"I've just discovered that there's new data: 7 percent . . ."
"
Which way?
"
"I'm trying to find out. I'll call you back."
I was so excited that I couldn't think. It's like when you're rushing for an airplane, and you don't know whether you're late or not, and you just
can't make it, when somebody says, "It's daylight saving time!" Yes, but which way? You can't think in the excitement.
So Christy went into one room, and I went into another room, each of us to be quiet, so we could think it through:
This moves
this
way, and that
moves
that
way--it wasn't very difficult, really; it's just exciting.
Christy came out, and I came out, and we both agreed: It's 2 percent, which is well within experimental error. After all, if they just changed the
constant by 7 percent, the 2 percent could have been an error. I called my sister back: "Two percent." The theory was right.
(Actually, it was wrong: it was off, really, by 1 percent, for a reason we hadn't appreciated, which was only understood later by Nicola Cabibbo.
So that 2 percent was not all experimental.)
Murray Gell-Mann compared and combined our ideas and wrote a paper on the theory. The theory was rather neat; it was relatively simple, and
it fit a lot of stuff. But as I told you, there was an awful lot of chaotic data. And in some cases, we even went so far as to
state that the experiments
were in error.
A good example of this was an experiment by Valentine Telegdi, in which he measured the number of electrons that go out in each direction
when a neutron disintegrates. Our theory had predicted that the number should be the same in all directions, whereas Telegdi found that 11 percent
more came out in one direction than the others. Telegdi was an excellent experimenter, and very careful. And once, when he was giving a talk
somewhere, he referred to our theory and said, "The trouble with theorists is, they never pay attention to the experiments!"
Telegdi also sent us a letter, which wasn't exactly scathing, but nevertheless showed he was convinced that our theory was wrong. At the end he
wrote, "The F-C (Feynman-- Gell-Mann) theory of beta decay is no F-C."
Murray says, "What should we do about this? You know, Telegdi's pretty good."
I say, "We just wait."
Two days later there's another letter from Telegdi. He's a complete convert. He found out from our theory that he had
disregarded the possibility
that the proton recoiling from the neutron is not the same in all directions. He had assumed it was the same. By putting in corrections that our theory
predicted instead of the ones
he
had been using, the results straightened out and were in complete agreement.
I knew that Telegdi was excellent, and it would be hard to go upstream against him. But I was convinced by that time that something must be
wrong with his experiment, and that
he
would find it--he's much better at finding it than we would he. That's why I said we shouldn't try to figure it
out but just wait.
I went to Professor Bacher and told him about our success, and he said, "Yes, you come out and say that the neutron-proton coupling is V instead
of T. Everybody used to think it was T. Where is the fundamental experiment that says it's T? Why don't you look at the early experiments and find
out what was wrong with them?"
I went out and found the original article on the experiment that said the
neutron-proton coupling is T, and I was
shocked
by something. I
remembered reading that article once before (back in the days when I read every article in the
Physical Review
--it was small enough). And I
remembered
, when I saw this article again, looking at that curve and thinking, "That doesn't prove
anything!
"
You see, it depended on one or two points at the very edge of the range of the data, and there's a principle that a point on the edge of the range of
the data--the last point-- isn't
very good, because if it was, they'd have another point further along. And I had realized that the whole idea that
neutron-proton coupling is T was based on the last point, which wasn't very good, and therefore it's not proved. I remember
noticing
that!
And when I became interested in beta decay, directly, I read all these reports by the "beta-decay experts," which said it's T. I never looked at the
original data; I only read those reports, like a dope. Had I been a
good
physicist, when I thought of the original idea back at the Rochester Conference
I would have immediately looked up "how strong do we know it's T?"--that would have been the sensible thing to do. I would have recognized right
away that I had already
noticed
it wasn't satisfactorily proved.
Since then I never pay any attention to anything by "experts." I calculate everything myself. When people said the quark theory was pretty good,
I got two Ph. D.s, Finn Ravndal and Mark Kislinger, to go through the
whole works
with me, just so I could check that
the thing was really giving
results that fit fairly well, and that it was a significantly good theory. I'll never make that mistake again, reading the experts' opinions. Of course, you
only live one life, and you make all your mistakes, and learn what not to do, and that's the end of you.