Reborn and become a Great Scientist

Chapter 192 Chapter 140

Chen Muwu felt that the aging old Prague was like that annoying Tang Monk who kept chanting mantras.

Because until he turned and left his laboratory, his mouth was still rambling.

After sending old Prague away, Oppenheimer took out a reply letter from his bag and handed it to Chen Muwu.

The person who wrote this letter was, of course, Dr. Chen's number one fanboy at Leiden University, Yoshio Nishina who was determined to devote his whole life to the cause of low temperature physics.

Yoshio Nishina's words and sentences in his reply letter were quite formal, showing full respect for Chen Muwu who helped and supported him a lot in physics.

At the same time, he also reported to Chen Muwu that his research on the superconductivity of metal thallium at Leiden University was not going well.

But after reading the encouragement from Dr. Chen, I will definitely persevere and never give up until I discover the superconducting properties of thallium metal!
After reading this reply letter, Chen Muwu realized how secondary the letter he sent to him was.

To write a letter in the tone of Heisei trash, it is more or less disrespectful to the Meiji man.

It is estimated that Yoshio Nishina who read the letter at that time also felt awkward, but out of respect for Chen Muwu, he did not say it in the reply letter.

In addition to this reply, Oppenheimer also sent a message from Kitham, director of the Low Temperature Physics Laboratory at Leiden University.

He could understand why Chen Muwu bought liquid hydrogen.

Although the liquefaction temperature of hydrogen is a few degrees Kelvin higher than that of the lowest gas, helium, the cooling effect is not as good as that of liquid helium.

But because hydrogen is relatively easy to prepare, unlike helium, which basically only exists in air.

Therefore, the price of liquid hydrogen is correspondingly much lower than that of liquid helium.

It’s just that he doesn’t buy liquid helium to buy liquid hydrogen, so why buy liquid nitrogen at the same time as liquid hydrogen, which has a boiling point tens of Kelvin higher than liquid hydrogen?
You must know that the metal element with the highest superconducting critical temperature that people have found now is only 7.2 Calvin of lead.

Liquid nitrogen of more than 70 Kelvin is useless for superconducting experiments!
And if liquid nitrogen is only used as a cooling medium, then liquid air, which is only a few Kelvin higher than liquid nitrogen, should be a more affordable choice.

I just heard from old Prague that Chen Muwu was cheated out of a large sum of money by the Dutch, and Oppenheimer has always been bitter about it.

So at the end of his recitation, he still did not forget to complain: "These Dutch people are really hypocritical. They obviously made a lot of money from this transaction, but they still pretend to be considerate of us and save us money. I believe that Mr. Chen, you have a reason for buying liquid nitrogen instead of liquid air, but they are just stupid and can't figure it out."

Can't figure it out?If you don't understand it, that's right!
I just miss the good time when I secretly used liquid nitrogen to freeze bananas in the modern physics laboratory, and I want to relive it again, can't I!
In fact, there is no reason for Chen Muwu, he didn't think about using liquid nitrogen at all, it was just a way of blinding his eyes.

If it was not Oppenheimer who was sent to buy equipment this time, but Yoshio Nishina, he would even want to buy some more liquid oxygen.

If you don’t buy these deceptive things, but just buy liquid hydrogen in large quantities, after Chen Muwu distills deuterium from the liquid hydrogen, it is estimated that Ketham will be more suspicious. Is it true that Dr. Chen has long known the existence of deuterium, an isotope of hydrogen? up?

Otherwise, why would he only buy so much liquid hydrogen by name?
"Okay, Robert, don't think about it so much. Next, we should do the experiment seriously. I only have one request for you, to quit smoking completely. Every time you come to the laboratory, let alone cigarettes, even You can't even bring in a single match."

The David Faraday Laboratory is a very metaphysical place, where Chen Muwu had to be cautious.

Nearly 40 years ago, in 1886, Sir Dewar already had a criminal record.

Here he once mixed liquid oxygen and liquid ethylene together, causing a big explosion that shocked London directly in the laboratory.

Fortunately, Sir Dewar was lucky enough to escape the catastrophe, otherwise he would never have survived the day when he successfully liquefied hydrogen.

The power of liquid hydrogen is several times greater than that of liquid ethylene.

It is a kind of slow suicide to conduct experiments in the environment of radioactive radiation like the Cavendish Laboratory and the Parisian Radium Researcher.

Then lighting a fire and smoking in the David-Faraday laboratory where there is liquid hydrogen is definitely a shortcut that can instantly surpass oneself and ascend to heaven.

What's more, it's a double ascension of spirit and body. Isn't the Long March [-] rocket that launched the space station just like liquid hydrogen?

If liquid hydrogen exploded in the David Faraday laboratory, maybe the first country to master the technology of sending people into space would become Britain instead of the Soviet Union.

The first person to enter space was not Yuri Gagarin, but Chen Muwu.

Of course, this doesn't change the fact that Sulian was the first country to send a living person into space.

Nor does it change the fact that Gagarin was the first living person to go into space.

"Mr. Chen, you don't need to tell me this, I understand it too! When they left Leiden University, they had already explained it clearly to me, and I didn't dare to neglect it at all."

Oppenheimer may have been a smoker, but when he entered the Cavendish Laboratory and learned that Chen Muwu did not smoke and hated the smell of tobacco, he had gradually reduced the frequency and frequency of smoking.

Even if Chen Muwu didn't say anything this time, he still has strong self-control to consciously abide by the matter of quitting smoking.

After the "No Smoking" signs were pasted all over the door of the laboratory and in the corridor, Chen Muwu and Oppenheimer gently lifted the unpacked refrigeration equipment from the box to a special place for smoking. On a test bench it built.

After careful inspection, Chen Muwu found that what Old Prague said was right or wrong.

This machine does have the Linde nameplate on it, but it has been modified by the staff of the Low Temperature Physics Laboratory of Leiden University.

Others charge him a modification fee, so it shouldn't be considered a middleman to make the difference.

Old Prague's words were full of malice, probably because he, as an Englishman, had a prejudice against the Dutch who had fought against them for hundreds of years.

According to the operating procedures that Chen Muwu learned during his visit to Leiden, and then compared with the operating instructions attached to the machine, he assembled the machine.

Then add refrigerant to start the power supply, and through layer-by-layer cooling, the temperature can indeed be reduced a lot.

There is no problem at all if you want to reach an extremely low temperature environment of about one Kelvin.

But Chen Muwu doesn't need to lower the temperature so low now.

He now only needs to transfer the liquid hydrogen into the experimental container, and then keep the ambient temperature of the experiment at about 20 Kelvin to 22 Kelvin.

In this temperature range, deuterium gas and deuterated hydrogen gas with higher boiling points can still maintain a liquid state, while liquid hydrogen gas will become a gas and be evaporated due to reaching the boiling point.

Keeping this temperature all the time and repeating the evaporation step will gradually reduce the liquid hydrogen content in the liquid.

Correspondingly, the contents of liquid deuterium (D) and liquid deuterated hydrogen (HD) also gradually increase.

When the concentration of deuterium increases to a certain level, the spectrum of deuterium can be observed in the spectral lines of this mixed gas.

Since the deuterium atom has one more neutron than the hydrogen atom, the Balmer spectrum line of the deuterium atom can be blue-shifted on the basis of the hydrogen atom spectrum line by simple calculation using the formula of the atomic spectrum. Between 0.1 nanometers and 0.2 nanometers.

Although the amount of this blue shift is very small, it is no problem at all when observed in the spectrometer.

To put it bluntly, the experiment of separating deuterium gas from liquid hydrogen is a process of slow work and careful work in addition to maintaining a low temperature environment and being careful to avoid explosions.

Although there is only one deuterium atom for every seven thousand hydrogen atoms, as long as you have patience, you can get the final desired result.

Of course Chen Muwu knew what he wanted, but Oppenheimer didn't.

From his perspective, Mr. Chen seems to be squandering the liquid gases he bought from the Netherlands after going through all kinds of hardships.

No matter how much Oppenheimer trusted Chen Muwu unconditionally, he could not turn a blind eye to the teacher's "wasteful" behavior.

In the end, he still couldn't help but asked: "Teacher, when you were in Leiden, didn't you say that you would do low-temperature physics experiments to study the superconducting properties of metals?

"But now I don't quite understand what you are doing. If all the liquid hydrogen is evaporated, what else can we use as a medium to obtain a lower temperature?"

At this point, Chen Muwu could only tell the truth to his good student: "Robert, during your time in Holland, I suddenly had a new idea.

"The superconducting properties of metals that suddenly lose electrical resistance in extremely low-temperature environments do look beautiful. But I think it is still a little bit less interesting than my new idea.

"So I plan to change my research direction, but please rest assured that the instruments and liquid gases you brought back from Holland are very important to me. Your journey is not a waste of time."

The last paragraph was added temporarily by Chen Muwu, because he saw that Oppenheimer's mood was rapidly declining.

Anyone who travels across mountains and rivers with a bunch of such dangerous things will not be happy when they are suddenly told that they are useless as soon as they return to the laboratory.

For the first time in the past year, Oppenheimer could not accept Chen Muwu's statement.

He decided to break the casserole and ask: "Then, Mr. Chen, what research are you doing now?"

"Have you heard of isotopes? Ever since Blackett and I discovered the first isotope of oxygen, oxygen-17, in the Cavendish Laboratory at the end of last year, there is only one isotope of an element left in the world. Not found, this element is the first on the periodic table, hydrogen."

"So, are you looking for isotopes of hydrogen? Now this low-temperature distillation experiment is doing this?"

"That's right, while I was waiting for you to come back from the Netherlands, I used the Debye model to perform a simple calculation. The result of the calculation is that the boiling point of molecules composed of heavy isotopes should be slightly higher than that of light isotopes.

"If it is replaced by other elements, I will also consider whether its isotope should be heavier or lighter than its real body.

"But for hydrogen, there is no such trouble at all.

"Because if you subtract one atomic mass unit from a hydrogen atom, there will be nothing left, so if there are isotopes of hydrogen, its mass must be heavier than that of hydrogen, and the corresponding boiling point will be higher."

"I understand. You intend to use repeated distillations to see if there will still be some liquid left in the end, right? If there is any remaining liquid, it can explain the existence of hydrogen isotopes?"

"It doesn't need to be so troublesome, just occasionally take some out of the remaining liquid and observe its spectrum, maybe you can find the existence of deuterium through new spectral lines.

"Observing the hydrogen atom spectrum experiment, I think Harvard University should have taught you how to do it?"

Chen Muwu felt that Oppenheimer could not be sent to complete the experiment alone like Blackett did, nor could he be allowed to do nothing like a shopkeeper who threw his hands away.

It is still necessary to increase the intensity of this good student and let him increase his sense of participation in the experiment.

In case this thorny head has nothing to do every day and surrounds him asking questions.

Maybe one day, if I was not paying attention while observing the experimental equipment, I would be tricked by him into saying something I shouldn't say.

The provocative method is really useful.

"Mr. Chen, you really know how to joke. I admit that my hands-on ability is a bit poor. If it weren't for you, I would never have been able to enter the Cavendish Laboratory. But if I can't even use a spectrometer to observe the spectrum, I can't do it." I don't have the face to stay by your side anymore.

"However, are you really sure that this heavy hydrogen isotope can be found in liquid hydrogen? And even if heavy hydrogen is found, what is the use of it?"

What can it do?

It seems that it is of no great use, but it can only bring you a mere Nobel Prize in Chemistry.

Lao Mo, Lao Mo, why don't you understand the good intentions of being a teacher?

And when there is a cyclotron in the future, deuterium nuclei can be used to bombard the molybdenum target, and the extremely mysterious No. 80 element that chemists have been looking for for more than 43 years can be obtained.

Uranium is already number 92 on the periodic table, but it's not a big deal that there is always a space in the middle, right?

Oppenheimer still set up a spectrometer in the laboratory, ready to observe the spectrum of the product.

And Chen Muwu was still staring at the evaporation process of the liquid hydrogen in the instrument as usual.

He suddenly felt like an old gentleman guarding the alchemy furnace, and Oppenheimer was the fan fan boy in Tushita Palace.

It's a pity that the furnace is not filled with Bi Mawen, who can go to heaven and earth, but hydrogen.

　Today I wrote something about May [-]th for a long time, but after much deliberation, in order to make this book live longer, I decided not to write it. I can only let the author and the protagonist forget about it selectively, so I deleted it. Minus changed for half a day.

　　
　
(End of this chapter)