Physical reality beyond the Standard Models: revolution in fundamental physics?

The quest for scientific truth is the lofty goal of science. Physics aims at understanding the fundamental questions in nature, therefore, it would seem that physical reality is the nearest expression of the scientific truth. What is physical reality? We may wonder if nature prevents us from knowing the true nature of the things and we could only build the models – howsoever perfect but never identical with the reality. Does the Standard Model of particle physics represent this reality? In Newton’s experimental natural philosophy the first rule of Reasoning reads: We are to admit no more causes of natural things than such as are both true and sufficient to explain their appearances. Thus, rather than the things in themselves, Newton is concerned with appearances or the things as presented to our intelligence. At the beginning of the twentieth century, the twin revolutions of quantum mechanics and relativity heralded a new era: pure thought is capable of comprehending the abstract physical reality. What is the role of experiments in this endeavour? Why should a creation of human mind manifest in the external world? An important issue also comes to the fore: the mind is free to speculate or there is some underlying principle to invent new ideas. Historically this issue had been intensely debated in connection with the mathematical truth. Ancient Greek philosopher Plato perceived three essences of divine origin: the Good, the Beautiful, and the Just. Do these essences guide the speculative mind in a subtle manner? Mathematicians differ on it; however, in the modern age dominated by advanced technology, Platonic reality and the idea of beauty have faded away from the mainstream. In spite of this I would prefer to put this book authored by Langacker, which deals with fundamental physics, in this philosophical perspective. The Standard Model is a great intellectual milestone in the path towards unification of fundamental forces of nature, however, it is not the last post in this pursuit – a vast arena beyond it remains as yet unknown. Paul Langacker is a pioneer in the field of high-precision tests of the Standard Model. Thoroughness of his approach was quite evident to me reading the review published by him nearly two decades ago, with M. Luo and A.K. Mann [Rev. Mod. Phys. 64 (1992), p. 87] while writing a monograph on the electron. First reading of the beginning chapters of the book under review, however, disappointed me. I was put off by the style of presentation that lacked aesthetics resembling more of a tool-kit for the ‘complicated technology’, a phrase used in the preface of the book itself. The question came to my mind: is advanced technology of the mega projects influencing the scientific discourse? That technology is a product of the human mind would not surprise us, however, R.L. Gregory argues that technology in general precedes scientific theory and asserts that the development of the human mind is shaped by progress in technology (Mind in Science, Weidenfeld and Nicholson, London, 1981). Is he right? After deep reflections spanning several days it dawned on me that Langacker’s book is likely to play a pivotal role at this juncture when the plethora of ‘new physics’ and alternative models have emerged while experimental data has become too intricate to be comprehensible even to the experts. There is no visible crisis in high energy physics (HEP), however, theorists need to be equipped with the techniques that enable them to make sense, independently, of the enormous empirical data churned out from the big collaborations and also expected from the Large Hadron Collider (LHC) so that the spirit of scientific scepticism is sustained. The utility of the book is emphasised primarily in this context. Let me first recall illuminating thoughts of two experimental physicists. Particle physicist V.L. Telegdi in an essay ‘Mind Over Matter’ (CERN Yellow Preprint, 1990) raised an important question: though physics is a natural science the intellectual insights and technical ingenuity of the experimentalists are not sufficiently appreciated amongst the physics community, in fact, many theorists are ignorant of the finer points of the actual Contemporary Physics Vol. 52, No. 3, May–June 2011, 243–248