A few days ago, a book was read — milan quintra's lightness in life. In high school, it was recalled that there was a reading in the language paper, the same subject, the philosophy of life, the heavy, the terrible, the light。
In fact, in some respects, this reading makes sense. When it comes to weight, we'll use weight as a metaphor. If we are given a scale to measure the things, the heavy things are easy to measure, even if they exceed the scale, and the light things are not easy to measure. For example, the ancients did not weigh the weight of elephants large enough, and cao tsao thought of replacing them with large quantities of stones. But if a substance is too light, it is difficult to measure。
This guy we're talking about today, he's too light to measure. That's neutrino。
Beta - decay
When it comes to neutrons, it starts with polly. Polly is the austrian physicist, and his best known idea is to introduce the principle of incompatibility. And besides that, the prophecy about neutrinos is very important。
This contribution came from his observation of beta decay. The so-called β decay refers to the transformation of an orbital electron from the launch or capture of an atomic nuclei, leading to the concept of neutrons, and to the release of β-depletion of the electron。
The process of beta-decomposition is actually a process in which neutrons release electrons and transform them into protons. We also said that neutron stars in the universe are the result of electrons being pressured into protons and turned into neutrons, and that beta-degradation is the reverse of the process。
According to that, the mass of a neutron should be equal to the quality of a proton plus electron, plus the quality of the energy released — what's the last one? In fact, einstein's mass equation refers to the conversion of energy and mass. The release of energy implies a reduction in quality。
Energy theft
But when scientists calculate, the mass of these three is still a little smaller than the neutron. Or energy: the energy of the original atoms is a little bit more energy and energy than the new atoms and beta particles。
Is that a miscalculation? Of course not. Scientists also found some incomprehensible aspects of the process when testing the spectral lines of beta-decomposition。
Since it's not a miscalculation, is there a problem with the law of energy
In song xiaobao's famous saying, "what's the matter with you?"
It was a matter of great excitement at the time, and indeed some scientists began to question the law of energy sustainability, and others gave it a name — energy theft。
Polly solved the case
Who's gonna solve the case
In 1930, he put forward his point of view: he believed that an unknown particle had been released during the beta-decomposition process. The particles are electroneutral and have a static mass of zero, but they are not photons. Another characteristic of it is that the interaction with other particles is very weak, making it difficult for scientific instruments to detect。
But when it comes to this story, we're actually kind of crossing. Because at that time, scientists had not fully understood beta-degradation, even neutrons had not been found, but only the presence of such particles. So polly called this predicted particle neutron when he put it forward。
The "face-to-face" moment is always so sudden. Just in 1932, scientists discovered real neutrons — different from what bully said。
More face-to-face, still in the back。
The new theory of humiliation
When it comes to this new particle, bully himself is a bit shy. As a result, when this idea was announced, he himself did not attend the physics conference, but wrote a letter to his friends to help read it. As for the reason he didn't attend, he was going to zurich to party and dance all night..
If i were a physicist there, i'd have run 10,000 camels in my heart:
Moreover, he explained in his letter that this assumption might not be credible, otherwise why has it not been discovered yet
Bulley message original
He even said that such particles were too difficult to detect, and that humans would never be able to detect them。
And the other scientists: you're so full of shit that you can't handle it. Are you kidding me
He didn't believe, but someone did. Like the famous physicist fermi, who is convinced of this. In 1934, he pointed out the nature of beta decay, where a neutron in the nucleus, by weak interaction, turned into an electron, a proton and a neutron microton, solved the mystery of beta decay。
Bully in the face
Until then, there was still suspicion about neutrino. Finally, at the time of the debate, a chinese scientist stood up and his theory ended the dispute, which was wang xianchang。
Wang xianchang is one of the greatest scientists in our country and has had the opportunity to win the nobel prize (and we will speak about it in the future). What we've just talked about, chadwick found the real neutrons and won the nobel prize was inspired by wang xianchang. During his studies in germany, wang xianchang was obsessed with neutrinos, and even when he returned home, in that time of turmoil, he kept it in mind。
In 1941, wang xianchang finally came up with a way to find the neutrino-k layer electronic capture. This way, we'll talk about it in the future. In short, wang xianchang has inspired a breakthrough for foreign scientists. Using this principle the following year, american scientist alan successfully demonstrated the existence of neutrinos in the experiment. So, the neutrino is finally known, and no one questions its existence。
However, it was not until 1956 that the united states physicists, corwin and reines, among others, carried out relevant research on nuclear reactors, which proved the existence of neutrinos for the first time. The search for neutrinos in humans is a phase. After the discovery of the neutron, the text contacted the rhine at the first time, informing the “good” news。
In 1958, polly died. In his lifetime, he saw that he had made assumptions and that he was ashamed to admit that the particles were there, and he didn't know what they were
So, did they find the neutrinos, the same as what polly or fermi described? What are the amazing characteristics of this particle? How can it affect the universe? We'll introduce you next time
