p = h/λ."

"This is a way of expressing the momentum of a light quantum in terms of its wavelength."

"Okay, now we can design an experiment like this."

"Since X-rays are a form of light, it's perfectly OK for us to use them."

"When X-rays interact with matter, since the interior of atoms is mostly empty, most of the X-rays will pass directly through without having any effect."

"But there must be a small fraction of X-rays that collide with electrons."

"The collision of a photon and an electron is like the collision of two billiard balls."

“In that process there’s a change in momentum.”

"The light quantum will transfer part of its momentum to the electron through the collision."

"The momentum of the light quantum decreases, and the momentum of the electron increases."

"Then according to the formula p=h/λ, when p decreases, it means that λ increases."

"That is to say, the wavelength of light quanta after colliding with electrons should become longer."

"As long as we can detect these larger wavelengths, that's enough to show that light has momentum."

“This proves that light does have particle properties.”

"That is: the wave-particle duality of light is correct."

Wow!
When Wu Youxun finished explaining his experimental ideas, Compton just felt that the world was so wonderful.

He was completely impressed by Wu Youxun's talent.

"Wu, I really love you."

"I have studied the wave-particle duality of light for so many years, but it is not as good as what you said today."

“Is this what you call genius?”

Suddenly, Compton asked again:
"So how do we measure the wavelength of the X-rays after the collision?"

"There is no instrument that can directly measure the wavelength of light."

Wu Youxun was well prepared. He quickly wrote down the derivation process on paper.

"We don't have to measure the exact value of the wavelength directly."

"All we have to do is calculate the difference in wavelength before and after the collision."

"If the difference is positive, then it means that the wavelength after the collision is greater than the wavelength before the collision."

"After the X-rays collide with electrons, the scattered X-rays will definitely change their angles."

"That is, there is an angle θ between the incident X-rays and the scattered X-rays."

"Then according to the law of conservation of energy, we will eventually find the relationship between the wavelength difference and this angle."

"Look, this is it."

As he spoke, Wu Youxun also provided a schematic diagram.

"As for how to visualize the X-ray tracks, I think we can use an instrument."

Compton asked, "What instrument?"

Wu Youxun smiled and said, “Wilson Cloud Room!”

"I have recently studied this instrument and found it to be particularly useful for observing the trajectories of microscopic particles."

"We can make the collision process happen in a Wilson cloud chamber, so we can measure the angle directly inside it."

"This cloud chamber in our laboratory should be improved, and the effect is very good."

At this moment, Compton's eyes were wide open with excitement.

Wu Youxun's deduction is simply flawless.

This makes the experiment much simpler.

By measuring the angle difference between the X-rays before and after the collision, the difference in their wavelengths can be calculated.

This proves that the wavelength has indeed changed.

Finally, it is proved that the momentum of the light quantum changes.

One thing after another, with strict logic.

Finally, Compton asked a crucial question.

"Wu, how do you know that this effect occurs when X-rays interact with matter?"

"X-rays have been studied for so many years, and their collision with matter has also been studied by many people."

"But I've never heard of anyone finding that the wavelength gets longer after a collision."

Wu Youxun laughed and said:
“I’m just analyzing it theoretically.”

"As for the specific situation of the experiment, we won't know until we do it."

“Just because other people can’t find it doesn’t mean it doesn’t exist.”

"It's because they don't have theoretical guidance. Maybe this phenomenon has occurred but has been ignored."

“Now, we are looking for the process with answers, which makes it much easier.”

"Compton, cheer up, I believe we will succeed."

After listening to Wu Youxun's analysis, Compton found that what he said did make sense.

"You're such a fucking genius!"

So, the two of them started the experiment immediately.

The first material they used was graphite crystal.

Because graphite is thinner, it is easier to measure angles.

After more than a month of crazy testing, the collision experiment between graphite and X-rays was a great success.

The two of them finally discovered that the wavelength of X-rays was becoming longer.

This is absolutely a completely new physical phenomenon.

It can only be perfectly explained by Professor Bruce's wave-particle duality of light.

There is no way to explain this phenomenon using traditional physics.

Wu Youxun and Compton hugged each other and laughed.

But they didn’t stop and relax because one material could have errors.

So they went on to test other types of materials.

until today.

Wu Youxun smiled and said, "Compton, this should be the tenth material."

Compton was already exhausted these days, but he was extremely happy.

"Yes, all ten materials showed a longer wavelength."

"This fully demonstrates that this phenomenon has nothing to do with the material itself, but is the nature of light."

"Wu, the two of us have proved the wave-particle duality of light."

"Oh God, I can't be dreaming now."

After saying that, he pinched his face hard and screamed in pain.

But the pain brings joy.

Compton is considered a fool by others.

I chose the most difficult topic for my PhD and almost didn’t graduate.

After graduation, I didn’t look for a big shot to study with, but instead hung out with an undergraduate.

Although this undergraduate student is a gold medalist in the Physics Olympiad, that does not mean he can make real achievements in physics.

But he still did not hesitate and became a partner with Wu Youxun.

Because when they were in Borneo, the two of them hit it off at first sight.

They both could have followed the boss.

Compton can follow Professor Millikan, and Wu Youxun can follow Professor Bruce.

But neither of them did so, perhaps this was God's will.

Compton said in a voice that only he could hear: "Thank you, Wu."

Wu Youxun also smiled happily.

At this moment, he thought about a lot.

During this period of time, he actually knew all the rumors about him outside.

A Chinese person actually wants to conduct original research on his own, beyond his own capabilities.

"He thinks he's Professor Bruce."

Wu Youxun knew that his Olympic gold medal halo had now turned into a pressure for him.

If he fails, those who mock him will use this opportunity to belittle China and at the same time belittle the value of the Physics Olympiad.

No one cares about the time issue in academic research.

Those people only knew that Professor Bruce had spoken personally, saying that Wu Youxun could prove it.

Then he must conduct the experiment immediately, otherwise he will be criticized.

Thinking of this, Wu Youxun smiled lightly.

"You are doomed to fail."

"Because the principal has already said that destiny lies with China."

Wu Youxun finally proved himself.

Without any guidance from anyone, he designed the experiment from start to finish on his own.

Although the principle of this experiment sounds simple, the difficulty of doing it far exceeded his imagination.

Even in the first twenty days or so, he and Compton could not find any X-rays from the collision.

This made the two of them feel discouraged for a while.

However, he was stubborn and did not give up.

Because he believed in his own analysis, and even more so in the principal, a god-like figure in his heart.

It was not until this moment that Wu Youxun realized how great the principal was.

He put in all his effort and squeezed out all his life's wisdom.

Wu Youxun knew that once his paper was published, it would definitely cause a sensation in the physics community.

He himself would not be easily crowned with the title of "Olympiad gold medalist".

Instead, he became "genius physicist Wu Youxun".

However, all his efforts to achieve were merely proof of a paper written casually by the principal.

This shows how big the gap is between him and the principal.

How big is the gap between the so-called genius and the principal.

However, Wu Youxun was not discouraged by this.

He smiled and shook his head.

"Why should I compete with the principal?"

"He is the sun in the sky, shining on the entire Chinese land."

"I am just a tree on the earth. I just need to ensure that the area where I live is fertile and fertile."

"I have proved on my own that China can also produce scientists, and that is enough."

"In the future, I will be like the principal. While continuing my research, I will also pay attention to the training of the younger generation."

“The fire of civilization is everlasting.”

At this moment, Wu Youxun's mood changed.

"Principal, I finally understand your painstaking efforts."

"If I had asked to be your doctoral student, I'm afraid you would have been disappointed."

"What you want is a self-reliant China, not a China that can only rely on others."

Li Qiwei worked hard for nineteen years, and his hard work was perfectly reflected in Wu Youxun.

Wu Youxun is no longer the Chinese man whose name only appeared in the paper in real history.

He was no longer Compton's student, a dispensable presence in the international physics community.

Instead, it was the prover of the wave-particle duality of light, the famous Chinese international physicist Wu Youxun.
-
1919 7 Month 20 Day.

The paper by Wu Youxun and Compton was published on the cover of Nature.

The title is "Quantum Theory of X-Ray Scattering by Elements".

In the paper, the two first explained a new phenomenon they discovered.

That is, after X-rays interact with matter, the wavelength of the scattered X-rays will become longer.

The wave-particle duality theory of light can perfectly explain this phenomenon.

Once the paper was published, it instantly caused a sensation in the entire physics community.

"Oh my God! The wave-particle duality of light has actually been proven experimentally."

"Hundreds of years of debate can finally come to an end."

"Newton was right. Light is indeed a particle."

"Thomas Young was right, too. Light is also a wave."

"Light has duality. It is both a wave and a particle. It is an existence that we cannot imagine."

However, the most surprising thing is the author of the paper.

"Compton said that the design of the experiment was almost entirely completed by Wu Youxun from China."

"Many people didn't think highly of them at the beginning."

"Is this the strength of a gold medalist in the Physics Olympiad? It's really terrifying."

“This achievement should be worthy of a Nobel Prize.”

"There shouldn't be any problem. After all, this is a brand new discovery."

Soon, the physics community named this phenomenon the "Wu-Compton effect."

In recognition of their contribution to this effect.

Wu Youxun's name once again resounded throughout the physics community, inspiring countless students.

Sidney Sussex College, Cambridge University.

Wilson looked at the paper in his hand with excitement.

No one could describe how he felt at the moment.

All the hard work comes!

The cloud chamber used by Wu Youxun and Compton in their experiment was Wilson's proudest work in his life.

This device has produced few important results since it was invented.

Most physicists consider it an auxiliary device.

However, in Wu Youxun's experiment, the Wilson cloud chamber became the key.

It can be said that without the development of the cloud chamber, Wu Youxun and his colleagues would not have been able to measure the angle.

In Wilson's view, this achievement is undoubtedly Nobel Prize-worthy.

As the inventor of the cloud chamber, his role naturally cannot be ignored.

Wilson smiled.

"Bruce, I'm finally going to have a Nobel Prize."

In fact, at his current age, Wilson is no longer so obsessed with the Nobel Prize.

What he cared more about was whether his name would appear in the history of physics.

And now, he can confirm it.

If there was a chapter on optics in the history of physics, it would be recorded like this:

“It took physicists a long time to develop an accurate understanding of light.

From the sages of ancient Greece to the Enlightenment scientists of the Middle Ages.

Human beings have always understood light from a simple perspective.

Until physics was formally established.

A group of physicists including Newton, Hooke, Huygens, and Thomas Young debated endlessly about this issue.

Some people think it is a particle, some people think it is a wave.

Later, Professor Bruce appeared out of nowhere.

He proposed the shocking idea that "light has the dual nature of wave and particle".

However, no one agreed with his point of view, even though he was the greatest physicist at the time.

Then, two young scholars, Wu Youxun and Compton, discovered the Wu-Compton effect.

Perfect proof of Professor Bruce's point.

The key instrument they used in the laboratory, the cloud chamber, was invented by Wilson.”

(End of this chapter)