Many people may only know about Rutherford's alpha particle scattering experiments and atomic nucleus model, but Rutherford won the Nobel Prize based on his research on radioactivity.
This is very similar to Einstein, another super super boss at the same time: everyone only knows Einstein’s theory of relativity, but most don’t know that Einstein won the Nobel Prize based on the photoelectric effect, which should belong to the quantum field. Achievement.
Rutherford's research on radioactivity is still very in-depth. He has taken the lead in proposing the concept of radioactive "half-life".
Owen Richardson was influenced by Thomson and also conducted very in-depth research on rays.
After listening to Li Yu's statement, Richardson pondered: "To tell you the truth, I have considered Mr. Academician's problem, but I doubt whether this kind of rays should be related to the sun."
Li Yu said: "Your guess can easily be verified as incorrect. You only need to measure the ray intensity once during the day and at night."
"The academician is right, otherwise it would be too simple," Richardson said.
Rutherford's experiment is very sensitive and said: "Can we verify it by launching a high-altitude balloon? If it increases as the altitude increases, we can verify that the rays come from the universe."
Li Yu said: "This is an experimental step, because it is impossible to put it into space at a high altitude, and if the ray intensity is very high, its change amplitude will not meet theoretical expectations, and it is difficult to rule out interference from the ground."
Rutherford's eyebrows furrowed, and he didn't even have a good idea: "Then how to verify that the rays come from space?"
Li Yu had the right idea a long time ago. He said: "We need to use a new concept in astronomy: penetrating ability. I think you must be familiar with it, which is the penetrating ability of various rays."
Rutherford naturally knows the field he is currently researching the most: "The penetrating power of gamma rays is hundreds of times stronger than beta rays, and beta rays are a hundred times stronger than alpha rays. It can't be stronger than the strongest gamma rays, right?"
There can be gamma rays on the earth. If cosmic rays can only reach this intensity, it is basically impossible to verify whether they come from the universe with current experimental methods.
Li Yu said: "So the most critical issue now is to eliminate the influence of atmospheric absorption, because if the rays outside the atmosphere are to be measured on the ground, the penetrating power must be extremely large, large enough to pass through ten meters of water - —That is, the general absorption capacity. But judging from the currently known natural radioactive elements, the radioactivity of no element can pass through 2 meters of water."
What kind of person is Rutherford? He knows everything at once. He immediately understood Li Yu's experimental idea: "Mr. Academician, are you going to put the detection instrument under water more than ten meters deep to detect rays?"
Li Yu nodded: "That's right!"
Rutherford said in surprise: "If it is true as you said, the intensity of this kind of ray is probably several times or even ten times stronger than gamma rays. What a terrifying energy it is! It simply subverts previous knowledge!"
Li Yu knew from his expression that Rutherford was already very interested, so he smiled and said, "How about it, do you want to do it together?"
Rutherford rubbed his hands and agreed: "It just so happens that I can design such a detection instrument."
This was Li Yu's biggest purpose in finding Rutherford.
At this point in time, in terms of experimental ability, if Rutherford says that he is second, others who want to be considered first must first weigh it carefully.
Li Yu asked Owen Richardson again: "Are you interested?"
Richardson was equally itchy: "Thanks for the invitation, Mr. Academician!"
Cosmic rays later became a source of research on elementary particles and were of very high value. In history, the discovery of cosmic rays alone won a Nobel Prize in 1936.
Men like Rutherford certainly knew its significance.
As the leader of the experiment, Li Yu assigned a task to Richardson: "In order to eliminate doubts and interference, we still need to conduct high-altitude experiments. Sir, this matter needs to be troublesome."
Richardson said: "No problem, I need to eliminate the interference of the sun first."
Lord Kelvin, President Huggins, and Cavendish Laboratory Director Thomson were shocked after listening.
Thomson said: "It's incredible. If it is really proven that the rays come from the universe, I can't even imagine the words to describe it!"
President Huggins said: "It is indeed unimaginable. Perhaps Li Yu will prove that rays are extremely widespread in the entire universe, and the rays on the earth are just the tip of the iceberg."
The duration of the experiment will not be short, and Li Yu will stay in London for at least one or two months.
According to the experimental plan designed by Li Yu, Richardson's task was ranked first.
It just so happened that Rutherford was going to the Royal Society to report on his recent research on the radioactivity of radium elements at Machill University in Canada. This was his main task in coming to the UK this time.
The content of Rutherford's work generally means that the radium element emits heat (gamma rays), indicating that there is energy inside the atom; and there is also about the "half-life" theory he proposed.
In fact, this was the result for which Rutherford won the Nobel Prize in Chemistry four years later.
As a foreign academician of the Royal Society, Li Yu is naturally qualified to participate in this report.
Also present at the meeting were Lord Kelvin, President Huggins, Lord Rayleigh and many other big figures in the British scientific community.
Li Yu and others came to the auditorium of the Royal Society. Although it was not a big place, it had always had a great influence.
The layout inside is very similar to the British Parliament you have seen on TV: the speaker sits at a table, surrounded by stepped seats.
Lord Kelvin and President Huggins invited Li Yu to sit beside them.
Before the report begins, everyone already knows the general content, especially the initiative to measure the age of the earth using half-life.
This is also the first time someone has proposed such a method.
Rutherford's report is really valuable.
There are not many methods available at the moment, and it is extremely difficult to measure the half-life of elements. But Rutherford came up with a plan like a genius, and it was a very simple and crude plan: relying on human power to count how many alpha particles emitted by atoms per unit time!
As long as you count this value, you will know the half-life of the element.
Rutherford completed this research in Canada. He and his assistant Geiger (the Geiger of the Geiger counter) designed an ingenious experiment that could amplify an alpha particle into a detectable current.
From this he learned the radiation rate of radium.
Rutherford even used experiments to estimate that the basic charge was 1.55×10-19 Coulomb, and the modern value is 1.6. There is only an error of 3%, and I am truly impressed.
You must know that measuring basic charge later also won a Nobel Prize! (Of course Millikan's experiments were more sophisticated at that time.)
Rutherford measured the half-life of radium element to be about 1500 years. He keenly felt that there was a problem: half of it decayed in 1500 years, so after 30,000 years, only 1/2 to the power of 20 was left!
That is less than one part per million, almost negligible.
The earth cannot be 30,000 years old, right?
How come there is so much radium in nature? If it had existed for tens of millions of years, it would have decayed into light long ago.
For Rutherford, it was just guesswork.
He imagined that the element radium was not only decaying but also being produced: radium was a product of the decay of other elements.
The ones most likely to decay into radium are uranium and thorium, because they always appear in minerals together with radium.
Rutherford tended to believe that the ability was generated by the decay of uranium, because uranium ore contained a large amount of radium.
Anyway, it's a genius idea.
Using the half-life of uranium (Rutherford guessed a few hundred million years, which was actually 4.5 billion years), Rutherford estimated the age of the Earth to be a few hundred million years.
Although there is a big gap between him and later generations, his ideas are extremely groundbreaking.
The carbon-14 measurement method commonly used in later archaeological research has the same principle as Rutherford's.
The above genius ideas are contrary to Lord Kelvin's theory.
Lord Kelvin once estimated the age of the earth to be 24 million to 100 million years using thermodynamic methods.
His method is equally simple and crude: He believes that the earth was originally a magma planet, and then the temperature slowly decreased. As long as the initial temperature, thermal conductivity, and temperature gradient are known, the age of the earth can be estimated.
Lord Rayleigh, being a good-natured man, said to Lord Kelvin: "My lord, if this young man on the stage is right, you are wrong."
Lord Kelvin said: "Then I would like to hear whether there are any flaws."
Lord Kelvin currently does not believe in Rutherford's theory. Last year, he also questioned Marie Curie's research and believed that it was nonsense that elements would spontaneously transform.
——It is indeed a bit difficult for the old man. It is already difficult for him to accept the atomic theory, and now someone is about to explain the decay of elements!
Today's young people are getting more and more outrageous!
In fact, Rutherford was also very nervous, especially after seeing Lord Kelvin in the audience.
With Lord Kelvin's qualifications, if he stood up to oppose, Rutherford would definitely not be able to stop it.
Li Yu, however, had enough free time to sit aside and watch the show.
It's not that he doesn't want to help Rutherford, but it's so rare to see big bosses tearing each other apart!
And Li Yu knew that Rutherford was actually a well-rounded person, and this scene should be held.
Rutherford swallowed, took a deep breath and began his report, sneaking a glance at Kelvin's reaction from time to time.
Although Kelvin is a bit old, his energy is not as good as that of ordinary people. Sometimes he seems to be asleep. But once Rutherford got to the key point, he immediately sat up straight, his eyes bright.
And Rutherford became even more nervous when he saw his eyes.
He had an idea and suddenly said directly: "Everyone here must have known for a long time that Lord Kelvin has calculated the age of the earth without a heat source. His prophetic insights are the reason why we are here to discuss radium today! Without him, there would be no me. Research!"
As soon as Rutherford said these words, Lord Kelvin looked really good and couldn't help but smile.
Li Yu sighed in his heart: He is worthy of being the principal of the kindergarten!
If Madame Curie had been on stage, Mars might have hit the earth by now.
Reporting after that was smooth sailing.
After it was over, Li Yu was the first to take the lead in applauding.
Then he said to Lord Kelvin: "My lord, do you now accept the theory of atomic transformation?"
Lord Kelvin shook his head: "At least for now, I can't completely agree."
Li Yu smiled and said, "Should we make a bet?"
"Bet with me? I have never lost! President Huggins can testify that he lost to I don't know how many fine Cuban cigars." Lord Kelvin said.
“I can certainly bear witness to that,” said President Huggins.
Li Yu was not afraid: "I bet it won't take long for you to accept Rutherford's radiation theory. It won't take more than three months."
Lord Kelvin asked: "What's the stakes?"
Li Yu said: "How about one pound?"
Lord Kelvin said without hesitation: "Okay, it's a deal!"
(End of chapter)
