Feynman at Caltech - John Preskill and Kip Thorne - 5/11/2018

So, we both knew Dick Feynman as a colleague, but for those who didn't know him personally, it's hard to explain how extraordinary he was, yes, he really is, it's amazing because sometimes he would come up with these amazing ideas, seemingly on the spur of the moment. At the time how he could do that, yes, I really don't know, but I do remember, I really remember one occasion of this in 1963, right after the crash, Martin Schmidt here at Cal Tech had discovered quasars in the sky and people, physicists and astronomers from Everyone was trying to figure out what these quasars were and here at Cal Tech actually Fowler along with Fred Hoyle who was visiting from Cambridge at the time they invented a theory of quasars that was based on supermassive stars, stars that are waiting a million times what the Sun weighs and they gave a seminar on their theory and in the middle of the seminar Richard Feynman stood up and objected, he said that those stars of yours are going to be unstable due to general relativity, they are going to collapse. and they destroyed themselves and everyone in the room was dumbfounded, they were just amazed by this idea.

Well, I bet Fowler in the foil was the funniest of them all. In fact, they were. Willy used to go around telling the story of this. He loved to tell the story. In retrospect, after they figured out how to deal with it, yeah, and then just a few months later, Chandrasekhar at the University of Chicago published a paper explaining this relativistic instability that no one had ever known about before, so it became part of the legend of Fineman. Somehow, Fineman knew this instinctively, but Chandrasekhar had to work hard to figure it out, you know? So when I came back here to college a few years later, I asked Dick, I said, Dick, how did you know? and Dick said, I'll show you.

So he went home and the next day he brought back 40 pages of handwritten calculations in which he had been calculating the details of the collapse of a star a month before Hoyle Fowler's theory appeared. He had been doing this because Johnny Wheeler, who is his Johnny Wheeler Winding Mine at Princeton had been challenging everyone to understand the collapse of things to form what would later be called black holes and so, driven by his intellectual curiosity, Dick He had figured all this out for himself and must have had to solve those equations. numerically I supposedly used a slide rule, in fact he did.

I watched the slide roll calculations step by step, but once he did the calculations, he went and put the calculations away in his desk drawer and didn't think much more about it. I thought other people knew about this and okay, now I understand I'm happy and then in the middle of Hoyle Fowler's seminar he suddenly realized that because of the calculations these things were going to be unstable and that's how it seemed to them to everyone in the audience. A remarkable idea was the result of very hard work fueled by his own intellectual curiosity. Well, that explains a lot of things.

He must have had a lot of secrets in that drawer of his. I think so. I think so. Have I ever told you about them? The first time I met Richard Fineman, well, trying to guess how old he was, I don't know twenty-one years old, I was actually nine years old and when I was nine I read this extraordinary book, a wonderful book called The World of Science, by Jane Vegetable garden. Watson and what especially caught my attention in this book was the chapter on theoretical physics and it begins with the story of a little boy who has a red car with a ball in the back and he realizes that when he pulls the car towards forward the ball rolls backwards and when he stops throwing the ball it rolls forward so he asked his father why that happens and his father said well that's called inertia but no one knows why and then I thought what's happening when I saw the interview years later this interview with Christopher Seitz this great interview called the pleasure of discovering things and finally tells the same story.

I thought this guy stole that story from the book I read when he was good but then I looked at the book I hadn't seen it in years. and I realized what had happened. Jane Werner Watson had based each chapter of the book on interviews with Caltech professors, so one mystery was clarified, although others remain yes, such as why Dick wears a bow tie and where exactly the glasses by Marie Gellmann. I don't know that I can't explain it, I don't really care, but you're right, you always put me down, it's an enduring mystery and what's really fantastic about this book is that it describes a discovery that had just been made in 1957, a year before it was discovered. publish the book, which was that the laws of nature actually know the difference between left and right and that's what Simon and Gellmann were working on at the time and I thought it was so exciting that it got me interested in physics which eventually took me to Caltech, where I joined Fineman on the faculty 21 years later.

Wow, they're going in another direction. You know, it was in the early 1960s that Richard Feynman revitalized and renewed our introductory physics course for freshmen and sophomores and wrote his three-volume lectures that came to be called the final lectures in physics, three volumes that had tremendous tremendous ideas due to his tremendous physical intuition, his great pedagogical power, those lectures have sold one and a half million copies in the English language alone and are the most influential set of books on physics. I think the world has ever seen the most influential. It's true, and many of the students who attended those lectures, looking back, consider Fineman's lectures to be the most memorable experience of his college years.

Simon loved the audience he loved performing so every class was like a meticulously prepared performance he had notes like you can see on the table but he didn't look at them every lecture was almost perfectly timed even the use of the whiteboards was very precise Corian It was really remarkable and even today, so many decades later, these lectures are of enormous value and interest to physicists, both mature and novice physicists, they are being read by people all over the world and, thanks to the heroic efforts of Michael Gottlieb , actually five-four and others are available online today in HTML format on the Fineman conference website.

It's great that they are available for free to anyone in the world because the lectures are amazing. I still check them from time to time. for fun and it is always a great experience to reread them. I bet you do too. I have them in my home office. Well, you know? That time he gave Fineman's lectures for two years, that was the only time. In his career at Caltech, Fineman officially taught an undergraduate course, but he was involved in undergraduate education and one form was an unofficial course that was called Ax Physics and it was early, just Fineman standing in front of a classroom saying, Ask me anything I want.

The students would ask him questions about trying to understand something and then he and the students would try to figure it out together with Fineman standing in front of the board. Do you remember physics? Oh, I remember well. I was a freshman here in 1958-59 and this Physics you could read and I vividly remember one of the physics sessions. X We all went, all, me and several of my first -year friends went to the classroom that was rumored at the time that was rumored and we hope PHIMAN appeared, the firefighters appeared, looked around the class of first -year students and He said why do they want to talk about it. today and someone said: I want to know about water waves on Mars it's pretty cold on Mars it's pretty cold on Mars and that's what the firefighters said we'll be frozen there won't be waves the next question and so one of the really smart kids said : "Okay, let's pretend we're doing it." Donkin experiment, let's imagine that we heat the surface of Mars.

Okay, now you have real water, you have real water waves, and then how fast are these waves going to propagate? So Fineman discussed things with us: Gravity pushes the crest of water into a valley, but the pull of gravity on Mars is three times weaker than the pull on Earth, so surely the waves will propagate further. slowly and so on. Let's review and calculate and solve together and hand in hand we worked on it to keep the whole class with phiman and we discovered that it propagates the square root of 3 times more slowly on Mars and on Earth and then the question was how big were they going to be the waves, so we speculated with him what causes the waves, how they are generated and finally he explained that it is the turbulent blow of the air on the surface of the water that generates the waves, but the density of the air will be lower on Mars, much lower that on the surface if it goes to the Earth, so the county will be much weaker, the waves would be much smaller and we review it and work on it.

Some of the details that came out of that class that day were so fixated, so tremendously inspired that I remember them to this day, more than half a century later, so it wasn't much fun to surf on Mars, it wasn't a lot of land. . one of those little marks, well I guess I was trying to remember a couple of lessons, one is that physics should be fun, yeah, and the other is that everything in science can be interesting if you dig into it, yeah, yeah , Well. he was a great explainer and he loved to explain things and that was definitely still true when I met him in the 1980s and I remember in 1987 the Rogers Commission had finished investigating the Challenger disaster and I was finally very eager to dive back into it.

Physics and was particularly about a new idea. He had a way of mathematically describing what happens when two protons collide at very high energy, but to pursue that idea he had to learn a topic that was new to him, something called integral models. He thought it would be fun to learn this by meeting with students to discuss it, so he had a weekly meeting in his office with a small group of students and they talked about integral models, and as the year went on, Fineman was becoming more and more . sick, but he really looked forward to those Wednesday meetings and never missed them.

It was very inspiring for the students to see how enthusiastic he was about the topic, how engaged and fun he had discussing it, and his exhortation to the students still continued. On his whiteboard at the time of his death, he told them that they must know the tools of mathematical physics, they must know how to solve exactly each problem that had been solved, but he also emphasized that they must find the solution, they solved the problems themselves. I did not simply follow the steps that others had followed because he said that what I cannot create, I do not understand, but he made an exception: he arranged for his notes to be shared with the students after his death and when the student saw them.

They were flabbergasted because these notes were so voluminous and so meticulously detailed and the firefighter had delved deeper into the subject than they suspected from those discussions. Yes, we lost Fineman on February 15, 1988. It was a tremendously sad day for all of us at Caltech. Richard Feynman was a dear, honored, dear friend to all of us, he was a hero to faculty, students and staff alike and he was built deeply embedded in the culture of this place, that's for sure, I remember that day and of course Actually, it was a sad day, you know? Thirty years have passed and since then many students have come and gone who did not know Fineman personally but, like us, have been deeply influenced by him in many ways, by his scientific achievements, by his ideas, by his writings and by his joy, so really The spirit of Dick Fineman lives on among curious scientists around the world.

In fact, you know? He will not be forgotten.