1900: A physics genius wandering around Europe

Chapter 417: Huge breakthrough in atomic science! The nucleus can be divided again! The proton is invented! A sensation in the physics world!

In the first thirty years of the 20th century, the most important theories in physics were relativity and quantum mechanics.

Both theories have their own material and existential basis.

The theory of relativity applies to the study of cosmic space and time and macroscopic celestial bodies.

Quantum mechanics describes the laws of motion of microscopic particles, and its foundation is the study of atomic structure.

The relationship between theory and practice is well reflected in the two major theories.

In Li Qiwei's previous life, astronomy and microscopic particle science each had their own ultimate problems.

Astronomy: What is the origin of the universe?
Microscopic Particles: What is the relationship between the dozens of elementary particles in the universe? Can they be unified?

These two ultimate questions have been puzzling countless physicists.

The pits dug by our predecessors can only be filled by future generations.

And now, in 1919, atomic science was about to start digging its way into the future.

University of Cambridge, Cavendish Laboratory.

After becoming the director of the laboratory, Rutherford quietly learned a lot of teaching experience from Li Qiwei.

Large group meetings are one of them.

One day per month is selected as a large group meeting, and everyone in the laboratory must attend.

Then, in a fixed order, each graduate student took turns to report their research results on stage, and others in the audience could ask questions at will.

Sometimes, mentors and researchers also have to come on stage to share.

In this way, students can fill in their gaps and see clearly the problems they are researching.

On the other hand, it can also create some psychological pressure on students.

In front of so many classmates and mentors, if my research is messed up and done as poorly as Xiang, I would be ashamed.

This model has no effect on geniuses, but it can effectively improve the self-control of ordinary students.

So after Rutherford tried it for a while, he immediately adopted it.

However, after the system was implemented, everyone had only one thought in their mind:
"Professor Bruce is too cruel."

"How on earth did he come up with such a trick?"

"Professor Rutherford used to be so kind and amiable. How come he has become so strange now?"

After hearing this, Rutherford said, "Let the students suffer a little more, and I will bear the blame."

However, today's group meeting was a little different.

The students who usually had sad faces now had rosy faces, as if they had encountered something extremely happy.

Rutherford stood in the front, full of energy and vigor, as if he was decades younger.

"You should have been notified before."

"Today, there is no need for you to share your research results."

There was a burst of wows from the audience.

However, Rutherford went on to say:

"Instead, I will let Chadwick share my research progress on the atomic nucleus with everyone on my behalf."

Wow!
Everyone immediately went from joy to shock!
Could it be that the tutor's experiment had made a breakthrough?

"Professor Rutherford is a big shot in the field of atomic structure."

"His experimental ability is unrivaled in the physics community. Professor Bruce said this himself."

“It took so much time to finally make some progress.”

"Today's sharing must be extraordinary."

All the students in the audience were whispering to each other, appearing extremely excited.

Like Rutherford and Thomson, they were both mentors who were as warm and helpful as a spring breeze.

They always encourage rather than criticize their students.

And no matter how busy he is, he will always take time to guide students in their studies.

Therefore, everyone in the laboratory respects and loves him very much.

Although everyone was crying and wailing about the group meeting, everyone understood that it was a good thing.

Ordinary students are not even qualified to meet Rutherford.

However, they can receive personal guidance and evaluation from the big guys every month, which is really enviable for others.

Fowler and Blackett looked at each other and saw shock in each other's eyes.

The two knew that Chadwick was Professor Rutherford's most important assistant at present.

The other party is not only extremely smart, but also loyal. He has always been by the professor's side and has made great contributions.

Therefore, the results that he needs to achieve must be shocking.

Soon, amid everyone's anticipation, Chadwick walked to the front.

The muscles on his face trembled with excitement and he swallowed unconsciously.

The results he is going to share today are absolutely explosive.

After receiving Rutherford's affirmative look, Chadwick spoke:

"In 1902, Professor Bruce proposed the planetary model of atomic structure."

"In this model, an atom consists of a nucleus in the center and electrons that move freely outside the nucleus."

"Professor Bruce at the time gave a wrong argument for how electrons move around the nucleus."

"Until his doctoral student, Professor Bohr, proposed the quantized orbital model."

"This solved the mutual motion relationship between the nucleus and the electrons."

"But Professor Bruce was always bothered by a certain problem, and he often discussed it with Professor Rutherford."

"That is, we know nothing about the nucleus."

"In terms of mass, the nucleus is hundreds or thousands of times more massive than the electron."

"Why is there such a big difference in mass for both microscopic particles?"

"Professor Bruce proposed a bold hypothesis: he believed that the atomic nucleus might be divisible."

"That is, the atomic nucleus has a more sophisticated structure."

"But as we all know, Professor Bruce's experimental ability is far inferior to his theoretical ability."

Everyone in the audience burst into laughter, and even Rutherford couldn't help but smile knowingly.

This is the only point that the physics community can hold against Professor Bruce.

"So Professor Bruce hopes that our Professor Rutherford can solve this problem."

“This is Professor Rutherford’s most important research topic.”

“But it’s very difficult.”

"It's already very difficult to study atoms, let alone the nucleus, which is even smaller than an atom."

"Also, unlike electrons, the nucleus is located in the center of the atom and its position is fixed. It does not move around like electrons, so it is difficult to observe."

“He was researching this before I became the professor’s student.”

"And now, after more than a decade of unremitting efforts by the professor, the experiment has finally made a huge breakthrough."

"The secret of the atomic nucleus has been discovered by the professor!"

Chadwick's words were very contagious. The students below began to breathe faster and became excited.

At the same time, this also reflects his profound knowledge and his easy knowledge of the history of the development of physics.

In just a few words, the whole story was explained clearly.

No wonder he was favored by Professor Rutherford and entrusted with important tasks.

At this time, Chadwick turned on the projection, which clearly showed the experimental plan.

"Please look at the specific experimental process as follows:"

"The method is to bombard nitrogen nuclei with alpha particles (helium nuclei)."

“The experimental setup is shown in the figure.”

"There is radioactive material in the container, which can emit alpha particles as a bombardment source."

"The emitted alpha particles will directly bombard the aluminum foil."

"Evacuate the container and adjust the thickness of the aluminum foil so that the alpha particles are absorbed by the foil without passing through."

"Next, place a fluorescent screen behind the foil."

"When microscopic particles hit the fluorescent screen and are observed through a microscope, obvious flashes can be seen."

"At this time, since all the alpha particles are absorbed by the aluminum foil, no flash can be seen on the fluorescent screen." "At this time, fill the container with nitrogen through the valve."

"The next step is to witness the miracle!"

"There was actually a flash on the screen."

"When the nitrogen was replaced with oxygen or carbon dioxide, the flash disappeared again."

"This shows that after the alpha particle hit the nitrogen nucleus, a new particle was generated and penetrated the aluminum foil, which is why the flash appeared."

"Because alpha particles themselves cannot penetrate aluminum foil, it can only be new particles."

"Finally, we introduce this newly created particle into electric and magnetic fields."

"Based on how the particle is deflected by the electric and magnetic fields, its mass and charge can be calculated."

Wow!
The audience was fascinated by the performance.

"Professor Rutherford is indeed worthy of being the number one in experimental physics. This experiment is so cleverly designed."

"Just by listening to Brother Chadwick's description, I can already feel how complicated it is."

“Without hundreds or thousands of experiments, it would be difficult to see this particle.”

"Professor Rutherford's perseverance is truly admirable."

Fowler and Blackett's eyes sparkled.

At this moment, they truly felt the strength of Professor Rutherford.

Although this physics giant is extremely low-key, he is extremely powerful.

Chadwick looked at the shocked expressions of the crowd and felt deeply moved.

This experiment took up a lot of Professor Rutherford's efforts.

Now it is finally time to harvest.

He raised his voice and said excitedly:
"Next, it will be Professor Rutherford's turn to announce his results."

Wow!
There was warm applause in the room.

Rutherford stretched out his hand, pressed it lightly, and said with a smile:

"I asked Chadwick to explain the experiment so that you can learn from his thinking."

“Before doing any experiment, you should simulate the whole process in your mind in advance.”

“Only when you fully understand the experiment you are going to do can you achieve twice the result with half the effort and do it with ease.”

Everyone became even more excited after drinking a bowl of chicken soup.

Rutherford went on to say:

"I had Chadwick conduct detailed tests on this new particle."

"Its mass is one unit, and it also carries one unit of positive charge."

"It was finally determined that it was a hydrogen nucleus."

"We know that the hydrogen atom is the first element in the periodic table."

“Its structure is the simplest.”

"And now, we can actually knock out a hydrogen nucleus from a nitrogen nucleus."

"This fully demonstrates that the nitrogen nucleus can be divided into two parts."

"Therefore, I believe that the hydrogen nucleus should be an elementary particle."

"I named this elementary particle proton."

"Proton means first in Greek, which indicates the special nature of the hydrogen nucleus."

"And the nucleus of a nitrogen atom is made up of protons."

“This is the result of my experiment.”

boom!
When Rutherford announced his experimental results, the room went wild.

Everyone stood up and applauded.

Everyone was shocked by the result.

"Oh, God, am I seeing right? The professor has cracked the secret of the atomic nucleus."

"An atom is made up of a nucleus and electrons, and the nucleus is made up of protons."

"What a huge impact this will have on the physics community."

Chadwick, Fowler and Blackett's admiration for Rutherford reached an unprecedented level at this moment.

If Professor Bruce is the best in theory of the time, then Professor Rutherford is the best in experiment.

Even the previous Wu-Compton effect is slightly inferior to this experiment.

The three of them couldn't wait to see the shocked expressions on the outside world's faces.

At this moment, Chadwick felt the deepest.

He knew that his mentor and Professor Bruce had a love-hate relationship.

However, because Professor Bruce was too extraordinary, Professor Rutherford's brilliance was overshadowed.

It is said that Professor Bruce's doctoral thesis was actually left by his supervisor.

But Rutherford was busy studying radioactivity and had no time to study atomic structure.

So we entrusted Professor Bruce to do it.

But the other party was too amazing. Even though he was not good at experiments, he still discovered the planetary model.

Chadwick could only sigh: "The shortcomings of the big guys are the peaks that ordinary people can never reach in their lifetime."

In recent years, my supervisor has hardly published any major papers.

Because he spent most of his time improving experiments.

"Professor, you finally did it!"

"Your fame will be celebrated in the physics community!"

At this time, the studious Fowler couldn't help asking:
"Professor Rutherford, this experiment is really wonderful."

"But please forgive me for being so rude, I have a question."

"Why did you think of using nitrogen as a target for bombardment?"

Rutherford heard this and looked at the other party with satisfaction.

He really hopes that all his students can be as brave and good at asking questions as Fuller.

Rutherford smiled and said:

"Fowler, you probably want to ask, this experiment shouldn't take so long, right?"

Fowler scratched his head shyly.

“That’s a very good question!”

"You only see the results I have shown, but subconsciously ignore what is behind it."

"Before I experimented with nitrogen, I actually tried several other gases, including hydrogen."

"Of course these experiments all failed!"

“So no one’s paying attention to them.”

"But it is precisely because of their failure that nitrogen has succeeded."

"This is the charm of experimental physics. As long as you don't give up, you never know what the next experiment will be like."

“The surprise is always in the next experiment.”

Rutherford's earnest teachings inspired everyone.

This kind of personal experience is convincing enough for students.

Today's group meeting immersed everyone in the Cavendish Laboratory in a sea of ​​happiness.

Everyone suddenly discovered a terrible fact.

"Why is it that when Professor Bruce comes here, physics is like taking stimulants."

“Breakthrough results are starting to emerge again.”

First, Professor Bruce proposed the wave-particle duality of light, which was then proven.

Now, Professor Bruce's close friend, Professor Rutherford, has discovered the proton.

This is a huge breakthrough in atomic science!

Sensation in the physics world!

(End of this chapter)