Unreal Nature

February 25, 2009

Deeper and Warmer Understanding

Filed under: Uncategorized — unrealnature @ 7:42 am

Omni: Maybe it’s the way the textbooks are written, but few people outside science appear to know just how quickly real, complicated physical problems get out of hand as far as theory is concerned.

Feynman: That’s very bad education. The lesson you learn as you grow older in physics is that what we can do is a very small fraction of what there is. Our theories are really very limited.

Omni: Do physicists vary greatly in their ability to see the qualitative consequences of an equation?

Feynman: Oh, yes — but nobody is very good at it. Dirac said that to understand a physical problem means to be able to see the answer without solving equations. Maybe he exaggerated; maybe solving equations is experience you need to gain understanding — but until you do understand, you’re just solving equations.

That’s Richard Feynman and the quote and all that follow are from the The Smartest Man in the World chapter within the book, The Pleasure of Finding Things Out. It’s a transcript of a 1979 interview of Feynman by Omni magazine. (Note that I have added bolding to the speakers to make them more visible than is found in the book’s formatting.)

Omni: To someone looking at high-energy physics from the outside, its goal seems to be to find the ultimate constituents of matter. [ … ] But with the big accelerators, you get fragments that are more massive than the particles you started with, and maybe quarks that can never be separated. What does that do to the quest?

Feynman: I don’t think that ever was the quest. Physicists are trying to find out how nature behaves; they may talk carelessly about some “ultimate particle” because that’s the way nature looks at a given moment, but ..Suppose people are exploring a new continent, OK? They see water coming along the ground, they’ve seen that before, and they call it “rivers.” So they say they’re exploring to find the headwaters, they go upriver and sure enough, there they are, it’s all going very well. But lo and behold, when they get up far enough they find the whole system’s different [ … ] As long as it looks like the way things are built is wheels within wheels, then you’re looking for the innermost wheel — but it might not be that way, in which case you’re looking for whatever the hell it is that you find!

Omni: But surely you must have some guess about what you’ll find; there are bound to be ridges and valleys and so on …?

Feynman: Yeah, but what if when you get there it’s all clouds? You can expect certain things, you can work out theorems about the topology of watersheds, but what if you find a kind of mist, maybe, with things coagulating out of it with no way to distinguish the land from the air? The whole idea you started with is gone! That’s the kind of exciting thing that happens from time to time. One is presumptuous if one says, “We’re going to find the ultimate particle, or the unified field laws,” or “the” anything. If it turns out surprising, the scientist is even more delighted. You think he’s going to say, “Oh, it’s not like I expected, there’s no ultimate particle, I don’t want to explore it”? No, he’s going to say, “What the hell is it, then?”

Omni: You’d rather see that happen?

Feynman: Rather doesn’t make any difference: I get what I get.

To me, that description could very easily be applied to photography, though with the added qualification that the photographer can — and surely will — elaborate, clarify, amplify … take your pick — whatever it is that she “get what” she “gets”.  The same might be said for this next bit:

Omni: Do you have any guesses on [the history of cosmology]?

Feynman: No.

Omni: None at all? No leaning either?

Feynman: No, really. That’s the way I am about almost everything. Earlier, you didn’t ask whether I thought that there’s a fundamental particle, or whether it’s all mist; I would have told you that I haven’t the slightest idea. Now, in order to work hard on something, you have to get yourself believing that the answer’s over there, so you’ll dig hard there right? So you temporarily prejudice or predispose yourself — but all the time, in the back of your mind, you’re laughing. Forget what you hear about science without prejudice. Here, in an interview, talking about the Big Bang, I have no prejudices — but when I’m working, I have a lot of them.

Omni: Prejudices in favor of … what? Symmetry, simplicity …?

Feynman: In favor of my mood of the day. One day I’ll be convinced there’s a certain type of symmetry that everybody believes in, the next day I’ll try to figure out the consequences if it’s not, and everybody’s crazy but me. But the thing that’s unusual about good scientists is that while they’re doing whatever they’re doing, they’re not so sure of themselves as others usually are. They can live with steady doubt, think “maybe it’s so” and act on that, all the time knowing it’s only “maybe.” Many people find that difficult; they think it means detachment or coldness. It’s not coldness! It’s a much deeper and warmer understanding, and it means you can be digging somewhere where you’re temporarily convinced you’ll find the answer, and somebody comes up and says, “Have you seen what they’re coming up with over there?”, and you look up and say, “Jeez! I’m in the wrong place!” It happens all the time.

Finally, here is my leading quote with a bit more preceding it that I think is of interest:

Omni: One more question from your lectures: you say there that “the next great era of awakening of human intellect may well produce a method of understanding the qualitative content of equations.” What do you mean by that?

Feynman: In that passage I was talking about the Schrödinger equation. Now, you can get from that equation to atoms bonding in molecules, chemical valences — but when you look at the equations, you can see nothing of the wealth of phenomena that the chemists know about; or the idea that quarks are permanently bound so you can’t get a free quark — maybe you can and maybe you can’t but the point is that when you look at the equations that supposedly describe quark behavior, you can’t see why it should be so. Look at the equations for the atomic and molecular force in water, and you can’t see the way water behaves; you can’t see turbulence.

Omni: That leaves the people with questions about turbulence — the meteorologists and oceanographers and geologists and airplane designers — kind of up the creek, doesn’t it?

Feynman: Absolutely. And it might be one of those up-the-creek people who’ll get so frustrated he’ll figure it out, and at that point he’ll be doing physics. With turbulence, it’s not just a case of physical theory being able to handle only simple cases — we can’t do any. We have no good fundamental theory at all.

Omni: Maybe it’s the way the textbooks are written, but few people outside science appear to know just how quickly real, complicated physical problems get out of hand as far as theory is concerned.

Feynman: That’s very bad education. The lesson you learn as you grow older in physics is that what we can do is a very small fraction of what there is. Our theories are really very limited.

Omni: Do physicists vary greatly in their ability to see the qualitative consequences of an equation?

Feynman: Oh, yes — but nobody is very good at it. Dirac said that to understand a physical problem means to be able to see the answer without solving equations. Maybe he exaggerated; maybe solving equations is experience you need to gain understanding — but until you do understand, you’re just solving equations.

Understand, understand, understand … scientists, artists, philosophers. Are we converging or diverging ?

-Julie

http://www.unrealnature.com/

1 Comment

  1. I have seen some digital art that almost fooled me into thinking it was real.

    This is neat stuff. Keep up the good work!

    Comment by ForestWander — February 25, 2009 @ 10:15 am


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