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. <. (shrink)

What makes a good experiment? Although experimental evidence plays an essential role in science, as Franklin argues, there is no algorithm or simple set of criteria for ranking or evaluating good experiments, and therefore no definitive answer to the question. Experiments can, in fact, be good in any number of ways: conceptually good, methodologically good, technically good, and pedagogically important. And perfection is not a requirement: even experiments with incorrect results can be good, though they must, he argues, be (...) methodologically good, providing good reasons for belief in their results. Franklin revisits the same important question he posed in his 1981 article in the British Journal for the Philosophy of Science, when it was generally believed that the only significant role of experiment in science was to test theories. But experiments can actually play a lot of different roles in science--they can, for example, investigate a subject for which a theory does not exist, help to articulate an existing theory, call for a new theory, or correct incorrect or misinterpreted results. This book provides details of good experiments, with examples from physics and biology, illustrating the various ways they can be good and the different roles they can play. (shrink)

Maher (1988, 1990) has recently argued that the way a hypothesis is generated can affect its confirmation by the available evidence, and that Bayesian confirmation theory can explain this. In particular, he argues that evidence known at the time a theory was proposed does not confirm the theory as much as it would had that evidence been discovered after the theory was proposed. We examine Maher's arguments for this "predictivist" position and conclude that they do not, in fact, support his (...) view. We also cast doubt on the assumptions of Maher's alleged Bayesian proofs. (shrink)

What role have experiments played, and should they play, in physics? How does one come to believe rationally in experimental results? The Neglect of Experiment attempts to provide answers to both of these questions. Professor Franklin's approach combines the detailed study of four episodes in the history of twentieth century physics with an examination of some of the philosophical issues involved. The episodes are the discovery of parity nonconservation in the 1950s; the nondiscovery of parity nonconservation in the 1930s, (...) when the results of experiments indicated, at least in retrospect, the symmetry violation, but the significance of those results was not realized; the discovery and acceptance of CP symmetry; and Millikan's oil-drop experiment. Franklin examines the various roles that experiment plays, including its role in deciding between competing theories, confirming theories, and calling fo new theories. The author argues that one can provide a philosophical justification for these roles. He contends that if experiment plays such important roles, then one must have good reason to believe in experimental results. He then deals with deveral problems concerning such reslults, including the epistemology of experiment, how one comes to believe rationally in experimental results, the question of the influence of theoretical presuppositions on results, and the problem of scientific fruad. This original and important contribution to the study of the philosophy of experimental science is an outgrowth of many years of research. Franklin brings to this work more than a decade of experience as an experimental high-energy physicist, along with his significant contributions to the history and philosophy of science. (shrink)

In Experiment, Right or Wrong, Allan Franklin continues his investigation of the history and philosophy of experiment presented in his previous book, The Neglect of Experiment. Using a combination of case studies and philosophical readings of those studies, Franklin again addresses two important questions: What role does and should experiment play in the choice between competing theories and in the confirmation or refutation of theories and hypotheses? How do we come to believe reasonably in experimental results? Experiment, (...) Right or Wrong makes a significant contribution to an important area in contemporary history and philosophy of science. Philosophers and historians of science, physicists, and advanced students in these areas will find much of interest in this engaging study. (shrink)

Specifically, Allan Franklin is concerned with two problems in the use of experimental results in science: selectivity of data or analysis procedures and the resolution of discordant results.

Theory-ladenness is the view that observation cannot function in an unbiased way in the testing of theories because observational judgments are affected by the theoretical beliefs of the observer. Its more radical cousin, incommensurability, argues that because there is no theory-neutral language, paradigms, or worldviews, cannot be compared because in different paradigms the meaning of observational terms is different, even when the word used is the same. There are both philosophical and practical components to these problems. I argue, using a (...) procedurally-defined, theory-neutral experiment that paradigms are indeed commensurable. The practical problems of theory ladenness include experimental design, failure to interpret observations correctly, possible experimenter bias, and difficulties in data acquisition. I suggest that there are methods to deal with these problems, although sometimes they cannot be dealt with completely. I believe that the philosophical problems of theory-ladenness have been solved, although the practical problems remain. (shrink)

Calibration, the use of a surrogate signal to standardize an instrument, is an important strategy for the establishment of the validity of an experimental result. In this paper, I present several examples, typical of physics experiments, that illustrate the adequacy of the surrogate. In addition, I discuss several episodes in which the question of calibration is both difficult to answer and of paramount importance. These episodes include early attempts to detect gravity waves, the question of the existence of a 17–keV (...) neutrino, and the question of the existence of a Fifth Force in gravity. I argue that in these more complex cases, the adequacy of calibration, in an extended sense, was both considered and established. (shrink)

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. (shrink)

The missing piece of the puzzle: the discovery of the Higgs boson On July 4, 2012 the CMS and ATLAS collaborations at the large hadron collider jointly announced the discovery of a new elementary particle, which resembled the Higgs boson, the last remaining undiscovered piece of the standard model of elementary particles. Both groups claimed to have observed a five-standard-deviation effect above background, the gold standard for discovery in high-energy physics. In this essay I will briefly discuss the how the (...) CMS collaboration performed the experiment and analyzed the data. I will also show the experimental results. (shrink)

In this article I suggest a tripartite classification of scientific activity; discovery, pursuit, and justification. I believe that such a classification can give us a more adequate description of scientific practice, help illuminate the various roles that evidence plays in science, and may also help to partially resolve differences between “constructivist” and “epistemologist” views of science. I argue that although factors suggested by the constructivists such as career goals, professional interests, utility for future practice, and agreement with existing commitments do (...) enter into pursuit, it is experimental evidence that is decisive in justification. I illustrate this with two case studies from the history of contemporary science, experiments on atomic parity violation and their relation to the Weinberg-Salam unified theory of electroweak interactions and the fifth force in gravity. I also answer some of the criticisms offered of my earlier account of the episode of atomic parity violation. (shrink)

On the basis of an analysis of a single paper on plate tectonics, a paper whose actual content is nowhere in evidence, Frederick Suppe concludes that no standard model of confirmation—hypothetico-deductive, Bayesian-inductive, or inference to the best explanation—can account for the structure of a scientific paper that reports an experimental result. He further argues on the basis of a survey of scientific papers, a survey whose data and results are also absent, that papers which have a rather stringent length limit, (...) such as the one on plate tectonics, are typical of science. Thus, he concludes that no standard confirmation scheme is capable of dealing with scientific practice. Suppe also requires that an adequate model of philosophical testing should be able to account for everything in such scientific papers, in which space is at a premium. (shrink)

Experiments often disagree. How then can scientific knowledge be based on experimental evidence? In this paper I will examine four episodes from the history of recent physics: the suggestion of a Fifth Force, a modification of Newton’s law of gravitation; early attempts to detect gravitational radiation ; the claim that a 17-keV neutrino exists; and experiments on atomic-parity violation and on the scattering of polarized electrons and their relation to the Weinberg-Salam unified theory of electroweak interactions. In each of these (...) episodes discordant results were reported, and a consensus was later reached that one result—or set of results—was incorrect. I will examine the process of reaching that consensus. I will show that the decision was reached by reasoned discussion based on epistemological and methodological criteria. It then follows that we may use experimental evidence as the basis of scientific knowledge. (shrink)

In this paper I argue, using two case studies of episodes from recent physics against the contingency view advocated by social constructionists. In this view, physics, or science in general, is, in Ian Hacking’s words, not determined by anything. Much of the previous discussion has centered on examples of scientific success. In this paper I argue that experimental evidence and reasoned and critical discussion played the crucial role in the refutation of a previously strongly believed hypothesis, and in the decision (...) that a proposed new elementary particle did not exist, leaving no reasonable doubt. I suggest that the argument against contingency does not require the absence of all possible doubt, but rather the absence of reasonable doubt.Keywords: Contingency; Refutation; 17-keV neutrino; Parity nonconservation. (shrink)

In this paper I will reexamine the history of the early experiments on atomic parity violation, presenting both Pickering's interpretation and an alternative explanation of my own. I argue that, contrary to Pickering, there were good reasons for the decision of the physics community. I will also explore some of the differences between my view of science and that proposed by the "strong programme" or social constructivist view in the sociology of science.

Social constructionists believe that experimental evidence plays a minimal role in the production of scientific knowledge, while rationalists such as myself believe that experimental evidence is crucial in it. As one historical example in support of the rationalist position, I trace in some detail the theoretical and experimental research that led to our understanding of beta decay, from Enrico Fermi’s pioneering theory of 1934 to George Sudarshan and Robert Marshak’s and Richard Feynman and Murray Gell-Mann’s suggestion in 1957 and 1958, (...) respectively, of the V–A theory of weak interactions. This is not a history of an unbroken string of successes, but one that includes incorrect experimental results, incorrect experiment-theory comparisons, and faulty theoretical analyses. Nevertheless, we shall see that the constraints that Nature imposed made the V–A theory an almost inevitable outcome of this theoretical and experimental research. (shrink)

Cooper has claimed to have found evidence for faster-than-light particles by reanalyzing the data of Chamberlain et al. in their paper reporting the discovery of the antiproton. A careful reanalysis of this same data gives no evidence to support Cooper's claim.

One important point that has emerged from recent work on the history and philosophy of experiment is that technology plays an integral role in experiment, and therefore in science. Technology determines what experimenters can measure and how well it can be measured. The importance of technology, along with several new questions that its use raises, has been made quite clear in the papers presented in this session.

In Constructing Quarks (1984) Andrew Pickering discussed the early experiments on atomic parity violation performed at Oxford University and at the University of Washington and published in 1976 and 1977. The results disagreed with the predictions of the Weinberg-Salam (W-S) theory of unified electroweak interactions. Another experiment, performed at the Stanford Linear Accelerator Center in 1978, on the scattering of polarized electrons from deuterons confirmed the theory. Pickering regards the Oxford and Washington experiments as mutants, slain by the SLAC experiment.By (...) 1979 the W-S theory was regarded by the high-energy physics community as established, despite the fact that as Pickering recounts, “there had been no intrinsic change [emphasis in original] in the status of the Washington-Oxford experiments.” (Pickering 1984, p. 301). (shrink)

The fallibility and corrigibility of experimental results, and of the confirmation or refutation based on those results, is illustrated in the 1930's history of Fermi's theory of decay. Early results favored the competing theory of Konopinski and Uhlenbeck. It was found that there were experimental difficulties along with an incorrect theoretical comparison. When the experiments were corrected and the proper theoretical calculations made, the evidence favored Fermi and refuted Konopinski and Uhlenbeck. The relevance of known evidence for confirmation and the (...) value of ad hoc hypotheses is also discussed. (shrink)

In this paper I examine the roles that experiment plays in science. Experiment can test theories, but it can also call for a new theory. Experiment can also provide hints about the mathematical form of a theory. Likewise it can provide evidence for the existence of the entities involved in our theories. Finally, it may also have a life of its own, independent of theory. I will illustrate these roles using episodes from the history of contemporary physics. I will also (...) discuss an epistemology of experiment, a set of strategies that provides grounds for reasonable belief in experimental results. (shrink)

In this paper I examine the roles that experiment plays in science. Experiment can test theories, but it can also call for a new theory. Experiment can also provide hints about the mathematical form of a theory. Likewise it can provide evidence for the existence of the entities involved in our theories. Finally, it may also have a life of its own, independent of theory. I will illustrate these roles using episodes from the history of contemporary physics. I will also (...) discuss an epistemology of experiment, a set of strategies that provides grounds for reasonable belief in experimental results. (shrink)

How does the physics community deal with the subsequent work of a scientist whose earlier work has been regarded as incorrect? An interesting case of this involves Joseph Weber whose claim to have observed gravitational waves was rejected by virtually all of the physics community, although Weber himself continued to defend his work until his death in 2000. In the course of this defense Weber made a startling suggestion regarding the scattering of neutrinos. I will summarize the history of gravity (...) waves including the rejection of Weber's claim around 1975, his later work on gravity waves, and examine the reaction of the physics community to his neutrino hypothesis.----------------------------------------------------------------------------------------- ---------------------------------------------------------------------------------------------------- ---------------------------------------------------------------------------------------------------- ---------------------------------------------------------------------------------------------------- ---------------------------------------------------------------------------------------------------- ---------------------------------------------------------------------------------------------------- ---------------------------------------------------. (shrink)