Tuesday, April 21, 2009

Define Triboluminescence

Richard Feynman, in Surely You're Joking, Mr. Feynman, narrates the following in a chapter called O Americano, Outra Vez!, where he talks about his experiences teaching in Brazil:

...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 by this time, I had 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 results of his exam in any way. The first question I ask is, "Can you give me some example of a diamagnetic substance?"


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...

Another excerpt:

...One other thing that I could never get them to do was to ask questions. Finally a student explained it to me: "If I ask you a question during the lecture, afterwards, everybody will be telling me, 'What are you wasting our time for in the class? We're trying to learn something. And you're stopping him by asking a question.'"

It was a kind of one-upmanship, where nobody knows what's going on, and they'd out the other one down as if they did know. They all fake that they know, and if one student admits that something is confusing for a moment by asking a question, the others take a high-handed attitude, acting as if it's not confusing at all, telling him that he's wasting their time...

Yet another excerpt:

...So, I came in, carrying the elementary physics textbook that they used in the first year of college. They thought this book was especially good because it had different kinds of typeface-bold black for the most important things to remember and so on...

..."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... "

Now, in my humble opinion, the education system in India is definitely better than this (Brazil in the 50s or 60s I think), but not too far ahead. I was able to relate to a lot of what was said above, from my own experiences in school. A lot of education here is still rote learning based, and no one knows exactly what they are learning.

Pity, don't you think?