Chapter 32 True Wisdom in Laughter Part 5-2

In the early 1950s, our problem was to find the correct theory for beta decay.This involves two kinds of particles, one is called "Tao particle" (represented by the Greek letter τ), and the other is called "other particle" (represented by θ).They have almost exactly the same mass, but one degenerates into two "pions" and the other into three pions.In fact, they are not only similar in quality, but also have the same life span, which is a strange coincidence.So everyone is very concerned about this issue. At a conference I attended, it was reported that Thao and non-other produced from a cyclotron, even when measured from different angles or when the energies of the particles were different, were always produced in the same ratio: always how many Thao pairs How many are not him.

Of course, one of the possibilities is that the two are actually the same kind of particle, but it sometimes degenerates into two pie particles and sometimes into three.But no one would agree with this idea, because there is a law in physics called "parity rule"-it is based on the assumption that "all laws of physics, the images in the mirror are symmetrical".Therefore, anything degenerates into either two pie particles or three. Back then, I was a little confused and I was always a little bit behind. Everyone else seems to be very smart, and I feel like I can't catch up.During the conference, I shared a room with Martin Block, an experimental physicist.One night, he said to me: "Why do you stick to the parity rule so stubbornly? Maybe the Tao particle and the non-other particle are one and two, and two are one. What if the parity rule is wrong?"

I thought for a while and said: "This is equivalent to saying that the laws of the universe can be divided into two types: left hand or right hand, and some physical phenomena can also be used to define right hand. I don't think that How terrible it would be, though there must be some ill consequences, I don't know. Why don't you ask the experts tomorrow?" He said, "No, they won't listen to me, you ask." So at the next day's meeting, when we talked about the big Thao-not-hi mystery, Oppenheimer said, "We should hear something new and weird."

So I stood up and said, "I'm asking this question for Bullock: What happens if the parity rules are wrong?" Gehrman often laughed at me afterwards, saying that I didn't have the guts to ask questions in my own name.But actually that's not the reason.The real reason is that I felt at the time that it might be a very important idea, and whoever raised this question is likely to go down in history. Li Zhengdao stood up and answered some very complicated things, but as usual I didn't quite understand them.Towards the end of the meeting, Bullock asked me what Lee had said, and I said I didn't know, but as far as I know, the question is unanswered—it could still happen.I don't think the odds are high, but I think it's possible.

Norman Ramsey asked me if he should do an experiment looking for examples of parity violation.I said, "The best answer is, I bet you 50 to 1 that you won't find anything." “The odds were high enough for me,” he says, but he never ran that experiment. In short, Wu Jianxiong later proved by experiments that there are times when parity is not conserved, and this has brought many new possibilities to the beta decay theory and inspired a lot of other experiments.Some prove that some of the electrons coming out of the nucleus fly to the left and some fly to the right; there are other forms of experiments, all of which are interesting discoveries related to parity.Yet the data was such a mess that no one could piece things together.

A conference was held in Rochester during the period - the annual Rochester Conference (Rochester Conference).I am still behind in everything, and Lee Tsung-dao is already publishing a paper on parity violation.He and Yang Zhenning came to the conclusion that parity is not conserved, and now he is proposing a theory to explain this phenomenon. During the conference, I stayed with my sister in Syracuse.I took the paper home and told her, "I don't understand what Li Zhengdao and Yang Zhenning said, it's all so complicated!" "No," she said, "you don't mean that you can't figure it out, but that you didn't invent it. You didn't use your method, start by hearing the clue, and work it out. You should. The thing to do is to imagine yourself as a student again, and take this paper upstairs, and read it word for word, checking every equation. And then you figure it all out."

I took her advice and took that thing from start to finish and found it to be really obvious and simple.I just always dreaded reading it, always thought it was too esoteric. This paper reminds me of some research I did a long time ago, which was related to left-right asymmetric equations.Looking at Tsung-Dao Lee's equation now, I find that his answer is relatively simple: everything is left-handedly coupled.As far as electrons and muons are concerned, my corollary predictions are the same as Lee's, except that I reversed some of the plus and minus signs.I didn't expect it at the time: In fact, Li Zhengdao only discussed the simplest example of muon particle coupling, and did not prove that all muon particles are right-handed; but according to my theory, all muon particles will automatically be right-handed.So in fact my reasoning is a step up from his.

My plus and minus signs were reversed from his, but I didn't realize I got everything else right. I made several more predictions, all of which no one had thought to test experimentally.But when I considered neutrons and protons and performed calculations, my conclusions could not be mutually verified with the known neutron and proton data at that time.This part is a bit cumbersome and hard to get right. Back at the conference the next day, a nice guy named Ken Case gave me 5 minutes of his presentation time to report on these new ideas.I said that I believed everything was left-handedly coupled, that electrons and muons had reversed signs, and that I was still working on neutrons.Some experimental physicists asked me some questions about my predictions.In the summer after the meeting, I went to Brazil.

Immediately after returning to the United States, I wondered how the research on beta decay was going.I ran to Jianxiong Wu's lab at Columbia University, but she wasn't there, and another woman showed me some data, but it didn't help.In my model, electrons should all be left-handed in beta decay, but experiments show that sometimes right-handed situations occur.I'm all sorry. Back at Caltech, I asked the experimenters what happened to beta decay.I still remember that Hans Jensen, Aaldert Wapstra and Felix Boehm sat me down and told me the results of other people's experiments and the data they got .Since I know them well and know how hard they work, I value their stats more.Their experimental results were quite consistent, but when added to the results of other laboratories, it became messy.

Finally, they handed all the data to me and said: "The current situation is so chaotic, even some theories that have been established for many years have been doubted, such as whether the beta decay of neutrons is still S and T. Everything is messed up. Ge Ullman said it might be V and A." I jumped up from the little bench: "Then I—all—understand!" They thought I was joking.But the difficulty I had at the Rochester meeting was that when neutrons and protons disintegrated, everything fit together except that it seemed to be V and A instead of S and T.So now my theory is flawless!

That night, I worked out everything using this theory.First, I calculated the decay speed of muons and neutrons.If the theory is correct, there should be some correlation between the two numbers.My result was 9% off the answer it should have been.That's pretty close, only 9%.Seems like it should be closer, but 9% is close enough. I continued to check some other calculations, all of which were consistent, and then calculated new things, which were also consistent.I couldn't be more excited.This is the first time in my life.In fact, it was the only time I knew a law of nature that no one else knew. (Of course that's not entirely true, but it didn't spoil my fun to discover later that Gehrman, Soda Hill, and Marshak et al. Use other people's theories and improve some of the calculation techniques; or use some equations, such as applying the Schrodinger Equation to the helium phenomenon.The question involved there is simply: You have these equations and phenomena, how do they work? I think of Paul Dirac, who at one point also "owned" alone His equations - equations used to explain electronic phenomena.And now I also have this new equation for beta decay.It's not as flashy as Equation Dirac, but it's pretty good too.This is the only time I have discovered a new law. I called my sister in New York and thanked her for suggesting that I sit down and read the papers of Li Zhengdao and Yang Zhenning.After a period of restlessness and feeling left behind in everything, I now finally feel like I've joined everyone; I've made new discoveries, too, thanks to her advice.Thanks to her, I have returned to the path of physics.I told her everything except the 9% difference. I was so excited, I kept calculating, and things flowed like water: everything fit automatically, without being forced.By this time, I had started to forget about the 9% because everything else was going so well. I sat at a small table by the inner window in the kitchen and worked until late at night.It was getting late—about two or three in the morning.I worked hard at the calculations and got a lot of results that agree with each other.I'm thinking, I'm concentrating, it's dark and quiet outside... Suddenly there's a rattling sound on the window.I saw a white face there, only inches from me, and I cried out in shock! It turned out to be a friend of mine who was mad that I didn't call her right away when I got back from vacation.I let her in and explained as best I could that I was busy and that I had just discovered some very important theories.I said, "Go outside, please, and let me finish it." She said, "No, I don't want to disturb you. I'll go and sit in the living room." I said, "Okay, but it won't be easy." She wasn't actually sitting in the living room.The best way to describe it is that she crouched in a corner and folded her hands.Don't come to "disturb" me.Of course her purpose is to disturb me!And she succeeded.I'm so angry, I can't stand it.I must go on counting, I am making some great discoveries, my spirits are high; and at this moment at least, that is more important than this lady.I forgot how to get her to leave afterwards, it wasn't easy anyway. After working a little longer, it was really late and I felt very hungry.I walked to a small restaurant down the street not far from my house.I used to eat late at night like this. There have been many times when I've been pulled over by the police because I'd walk and think and then stop - sometimes so much that I couldn't even walk.You have to stop to clarify something; sometimes you stretch out your hands and say to yourself: "This is the distance from here, and then this will be like that..." The policeman saw it and came over and asked: "What's your name? Where do you live? What are you doing?" "Oh! I was thinking about something. I'm sorry, I live here and go to this restaurant a lot..." Then they all knew who I was and stopped stopping me. Walking to the restaurant, eating, I couldn't help but tell a lady there excitedly that I just made a big discovery.She started saying that she was a fireman's wife or something and was lonely -- but I wasn't interested.Sometimes life is so intertwined. The next day I went to Vipstara and the others and told them, "I've got it all figured out, and everything is correct." Christie was there too, and he said, "What beta decay constant are you using?" "How much is in a certain book." "But that's not true anymore. Recent experiments show a 7 percent error in that number." I remembered the 9%.I seemed to be predicting something: I used this theory at home, and it said there was a 9% difference in neutron decay, but someone told me the next day that the beta decay constant I quoted had a 7% difference.But the important thing is, will the change be from 9% to 16% (which would be bad), or from 9% to the ideal 2%? That's when my sister called from New York: "What's up with the 9%?" "I just found out that there's new data... 7%..." "Where to change?" "I'm still asking, I'll call you again." I was so excited that I couldn't think, as if I was catching a flight, and I didn't know how late I was.You really can't catch up, and suddenly someone next to you says: "It's daylight saving time!" Yes, but is it forward one hour or backward one hour?I can't think of it when I'm too excited. Christie went into his room and I went into the other room.We've all got to sit back and think: change this way, change that way - it's not too difficult, really, just exciting. Christie came out, and I came out of the room, and we both agreed: The difference will be 2% - within the allowed experimental error.After all, if they just changed the constant by 7%, that 2% is most likely an error.I called my sister: "2%." The theory is correct. (For reasons unknown to us at the time, the difference was actually only 1%. Later Nicola Cabibbo clarified this point.So the 2% is not all experimental error. ) Gellman synthesized our ideas and wrote a paper.This theory is quite cute, it is not difficult, but it can explain many phenomena.But as I said before, there were a lot of messy data at the time.In some cases, we even declare which experiments were wrong. The best example is the experiment of Valentine Telegdi.He measured the number of electrons that came out in different directions as the neutron disintegrated.Our theory predicted that these numbers were all the same, but he found that there were 11 percent more electrons coming out of one direction than others.Teledi was an excellent experimental physicist, and very careful.Once, when he was giving a lecture somewhere, he referred to our theory and said, "The trouble with people who do theory is that they never pay attention to experiment!" Tredi also wrote to us, not exactly reproachful, but clearly expressing his opinion that our theory was wrong.At the end of the letter, he said: "This F-G (referring to Feynman-Gell-Mann) theory is not at all F-G (referring to fit-good, which means matching)." Gellman said, "What shall we do? You also know that Treddy is a very good experimental physicist." I said, "We'll wait." Two days later, Treddy wrote again, completely changing his position. From our theory, he found: He ignored the fact that in experiments, the protons bouncing off the neutrons were not uniform in all directions; he assumed that it was the same in every direction. He replaced the corrected value speculated by our theory with the data he was originally using, and the result was completely changed, and the experiment and theory were completely consistent. I knew Trellet was excellent, and it was hard to argue with him.But at that time, I was convinced that there was a problem with his experimental data, and he would find it himself-of course he knew how to find the error better than me, so I said let's not try to find the problem, just wait patiently Can. I ran to tell Professor Bacha about our success.He said: "Yes, you have proposed that the neutron-proton coupling is V instead of T, and everyone thought it was T. Which experiment said it was T? Why don't you check the previous experiments and see What's the problem?" I ran to find the paper that first said it should be T, and I was immediately taken aback. I remembered reading that paper before (Physical Review at the time) It's not very thick, I read every article), and when I look at the paper again and see those graphs, I think: "That proves nothing?" Because, the curve in the graph depends on the extreme edge of the data range one or two data points of the data - usually these points are relatively unreliable.And I clearly remember thinking about this when I first read this paper! When I started thinking about beta decay, I read a lot of reports written by "experts" and they all said it was T.I never looked at the original data, I just read the other papers like a drug.If I were a really good physicist, when Rochester thought about it, I'd immediately look at "How reliable is T's claim?"--that would be a wise thing to do. I'll see right away that I've noticed something wrong with that chart. Since then, I have never bothered to give results from "experts". I always calculate each step by myself.When everyone said that the quark theory was very good, I asked two doctors, Finn Ravndal and Mark Kislinger, to check all the theories with me to make sure that the results it gave were consistent with the experimental results. fit, and it's really an important good theory.I no longer make the mistake of trusting expert opinion.Of course, you only live once, so you make your mistakes, learn what not to do, and your life goes by.