Chapter 246 Superconductivity! The physics community is shocked again!
With the sudden rise of Laue, Bragg and Sons, Bakla and others, they have achieved such brilliant achievements in the field of X-rays.
Rutherford and others quickly followed up and proved the nature of gamma rays, unifying the four major rays.
This allows all physicists to see a bright future.
The First Bruce Conference predicted that modern physics will have relativity and quantum theory as its two cores.
Research directions such as X-rays, radioactivity, element spectroscopy, and atomic research go hand in hand.
Now X-rays have made a major breakthrough.
But this is not enough, because now physicists only know the nature of X-rays.
What is the mechanism of its production?
How does it interact with other substances?
These require further in-depth research.
But the good news is that physicists at least have a general direction to ensure that they will not make mistakes.
At the same time, everyone has almost reached a consensus that the main content of modern physics is the above.
However, physics never follows human will.
Tiny human beings think they can grasp the truth of the universe.
As everyone knows, hundreds of years of research by countless physicists has only given them a glimpse of the universe.
The magic of the universe is far beyond everyone's imagination.
June 30, 1910, King's College London.
More than twenty people were already sitting in the conference room of the Physics Department.
In addition to Li Qiwei’s team, there are also Bakla and others.
As head of the physics department, Li Qiwei set a rule.
On the last day of every month, the entire physics department holds a meeting.
Dedicated to discussing the problems encountered by students in experiments, or the latest research results.
This is a model that Li Qiwei imitated from his own research group in later generations.
He was tortured to death by his mentor before, but now he has to pay back double the amount.
The boys were out of luck.
Today's meeting was the turn of Qian Wushi, Qian Huzhou, and Deng Huaining.
Since the three of them are doing a systematic job, Master Qian will give the lecture.
"Professor Bruce, Qian Huzhou, Deng Huaining and I are currently conducting low-temperature experiments on three elements: gold, platinum, and mercury."
Li Qiwei nodded and asked: "Use What refrigerant?”
Qian Wushi said: "With reference to the opinions of Professor Onnes of Leiden University, we use liquid helium."
"Because the temperature of liquid nitrogen can only reach -196.56°C, and liquid helium It can be close to absolute zero."
"And the stability of helium is much higher than that of nitrogen."
"So, from the perspective of safety and practicality, we finally chose liquid helium. ”
Bakla, his student Sadler and others had envy in their eyes.
The cryogenic laboratory of Leiden University is world-famous.
Professor Bruce’s students can easily visit and get help from each other.
This kind of invisible soft power can truly reflect the background of a physicist.
Although Sadler envied Qian Wushi and others, he still believed that his mentor Bakla was the best.
At this time, Master Qian skillfully used the projector, and a data chart was displayed in front of everyone.
Qian Huzhou stepped forward and said: "This is the experimental data I used to cool the temperature of gold with liquid helium and measure its resistance."
"It can be seen that as the temperature decreases, the resistance of gold continues to decrease. "
"When it decreases to a certain level, it remains at a fixed value."
"This picture measured 4.3K."
The so-called K is. Kelvin temperature scale, which was created by the late Lord Kelvin.
0K is absolute zero, which is -273.15℃.
4.3K is -268.85℃.
Then, Deng Huaining also shared a data chart.
“My experimental results are the same as those of Qian Huzhou.”
“I found that the resistance of platinum reaches a fixed value when it is close to 4.3K.”
At this time, Qian Wushi also shared his mercury experiment.
“My experiment is a little different from theirs.”
“I found that as the temperature decreases to 4.3K, the resistance of mercury still decreases, rather than becoming a fixed value.”< br>
“However, I guess the final result may be the same as gold and platinum, becoming a constant value.”
“It’s just because the properties of different elements will be slightly different.”
"Perhaps it will become a fixed value at 4.2K or 4.1K."
"So, I did not do data below 4.3K."
Obviously, Qian Wushi also thinks that he There will be nothing special about the experiment.
Gold, platinum, and mercury are all metal elements, and there cannot be any essential difference.
Li Qiwei looked at the three pictures quietly and said nothing.
Bachla suddenly said: "According to classical theory, the resistance of pure metals should decrease as the temperature decreases."
"It drops to zero when it reaches absolute zero."
"Of course, Since absolute zero can never be reached, the resistance of metal cannot be zero."
"This fixed value is indeed a bit abnormal."
At this time, Bohr suddenly retorted: "Bakla. Professor, is it possible that this theory does not apply to extremely low temperatures?"
"After all, Professor Einstein's quantum specific heat theory only works at extremely low temperatures."
"Perhaps the resistance of the metal may first reach a minimum value and then increase again."
< br>"At absolute zero, the resistance of metal may be infinite."
The views of Bohr and Bachla made everyone present ponder.
Obviously both theories are very reasonable.
However, it seems that there is nothing special about the properties of matter at extremely low temperatures.
Whether it is continuously decreasing, or whether it is decreasing first and then increasing.
They all seem to be ordinary and there is nothing worth studying.
Absolute zero cannot be reached anyway, and the resistance of metal cannot become zero.
This made Qian Wushi and others feel a little frustrated.
Could it be that Professor Li Qiwei made a mistake?
Perhaps the research direction of extremely low temperature is not worth investing in.
However, the three of them had no complaints.
This situation is too normal in the scientific research world.
Even if he is as strong as Professor Ridgway, he cannot be 100% successful.
Others present had similar sentiments.
Bakla already knew that Li Qiwei was doing research on low temperature.
In his view, this direction is typically thankless.
Obtaining a low-temperature environment is very difficult in this era.
Don’t think that liquefying helium is easy. It requires countless attempts and is very dangerous.
Even if the properties of matter at low temperatures can change, it is certainly to be expected.
It’s nothing more than getting bigger and smaller.
In Bakla’s view, Li Qiwei’s direction is likely to fail.
He sighed in his heart, he did not expect that Bruce would also fail one day.
The world of physics has been turbulent recently, and many people even think that Professor Bruce is a bit out of step with the times.
Now, he encountered another problem in one direction.
I guess I must be feeling stressed.
Bakla looked towards Li Qiwei, and saw the other person's deep eyes staring at the temperature resistance curve of mercury, as if there was a flash of light.
Bakla was shocked. Li Qiwei's momentum just now made him tremble a little.
As if he himself were a naive child who said the wrong thing.
At this time, everyone in the conference room felt a sense of oppression.
They all looked towards the main seat in unison.
Li Qiwei sat in a relaxed posture, as if he were the king of the world, and quietly listened to the discussion.
At this time, the sound became smaller and smaller, gradually becoming quieter.
Then, Li Qiwei finally spoke.
"Fifth Division, the experiments on gold and platinum can be suspended." "The resistance of metal cannot be fixed to a constant value."
"I think it is impurities in the metal. I have no idea about the experimental results. It has an impact."
"Mercury can be infinitely purified by distillation."
"You have to use extreme purity of mercury for experiments."
At this time, everyone in the venue couldn't help but be shocked.
As expected of Professor Bruce, he saw the problem at a glance.
Why didn’t they think it was the impurities?
At this time, Li Qiwei continued:
"Fifth Division, you cannot rely on guessing when conducting experiments."
"You just subjectively believe that the properties of mercury, gold and platinum should be the same."
"But you have no theoretical support."
"Since mercury can continue to decrease in resistance at 4.3K, then Just try a lower temperature."
"There are previous examples of quantum specific heat, which shows that certain changes at the quantum level will definitely occur in low temperature environments."
"3K is not enough. , 3K is not enough, just 2K.”
"You must do it to the limit."
"Usually when doing experiments, you are always a little bit close, but when it comes to the real critical moment, you will be just a little bit close."
"And a little bit, very close. You may miss out on a great discovery."
Li Qiwei's inspiring words shocked everyone present.
This is the charm of top physicists.
Never give up!
Always challenge the limits!
Qian Wushi and others suddenly felt ashamed.
They wanted to give up so quickly, but Professor Ridgway never gave up.
Yes, mercury is obviously different from gold and platinum, so why not continue to do it.
This is the subconscious mind at work.
Only at this moment did Qian Wushi and the other two people feel Li Qiwei's pure scientific enthusiasm.
At the same time, I am lucky to get the teachings from the other party.
Decades later, Qian Wushi and several others were already academic leaders with high moral standards and high respect.
But every time in public, they will mention this meeting.
"Without Professor Ridgway's strictness, we would not be what we are today."
This meeting allowed everyone to see the strict side of Professor Bruce.
Especially those students, whether it was Bohr or Sadler, were extremely scared.
When Li Qiwei spoke, they stopped breathing.
Especially Sadler, thinking silently: When I become a professor in the future, I will also hold conferences!
But this kind of severity is not directed at individuals, but to help students discover and solve problems.
Soon, Qian Wushi and others will worship their mentor forever because of this severity.
Bohr and others even ran to the office and wanted Li Qiwei to scold them too.
——
On July 30, 1910, Li Qiwei was reviewing documents in his office.
Suddenly, there was a noise outside the room.
It seemed to be the voices of Qian Wushi, Bohr and others, and later the voices of Bakla and Sadler appeared.
The sound grew louder and moved towards the office.
Li Qiwei smiled knowingly, have the boys finally done it?
"No, I have to stay calm. It's just a superconductor, not worth mentioning."
At this time, there was a knock on the door outside the office.
“Come in.”
Boom!
Qian Wushi took the lead, followed by Wu Yangyang and a dozen people.
Everyone’s face is full of incredible and unstoppable smiles.
There were tears in the corners of Qian Wushi's excited eyes. He shouted excitedly:
"Professor, we have done it! We have done it!"
Li Qiwei had a heavy expression on his face. With a smile on his face, he did not interrupt Qian Wushi, but let him vent his emotions.
It took a while before Master Qian calmed down. He said tremblingly:
“I did an experiment with purified mercury and found that the resistance of mercury is between 4.2K and 4.19K. Decreased extremely quickly.”
"At 4.19K, the resistance of mercury suddenly becomes zero!"
"The resistance of mercury becomes zero without reaching absolute zero. This is incredible."
"Later, I experimented with several other metals."
"When tin is at 3.8K, the resistance will become zero; when lead is at 7.2K, the resistance will also become zero."< br>
“Professor, we have discovered a new phenomenon.”
"The properties of metals really undergo special changes at extremely low temperatures."
At this moment, everyone in the office became extremely excited.
Even students can know that this is definitely a Nobel Prize-level achievement.
And it is the kind that is undisputed and will definitely win the Nobel Prize.
After all, Nobel Prize-level results do not necessarily mean you will win the Nobel Prize.
In the case of non-absolute zero, the resistance is zero!
Everyone can imagine what this means.
The heating problem of metal has always been the key to energy loss.
The essence of heating is due to the existence of resistance.
If the resistor no longer exists, wouldn't it be possible to transmit 100% of electrical energy in the future?
And physicists are thinking further ahead.
Bakla and Sadler, masters and apprentices, among the crowd, simply admired Ridgway.
"Professor Bruce, this is really scary."
"Normal people should be upset when faced with the experimental results under pressure."
“But he is like a magic needle that fixes the sea. He always says that you can’t always be wrong when doing experiments. It has almost become the mantra of the physics department.”
At this moment, everyone felt the greatness of Li Qiwei.
Bakla sighed: "The key to Professor Bruce's success is not only his amazing mind, but also the spirit of pursuing the limit!"
The reason why everyone present was equally happy is that Because this is what was done at King's College.
After receiving the Nobel Prize for this achievement in the future, King’s College’s reputation will surely increase.
They also felt proud.
When you go out, you can proudly say: "I graduated from the Physics Department of King's College."
Li Qiwei looked at everyone's excitement and felt happy in his heart.
At this time, Qian Wushi suddenly said: "Professor, how about you give this phenomenon a name."
"We can name it when we publish the paper next."
After saying that, Master Qian smiled.
Bohr and the others were suddenly startled, thinking that Fifth Master Qian, you are really good at flattering.
No, they have to figure out how to take pictures.
Li Qiwei smiled and said: "Since the resistance of the metal becomes zero, it means it has super conductivity."
"Let's call this phenomenon [superconductivity] . ”
Qian Wushi and the other three tasted this word and thought it was very good.
It's both vivid and atmospheric.
Immediately decided to publish the paper in the name of superconductivity.
It looked sour to Bohr and others, and their saliva almost dropped with envy.
On August 20, 1910, "Nature" published an additional issue overnight and published a paper by Qian Wushi and three others on the cover.
At the same time, Bruce’s name is clearly listed in the corresponding author column of the paper.
Nowadays, when others publish papers in Nature, there are naturally various types of review.
But Li Qiwei only needs one sentence.
In the paper, it was discovered for the first time that the resistance of metals suddenly becomes zero at extremely low temperatures, and was named "superconducting".
Once the paper was published, it caused a huge sensation in the physics community.
The impact this time was greater than Laue's X-rays.
Because this simply opens up a whole new field.
And it is a field with endless application potential.
Boom!
The whole world is shocked!
(End of this chapter)