Saturday, December 29, 2012

Feynman wasn't joking

Angular correlation data at three energy ranges in Rustad-Ruby experiment. Feynman questions the validity of the curve-fitting to the predicted tensor (T) values.
I managed to get seriously ill two weeks ago and had to set aside the blogging project right at the crucial moment of my discovery of Allan Franklin's writings on the Rustad-Ruby experiment. Now I can pick up the story again, but without any pretense of it unfolding in real time. The following will be my best attempt at reconstructing the revelation of information about this incident beginning the morning following my return home by Amtrak from a visit to Twyla in Los Angeles. 

For starters, I have my own bookshelves, including a generous selection of my father's science library. Some is in his specialized field of physics and I select titles by Hans Frauenfelder and Harry J. Lipkin. Also, The Story of Spin by Sin-Itiro Tomonaga, which Joanne reminded me that Stan was reading in the last week of his life.

Tomonaga was among a number of physicists who were involved in one way or another in the history of weak force unification, and which might be relevant to the Rustad-Ruby matter. Here we have Leon Lederman's The God Particle, Freeman Dyson's From Eros to Gaia, The First Three Minutes by Steven Weinberg, and What Is the World Made Of? by Gerald Feinberg.

Some of these are more popular treatments for general audiences, none more so than Richard Feynman's classic memoir Surely You're Joking, Mr. Feynman! This volume gives an immediate playback in a full chapter, "The 7 Percent Solution," covering Feynman's involvement in events following the discovery of parity non-conservation. Here, he references the Rustad-Ruby He-6 recoil experiment and reflects on the possibility of scientific errors.
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 neutron-proton coupling is T, and I was shocked by someting. 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 the 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 preetty good, I go 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. 

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