Chapter 76 The boss was equally sharp when he was young
On August 30, 1901, the first conference of young scholars in physics and chemistry was held at the Metropolitan Hotel in Brussels, the capital of Belgium.
At the physics branch, a dozen people sat casually on both sides of the long table.
Seated at the head of the long table were naturally Li Qiwei and Rutherford, the two big guys, on both sides.
In front of them, there is a board as high as one person with white paper on it for everyone to calculate and write at any time.
Li Qiwei stood up first and delivered a brief speech about the original intention of holding this conference, and welcomed all the young talents who came to participate.
Then let Rutherford start by talking about the current results of the Cavendish Laboratory in the field of atomic structure and his radioactivity research.
Rutherford was not proud of his own identity, and would not look down on the people present because of their status as students.
In the field of physics, those who achieve success always come first, and heroes are not judged based on their status.
On the contrary, he spoke in a more detailed and easy-to-understand manner than at the European Radiology Conference, without any hint of impatience.
The scholars in the room were all fascinated. They cherished having access to such high-end knowledge. Some were even taking notes.
“Since the British physicist Dalton founded the atomic theory, for a long time, people thought that the atom was a solid ball that could not be divided.”
“But , In 1858, the German physicist Plucker discovered a strange ray while doing gas discharge experiments."
"Later, in 1876, the German physicist Goldstein re-optimized it. Experiment."
"He placed two electrodes on both sides of a transparent glass tube."
"Then when a voltage of nearly ten thousand volts was applied between the electrodes, a faint fluorescence appeared on the wall of the glass tube."
"Since this fluorescence is emitted from the cathode of the electrode, Ge Destin named it cathode rays."
"Since then, many physicists have studied the nature of cathode rays. Some people think they are electromagnetic radiation, and some think they are charged particles."
< br>"Finally, my mentor Thomson used a variety of different materials as cathodes and found that the charge-to-mass ratio of the resulting cathode rays was the same."
"Then he measured the ray composition through experiments The mass of the particle was found to be 1/2000 of the hydrogen atom.”
"This shows that there is a smaller structure inside the atom, and my tutor named it 'electron'."
After that, Rutherford drew a jujube cake model of the atom on the white paper. Paired with the corresponding equations of motion.
“This is the atomic structure model proposed by my tutor. The movement of these electrons can be perfectly explained by the laws of mechanics.”
“But currently, we still know nothing about the positive charge inside the atom. I don’t know what form it exists in.”
“My tutor believes that positive charges are evenly distributed inside the atom.”
"And my research direction is to explore the internal structure and composition of atoms."
Li Qiwei looked at Rutherford with admiration. He was indeed a genius who could teach several Nobel Prize-winning students.
It is not only clear and vivid, even a person who does not understand physics can understand what Rutherford is talking about.
This proves his profound foundation in physics, because only when he fully understands it can he explain it to others with ease.
He complained in his heart that if he had such a teacher in the future, he might be able to win a Nobel Prize.
At this time, Laue raised his hand cautiously, and Li Qiwei said: "Laue, relax, this is not your graduation defense, if you have any questions, just ask."
This sentence made everyone laugh, Laue Er touched his head embarrassedly, and then said: "Hello, Professor Rutherford, I have been learning about X-rays from Professor Roentgen recently."
"I want to know, what is the relationship between X-rays and electron rays? Is there any difference between the so-called radioactive rays?"
Rutherford smiled slightly, "If you had listened to my previous lectures in Paris, you would know better."
" Roentgen. When the professor discovered X-rays, he did not know the existence of electrons. "X-rays were discovered when he bombarded the anode metal target with cathode rays."
“Now we know that X-rays are new substances produced after some interaction between electrons and metal atoms.”
“I think you have seen that, whether it is X-rays or electrons , their production requires certain specific conditions. "
"Natural rays are different. No matter what physical or chemical conditions are imposed on radioactive substances, they can emit rays spontaneously. "
Laue suddenly said: "Does that mean that there must be more than one structure of electrons inside the atom, otherwise how could there be various rays?"
Rutherford was shocked, what a keen insight and logical ability, this young man is not simple.
So, he said: "Laue, right? Sure enough, famous teachers produce great disciples. Your idea is very interesting, and it can almost prove that there must be another structure inside the atom."
"At least from what we already know Judging from the nature of alpha rays, electrons alone cannot explain these phenomena."
Li Qiwei also looked at Laue in shock. Sure enough, the boss was already very good when he was young and could only use his talent. to explain.
At this time, Born suddenly asked: "Professor Rutherford, since there are many electrons inside the atom, and you said that the motion of electrons conforms to Newton's laws of mechanics."
"So how does the electron ensure that it can keep moving? What is its energy source?"
"If we solve it according to the equation of centrifugal force of circular motion, then where do the electrons go after they fall into the orbit? They are emitted. "?"
"This" Rutherford was suddenly speechless, thinking Bruce, where did you find these monsters, each one is more powerful than the last.
He really couldn't explain it, he could only say that electrons have always been like that.
Even this question made Li Qiwei stunned. He couldn't think of how to explain it for a moment.
The two of them were thankful at the same time. Fortunately, they didn't act too pretentious, otherwise they would be in trouble now.
Rutherford cleared his throat. At this moment, he no longer dared to underestimate these young people. Although they were undergraduates, their thinking was extremely fast.
This meeting also made him feel very satisfied and felt like he was being challenged.
“I can’t answer this question yet. Both Bruce and I are skeptical about the current jujube cake model.”
“Perhaps in the future, when my research makes further breakthroughs, I Might be able to answer your question ”
Born nodded, still expressing his gratitude.
Li Qiwei looked at him and thought that he was indeed the person who would create the matrix mechanics expression of quantum mechanics together with Heisenberg. His sharpness was already beginning to show.
At this time, Millikan spoke again: "Professor Rutherford, I would like to ask what instruments and methods Professor Thomson used when measuring the charge of electrons."
Rutherford knew that he was the one who had demonstrated the photoelectric effect, a brilliant experimental physicist.
But he was not particularly proficient in instruments, so he asked Wilson to answer for him.
Wilson finally found an opportunity to express himself, and he talked about everything from mechanical design to circuit construction.
Then he mentioned how awesome his cloud room was.
Millikan's eyes shone when he heard it, and he felt as if he had found a treasure.
In real history, Millikan was inspired by the cloud method. In 1909, he accurately measured the charge of electrons through experiments.
Soon, Li Qiwei shared it next.
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(End of this chapter)