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During that ten-month stay in Brazil I got interested in the energy levels of the lighter nuclei. I worked out all the theory for it in my hotel room, but I wanted to check how the data from the experiments looked. This was new stuff that was being worked out up at the Kellogg Laboratory by the experts at Caltech, so I made contact with them—the timing was all arranged—by ham radio. I found an amateur radio operator in Brazil, and about once a week I’d go over to his house. He’d make contact with the ham radio operator in Pasadena, and then, because there was something slightly illegal about it, he’d give me some call letters and would say, “Now I’ll turn you over to WKWX, who’s sitting next to me and would like to talk to you.”
So I’d say, “This is WKWX. Could you please tell me the spacing between the certain levels in boron we talked about last week,” and so on. I would use the data from the experiments to adjust my constants and check whether I was on the right track.
The first guy went on vacation, but he gave me another amateur radio operator to go to. This second guy was blind and operated his station. They were both very nice, and the contact I had with Caltech by ham radio was very effective and useful to me.
As for the physics itself, I worked out quite a good deal, and it was sensible. It was worked out and verified by other people later. I decided, though, that I had so many parameters that I had to adjust—too much “phenomenological adjustment of constants” to make everything fit—that I couldn’t be sure it was very useful. I wanted a rather deeper understanding of the nuclei, and I was never quite convinced it was very significant, so I never did anything with it.
In regard to education in Brazil, I had a very interesting experience. I was teaching a group of students who would ultimately become teachers, since at that time there were not many opportunities in Brazil for a highly trained person in science. These students had already had many courses, and this was to be their most advanced course in electricity and magnetism—Maxwell’s equations, and so on.
The university was located in various office buildings throughout the city, and the course I taught met in a building which overlooked the bay.
I discovered a very strange phenomenon: I could ask a question, which the students would answer immediately. But the next time I would ask the question—the same subject, and the same question, as far as I could tell—they couldn’t answer it at all! For instance, one time I was talking about polarized light, and I gave them all some strips of polaroid.
Polaroid passes only light whose electric vector is in a certain direction, so I explained how you could tell which way the light is polarized from whether the polaroid is dark or light.
We first took two strips of polaroid and rotated them until they let the most light through. From doing that we could tell that the two strips were now admitting light polarized in the same direction—what passed through one piece of polaroid could also pass through the other. But then I asked them how one could tell the absolute direction of polarization, for a single piece of polaroid.
They hadn’t any idea.
I knew this took a certain amount of ingenuity, so I gave them a hint: “Look at the light reflected from the bay outside.”
Nobody said anything.
Then I said, “Have you ever heard of Brewster’s Angle?”
“Yes, sir! Brewster’s Angle is the angle at which light reflected from a medium with an index of refraction is completely polarized.”
“And which way is the light polarized when it’s reflected?”
“The light is polarized perpendicular to the plane of reflection, sir.” Even now, I have to think about it; they knew it cold! They even knew the tangent of the angle equals the index!
I said, “Well?”
Still nothing. They had just told me that light reflected from a medium with an index, such as the bay outside, was polarized; they had even told me which way it was polarized.
I said, “Look at the bay outside, through the polaroid. Now turn the polaroid.”
“Ooh, it’s polarized!” they said.
After a lot of investigation, I finally figured out that the students had memorized everything, but they didn’t know what anything meant. When they heard “light that is reflected from a medium with an index,” they didn’t know that it meant a material such as water. They didn’t know that the “direction of the light” is the direction in which you see something when you’re looking at it, and so on. Everything was entirely memorized, yet nothing had been translated into meaningful words. So if I asked, “What is Brewster’s Angle?” I’m going into the computer with the right keywords. But if I say, “Look at the water,” nothing happens—they don’t have anything under “Look at the water”!
Later I attended a lecture at the engineering school. The lecture went like this, translated into English: “Two bodies … are considered equivalent … if equal torques … will produce … equal acceleration. Two bodies, are considered equivalent, if equal torques, will produce equal acceleration.” The students were all sitting there taking dictation, and when the professor repeated the sentence, they checked it to make sure they wrote it down all right. Then they wrote down the next sentence, and on and on. I was the only one who knew the professor was talking about objects with the same moment of inertia, and it was hard to figure out.
I didn’t see how they were going to learn anything from that. Here he was talking about moments of inertia, but there was no discussion about how hard it is to push a door open when you put heavy weights on the outside, compared to when you put them near the hinge—nothing!
After the lecture, I talked to a student: “You take all those notes—what do you do with them?”
“Oh, we study them,” he says. “We’ll have an exam.”
“What will the exam be like?”
“Very easy. I can tell you now one of the questions.” He looks at his notebook and says, “ ‘When are two bodies equivalent?’ And the answer is, ‘Two bodies are considered equivalent if equal torques will produce equal acceleration.’ So, you see, they could pass the examinations, and “learn” all this stuff, and not know anything at all, except what they had memorized.
Then I went to an entrance exam for students coming into the engineering school. It was an oral exam, and I was allowed to listen to it. One of the students was absolutely super: He answered everything nifty! The examiners asked him what diamagnetism was, and he answered it perfectly. Then they asked, “When light comes at an angle through a sheet of material with a certain thickness, and a certain index N, what happens to the light?”
“It comes out parallel to itself, sir—displaced.”
“And how much is it displaced?”
“I don’t know, sir, but I can figure it out.” So he figured it out. He was very good. But I had, by this time, my suspicions.
After the exam I went up to this bright young man, and explained to him that I was from the United States, and that I wanted to ask him some questions that would not affect the result of his examination in any way. The first question I ask is, “Can you give me some example of a diamagnetic substance?”
“No.”
Then I asked, “If this book was made of glass, and I was looking at something on the table through it, what would happen to the image if I tilted the glass?”
“It would be deflected, sir, by twice the angle that you’ve turned the book.”
I said, “You haven’t got it mixed up with a mirror, have you?”
“No, sir!”
He had just told me in the examination that the light would be displaced, parallel to itself, and therefore the image would move over to one side, but would not be turned by any angle. He had even figured out how much it would be displaced, but he didn’t realize that a piece of glass is a material with an index, and that his calculation had applied to my question.