This book provides the reader with a detailed and captivating account of the story where, for the first time, physicists ventured into proposing a new force of nature beyond the four known ones - the electromagnetic, weak and strong forces, and gravitation - based entirely on the reanalysis of existing experimental data. Back in 1986, Ephraim Fischbach, Sam Aronson, Carrick Talmadge and their collaborators proposed a modification of Newton’s Law of universal gravitation. Underlying this proposal were three tantalizing pieces of evidence: 1) an energy dependence of the CP (particle-antiparticle and reflection symmetry) parameters, 2) differences between the measurements of G, the universal gravitational constant, in laboratories and in mineshafts, and 3) a reanalysis of the Eötvos experiment, which had previously been used to show that the gravitational mass of an object and its inertia mass were equal to approximately one part in a billion. The reanalysis revealed that, contrary to Galileo’s position, the force of gravity was in fact very slightly different for different substances. The resulting Fifth Force hypothesis included this composition dependence and also added a small distance dependence to the inverse-square gravitational force. Over the next four years numerous experiments were performed to test the hypothesis. By 1990 there was overwhelming evidence that the Fifth Force, as initially proposed, did not exist. This book discusses how the Fifth Force hypothesis came to be proposed and how it went on to become a showcase of discovery, pursuit and justification in modern physics, prior to its demise. In this new and significantly expanded edition, the material from the first edition is complemented by two essays, one containing Fischbach’s personal reminiscences of the proposal, and a second on the ongoing history and impact of the Fifth Force hypothesis from 1990 to the present.

In No Easy Answers, Allan Franklin offers an accurate picture of science to both a general reader and to scholars in the humanities and social sciences who may not have any background in physics. Through the examination of nontechnical case studies, he illustrates the various roles that experiment plays in science. He uses examples of unquestioned success, such as the discoveries of the electron and of three types of neutrino, as well as studies that were dead ends, wrong turns, or just plain mistakes, such as the "fifth force," a proposed modification of Newton's law of gravity. Franklin argues that science is a reasonable enterprise that provides us with knowledge of the natural world based on valid experimental evidence and reasoned and critical discussion, and he makes clear that it behooves all of us to understand how it works.

Beyond Einstein: Perspectives on Geometry, Gravitation, and Cosmology explores the rich interplay between mathematical and physical ideas by studying the interactions of major actors and the roles of important research communities over the course of the last century.

This book addresses the pursuit and further investigation of experimental results by analyzing classic examples from physics. The authors concentrate on the investigation of experimental results by examining case studies from the history of 20th and 21st century physics. Discussions on the discovery of parity nonconservation, the rise and fall of the Fifth Force, the search for neutrinoless double β decay, supersymmetry and the expansion of the Standard Model, and measurements of the anomalous magnetic moment of the muons are provided. Experimental results may achieve acceptance to the point that even well known principles, such as conservation of energy and quantization, lose their status as accepted. Such principles and their options are treated on an equal footing as being pursuit worthy even though there is no plausible explanation as to why and how they might have failed.

This is a revised edition of a classic and highly regarded book, first published in 1981, describing the status of theory and experiment in general relativity. The book provides all the necessary theoretical background, and covers all the important experimental tests. A new chapter has been added to cover recent important experimental tests, and the bibliography has been brought right up to date. Reviews of the previous edition: ' ... consolidates much of the literature on experimental gravity and should be invaluable to researchers in gravitation ...' Science ' ... a concise and meaty book ... and a most useful reference work ... researchers and serious students of gravitation should be pleased with it ...' Nature

There have been many recent discussions of the 'replication crisis' in psychology and other social sciences. This has been attributed, in part, to the fact that researchers hesitate to submit null results and journals fail to publish such results. In this book Allan Franklin and Ronald Laymon analyze what constitutes a null result and present evidence, covering a 400-year history, that null results play significant roles in physics.

A Mind Over Matter is a biography of the Nobel-prize winner Philip W. Anderson, a person widely regarded as one of the most accomplished and influential physicists of the second half of the twentieth century. Anderson (1923-2020) was a theoretician who specialized in the physics of matter, including window glass and metals, magnets and semiconductors, liquid crystals and superconductors. More than any other single person, Anderson transformed the patchwork subject of solid-state physics into the deep, subtle, and coherent discipline known today as condensed matter physics. Among his many world-class research achievements, Anderson discovered an aspect of wave physics that had been missed by all previous scientists going back to Isaac Newton. He became a public figure when he testified before Congress to oppose its funding of an expensive project intended exclusively for particle physics research. Over the years, he published many articles designed to influence a broad audience about issues where science impacted public policy and culture. Anderson grew up in the American mid-west, was educated at Harvard, and rose to the pinnacle of his profession during the first decade of his thirty-five career as a theoretical physicist at Bell Telephone Laboratories. Almost uniquely, he spent many years working half-time as a professor at the University of Cambridge and at Princeton University. The outspoken Anderson enjoyed broad influence outside of physics when he helped develop and champion the concepts of emergence and complexity as organizing principles to help attack very difficult problems in technically challenging disciplines.