Chapter 418 Bohr questions again! How protons are produced! Nuclear fission appears!
In September and October of 1919, three major events occurred in the world of physics.
The first thing is that Professor Bruce, the world's number one in physics, participated in the formation of the International Astronomical Union and was elected as the first president.
He proposed holding the great debate of the century in astronomy: How big is the universe?
As soon as the news came out, it caused a huge sensation in the scientific community and even the entire society.
Astronomy instantly became the hottest subject, attracting the attention of countless people.
Observatories in various countries even receive many tourists.
The universe and stars, these mysterious and vast existences, have an inexplicable attraction to ordinary people.
But what the academic community is more concerned about is that Professor Bruce is preparing to enter the astronomy community.
After returning to Cambridge University, Eddington inadvertently revealed Li Qiwei's idea of preparing to study stars.
Instantly causing a shock.
“Oh, God, Professor Bruce is studying quantum theory and studying stars, how can he have so much time?”
“With Professor Bruce’s peerless talent, even in his spare time He is also better at studying astronomy than most astronomers."
"Perhaps one day in the future, the smallest quantum particles and the largest celestial objects will be connected."
"It's still Bruce. The professor sees far.”
The second thing was that on October 15, 1919, the Nobel Prize was announced.
Due to the war, the Nobel Prize has been greatly affected in the past five years.
Now it has finally fully recovered and once again brought surprises to people.
The winners of this physics Nobel Prize are: Gregory, Chris, and Yu Yin.
The reason for the award is: in recognition of their research on the phenomenon of spectral line splitting under the action of electric field.
This is the so-called GKY effect.
This effect, together with the Zeeman effect, gave birth to the third quantum number of the Bohr-Lee model.
So it is well deserved to win the Nobel Prize.
Suddenly, people discovered a terrible fact:
“Six of Professor Bruce’s seven doctoral students have won the Nobel Prize so far.”
"As for the remaining Bohr, he is the most outrageous and has locked up the Nobel Prize in advance."
"Soon, all of Professor Bruce's doctoral students will win the Nobel Prize in Physics."
Countless students are crazy with envy.
Moreover, Yu Yin discovered the anomalous Zeeman effect based on the GKY effect, which became famous in the physics community.
This shows that the Nobel Prize is far from the limit for these geniuses, and they can continue to climb the highest peak of physics.
However, it is difficult for the anomalous Zeeman effect to win another Nobel Prize.
In this regard, Yu Yin said that he didn't care.
He even sent a telegram asking Li Qiwei to accept the award on his behalf.
Because he didn’t want to spend two months on the road just to get a medal, which would greatly delay his research work.
Yu Yin's operation really made Qian Wushi and others look stupid.
The brothers complained:
"Yu Yin, your ability to show off is ten times better than your scientific research ability."
Li Qiwei couldn't laugh or cry about this.
Among the four of them, Yu Yin's character is the most withdrawn, and he doesn't feel much about everything.
This is not to be indifferent, but more like simply not caring.
Yu Yin wanted to do the job Li Qiwei asked him to do well.
Pangu Project has not been launched yet, so he waited silently.
However, Yu Yin’s choice is not a precedent.
Darren, the 1912 Nobel Prize winner in Physics, did not go to accept the award, but asked his younger brother to take his place.
And in real history, there were still people who refused to accept the award.
So, Li Qiwei said to Gregory who came to the Quantum Institute:
"You can accept the award on behalf of Yu Yin."
Gregory was flattered.
He never dared to imagine in his life that he could win the Nobel Prize.
When he was an editor before, he was envious when he saw others publishing papers.
But now, he has won the Nobel Prize in Physics that no number of papers can match.
All these honors were given by the man in front of me.
"Professor, I sincerely thank you!"
Although Gregory is one year older than Li Qiwei.
But in front of his tutor, he always regarded himself as a student and was extremely respectful.
Li Qiwei smiled and said:
“You are also a big figure in the academic world now.”
“You don’t have to be so formal.”
“We are not only a teacher-student relationship, but also a friend. "
Hearing this, Gregory smiled happily and was very moved.
Suddenly, he thought of something very important.
At the same time it is also the third big thing.
"Professor, a major paper will be published soon."
"I believe you will be interested."
Gregory's tone was slightly Excited.
Even when facing his mentor, Professor Bruce, he still abides by his professional ethics.
Rutherford’s paper cannot be disclosed to anyone before it is officially published.
However, Li Qiwei saw through his little thoughts at a glance and teased him:
"I guess Professor Rutherford's research has made a major breakthrough."
Huh?
Gregory's mouth opened wide in shock.
This.
“Is the rumor true, that Professor Bruce can really see the future?”
Li Qiwei smiled slightly.
“There is no such thing as foretelling, it’s just that Professor Rutherford showed it off to me in advance.”
Gregory smiled bitterly, feeling a little upset.
“As the editor-in-chief of Nature, I am indeed lagging behind in news in front of the real big guys.”
——
October 20, 1919 .
"Nature" published Rutherford's paper on the cover.
As soon as the paper was published, it instantly shocked the entire physics community.
Everyone was surprised by the results.
The nucleus of an atom can really be divided.
“Oh, God, how many secrets of the atom are there?”
“A small atom can actually have so many structures.”
"It seems that the frontier of physics is not only relativity, quantum theory, but also atomic science."
"With so many directions, how many super bosses like Professor Bruce and Professor Rutherford will be born."
“Modern physics is really too bright.”
Rutherford, the man whose light was overshadowed by Professor Bruce, finally shocked everyone again.
He used his achievements to declare to the world that he, a radioactive boss, is still young.
Physics giants such as Thomson and Li Qiwei immediately sent congratulations to Rutherford.
Li Qiwei even publicly stated:
"Rutherford's discovery is a great breakthrough in the field of atomic research."
"The world is composed of atoms, and we humans are gradually Getting in touch with the origin of the world”
This is exciting for all physicists.
They are really getting closer to the truth!
At the same time, everyone was also shocked by the results of the Cavendish Laboratory.
In 1897, Thomson discovered the existence of electrons.
Since then, the idea that atoms are indivisible has been broken.
Following this, in 1902, Bruce discovered the existence of atomic nuclei and proposed a planetary model.
Further expanded physicists' understanding of atomic structure.
And now, Rutherford discovered that the nucleus is composed of protons.
In this way, the secrets of atoms are being revealed bit by bit.
These achievements were all completed in Cavendish. There is simply the holy place of atomic science in everyone's heart.
However, like Wu Youxun's experiment, some people soon questioned Rutherford's experiment.
The doubter was Bohr again.
Bohr has been paying attention to everything related to quantum theory recently.
The atomic structure is the foundation of quantum theory and the basis of the theory.
So, Bohr would study any achievements in the field of atomic structure.
He looks forward to finding inspiration from experiments to make breakthroughs in quantum theory.
This time, Bohr did not propose the appalling idea of negating the law of conservation.
His doubts are very reasonable.
Bohr said in the article:
“Although Professor Rutherford proved that alpha particles can produce protons after impacting the nucleus of a nitrogen atom.”
“But he had no idea about protons. The production mechanism has not been given an accurate explanation.”
"There are two situations in which protons are produced."
"One is that alpha particles are directly ejected from the nucleus of nitrogen atoms. This is also the view favored by Professor Rutherford in the paper."
" But there is another situation. "
"That is, after the alpha particle hits the nitrogen nucleus, the two stick together first, forming a composite nucleus."
"And then this composite nucleus. Another decay occurs, releasing a proton.”
"So, I think we need to continue to confirm through experiments what is the cause of the generation of protons."
Quantum Institute.
When Li Qiwei saw Bohr's question, he couldn't help but smile.
Of course he knows the answer, it’s the second one.
In fact, Rutherford’s experimental results, if expressed by an equation, should be like this:
N+α particle=O+proton.
Alpha particles are helium nuclei, composed of two protons and two neutrons.
There are 7 protons in the nucleus of N atom.
When the alpha particles rush into the nucleus of the N atom, the number of protons in the composite nucleus formed becomes nine.
Corresponds to the ninth element in the periodic table: fluorine. (The order of the periodic table of elements is arranged according to the number of protons)
But this kind of review is very unstable. It will decay as soon as it is formed and squeeze out a proton.
At this time, the number of protons reviewed becomes eight, corresponding to the eighth element: oxygen.
What is formed at this time is the oxygen nucleus.
It can be seen from Rutherford's discovery of the proton that there are actually signs of nuclear fission.
If a careful person studies this issue deeply, it is easy to come up with the concept of nuclear fission.
However, this is all looking at the problem from the perspective of future generations.
The physicists at that time did not understand this.
After all, not even neutrons have been discovered yet.
The so-called decay is just a conceptual explanation modeled on the radioactivity at that time.
Physicists actually don’t know the real mechanism.
But this does not prevent the problem from being solved.
Because, if you want to prove Bohr's question, you don't need to understand all the structures of atoms.
In real history, this experiment was completed by the British physicist Brackett.
But now, the situation has changed.
Cavendish Laboratory.
When Rutherford saw Bohr's question, he immediately frowned.
He had to admit that Bohr's question hit the nail on the head and went straight to the essence.
This problem must be solved!
Wilson on the side thought quietly for a while, with a smile on his face.
The introduction of the Wu-Compton effect has made Wilson very high-spirited recently.
Even my mind became brighter.
"Alu, I thought of an idea."
"This problem can be easily solved with my cloud chamber."
Rutherford smiled slightly, "Oh ?Awei, please tell me carefully."
Wilson said confidently:
"We can redo this experiment in a nitrogen-filled cloud chamber."
"If the production of protons is the first cause, then four tracks should be observed in the cloud chamber."
< br>"They are: the trajectory of the incident α particles, the trajectory of the α particles scattered after the collision, the trajectory of the proton, and the recoil trajectory of the nucleus after the proton is thrown."
"But if it is For the second reason, only three kinds of tracks can be observed in the cloud chamber. "
"They are: the track of the incident α particle, the track of the proton, and the recoil track of the nucleus after the proton is thrown. Traces.”
"Compared with the first type, the second type has fewer alpha particles scattered after collision."
"Because they have been fused in the nitrogen nucleus."
Luthor After hearing Wilson's experimental plan, Fu couldn't help but admire it.
“Wonderful!”
“Awei, your cloud chamber is so useful.”
Just by observing the number of tracks in a cloud chamber, you can figure out why protons are produced.
This is so in line with the beauty of physics.
Wilson smiled slightly, hiding his merit and fame.
Rutherford was very excited and did what he said, but not by himself.
"Chadwick, come here."
"I have an important experiment for you."
After hearing this, Chadwick looked excited and hurried to do the experiment excitedly.
Rutherford looked at his back and sighed:
“It’s better to be young.”
“It’s easy to lie.”
Chadwick forgot about food and sleep, took more than 20,000 photos of the Wilson Cloud Chamber, and analyzed the trajectories of more than 400,000 particles.
Finally, after accurate analysis, it was discovered that there were only three types of particle tracks in the cloud chamber.
The result is clear!
The production of protons is the second reason Bohr said.
When Rutherford published the paper, it immediately caused a sensation.
Everyone was surprised that Rutherford was indeed a master of experiments and designed and completed the experiment so quickly.
Soon, many physicists used the same method to undergo similar transformations in the nuclei of fluorine, sodium, aluminum and other atoms, and all produced protons.
Protons are bombarded from various atomic nuclei.
There is no longer any doubt about the results of Rutherford's experiment.
Protons are the building blocks of the atomic nucleus.
Rutherford, who caused a sensation in the world of physics, immediately brought Chadwick and others to the Quantum Research Institute.
He wanted to show off to his old friend, Professor Bruce.
"Bruce, it's almost the New Year."
"The Royal Society is going to hold a lecture before the year."
"Have you received the invitation? ”
"Hey, Professor Thomson insists that I share the discovery process of the proton, and I don't want to go."
Looking at Rutherford's stinky fart, Li Qiwei feigned anger and said:
"Why, my wave-particle duality is not as good as your proton."
"I was the first to propose that the atomic nucleus can be subdivided."
"Yes. It’s not that I’m not good at experimenting, so it’s your turn.”
"You should name the proton plum."
"."
Chadwick and others next to him were stunned.
The big guys are all so naive
After laughing, Li Qiwei’s eyes were deep and he murmured:
"Now that the proton has been discovered, it is time to predict the existence of neutrons."
The world of physics is about to be shaken again!
(End of this chapter)