His Nobel Prive was for the weak interaction, but he shared it with two others who came up with the same equations at the same time. His paper had essentially no citations, until others developed gauge theory more fully. So while the theory is important to the standard model, I am not so sure his 1967 paper was important.
Weinberg wrote this in the preface to his 1972 general relavity book:
There was another, more personal reason for my writing this book. In learning general relativity, and then in teaching it to classes at Berkeley and MIT, I became dissatisfied with what seemed to be the usual approach to the subject. I found that in most textbooks geometric ideas were given a starring role, so that a student who asked why the gravitational field is represented by a metric tensor, or why freely falling particles move on geodesics, or why the field equations are generally covariant would come away with an impression that this had something to do with the fact that spacetime is a Riemannian manifold.This opinion is so bizarre that it is hard to believe it came from such a smart man.
Of course, this was Einstein's point of view, and his preeminent genius necessarily shapes our understanding of the theory he created. However, I believe that the geometrical approach has driven a wedge between general relativity and the theory of elementary particles. As long as it could be hoped, as Einstein did hope, that matter would eventually be understood in geometrical terms, it made sense to give Riemannian geometry a primary role in describing the theory of gravitation. But now the passage of time has taught us not to expect that the strong, weak, and electromagnetic interactions can be understood in geometrical terms, and that too great an emphasis on geometry can only obscure the deep connections between gravitation and the rest of physics.
All general relativity scholars give geometric ideas a starring role. But that was not Einstein's view. Einstein explicitly rejected the geometry.
This rejection was puzzling for both Einstein and Weinberg, as parts of general relativity have only geometric explanations, and their books do give those explanations. They did not succeed in purging the geometry.
It was also bizarre for his to deny that geometry was important for the other forces. This was five years after his Nobel prizewinning paper, and the work was credited with giving a geometrical unification of electromagnetism and weak forces. If he did not do that, what did he do? Was he repudiating his work? Did he not understand that gauge theories were geometric?
I am not trying to criticize him here. I am just pointing out some puzzling aspects of his beliefs.
He was also a hardcore atheist and scientific reductionist. He opposed religion, and considered Islam much worse that Christianity. He opposed paradigm shifters and other modern philosophy. He was a typical academic leftist, but had not bought into the current racial wokeness fanaticism.
Okay, that's all fine with me, but he also rejected positivism, and in his later years, endorsed many-worlds quantum theory. Again, these opinions are bizarre, coming from him. Lubos Motl also found them strange:
Years ago, I was only gradually noticing weird comments about quantum mechanics that Weinberg sometimes made.... At any rate, I consider Weinberg to be a 100% anti-quantum zealot ... It's sad.He was of Jewish descent, but against Judaism the religion. He was extremely pro-Israel, and an extreme idolizer of Einstein. He studies the history of science enough to know what Einstein did and did not do, but excessively praised him anyway.
And Einstein had a good point when he said the so-called geometrization of GR was as trivial as that in electromagnetism. It was! The hole experiment showed that a dynamical view makes a lot more sense with less extraneous metaphysics. In fact, the geometrical view has problems, considering Jacobson-Mattingly and biometric theories. Manifold substantivalism is dismissed with "flat-space" gauge theories (for instance, see Lasenby, Doran & Gull) that leave everything relational. The issue of minimal coupling isn't really a problem. Your definition of geometrical is so broad as to be meaningless. The "geometrical" view is a special case of the field approach.ReplyDelete