more on fragile knowledge

More from Feynman on "Fragile Knowledge". The reason I quote this is that I am reading Hirsch's book called The Schools We Need -- and Why We Don't Have Them. While I think the book makes good sense, I have been wondering about some of the points.

For example -- he calls our educational system one of the worst in the world. The evidence is that we "test" poorly compared to other countries like Finland which have a core curriculum. While I'm sympathetic to the idea of a core curriculum, I do wonder -- why, if we are doing so badly in the USA, are we leaders of the world in so many intellectual things? He mentions that our universities are like intellectual meccas for the academic world. .... people come here from all over. So what are we doing RIGHT, then?

Now please, note, I am not arguing that Hirsch is FOR "merely verbal knowledge". He explicitly says he thinks it ought to be Both.... And, not either.,... or. Nor does Feynman sympathize with the progressive, "formalist" curriculum. I think he thinks that the loose US curriculum is almost as bad as the rigid, abstract Brazilian one. It's just that this reading the books together brings up some interesting questions.

Feynman discusses the Brazilian science curriculum, then:

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.

He gives several more examples in this line, and finally talks about a talk he gave to the Brazilian science school where he talked about the problems with their system:

Then I gave the analogy of a Greek scholar who loves the Greek language, who knows that in his own country there aren't many children studying Greek. But he comes to another country, where he is delighted to find everybody studying Greek -- even the smaller kids in the elementary schools. He goes to the examination of a student who is coming to get his degree in Greek, and asks him, "What were Socrates' ideas on the relationship between Truth and Beauty?" -- and the student can't answer.

Then he asks the student, "What did Socrates say to Plato in the Third symposium?" the student lights up and goes, "Brrrrrrrrr-up" -- he tells you everything, word for word, that Socrates said, in beautiful Greek.

But what Socrates was talking about in the Third Symposium was the relationship between Truth and Beauty!

What this Greek scholar discovers is, the students in another country learn Greek by first learning to pronounce the letters, then the words, and then sentences and paragraphs. They can recite, word for word, what Socrates said, without realizing that those Greek words actually mean something. To the student they are all artificial sounds. Nobody has ever translated them into words the students can understand.

I said, "That's how it looks to me, when I see you teaching the kids 'science' here in Brazil." (Big blast, right?)

Then I held up the elementary physics textbook they were using. "There are no experimental results mentioned anywhere in this book, except in one place where there is a ball, rolling down an inclined plane, in which it says how far the ball got after one second, two seconds, three seconds, and so on. The numbers have 'errors' in them -- that is, if you look at them, you think you're looking at experimental results, because the numbers are a little above, or a little below, the theoretical values. The book even talks about having to correct the experimental errors -- very fine. The trouble is, when you calculate the value of the acceleration constant from these values, you get the right answer. But a ball rolling down an inclined plane, if it is actually done, has an inertia to get it to turn, and will, if you do the experiment, produce five-sevenths of the right answer, because of the extra energy needed to go into the rotation of the ball. Therefore this single example of experimental 'results' is obtained from a fake experiment. Nobody had rolled such a ball, or they would never have gotten those results!

"I have discovered something else," I continued. "By flipping the pages at random, and putting my finger in and reading the sentences on that page, I can show you what's the matter -- how it's not science, but memorizing, in every circumstance. Therefore I am brave enough to flip through the pages now, in front of this audience, to put my finger in, to read, and to show you."

So I did it. Brrrrrrrup -- I stuck my finger in, and I started to read:

"Triboluminescence. Triboluminescence is the light emitted when crystals are crushed..."

I said, "And there, have you got science? No! You have only told what a word means in terms of other words. You haven't told anything about nature -- what crystals produce light when you crush them, why they produce light. Did you see any student go home and try it? He can't.

"But if, instead, you were to write, 'When you take a lump of sugar and crush it with a pair of pliers in the dark, you can see a bluish flash. Some other crystals do that too. Nobody knows why. The phenomenon is called "triboluminescence." ' Then someone will go home and try it. Then there's an experience of nature." I used that example to show them, but it didn't make any difference where I would have put my finger in the book; it was like that everywhere.