Letter from the Editor
Physics is arguably the oldest of scientific disciplines; in many respects it is the broadest and most far-reaching in both scope and ambition. It has its origins in the human fascination with the patterns that can be observed in natural phenomena: the points of light in the night sky, traversed by the moon; the colors of the rainbow; the weather. Early thinkers ascribed natural phenomena to divine intervention, to be propitiated rather than studied, but slowly there arose a realization that some were amenable to human analysis and understanding. The astronomical observations of the Chaldeans and the Egyptians, and the attempts of Greek philosophers to understand the diversity of natural phenomena in terms of a small number of basic “elements,” pushed forward the growing body of knowledge and speculation known for many centuries as “Natural Philosophy.” Although the fall of Rome and the subsequent Dark Ages temporarily slowed progress, the Arab world maintained and advanced the study of physics and its language, mathematics. In Europe, great medieval thinkers gradually rediscovered the works of the classical authors who had speculated on the causes of things and began to build on these foundations. The medieval search for the Philosopher’s Stone was driven both by cupidity and curiosity; whereas no precious metals were produced, the result was a growth in knowledge and the beginnings of the experimental method.
The turmoil of the Renaissance and Reformation in Europe, with the concomitant loosening of the stranglehold of the Roman Catholic Church on new ideas, fertilized the ground from which the astronomers Brahe, Copernicus, and Galileo sprang. The Copernican model of a heliocentric solar system spawned a universal theory of gravity constructed by the genius of Newton in terms of an absolute time and space. For more than 200 years, Newton’s concepts, as embodied in his Principles of Natural Philosophy, reigned supreme. More and more physicists, as they had by then become, saw their job as employing Newtonian mechanics to explain a broad range of phenomena, from the thermodynamics of gases to electromagnetic radiation. Despite strenuous opposition, this period also saw the triumph of the atomistic ideas first postulated by Democritus in Ancient Greece. The redundancy of the luminiferous aether, established by the genius of Albert Einstein in the early 20th century, rang the death-knell of this “mechanical” program and laid the foundations for our modern view of the universe. In this view, the so-called “Standard Model” comprises a small number of “fundamental” forces acting on a small number of “fundamental” particles inside the framework of relativistic quantum mechanics; “bolted on” is the entire framework of Einsteinian General Relativity. Although incompatible in its basic theoretical principles with the Standard Model, it is triumphant in its phenomenological power, exemplified by the recent experimental confirmation of the existence of gravitational waves. The power of this ad hoc framework to explain the universe around us is astonishing; its unsatisfactory theoretical basis, implying the necessity for future revolutionary developments, is apparent.
The power of physics lies not only in its ability to explain phenomena in terms of simple basic principles, but also in its capacity to apply these principles across the enormous breadth of modern science. Although exact solutions are in general not possible for the many degrees of freedom usually encountered in applications, such problems can be approached by approximate methods based on physical principles, which makes physics an enabling discipline that interfaces strongly with chemistry, biology, medicine and many other fields. In addition to this breadth and inherent multidisciplinarity, the depth, beauty, and intellectual coherence of individual subdisciplines in physics and the connections between them are striking. For example, the physics underlying the varied phenomena of superconductivity reaches across to the Standard Model; calculations in atomic physics find application in physical chemistry; the laser, the famous “solution searching for a problem,” is almost ubiquitous, linking particle acceleration, plasma physics, quantum information, and optics; mathematical physics underpins all.
It is the bewildering richness and diversity of physics that makes producing the Oxford Research Encyclopedia of Physics such a daunting task. Our approach is to engage international experts of the highest distinction at all levels in the enterprise, and to use the latest online technology and design to facilitate ease of use. By these mechanisms, we aim to ensure that the ORE of Physics is the first point of call for those who wish to refresh their expertise in a particular topic, learn about it for the first time, or investigate the linkages with other cognate disciplines. Readers can be secure in the knowledge that the contents of the ORE of Physics have been authored and reviewed by world-leading authorities. Written by physicists for physicists, it should also be useful for other scientists, scholars and students in adjacent disciplines, and any reader for whom the big questions that physics attempts to answer and the stunning applications of basic physics techniques are demonstrably a source of endless fascination.
Editor in Chief