Speeches by James Clear, Wolves Forever (ebook reader online TXT) 📖

that you invent a good guess, calculate the consequences, and discover that every consequence that you calculate agrees with experiment. Your theory is then right?

No, it is simply not proved wrong. Because in the future, there could be a wider range of experiments, you can compute a wider range of consequences. And you may discover, then, that the thing is wrong.

That's why laws like Newton's Laws for the Motion of Planets lasts such a long time. He guessed the law of gravitation, tackling all the kinds of consequences for the solar system and so on, compared them to experiment, and it took several years before the slight error of the motion of Mercury was developed. During all that time, the theory had been failed to be proved wrong and could be taken to be temporarily right.

But it can never be proved right, because tomorrow's experiment may succeed in proving what you thought was right, wrong. So we never are right. We can only be sure we're wrong.

However, it's rather remarkable that we can last so long, I mean to have some idea which will last so long.

Incidentally, some people, one of the ways of stopping the science would be to only do experiments in the region where you know the laws. But the experimenters search most diligently and with the greatest effort in exactly those places where it seems most likely that we can prove their theories wrong. In other words, we're trying to prove ourselves wrong as quickly as possible. Because only in that way do we find workers progress.

For example, today among ordinary low energy phenomena, we don't know where to look for trouble. We think everything's all right. And so there isn't any particular big program looking for trouble in nuclear reactions or in superconductivity.

I must say, I'm concentrating on discovering fundamental laws. There's a whole range of physics, which is interesting and understanding at another level these phenomena like super conductivity in nuclear reactions. But I'm talking about discovering trouble, something wrong with the fundamental law. So nobody knows where to look there, therefore all the experiments today– in this field, of finding out a new law– are in high energy.

I must also point out to you that you cannot prove a vague theory wrong. If the guess that you make is poorly expressed and rather vague, and the method that you used for figuring out the consequences is rather vague, you're not sure, and you just say I think everything is because it's all due to moogles, and moogles do this and that, more or less. So I can sort of explain how this works. Then you say that that theory is good, because it can't be proved wrong.

If the process of computing the consequences is indefinite, then with a little skill, any experimental result can be made to look like an expected consequence. You're probably familiar with that in other fields. For example, a hates his mother. The reason is, of course, because she didn't caress him or love him enough when he was a child.

Actually, if you investigate, you find out that as a matter of fact, she did love him very much. And everything was all right. Well, then, it's because she was overindulgent when he was young.

So by having a vague theory, it's possible to get either result.

Now wait, the cure for this one is the following. It would be possible to say if it were possible to state ahead of time how much love is not enough, and how much love is overindulgent exactly, then there would be a perfectly legitimate theory, against which you could make tests. It is usually said when this is pointed out, how much love and so on, oh, you're dealing with psychological matters, and things can't be defined so precisely. Yes, but then you can't claim to know anything about it.

Now, we have examples, you'll be are horrified to hear, in physics of exactly the same kind. We have these approximate symmetries. It works something like this. You have approximate symmetry, you suppose it's perfect. Calculate the consequences, it's easy if you suppose it's perfect.

You compare with experiment, of course it doesn't agree. The symmetry you're supposed to expect is approximate. So if the agreement is pretty good, you say, nice. If the agreement is very poor, you say, well this particular thing must be especially sensitive to the failure of the symmetry.

Now you laugh, but we have to make progress in that way. In the beginning, when our subject is first new, and these particles are new to us, this jockeying around, this is a feeling way of guessing at the result. And this is the beginning of any science.

And the same thing is true of psychology as it is of the symmetry propositions in physics. So don't laugh too hard, it's necessary in the very beginning to be very careful. It's easy to fall over the deep end by this kind of a vague theory. It's hard to prove it wrong. It takes a certain skill and experience to not walk off the plank on the game.

In this process of guessing, computing consequences, and comparing to experiment, we can get stuck at various stages. For example, we may in the guess stage get stuck. We have no ideas, we can't guess an idea.

Or we may get in the computing stage stuck. For example, Yukawa guessed an idea for the nuclear forces in 1934. Nobody could compute the consequences, because the mathematics was too difficult.

So therefore, they couldn't compare it with experiments successfully. And the theory remained– for a long time, until we discovered all this junk. And this junk was not contemplated by Yukawa, and therefore, it's undoubtedly not as simple, as least, as the way Yukawa did it.

Another place you can get stuck is at the experimental end. For example, the quantum theory of gravitation is going very slowly, if at all, because there's no use. All the experiments that you can do never involve quantum mechanics and gravitation at the same time, because the gravity force is so weak, compared to electrical forces.

Now I want to concentrate from now on– because I'm a theoretical physicist, I'm more delighted with this end of the problem– as to how do you make the guesses. Now it's strictly, as I said before, not of any importance where the guess comes from. It's only important that it should agree with experiment and that it should be as definite as possible.

But you say that is very simple. We've set up a machine, a great computing machine, which has a random wheel in it, that makes a succession of guesses. And each time it guesses a hypothesis about how nature should work, it computes immediately the consequences and makes a comparison to a list of experimental results it has at the other end.

In other words, guessing is a dumb man's job. Actually, it's quite the opposite. And I will try to explain why.

The first problem is how to start. You say, I'll start with all the known principles. But the principles that are all known are inconsistent with each other. So something has to be removed.

So we get a lot of letters from people. We're always getting letters from people who are insisting that we ought to make holes in our guesses. You make a hole to make room for a new guess.

Somebody says, do you know, you people always say space is continuous. But how do you know when you get to a small enough dimension that there really are enough points in between, it isn't just a lot of dots separated by little distances? Or they say, you know, those quantum mechanical amplitudes you just told me about, they're so complicated and absurd. What makes you think those are right? Maybe they aren't right.

I get a lot of letters with such content. But I must say that such remarks are perfectly obvious and are perfectly clear to anybody who's working on this problem. And it doesn't do any good to point this out. The problem is not what might be wrong, but what might be substituted precisely in place of it.

If you say anything precise, for example in the case of a continuous space, suppose the precise proposition is that space really consists of a series of dots only. And the space between them doesn't mean anything. And the dots are in a cubic array. Then we can prove that immediately is wrong, that doesn't work.

You see, the problem is not to change or to say something might be wrong but to replace it by something. And that is not so easy. As soon as any real, definite idea is substituted, it becomes almost immediately apparent that it doesn't work.

Secondly, there's an infinite number of possibilities of these the simple types. It's something like this. You're sitting, working very hard. You work for a long time, trying to open a safe.

And some Joe comes along, who doesn't know anything about what you're doing or anything, except that you're trying to open a safe. He says, you know, why don't you try the combination 10-20-30? Because you're busy, you're trying a lot of things.

Maybe you already tried 10-20-30. Maybe you know that the middle number is already 32 and not 20. Maybe you know that as a matter of fact this is a five digit combination.

So these letters don't do any good. And so please don't send me any letters, trying to tell me how the thing is going to work. I read them to make sure that I haven't already thought of that. But it takes too long to answer them, because they're usually in the class try 10-20-30.

And as usual, nature's imagination far surpasses our own. As we've seen from the other theories, they are really quite subtle and deep. And to get such a subtle and deep guess is not so easy. One must be really clever to guess. And it's not possible to do it blindly, by machine.

So I wanted to discuss the art of guessing nature's laws. It's an art. How is it done?

One way, you might think, well, look at history. How did the other guys do it? So we look at history.

Let's first start out with Newton. He has in a situation where he had incomplete knowledge. And he was able to get the laws, by putting together ideas, which all were relatively close to experiment. There wasn't a great distance between the observations on the test. That's the first, but now it doesn't work so good.

Now the next guy who did something– well, another man who did something great was Maxwell, who obtained the laws of electricity and magnetism. But what he did was this. He put together all the laws of electricity, due to Faraday and other people who came before him. And he looked at them, and he realized that they were mutually inconsistent. They were mathematically inconsistent.

In order to straighten it out, he had to add one term to an equation. By the way, he did this by inventing a model for himself of idle wheels and gears and so on in space. And then he found that what the new law was.

And nobody paid much attention, because they didn't believe in the idle wheels. We don't believe in the idle wheels today. But the equations that he obtained were correct.

So the logic may be wrong, but the answer is all right. In the case of relativity, the discovery of relativity was completely different. There was an accumulation of paradoxes. The known laws gave inconsistent results. And it was a new kind of thinking, a thinking in terms of discussing the possible symmetries of laws.

And it was especially difficult, because it was the first time realized how long something like Newton's laws could be right and still, ultimately, be wrong. And second, that ordinary ideas of time and space that seems so instinctive could