Monday, August 22, 2016

Weinberg's Final Theory

In the June 10, 2010 edition of the NYROB is a review of Lake Views: This World and the Universe by Steven Weinberg.  The reviewer is Freeman Dyson.  After reviewing the subject book, Dyson writes,

"I find it ironic that Weinberg, after declaring so vehemently his hostility to religious beliefs, emerges in his writing about science as a man of faith.  He believes passionately in the possibility of a Final Theory.  He wrote a book with the title Dreams of a Final Theory, and the notion of a Final Theory permeates his thinking in this book too.  A Final Theory means a set of mathematical rules that describe with complete generality and complete precision the way the physical universe behaves.  Complete generality means that the rules are obeyed everywhere and at all times.  Complete precision means that any discrepancies between the rules and the results of experimental measurements will be due to the limited accuracy of the measurements.

"For Weinberg, the Final Theory is not merely a dream to inspire his brilliant work as a mathematical physicist exploring the universe.  For him it is an already existing reality that we humans will soon discover.  It is a real presence hidden in the motions of atoms and galaxies, waiting for us to find it.  The faith that a Final Theory exists, ruling over the operations of nature, strongly influences his thinking about history and ethics as well as his thinking about science.

"I have profound respect for Steven Weinberg as a scientist.  I also have profound respect for his faith, although I do not share it.  I accept the possibility that he may be right and I may be wrong.  I do not forget the disagreement we had forty-four years about about a hypothetical partial called the W.  The letter W does not stand for Weinberg, but it was Weinberg who imagined it before it was discovered.  Weinberg believed that the W must exist, because he needed it as an essential component of the theory with which he triumphantly unified the weak forces in nature.  I believed that the Would not exist because its existence would contradict a mathematical argument that I held dear.  His belief was based on physical intuition.  Mine on mathematical calculation.

"It soon turned out that he was right and I was wrong.  First, his theory of unification was confirmed by a number of experiments, and a few years later the W particle was directly observed.  My mathematical argument turned out to be irrelevant and misleading.  I was happy to celebrate Weinberg's triumph, and consoled myself with a quotation from my favorite poet, William Blake: 'To be in Error and to be Cast Out is Part of God's design.'  Black had an other piece of wisdom, 'Opposition is true Friendship,' which made it easy for us to remain friends  As members of the scientific community, we can disagree passionately about the facts and theories and still be friends.

"Since Weinberg was right about the W particle, why do I not believe that he is right about the Final Theory?  I distrust his judgment about philosophical questions because I think he over-rates the capacity of the human mind to comprehend the totality of nature.  He has spent his professional life within the discipline of mathematical physics, a narrow area of science that has been uniquely successful.  In this narrow area, our theories describe a small part of nature with astonishing clarity.  Our ape-brains and tool-making hands were marvelously effective for solving a limited class of puzzles.  Weinberg expects the same brains and hands to illuminate far broad areas of nature with the same clarity.  I would be disappointed if nature could be so easily tamed.  I find the idea of a Final Theory repugnant because it diminishes both the richness of nature and the richness of human destiny.  I prefer to live in a universe full of inexhaustible mysteries, and to belong to a species destined for inexhaustible intellectual growth."

On the Other Hand:  Another theory that is not accepted (as Dyson does not accept Weinberg's), is that the human brain is no longer an "ape-brain."  Human evolution has not stopped, and while there is no physical evidence to show the difference between earlier versions of the human brain, there is objective evidence (if one is willing to accept it) that the modern brain (in some of us) has been responsible for achievements far beyond the capability of the ape-brain.  And if Dyson's main argument is that we have the same brain as the ape and the modern evolutionary studies (eventually) prove him to be wrong, then perhaps he is also wrong about the Final Theory as well.

May 2015:  Steven Weinberg "still dreams of a Final Theory" . . . but probably not in this century.

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