Chapter 30 The fourth big professor-9

I'm not very interested in many departments at Cornell University.It doesn't mean there's anything wrong with them, it's just that I just don't have an interest in those departments.This includes home science, philosophy (guys in this department are very abnormal), and other cultural things, like music and so on.Of course, Cornell has a lot of people I like to hang out with, such as Professors Kac and Feller in the Department of Mathematics, Professor Calvin in the Department of Chemistry, and the good man Griffin in the Department of Zoology ( Griffin - the man who discovered that bats navigate themselves by echoes.But there aren't enough people like them, and a lot of other things I don't think are up to par, full of crap.Besides, Itsika is just a small town.

The weather here is not very good. One day I was driving the car, and it suddenly started snowing. There was no warning beforehand, and I was not mentally prepared. I thought to myself: "Oh, it's not serious, just keep driving." But the snow was getting deeper and deeper, and the car started to slide occasionally. I thought: Had to tie the tires to chains.I went out of the car and put the chain on the snow; it was so cold that my whole body was shaking.Put the car back on the chain and you have this problem - or the problem we had at the time - you have to hook one of the hooks inside first.Because the hook must be tied tightly, it is difficult to hook the hook.Then you have to press a clamp down with your freezing fingers.You are on the outside next to the tire, but the hook is on the inside of the tire, so everything is very difficult to control.It keeps slipping off, and it's cold, and the snow keeps falling, and you're trying to get this clamp down, and it hurts like hell, but the damn thing won't come down.I remember at that moment I decided—this was crazy—that there must be other places in the world where people don’t have to worry about this kind of thing.

I remembered that I had visited Caltech twice at the invitation of Professor Bacha; Bacha also taught at Cornell before.He is very smart and knows my personality like the back of his hand.He said: "Feynman, I have one more car here, and I will lend it to you. In addition, here is a map to Hollywood and the Sunset District, enjoy it." So I drove his car to the Sunset District every night—to join in the fun at the nightclubs and bars there.I learned to like these things from Las Vegas - pretty girls, big gamblers, whatever.Bacha really knew how to get me interested in Caltech! You must have heard the story of the donkey.The donkey stood in the middle of two piles of hay, not knowing which one to go to because there was the same amount of grass on both sides.

Alas, that's nothing.Cornell and Caltech competed to offer favorable treatment: Whenever I think Caltech is really better and decide to leave, Cornell will offer better conditions; and when I want to stay in Cornell, Caltech people will propose something.So you can imagine a donkey standing in the middle of two piles of grass, but the situation is more complicated because as soon as it starts walking towards one pile, the other pile immediately grows. What made my final decision was my professor's sabbatical year.At that time I wanted to visit Brazil again, this time for 10 months, and I happened to be at Cornell at the time when I could take a year off.I don't want to lose this right, so I create a reason to make a decision.I wrote to Bacha and told him my decision.

Bacha wrote back: "We'll hire you right away, and you can use your first year as a sabbatical year." They were that virtue: No matter what my decision was, they had a way of screwing it up.So my first year at Caltech was actually spent in Brazil.It was not until the second year that I officially taught at Caltech.This is the beginning and end of the whole thing. I've been at Caltech since 1951 and have always been happy.For people with my personality, there is nothing more suitable here. There are a lot of top people there who are very interested in what they do; I also enjoy talking to them, so I always feel very comfortable.

But not long after I arrived at Caltech, one day we were hit by smoke.The smog was much worse then than it is now—my eyes were stinging.I stood in the corner, tearing up, and thought, "This is crazy! This is absolutely nuts! I was fine at Cornell. I'm getting out of here!" So I called Cornell and asked if it was possible for me to go back. They said, "Of course! We'll make arrangements right away and call you tomorrow." The next day, I had great luck and made a decision—maybe God was doing it for me.I was walking back to the office when a guy came up to me and said, "Hey, Feynman! Did you hear the latest big thing? Walter Baade discovered that there are two different types of planets! We used to There used to be only one type of Cepheid variable used to calculate the distance between galaxies and us, but now it has been discovered that there is another, so the universe may be two, three, or even four times older than we thought! "

I know exactly what's going on here.At that time, the earth seemed to be older than the universe.According to estimates, the age of the earth is 4.6 billion years, but the age of the universe is only 2 or 3 billion years.That's a big mystery; and this discovery solves it: after recalculations, it turns out that the universe is older than previously thought.But the point is, I knew about this new discovery right away—the guy came over and told me firsthand. Before I got across campus, back to my office, another guy came by again.This is Matheson. He majored in biology and minored in physics. I was one of the committee members of his doctoral dissertation oral examination.He built the first "density gradient centrifuge" to separate and measure the density of molecules.He said to me: "Look at the experimental data I just got!"

He showed that when a bacterium makes a new bacterium, it passes on an entire molecule to the new bacterium; this molecule is DNA.Before this, we always thought that everything was splitting, splitting.Therefore, everyone originally thought that bacteria would divide and half of them would become new bacteria.But that's impossible: the tiniest molecule that contains the genetic information cannot be split in two; it has to duplicate itself, and give the copy to the new bacterium, keeping a copy for itself.Methosen confirmed this idea by growing the bacteria first in heavy nitrogen and then in ordinary nitrogen.During the experiments, he used his density gradient centrifuge to measure the weight of the molecules.

In the first generation of new bacteria, the molecular weight of the chromosomes was just in between those made with heavy nitrogen and those made with ordinary nitrogen.This result is reasonable if all molecules, including chromosome one, are split in two.But in the next many generations of bacteria, if it is still divided into two, then the weight of the chromosome molecule should be 1/4, 1/8 and 1/16 of the difference between the heavy molecule and the light molecule, etc., but Experimental results show that the molecular weight is only two groups.One set weighed the same as the new first generation (between heavier and lighter molecules), and the other set was lighter—just the same molecular weight as would be produced with ordinary nitrogen.So even though the proportion of heavier molecules halved with each passing generation, they didn't lose weight, which is a very exciting result, and it's a very important finding with fundamental implications for fundamental research.

As I walked into the office, I realized that this was where I wanted to be.It's exciting to be here where people from all walks of life in the scientific community tell me about their research.This is what I want, really! So when Cornell called me later and said they were almost all set up, I said, "I'm sorry, I changed my mind again."Nothing—absolutely nothing—could make me change my mind. When a person is young, you have many things to worry about: whether you will go to this place, what will happen to your mother, and so on.You worry, make decisions, but something else happens.In fact, it's easier to just ignore it and just decide.Don't worry about it - nothing will change your mind.I had this experience once when I was a student at MIT.I was so annoyed with not being able to decide which dessert to have every time I was in a restaurant, so I decided to just choose chocolate ice cream from now on and not bother - and that problem was solved.Anyway, that's what I decided to do, and I stayed at Caltech from now on.

Still, someone tried to change my mind about staying at Caltech. Not long after Fermi's death at the time, people at the University of Chicago were looking for a replacement for Fermi.They sent two men to visit my house—their motives I knew nothing about at the time.And they started talking about all kinds of good reasons why I should go to Chicago: I could do this and that, there were a lot of great people there, I had the opportunity to do a lot of things.I never asked them about their treatment, and they tried their best to imply that if I asked, they would tell me.Finally, they still asked me if I wanted to know how much my salary was. "Oh, no!" I said, "I've decided to stay at Caltech. My wife, Marylou, is next door, and if she hears that the salary is that high, we'll fight again. And I've already decided not to." It’s up to you to decide. I’m here forever.” I wouldn’t let them tell me what Chicago was going to pay me. About a month later, at an academic conference, Leona Marshall came to me and said, "It's strange that you didn't accept the position in Chicago. We are disappointed and do not understand why you would refuse such a generous offer. " "That's easy," I said, "because I never let them tell me how I was treated." A week later, I got a letter from Marshall.I opened the letter, and the first sentence said: "The salary they proposed is—" A very huge sum, about three or four times my original salary, which is amazing!The letter continued: "Before you read on, I let you know how much it's going to cost. Maybe now you'll reconsider, because they told me there's still a vacancy and we all want you to join us." I wrote them a letter saying, "After knowing the amount of the salary, I decided I had to say no. I had to say no to such a high salary because if I really got that high salary, I could achieve everything I had before. I want to do something - find a beautiful mistress, find her an apartment, buy her beautiful things... With the salary you guys are giving me, I can really do that, but I also know what I will become I'll start worrying about what she's doing and when I get home I'll be arguing and it's going to make me very uncomfortable and unhappy. I can't do physics anymore and it's going to be a mess! I've always been Everything I want to do is harmful to me, so I have to decide that I can't accept your invitation."