Fundamental Constants

The book is devoted to one of the important areas of theoretical and experimental physics—the calculation of the accuracy of measurements of fundamental physical constants. To achieve this goal, numerous methods and criteria have been proposed. However, all of them are focused on identifying a posteriori uncertainty caused by the idealization of the model and its subsequent computerization in comparison with the physical system. This book focuses on formulating an a priori interaction between the level of a detailed description of a material object (the number of registered quantities) and the lowest uncertainty in measuring a physical constant. It contains the materials necessary for the optimal design of models describing a physical phenomenon. It will appeal to scientists and engineers, as well as university students.

The question of a possible temporal variation of the fundamental constants was raised by Paul Dirac in his "large number hypothesis" in 1937. Today it appears in the context of the search for a unified theory of the fundamental interactions. It touches both fundamental and applied physics, as the postulate of the unalterability of the constants is the foundation for modern metrology. The book presents reviews written by leading experts in the field. Focussing on the question of variations of the fundamental "constants" in time or space, the chapters cover the theoretical framework in which variations are expected and the search for variations of quantities like the fine-structure constant, the electron/proton mass ratio, g-factors of proton and neutron etc. in astrophysical and geophysical observations and in precision experiments with atomic clocks and frequency standards.

Over the last decade of the 20th century, many improvements took place in the field of metrology and fundamental constants. These developments and improvements are discussed in this book. The old caesium SI second definition has found a new realization with the fountain approach, replacing the classical thermal atomic beam. The use of cold atom techniques, slowed down and cooled, has opened a number of unexpected avenues for metrology and fundamental constants, one of these possibilities being the atom interferometry. Another development was the demonstration of the possiblility of performing a direct frequency division in the visible, using short femtosecond pulses. Many other developments are also discussed.

The constants of nature are the numbers that define the essence of the Universe. They tell us how strong its forces are, and what its fundamental laws can do: the strength of gravity, of magnetism, the speed of light, and the masses of the smallest particles of matter. They encode the deepest secrets of the Universe and express at once our greatest knowledge and our greatest ignorance about the cosmos. Their existence has taught us the profound truth that Nature abounds with unseen regularities. Yet, while we have become skilled at measuring the values of these constants, our frustrating inability to explain or predict their values shows how much we still have to learn about the inner workings of the Universe. What is the ultimate status of these constants of Nature? Are they truly constant? Could life have evolved and persisted if they were even slightly different? And are there other Universes where they are different? These are some of the issues that this book grapples with. It looks back to the discoveries of the first constants of Nature and the impact they had on scientists like Einstein. This book also tells the story of a tantalising new development in astronomy. For the first time astronomical observations are suggesting that some of the constants of Nature were different when the Universe was younger. So are our laws of Nature slowly changing? Is anything about our Universe immune from the ravages of time? Are there any constants of Nature at all?

One of the exciting characteristics of metrology is its intimate relationship between fundamental physics and the leading edge of technology which is needed to perform advanced and challenging experiments and measurements. This title includes a set of lectures which present the relevant progress in Metrology.

A new theoretical framework is presented to explain the evolution of the universe based on the time-varying properties of the fundamental constants. A static universe with time-varying constants can explain the origin of the cosmic microwave background radiation, CMB anisotropies, the CMB cold spot, the observed redshift-distance modulus data, the origin and composition of dark matter in the universe, galaxy cluster mass estimates, Milky Way galaxy luminosity estimates, population II stellar properties, vacuum-photon interactions, energy cycling between matter, radiation and vacuum field components, time-varying Higgs mechanism and particle mass, and the observed matter-antimatter dichotomy. This is a complete theoretical framework that explains the observable universe and resolves many of the issues with modern-day cosmology.