Chapter 417 A huge breakthrough in atomic science! The nucleus can be divided again! Proton is released! A sensation in the world of physics!
For more than thirty years in the first half of the 20th century, the most important theories in physics were the theory of relativity and quantum mechanics.
Both theories have their own material and existential basis.
The theory of relativity is applicable to the study of space, time and macroscopic objects in the universe.
Quantum mechanics describes the movement laws 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 had their own ultimate problems.
Astronomy: What is the origin of the universe?
Microparticle science: There are dozens of elementary particles in the universe. What is the relationship between them? Can it be unified?
These two ultimate questions have always troubled countless physicists.
The holes dug by predecessors can only be filled by future generations.
And now, in 1919, atomic science is about to start digging holes.
Cambridge University, Cavendish Laboratory.
After Rutherford became the director of the laboratory, he quietly stole a lot of teaching experience from Ridgway.
The group meeting is one of them.
One day per month is selected as a large group meeting, and everyone in the laboratory must participate.
Then according to a fixed order, each graduate student took turns to come on stage to report his or her research results, and others in the audience were free to ask questions.
Sometimes, tutors and researchers also have to go on stage to share.
In this way, on the one hand, students can check for omissions and fill in the gaps, and see clearly the problems they are studying.
On the other hand, it can also create a little psychological pressure on students.
In front of so many fellow students and mentors, if my research was just a fool and I did the same thing as Xiang, I would be ashamed of myself.
This model has no effect on geniuses, but it can effectively improve the self-control of ordinary students.
So Rutherford immediately adopted it after trying it for a while.
However, after the system was implemented, everyone had only one thought in their minds:
“Professor Bruce is too cruel.”
"How did he come up with such a trick?"
"Professor Rutherford used to be so amiable, how come he has become so strange now."
After hearing this, Rutherford said, Said: "If the students suffer any more hardships, I will bear the blame."
However, today's group meeting was a little different.
The students who usually had gloomy faces were now glowing red, as if they had encountered something extremely happy.
Rutherford stood in front, high-spirited, as if he were decades younger.
"You should have been notified before."
"Today, there is no need for you to share your research results."
There was a wow sound from the audience.
However, Rutherford then said:
"But let Chadwick take my place and share with you my progress in research on atomic nuclei."
Wow!
Everyone immediately turned from joy to shock!
Did the mentor’s experiment make a breakthrough?
“Professor Rutherford is a giant in the field of atomic structure.”
"His experimental ability is unparalleled in the physics community. This is what Professor Bruce said personally."
"It took so much time to finally make progress."
" Today’s sharing must be no small matter.”
All the students in the audience were whispering to each other and seemed extremely excited.
Rutherford, like Thomson, is the kind of mentor who is like a breath of fresh air.
They always encourage students more than criticize them.
And no matter how busy he is, he will definitely find time to guide students in their studies.
So, everyone in the laboratory respects and loves him very much.
Although everyone will cry over the big group, everyone understands that it is a good thing.
Ordinary students are not even qualified to see Rutherford.
But they can get personal guidance and evaluation from the boss every month, which is simply the envy of others.
Fowler and Blackett looked at each other and saw shock in each other's eyes.
The two know that Chadwick is Professor Rutherford's most important assistant at present.
The other party is not only extremely smart, but also loyal. He has always been with the professor and made great contributions.
Therefore, the results that require his action must be shocking.
Soon, amidst everyone's expectations, Chadwick stepped forward.
The muscles on his face trembled with excitement, and he swallowed unconsciously.
In fact, the results he wants to share today are absolutely explosive.
After receiving Rutherford’s affirmative look, Chadwick spoke:
“In 1902, Professor Bruce proposed a planetary model of atomic structure.”
"In this model, an atom is composed of a nucleus in the center and electrons moving freely outside the nucleus."
"Professor Bruce at the time gave a wrong argument for how electrons move around the nucleus."< br>
“It wasn’t until his doctoral student, Professor Bohr, proposed the quantized orbital model.”
“This solved the mutual motion relationship between the nucleus and electrons.”
“ But Professor Bruce has always been worried about a certain issue, and he often discusses it with Professor Rutherford."
“That’s because we know nothing about the nucleus.”
“In terms of mass, the nucleus is hundreds or thousands of times larger than the electron.”
“They are both microscopic particles, why do they have so much mass? Is there such a big gap?"
"Professor Bruce put forward a bold hypothesis: He believes that the nucleus may be subdivided."
"That is, there are more refined nuclei. composition structure.”
"But as we all know, Professor Bruce's experimental ability is simply as high as heaven and earth compared to his theoretical ability."
Everyone in the audience laughed, and even Rutherford couldn't help but smile knowingly. .
This is the only point where the physics community can take advantage of Professor Bruce.
“So Professor Bruce hopes that our Professor Rutherford can solve this problem.”
“This is the most important research topic of Professor Rutherford.”
"But it is very difficult."
"It is already very difficult to even study atoms, let alone atomic nuclei smaller than atoms."
"And atomic nuclei and The electron is different. It exists in the center of the atom and its position is fixed. It does not move around like electrons, and it is difficult to observe."
"He was studying it before I became a student of the professor."
“And now, after more than ten years 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 so contagious that the students below all breathed rapidly and became excited.
At the same time, this also reflects his profound knowledge and his familiarity with the history of the development of physics.
In 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 displayed the experimental plan.
"Please take a look, the specific experimental process is as follows:"
"The method is to bombard the nitrogen atom nucleus with alpha particles (helium atom nuclei)."
"The experimental device is as shown in the figure Shown."
"There is radioactive material in the container, which can emit alpha particles as a bombardment source."
"The ejected alpha particles will directly bombard the aluminum foil."
"Evacuate the container, and then adjust the thickness of the aluminum foil so that the alpha particles can be absorbed by the aluminum foil without passing through."
"Then, put a fluorescent screen behind the aluminum foil."
"Microscopic particles hit the fluorescent screen, and when observed through a microscope, you can see an obvious flash."
"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!"
"A flash of light actually appeared on the fluorescent screen."
"After replacing the nitrogen with oxygen or carbon dioxide, the flash disappeared again."
“This shows that after the alpha particles hit the nitrogen nucleus, new particles were produced and penetrated the aluminum foil, so the flash occurred.”
“Because the alpha particles themselves cannot penetrate the aluminum foil. , so it can only be a new particle. ”
"Finally, we introduce this newly created particle into electric and magnetic fields."
"Based on the deflection of the particle in the electric and magnetic fields, its mass and charge can be calculated."
< br>Wow!
Everyone in the audience was mesmerized.
“Professor Rutherford is indeed the number one in experimental physics. This experiment is so cleverly designed.”
"Just listening to Brother Chadwick's description, I can already feel how complicated it is."
"Without hundreds of experiments, it would be difficult to see this kind of particle."
"Professor Rutherford's perseverance is really admirable."
Fowler and Blackett's eyes shone.
At this moment, they truly felt the strength of Professor Rutherford.
Although this physics boss is extremely low-key, he is terrifyingly powerful.
Chadwick looked at the shocked expressions of everyone and felt very emotional.
This experiment cost Professor Rutherford too much effort.
Now it’s finally harvest time.
He raised his voice and said excitedly:
"Next, Professor Rutherford will announce his results."
Wow!
The room burst into warm applause.
Rutherford stretched out his hand, pressed it lightly, and said with a smile:
"I asked Chadwick to explain the experiment because I want you to learn his ideas."< br>
"Before doing any experiment, you must simulate the entire process in your mind in advance."
"Only when you fully understand the experiment you are going to do, can you get twice the result with half the effort and be more comfortable."
Everyone drank. After a bowl of chicken soup, I became even more excited.
Rutherford continued:
“I asked Chadwick to conduct detailed tests on this new particle.”
"Its mass is one unit, and it also carries one unit of positive charge."
"Finally determined, it is the hydrogen nucleus."
"We know that the hydrogen atom is a member of the periodic table of elements. The first element in ."
"Its structure is the simplest."
"And now, we can actually make a hydrogen nucleus from the nitrogen nucleus."
"This fully demonstrates that the nitrogen nucleus can be subdivided."
"Therefore, I think that the hydrogen nucleus should be an elementary particle."
"I named this elementary particle proton [Proton]. "
"Proton means first in Greek, which indicates the special nature of the hydrogen nucleus."
"The nitrogen nucleus is composed of protons."
"This is the result of my experiment."
Boom!
When Rutherford announced the results of his experiment, the room was completely boiling.
Everyone stood up and clapped.
Everyone was shocked by this result.
"Oh, God, did I read that right? The professor actually cracked the secret of the atomic nucleus."
"Atoms are composed of nuclei and electrons, and the nuclei are composed of protons."
"What a huge impact this will have on the world of physics."
Chadwick, Fowler, and Blackett's admiration for Rutherford has reached an unparalleled level at this moment.
If Professor Bruce is the world’s number one in theory, then Professor Rutherford is the world’s number one in experimentation.
Even the previous Wu-Compton effect was slightly inferior compared to this experiment.
The three of them couldn't help but want to see the shock of the outside world.
At this moment, Chadwick felt the deepest feeling in his heart.
He knew that his mentor and Professor Bruce were in a love-killing relationship.
But because Professor Bruce was too unfaithful, Professor Rutherford's light was obscured.
It is said that Professor Bruce’s doctoral topic was actually left by his mentor.
But Rutherford was too busy studying radioactivity to be distracted from studying atomic structure.
So I entrusted Professor Bruce.
But the other party was so unbelievable. Even though he was not good at experiments, he still discovered the planetary model.
Chadwick could only sigh: "The shortcomings of the boss are all peaks that ordinary people cannot reach in their lifetime."
In recent years, the tutor has almost never published any blockbuster papers.
Because he spent most of his time improving experiments.
"Professor, you finally did it!"
"The physics community will praise your reputation!"
At this time, the studious Fowler couldn't help but ask ：
"Professor Rutherford, this experiment is really wonderful."
"But please forgive me for being presumptuous, I have a question."
"Why would you think of using nitrogen as a bombardment?" The target?”
Hearing this, Rutherford looked at the other party with satisfaction.
He hopes that his students can be as courageous and good at asking questions as Fowler.
Rutherford smiled and said:
"Fowler, you probably want to ask, this experiment shouldn't last so long, right?"
Fowler scratched his head shyly.
“This is a very good question!”
“You only saw the results I showed, but subconsciously ignored the things behind it.”
"Before I experimented with nitrogen, I actually tried several gases such as hydrogen."
"Of course these experiments failed!"
"So no one paid attention to them."< br>
“But it is precisely because of their failure that nitrogen 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. What’s going on?”
"The surprise is always in the next experiment."
Rutherford's earnest teachings inspired everyone.
This kind of personal experience is sufficiently convincing for students.
Today’s group meeting made everyone in the Cavendish Laboratory immersed in a sea of happiness.
Everyone suddenly discovered a terrible fact.
"How come when Professor Bruce came, physics was like taking stimulants."
"Breakthrough results began to appear explosively again."
First, Professor Bruce proposed the idea of light. Wave-particle duality was immediately proved.
Now, Professor Bruce's best friend, Professor Rutherford, has discovered the proton again.
This is a huge breakthrough in atomic science!
A sensation in the world of physics!
(End of this chapter)