Chapter 276 Cathode rays discovered in advance! (7.8K)
math.
As one of the most far-reaching subjects in human history, its formation time even preceded physics.
Whether in the East or the West, there were a large number of documents or works related to it thousands of years ago.
This is actually inevitable due to living habits.
For example, a farmer.
When he sees the sun, he may wonder why it rises and sets at night, or why it is warm in winter and cool in summer, but this is just curiosity, and he cannot and cannot conduct in-depth research.
But mathematics is different.
The harvest from your fields and the change in price for buying and selling goods all involve mathematical knowledge.
Once there is more basic soil, the formation of the system will naturally be faster.
Before the establishment of natural science, the European education system was called classical or classical literature system.
And the core subject of this system with the name of ‘literature’ is mathematics.
Therefore, from the 13th to the 17th centuries, many mathematicians were often philosophers or artists.
For example, Descartes, Bernoulli, etc.
This is also the reason why many early mathematical models are often linked to violins and pianos.
Mathematics is a subject with a long history and numerous major sects. Therefore, it is inevitable that the mathematics community will often come up with various rankings.
These so-called rankings of the top ten or top mathematicians are also highly controversial, and it is difficult to reach a conclusion.
But on the other hand.
Just like the Mavericks in physics always love to fight with the gods, the third child Wheat is as stable as Mount Tai.
There are also four figures in the world of mathematics whose historical status will always be among the top four.
They are:
Archimedes, Mavericks, Gauss and Euler, and occasionally Riemann, but not often.
Anyway, there are five of the four heavenly kings, it’s normal, right?
all in all.
These people are in the first echelon. Among them, Archimedes is most often revered as the first person in the history of mathematics because of his era bonus.
Below them were Cauchy, Poincaré, Fermat, Pythagoras, and Lagrange, all vying for hegemony.
As one of the four heavenly kings who can be ranked alongside Archimedes, Gauss's ability is self-evident.
He left behind a large number of theorems starting with Gauss, which tortured countless college students in later generations. I don’t know how many people hanged on the tall tree with Gauss’s name engraved on it.
When Xu Yun was studying in Dawu, his tutor once said a joke, which still leaves a deep impression on him:
If during the exam you prove a theorem but forget its name, but the proof question asks you to give its name, then Gauss is obviously always a good answer.
At present, the mathematics department is short of computing power, so Xu Yun naturally puts his thoughts on foreign aid.
And since we are looking for foreign aid, we should obviously find the most capable boss to support us.
It is now 1850, Archimedes has been dead nearly 2,000 years ago, and Euler died of illness more than 70 years ago.
As for the Mavericks?
Xu Yunze had just visited his grave.
Currently, the only big men alive in the world are King Gauss, and half-step King Riemann, who has cultivated to the level of the Great Perfection of the Little King and can take a blow from the King without dying.
At the same time, it is a coincidence that these two people are German.
Therefore, with the idea that he had done everything, Xu Yun simply took off the condom and packed up the German mathematical elites together.
Of course.
Xu Yun's request to Gauss for help this time was not purely because of Gauss's reputation.
It's because Gauss had very, very rich experience in celestial calculations.
This experience is called Ceres.
Ceres was discovered by Italian astronomer Piazzi in 1801. Piazzi named it Ceres after the "harvest goddess" in Greek mythology.
But later Piazzi delayed the observation due to illness, thus losing the trajectory of the asteroid.
So in desperation.
Piazzi published his previous observation data and hoped that astronomers around the world would search for it together.
After receiving the news, Gauss easily calculated the trajectory of Ceres through the previous three observation data.
Austrian astronomer Olbers finally succeeded in discovering Ceres based on the orbit calculated by Gauss.
This method was also published by Gauss in his book "On the Movement of Celestial Bodies", and is similar to Pallas.
Although Gauss is now 73 years old and has only five years to live, he seems to have reached the end of his life.
But according to a large number of documents recorded in later generations.
Gauss's old age is somewhat similar to that of Lao Su. He was very active in the previous period, but suddenly deteriorated in a short period of time.
He also calculated the trajectory of trans-Neptunian objects in September 1851, and completed the entire process independently. It would not start to deteriorate until around October 1853.
So it's not difficult to ask him to come.
all in all.
With so many math masters as tool men, if there were any accidents during the observation of Pluto, Xu Yun would eat the ax on the spot!
It’s really delicious this time!
In the office.
Looking at the dense list in front of him, Faraday and Weber couldn't help but look at each other.
Both of them saw the same thought in each other's eyes:
I can take this job!
Mentioned before.
Gauss was an avid reader of Faraday. Historically, in order to catch up with Faraday, he even went to his door to send a blade in person.
Weber, on the other hand, was one of Gauss's only two good friends.
How good was the relationship between Weber and Gauss?
Together they invented the world's first telephone and telegraph system, together they invented the geomagnetometer, and together they drew the world's first map of the Earth's magnetic field.
To commemorate their achievement.
In later generations, a statue of Weber and Gauss was erected in Leipzig Park.
Among the two statues, Weber is standing on the ground, while Gauss is sitting on an arsenic stone chair. The two are chatting and laughing, and fifty meters away is the park shooting range.
Later, Gauss even wanted to marry his daughter to Weber. In Gauss's autobiography, he even wrote about the two rubbing each other's backs.
When Xu Yun was in graduate school, there was an old woman in the group who claimed to have discovered the secret:
Gauss married his daughter to someone else behind each other's backs, indicating that Weber is likely to have some parts below average.
Later, the old filthy woman married a good husband. She was extremely quiet during gatherings in the early years, and she no longer looked like the manly woman she once was.
His eyes returned to reality.
So after making eye contact.
Faraday nodded happily and said to Xu Yun:
"No problem, classmate Luo Feng, I will write a telegram to Friedrich after dinner."
"I don't dare to say that I will invite all the people on the list, but I am at least 60% sure, and 70% sure."
Xu Yun nodded with understanding.
be honest.
He didn't expect Faraday to invite all these people.
After all, he only knew the names of these people, and he was sure that they were not dead and in good condition, but he was not very clear about their situation.
Maybe they were busy with a project when they received the telegram, or maybe they just happened to have a cold and fever recently. You can't force them to come here because of their illness, right?
According to Xu Yun's prediction.
In the end, only ten people arrived, so there would be no problem with this observation.
If it exceeds fifteen, it is so stable that you can directly take your hands off the keyboard.
Then Faraday put the paper with his name back on the table, pressed it with a book, and said to Xu Yun:
"Classmate Luo Feng, what about the operating procedures you mentioned before?"
Xu Yun smiled at him and said knowingly:
"Don't worry, Professor Faraday, I will draw the schematic diagram for you now."
After speaking, he picked up the pen and pondered for a moment.
I drew a schematic diagram on the table.
I saw that he first drew a sketch of a long tube, and at the same time asked Faraday:
"Mr. Faraday, do you still remember the vacuum level when you made the vacuum tube?"
Faraday nodded, with a trace of regret on his face:
"Of course you remember, the value is seven percent."
Faraday's original vacuum tube experiment was inspired by Haukesby's plan. Their purpose was to study the phenomenon discovered by Liangkard:
In 1676, Liangcard moved the mercury barometer at night and discovered the phenomenon of "mercury fluorescence".
That is, when the mercury in the barometer oscillates, a flash of light will emit at the Torricelli vacuum part.
Unfortunately, the vacuum tube that Faraday could make at that time only had a pressure of 7% of the atmosphere, so he had no choice but to give up the experiment. This is the origin of the Faraday Dark Zone mentioned before.
Then Xu Yun didn't answer anymore, lowered his head and drew on the paper for a few more minutes.
soon.
A long tube with a more complex structure appeared:
This long tube is thick at the front and narrow at the back. The tail is connected to a black area. Xu Yun noted on the side that it is a platinum electrode with mercury flowing in the middle and a Rumkov coil wrapped around the outside.
Of course.
Xu Yun's impression is that the Rumkov coil should have appeared around 1850, but he is not sure in the specific month.
Therefore, in order to avoid unnecessary trouble, he did not mark the name of the Rumkov coil, and also modified some external resistances.
See here.
Presumably some students have already guessed it.
That's right.
What Xu Yun took out this time was the reinforced Geissler tube!
The degree of vacuum that could be achieved in 1850 was about six thousandths of an atmosphere, which was about ten times more precise than Faraday's original 7%.
But tell the truth.
This kind of vacuum degree is still not enough in experiments, and it is easy for observation errors to occur.
So after thinking carefully, Xu Yun came up with a big killer weapon:
The Geissler tube was modified by Hitov, a student of Plücke.
This magically modified version of the Geissler tube can reach a pressure of one hundred thousandth of an atmosphere, which is 600 times finer than Faraday's original!
Although it is still a younger brother compared to the vacuum degree of later generations of the Large Hadron Collider, which is often minus 12 minus 13, it is still enough for Faraday and others to tinker with these days.
Then Xu Yun raised his head, pointed at the diagram and asked Faraday:
"Mr. Faraday, can you understand the principle of this catheter?"
Faraday stepped forward and took a few glances, and his eyes suddenly lit up:
"What a good idea. Platinum electrodes are combined with mercury extraction to exhaust the air from above. Why didn't I think of that!"
Xu Yun glanced at Farah for the first time and said nothing.
Physics, or science experiments, are sometimes so realistic.
Even if you are a big shot in the industry, and you are one of the top theoretical founders in history, some problems are beyond your imagination.
Faraday is actually quite good.
Although from the perspective of later generations, it is a pity that he did not discover electromagnetic waves, but Faraday himself had no concept of it.
From one's own perspective.
His life can be regarded as a complete one with no regrets.
It’s really miserable for some unlucky people. They may have solved a problem that they have been studying for a lifetime by a young man in their twenties. They may even suddenly realize that their lifelong research direction is wrong three months before they die.
This is also the cruel side of science.
Then Xu Yun paused and continued:
"After the Fat Fish Ancestor designed this tube, some readers came to his door because there were too many broken chapters, so he had to take his wife Tifa and Alice and evacuate in a hurry."
"So this vacuum tube has always been just a design. In fact, we descendants have had the idea of trying to make it. Unfortunately, our family has fallen into decline, so we have never had the opportunity to conduct related experiments."
Hearing this, Faraday also nodded with deep sympathy.
As a code writer, he often encounters readers who come to send razor blades to his door.
Isn’t it just that one chapter is updated every five or six years? What’s the rush?
One chapter is over 5,000 words, which means I have to write three or four words every day.
Then Xu Yun straightened his expression and said again:
"Mr. Faraday, according to the design of Fat Fish Ancestor, this vacuum tube should be able to observe relatively obvious phenomena."
"Then just put a small windmill in the glass tube and let the current derivative hit the windmill. If the windmill can rotate, it means it has momentum."
"At the same time, you can also put your hand deep into it. If there is temperature, it means it has thermal energy."
Farah nodded while listening, not realizing the possible consequences of Xu Yun's last words.
After a while, he understood all the ideas and asked again:
"I have written down the process, but classmate Luo Feng, this seems to be somewhat different from what you said about verifying the charge, right?"
Xu Yun glanced at him, shook his head and said:
"You are wrong, Mr. Faraday. Didn't you discover something?"
Faraday was slightly startled:
"What's up?"
Xu Yun pointed to the tube indicating the intention and said
"According to the Fat Fish Ancestor's idea, those light rays derived from electric current are particle flows of charged particles."
Faraday and Weber were stunned for a moment when they heard this, and then their pupils shrank suddenly!
If a microscope is present at this time, you can find goose bumps slowly appearing on their exposed skin.
There was obviously a fireplace heating the house, but the atmosphere was as cold as ice.
After a while.
Faraday's eyes moved.
He turned his head, looked at Xu Yun, and said word by word:
"Electromagnetic waves?"
Xu Yun nodded heavily:
"That's right."
Then looking at Faraday who looked shocked, Xu Yun said again:
"Mr. Faraday, it is actually very simple to verify the charged properties of fluorescence. Just verify whether they will deflect in the electric and magnetic fields."
"We can apply a magnetic field and an electric field at the same time, so that the magnetic field force and the electric field force cancel each other out, so that it can move in a straight line, thereby finding the initial velocity."
"Then after obtaining the initial velocity, the electric field is removed, leaving only the magnetic field."
"If the light is deflected, as long as the angle when it exits the magnetic field is measured, the charge-to-mass ratio of the particles can be calculated."
Faraday was silent for a long time, and an unknown sound of "ho ho" came from his throat.
A long time passed.
He just exhaled a breath of turbid air with a complex expression, and was filled with emotions in his heart.
It turns out that there was only a thin line between me and electromagnetic waves and electric charges.
To know.
It was he who discovered the concept that charged particles will deflect in electric and magnetic fields.
Unfortunately, in order to study the vertical component of geomagnetism, I gave up the idea of continuing to improve the accuracy of vacuum tubes.
Thus, we missed out on such an important achievement.
Opposite him.
Looking at Faraday with a gloomy expression, Xu Yun looked a little sad.
Readers who have taken the history of physics as an elective should all know this.
When Faraday studied the glow effect in 1838, he actually observed the behavior of vacuum tubes in electromagnetic fields.
However, due to vacuum problems, the fluorescence was not deflected in the end.
It may be better to understand with another example:
Fluorescence is like a group of soldiers. After hearing the order, they must immediately move forward ten meters.
If they were in the wilderness, that is, in a complete vacuum environment, this group of soldiers would naturally complete the order easily.
But if they are in a sea of people, and every soldier who hears the order has to push aside the crowd around them before they can move forward, it will be very troublesome.
It might just be a little difficult if the crowd density is not high.
But once the crowd became particularly dense, the soldiers could not even move forward, but could only be driven around aimlessly by the crowd.
The air molecules in the vacuum tube are the crowd, and the electric field is the command for fluorescence deflection.
The vacuum tube used in the experiment is equivalent to the conditions of different crowd densities.
Faraday's 7% vacuum tube at that time was still equivalent to a busy city, so the fluorescence did not fluctuate.
The reinforced Geissler tube can reach a vacuum degree of one ten thousandth, making it very easy to deflect fluorescence.
More importantly,
It is different from the original history.
Before today, Xu Yun had already proved the existence of electromagnetic waves using the photoelectric effect.
Therefore, Xu Yun just mentioned the colorless "light" of the opposite current derivative, and Faraday thought of its essence.
Since the 'light' derived from electric current is an electromagnetic wave, it must have particle properties.
It has particle properties and can be deflected under electromagnetic fields.
What is this if it's not an electric charge?
Of course.
Readers of later generations must know it very well.
This kind of light emitted in the vacuum tube is the cathode ray, which was originally discovered by Plück in 1858 and named by Goldstein.
Its concept does not need to be described in detail, because its importance lies in helping mankind complete the early understanding of rays, and its application range in later generations is also very wide.
But there's nothing particularly complicated about it.
But one of the more outrageous things is that
If you search the question "Who discovered cathode rays" on Baidu, the answer that appears is not Plucker.
But another person:
Joseph John Thomson.
That is, the JJ Thomson who Xu Yun misjudged Lao Tang at the beginning of the dungeon.
What a pity.
JJ Thomson was only two years old in 1858. How could He De discover cathode rays?
What's even more outrageous is that Xu Yun proposed a correction to this problem, but Baidu sent him back.
To know.
Neither the discovery nor the naming of cathode rays had anything to do with JJ Thomson.
The reason why cathode rays are called cathodes has nothing to do with their electrical properties, but because they are rays emitted from the cathode.
JJ Thomson's contribution was to determine the negatively charged nature of cathode rays, thereby calculating the electron specific charge, which is the charge-to-mass ratio.
As for the charge of electrons, it was measured by Millikan's oil drop experiment. However, this experiment is a famous scandal in the history of science, a Nobel Prize winner who cheated.
Back then, Xu Yun and his friends were looking for oil drops in the laboratory and found eye pain, but the data did not match up at all. The result was that it took an average of fifty squeezes per person to get one drop of oil. If you say too much, you will be in tears.
His eyes returned to reality.
Opposite Faraday.
While Xu Yun was sighing, there was also a hint of expectation in his heart.
Next, Faraday will definitely repeat the experiment according to his own plan.
That is to say, set up a small windmill and touch the rays with your hands.
And it is worth mentioning that.
The platinum base of this vacuum tube designed by Xu Yun can be regarded as a metal plate.
What happens when cathode rays hit a metal plate? This is a story recorded in Chapter 8 of the second volume of the fifth grade Chinese language course.
all in all.
Although I felt sorry for Pluck and JJ Thomson, it turned out to be a good thing. Faraday patted his chest with a firmer attitude than before, saying that he would definitely be able to fool the people on the list.
I don’t know where Faraday got the confidence, as if those people who knew what he was doing would definitely rush to Cambridge University.
that's all.
In a somewhat delicate atmosphere, Xu Yun completed the transaction with Faraday and said goodbye to each other.
That night.
A telegram was sent from Cambridge University to London.
From London to Manchester
birmingham
Finally arrived in Germany, branches and leaves spread.
The content of the telegram is only one:
[Faraday is critically ill, come to Cambridge quickly!]
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