Walter Both, director of the Laboratory of Radiophysics at the Imperial Institute of Physics and Technology in Germany and previously an assistant to the former director Hans Geiger, was one of Planck's students.

As early as 1923, Einstein recommended to Planck a Chinese student he knew in Qihai, Chen Muwu, and said that after a paper of his Chinese student had been submitted to the editorial office of the Annals of Physics, Planck approached Geiger and Bot respectively and asked them to design experiments to verify whether the theory of gamma ray scattering was correct.

The fate of Bot is somewhat similar to that of Chadwick in Cavendish Labs.

The latter spent several years in a prisoner of war camp during World War I because he was an Englishman stranded in Germany.

Both's situation was surprisingly similar to Chadwick's, he also joined the German cavalry during World War I, and then became a prisoner of war after losing the battle, but it was not the British government that held him captive, but Tsarist Russia.

To a certain extent, both of them became victims of this war.

But both of them did not forget to learn physics in the prisoner of war camp, and did not waste those painful and boring years of time.

But the similarities between Bot and Chadwick, or rather the connection between the two of them, don't stop there.

In 1930, Bot left the Imperial Institute of Physics and Technology to become professor and chair of the physics department at Giessen-Justus Liebig University.

It was also in this year that he began to experiment with alpha particles to bombard the relatively light nuclei of lithium-beryllium boron, and detected that after the bombardment of the nuclear reaction, an electrically neutral particle that would not be deflected by the electric field would be emitted from it.

Because at that time, in people's understanding of particles, if a particle was deflected in an electric or magnetic field, it could be detected as positively charged, and it would correspond to various situations, the simplest of which was a variety of atomic nuclei.

But if a particle does not change in the detection of an electric or magnetic field, that is to say, this particle is an electrically neutral particle that is not charged, then in the scope of people's knowledge, this particle can only be one of the three major rays, gamma rays, which is the so-called photon.

Because Germany shares a border with France, Bote's research first spread to the Radium Institute of the University of Paris, France, where Marie Curie and the younger Curie lived and worked.

The Curies studied the hard gamma rays newly discovered by Bote, and also believed that the emitted material was gamma particles, but the energy was relatively high.

The research then spread across the ocean from France to England and to the Cavendish laboratory.

Rutherford, who was fascinated by the electroneutral particles in the nucleus, and his assistant Chadwick were not convinced of the conclusions of Bott and the Curies, and they redesigned the experiment, and finally got a completely different result:

It is true that these particles are not charged, but the mass of the particles is not small, but about the same as the mass of protons, which is completely consistent with people's theoretical estimation of neutrons.

In this experiment, although the Curies were exposed to neutrons earlier, they missed the opportunity to discover them.

If you exclude the Curies Jr., the two people who made a significant contribution to the attack and the final discovery of the neutron also happened to be Bot and Chadwick, who were imprisoned in a prisoner of war camp in World War I.

In the dark, it can be regarded as a coincidence.

At this time, Frederick, who was at Cambridge University, didn't know what it meant to use the accelerated alpha particles he proposed to Chen Muwu to bombard the lighter atomic nuclei, he just faced the world's most advanced particle accelerator and diverged his thinking a little.

But in fact, it is not necessary to put the alpha particles into an electric field with such a large potential difference to accelerate, but only need to add an electric field of similar size in front of the particle source, accelerate it slightly, and then bombard the target nucleus on the target to obtain this experimental phenomenon.

Frederick asked a good question, but Chen Muwu couldn't give a correct answer to that good question right now.

"Well, Frederick, the particle source in this machine now is a proton source that uses hydrogen to produce protons. If you want to accelerate the alpha particles, you need to disassemble the machine and modify the internal structure to a certain extent. Not to mention the large amount of work, and the fact that one of my two assistants is now in the United States and the other in Germany, neither of them is in the Cavendish laboratory, I will definitely not be able to complete this transformation work alone. ”

Chen Muwu finally made up a temporary reason and temporarily fooled his quasi-brother-in-law.

But after saying this, he was very afraid that Frederick would suddenly want to help others, and said that he and Irena would stay at Cambridge University to help Chen Muwu complete the transformation of the particle accelerator.

In that case, the structure of the accelerator, including the principle of high potential difference, will be revealed when the proton source is removed and replaced with an alpha particle source.

When the little Curies returned to France, they could apply for vacant land at the University of Paris and reproduce the particle accelerator at the Radium Institute with little money.

If there is a particle accelerator in Paris, it will be even more difficult for Chen Muwu to fool Marie Curie and her family into leaving France for Sweden in the future.

What worried Chen Muwu did not happen, and Frederick knew in his heart that although the two of them would soon become relatives, he and Irena's current identity was not to visit relatives and friends at Cambridge University, but to visit and interview as guests of Cavendish Laboratory.

If there is a big or small affair between relatives, it doesn't matter if you do a favor or something, but if the guest behaves too actively, it will be a bit noisy.

The three of them stood in the laboratory of the particle accelerator for a while, chatting about some topics related to physics or unrelated, Chen Muwu also turned out the photos of the cloud room taken during the previous experiment, pointed to the trajectory on it and told the two of them which was the accelerated hydrogen nucleus, and which was the alpha particle produced after being bombarded.

The Curie couple's visit to the particle accelerator laboratory finally came to an end, and they left here to follow the host's arrangement and go to the most famous Cavendish laboratory at Cambridge University.

Founded in Maxwell's time, this laboratory is one of the most famous physics laboratories in the world, attracting many physicists every year.

However, many physicists from the United States, who want to learn advanced physics knowledge from Europe and Britain, will always have a great sense of disparity in their hearts after seeing the true face of the Cavendish laboratory, because they are disappointed by the scene in front of them, and it is completely different from the laboratory they imagined in their hearts.

The Cavendish laboratory has long been not the best laboratory in the world, with the best instruments, and even the management level is not advanced enough, only relying on the macho Rutherford who fell from the sky, with a group of little macho men, to maintain the last glory of the laboratory.

This is more like a response to the words that the future president of Tsinghua University has not yet spoken: "The so-called university is not only a building, but also a master." ”

However, the disappointment of physicists in the United States does not mean that Frederick and Irena, who are here today, will be disappointed.

In recent years, the Cavendish Laboratory seems to be releasing the second spring of its career: increasing funding, newer instruments and equipment, and more and more research results.

The situation in the laboratory now is much better than when Chen Muwu first arrived in England in 1923.

In the eyes of the little Curie, the Cavendish laboratory is a big one, not only has a long history, but also has abundant funds, compared with the radium research institute under the dismal management of his mother Marie Curie, not to mention a heaven and an underground, but the gap between the two is not something that can be caught up in three years and five years.

Irena and Frederick are Eve's maiden family, so everyone in Cavendis's lab is a relative of Chen Muwu's family.

For a man like Capitsa who runs to Paris every day, the little Curies have lost count of how many times they have seen him.

The rest of Chadwick and Blackett were seeing each other for the first time, but both sides had their own regrets.

The Curies unfortunately came to Cambridge University and were not able to meet the director of the laboratory, Rutherford.

Unfortunately, the people in Cavendish did not meet Marie Curie.

But it shouldn't take long for everyone's regrets to disappear, because it won't be long before the bond between them - Chen Muwu and Eve will get married, and on that wedding, if nothing else, the two sides will be able to meet again.

After visiting the Cavendish Laboratory, Chen Muwu took Curie and his wife to the River Cams, and went to Newton's room at Trinity College.

After ending his trip to Cambridgeshire, Chen Muwu did not follow them back to London.

On the one hand, Chen Muwu felt that it would be too long to go home, and if he left the school again, he would be too derelict and undeserved, and on the other hand, it was also the repeated request of the little Curie couple.

They said that as long as Chen Muwu also went back to London and returned to his home, then they would probably have to stay in the Chen Mansion every day on their honeymoon trip and chat with the Chen family.

If Chen Muwu doesn't go back, there will be no interpreters between them, but on the contrary, they will be able to find time to visit other places near London, such as Oxford University, and Stonehenge, which is suspected to be an alien relic, and so on.

Speaking of Stonehenge, Irena, who was waiting for the train on the platform of Cambridgeshire Railway Station, suddenly revealed something else to Chen Muwu after the train entered the station.

"Eve is very interested in the alien problem that you suddenly got on fire, and she seems to be trying to write about aliens lately. If you have any good ideas, you might as well write more to communicate with her,—— don't say that I told you, she still wants to surprise you after writing it! ”

Chen Muwu waved his sleeves and said goodbye to the southbound train.

What he was thinking about was not what kind of alien sci-fi theme he should subtly tell Eve, but something more important.

In the laboratory where there was a particle accelerator, although Chen Muwu temporarily used a witty answer to fool Frederick for the time being.

But the question raised by the other party still makes Chen Muwu a little frightened.

Even if there is no particle accelerator at the Radium Institute, when the Curies return to Paris, they will either put this idea into practice themselves or talk to Marie Curie and put it into practice, then neutrons, which have been looking for physicists for many years, may have to meet humanity in advance.

Chen Muwu is not a little Curie couple who don't want to let the last life regret rubbing shoulders with neutrons, and they can discover neutrons as they wish in this life.

Since they are related to each other and are great physicists, it is reasonable for him to be happy to see the little Curies make breakthroughs in their research on neutrons.

However, Chen Muwu had long wanted to keep the neutrons in the Cavendish laboratory as he had done in his previous life.

After all, this kind of particle has been playing hide-and-seek with humans for decades, but his teacher Rutherford has always been thinking about what he wants to find after he entered the Cavendish laboratory.

Chen Muwu felt as if he had suddenly understood a sentence, called "Since ancient times, loyalty and filial piety cannot be both".

Although there is still a certain gap between the actual meaning of this sentence and his current situation, the mood behind the hiding is the same.

Rutherford and Chadwick were the people he respected, and Marie Curie and the little Curie were also people he respected.

You can't have both, give up ......

The palms and backs of these hands are full of meat, and no one can give it up!

On the way back to the university from Cambridge Railway Station, Chen Muwu was still thinking about it in his heart.

Why did the Curies think so many years in advance of bombarding light nuclei with accelerated alpha particles? Could it be that he also developed the particle accelerator in advance, which brought about the butterfly effect?

If they can think of this, then physicists in other parts of the world can think of it too.

Maybe Professor Bot in Germany is already doing this experiment.

Chen Muwu felt that if he invited the Curie couple to Cambridge University to do experiments, or other methods, he had to come up with a solution after the teacher Rutherford returned to the Cavendish laboratory.

The neutron egg has been incubating for so long, and it is finally time for it to blossom and bear fruit.

(End of chapter)