Two Senses of Experimental Robustness: Result Robustness and Procedure Robustness

In the philosophical literature concerning scientific experimentation, the notion of robustness has been solely discussed in relation to experimental results. In this paper, I propose a novel sense of experimental robustness that applies to experimental procedures. I call the foregoing sense of robustness procedure robustness (PR) and characterize it as the capacity of an experimental procedure to maintain its intended function invariant during the experimental process despite possible variations in its inputs. I argue that PR is a precondition for what I call result robustness (RR), which refers to the traditional sense of experimental robustness, namely the existence of convergent experimental results obtained through different and independent means of detection. Furthermore, I argue, PR and RR constitute useful experimental strategies in the context of high-energy physics experiments, but these strategies are not without limitations

Representing Experimental Procedures through Diagrams at CERN’s Large Hadron Collider: The Communicatory Value of Diagrammatic Representations in Collaborative Research

The aim of this paper is to elucidate the use and role of diagrams in the design of present day high energy physics experiments. To this end, drawing upon a prominent account of diagrammatic representations advanced by the cognitive scientists Jill Larkin and Herbert Simon, I provide an analysis of the diagrammatic representations of the data selection and acquisition procedures presented in the Technical Design Report of the ATLAS experiment at CERN’s Large Hadron Collider, where the Higgs particle was discovered in 2012. Based upon this analysis, I argue that diagrams are more useful than texts in organizing and communicating the procedural information concerning the design of the aforementioned experimental procedures in the ATLAS experiment. Moreover, I point out that by virtue of their representational features, diagrams have a particular communicatory value in the collaborative work of designing the data acquisition system of the ATLAS experiment

Lessons from the Large Hadron Collider for model-based experimentation: The concept of a model of data acquisition and the scope of the hierarchy of models

According to the hierarchy of models (HoM) account of scientific experimentation developed by Patrick Suppes and elaborated by Deborah Mayo, theoretical considerations about the phenomena of interest are involved in an experiment through theoretical models that in turn relate to experimental data through data models, via the linkage of experimental models. In this paper, I dispute the HoM account in the context of present-day high-energy physics (HEP) experiments. I argue that even though the HoM account aims to characterize experimentation as a model-based activity, it does not involve a modeling concept for the process of data acquisition and thus fails to provide a model-based characterization of the theory-experiment relationship underlying this process. In order to characterize the foregoing relationship, I propose the concept of a model of data acquisition and illustrate it in the case of the ATLAS experiment at CERN’s Large Hadron Collider, where the Higgs boson was discovered in 2012. I show that the process of data acquisition in the ATLAS experiment is performed according to a model of data acquisition that specifies and organizes the experimental procedures necessary to select the data according to a predetermined set of selection criteria. I also point out that this data acquisition model is theory-laden, in the sense that the underlying data selection criteria are determined in accordance with the testable predictions of the theoretical models that the ATLAS experiment is aimed to test. I take the foregoing theory-ladenness to indicate that the relationship between the procedures of the ATLAS experiment and the theoretical models of the phenomena of interest is first established, prior to the formation of data models, through the data acquisition model of the experiment, thus not requiring the intermediary of other types of models as suggested by the HoM account. I therefore conclude that in the context of HEP experiments, the HoM account does not consistently extend to the process of data acquisition so as to include models of data acquisition

An Open Singularity-Free Cosmological Model with Inflation

In the light of recent observations which point to an open universe $(\Omega_{0}<1)$, we construct an open singularity-free cosmological model by reconsidering a model originally constructed for a closed universe. Our model starts from a nonsingular state called prematter, governed by an inflationary equation of state $P=(\gamma_{p}-1)\rho$ where $\gamma_{p}$ $(\simeq 10^{-3})$ is a small positive parameter representing the initial vacuum dominance of the universe. Unlike the closed models universe cannot be initially static hence, starts with an initial expansion rate represented by the initial value of the Hubble constant H(0). Therefore, our model is a two-parameter universe model $(\gamma_{p},H(0))$. Comparing the predictions of this model for the present properties of the universe with the recent observational results, we argue that the model constructed in this work could be used as a realistic universe model.Comment: 6 pages Journalref: Int.J.Mod.Phys. A17 (2002) 445