Dark matter in astrophysics offers a rare treat for philosophers of science. When they look at the contemporary science of dark matter, they see reports of a widely accepted theoretical posit indispensable to our best theories and models but without an accepted experimental confirmation of its existence. Nearly all astrophysicists and cosmologists believe that dark matter exists and makes up approximately a quarter of the mass-energy content of the universe. However, they seem to know almost nothing about its nature, cannot (...) directly observe it, and have been unable to detect the products of any interactions with any of the candidate dark matter particles. This project addresses the apparent tension between the impressive knowledge taken to have been obtained in contemporary sciences of the cosmos and the methodological and theoretical limitations in obtaining such knowledge. To do so, this dissertation investigates the ways in which astronomers and astrophysicists are making progress by looking more closely at their experimental practices and actual theoretical commitments. More specifically, the goal is to determine how this bears on longstanding philosophical questions of scientific realism and the nature of scientific experimentation. Ultimately, I argue that astronomers do conduct traditional, interventionist experiments and that we can be realists about dark matter. These two views offer a way of thinking differently about how scientists can and do obtain knowledge about inaccessible and unobservable targets systems. -/- . (shrink)

There is a complex interplay between the models in dark matter detection experiments that have led to a difficulty in interpreting the results of the experiments and ascertain whether we have detected the particle or not. The aim of this paper is to categorise and explore the different models used in said experiments, by emphasizing the distinctions and dependencies among different types of models used in this field. With a background theory, models are categorised into four distinct types: background theory, (...) theoretical, phenomenological, experimental and data. This taxonomy highlights how each model serves a unique purpose and operates under varying degrees of independence from their respective frameworks. A key focus is on the experimental model, which is shown to rely on constraints from both data and phenomenological ones. The article argues that while theoretical models provide a backdrop for understanding the nature of dark matter, the experimental models must stand independently, particularly in their methodological approaches. This is done via a discussion of the inherent challenges in dark matter detection, such as inconsistent results and difficulties in cross-comparison, stemming from the diverse modelling approaches. (shrink)

Le présent travail s'inscrit à l'intersection de deux problèmes épistémologiques majeurs. D'une part, le problème de la démarcation scientifique, qui consiste à identifier ce qui distingue intrinsèquement un système (un énoncé, une théorie, ...) scientifique d'un système non scientifique ou pseudo-scientifique. D'autre part, le problème de l'unité épistémologique des sciences, qui consiste à se demander si toutes les disciplines à vocation scientifique peuvent être vues comme des instanciations d'une notion unique de la scientificité. Ces deux problèmes ont soulevé de nombreux (...) débats ayant mis en évidence un ensemble important de difficultés. Le terme « scientifique » désigne en effet des méthodes empiriques, des constructions théoriques et des pratiques de recherche si hétérogènes qu’il semble voué à l’échec d’en chercher une définition aisée à circonscrire. De plus, les objets des disciplines scientifiques sont eux-mêmes de natures très diverses, ce qui semble rendre pareillement caduque toute recherche d’un concept unique de science qui pourrait s’appliquer indépendamment de la discipline en question. Dans cette thèse, je me propose de prendre à contre-pied cet état de fait en soutenant la possibilité et la pertinence d'un modèle unitaire de la scientificité, tout en me restreignant à une approche épistémologique comparée entre les sciences physiques et les sciences sociales. Pour défendre mon propos, j’ai mobilisé deux types de réponses pouvant être opposées au constat présenté plus haut. D’une part, des réponses de principe, où j’examine et m’oppose à des arguments théoriques soutenant l’impossibilité ou en tout cas la difficulté de définir la scientificité en général, et la nécessité pour les sciences sociales de jouir d’une définition à part. D’autre part, je mobilise également des réponses par l’exemple. J’étudie alors plus en détail l’approche dite « analytique » en sociologie. Ce courant a cela d’intéressant pour mon propos qu’il ne semble pas nécessiter d’épistémologie alternative à celle ayant cours, par exemple, en physique ou en biologie, tout en prétendant bien produire des connaissances sur le monde social. Il s’agit donc d’un contre-exemple concret et manifeste de la thèse soutenant que la sociologie ne peut pas jouir du même type d’épistémologie que les autres disciplines. Plus concrètement, j’élabore un (méta-)modèle unitaire de la scientificité en me concentrant sur une unité d’analyse bien circonscrite : les modèles. Je distingue chez ses derniers, classiquement, deux composantes principales : une composante empirique, qui a pour vocation à identifier des régularités dans le réel auquel on a accès à travers des données, et une composante théorique, à visée explicative et classificatoire. Je propose alors de construire formellement un degré de scientificité global dans lequel se combinent la maximisation d’une certaine quantité d’information définie sur la composante empirique et un critère d’invariance structurelle défini sur la composante théorique. Ces diverses constructions, bien que formelles, permettent d’éclairer efficacement les questions épistémologiques que je me suis données au départ de mon travail, ce dernier ayant vocation à constituer une étape supplémentaire vers un modèle unitaire de la scientificité. (shrink)

Observational discrepancies in galactic rotation curves and cluster dispersion data have been interpreted to imply the existence of dark matter. Numerous efforts at its detection, however, have failed to turn up any positive result. As a dynamical theory is always operative on the assumed mass distribution to predict kinematic observations, some scientists see the discrepancy as telling against General Relativity. Among the many theories that seek to modify gravity, those that are built on Modified Newtonian Dynamics (MOND), or yield MOND (...) behaviour at appropriate scales, achieve remarkable empirical success without assuming dark matter. The continued non-detection of dark matter and the empirical success of MOND supports the claim that the current evidential and theoretical context underdetermines General Relativity. In this article, I clarify the kind of underdetermination that can be said to threaten General Relativity. Specifically, I argue that the present evidential and theoretical context increase the possibility of an unconceived alternative to GR which would be just as well supported by the available evidence. (shrink)

Some scientists or philosophers argue that multiverse theories are unfalsifiable and thus not scientific. However, some advocates of multiverse theories have recently argued that although the multiverse is not observable, multiverse theories are indeed falsifiable in principle. Therefore, they share similar features with a conventional scientific theory. On the other hand, the proposals of an epistemic shift and nonempirical theory assessment have possibly revived the discussions of the scientific nature of multiverse theories. In this article, I revisit the falsifiable arguments (...) made by the advocates of multiverse theories and show that these arguments do not justify arguing the scientific nature of such theories. Moreover, even if we accept the proposals of the epistemic shift and the nonempirical theory assessment, I argue that multiverse theories still cannot pass or satisfy the required assessments based on the new theoretical virtues and the nonempirical arguments. (shrink)

The problem of demarcating between what is scientific and what is pseudoscientific or merely unscientific - in other words, the problem of defining scientificity - remains open. The modern debate was firstly structured around Karl Popper's falsificationist epistemology from the 1930's, before diversifying a few decades later. His central idea is that what makes something scientific is not so much how adequate it is with data, but rather to what extent it might not have been so. Since the second half (...) of the century, and in the wake of criticisms, such as the Duhem-Quine thesis, that were raised against falsificationism(s), most approaches to the problem of scientific demarcation are now multicriteria and holistic. However, the approach presented in this paper does not follow the same guideline. The present work can be seen as an attempt to adapt Popper's (sophisticated) falsificationism to a model-based view of scientific knowledge. Using formalization and focusing on a particular epistemic unit of analysis (namely, empirical models) allows to properly define the popperian corroboration degree and to view scientificity as the maximization of this degree of corroboration over all available models and data. We eventually recover, in a natural way, well-accepted scientificity criteria: empirical adequacy, Lakatos' progressive problemshifts, balance between strength and simplicity, parsimony, and coherence as special cases of this general scientificity principle. From this viewpoint, the language dependency of our empirical knowledge no longer appears as a limitation of falsificationism but as one more reason to take it as a good epistemological framework. (shrink)

I discuss the relevance of the current predicament in cosmology to the debate over scientific realism. I argue that the existence of two, empirically successful but ontologically inconsistent cosmological theories presents difficulties for the realist position.

In Logik der Forschung (1934) and later works, Karl Popper proposed a set of methodological rules for scientists. Among these were requirements that theories should evolve in the direction of increasing content, and that new theories should only be accepted if some of their novel predictions are experimentally confirmed. There are currently two, viable theories of cosmology: the standard cosmological model, and a theory due to Mordehai Milgrom called MOND. Both theories can point to successes and failures, but only MOND (...) has repeatedly made novel predictions that were subsequently found to be correct. Standard-model cosmologists, by contrast, have almost always responded to new observations in a post-hoc manner, adjusting or augmenting their theory as needed to obtain correspondence with the facts. I argue that these methodological differences render a comparison of the two theories in terms of their ‘truthlikeness’ or ‘verisimilitude’ essentially impossible since the two groups of scientists achieve correspondence with the facts in fundamentally different ways, and I suggest that a better guide to the theories’ progress toward the truth might be the methodologies themselves. (shrink)

We critically analyze the rationale of arguments from finetuning and naturalness in particle physics and cosmology, notably the small values of the mass of the Higgs-boson and the cosmological constant. We identify several new reasons why these arguments are not scientifically relevant. Besides laying out why the necessity to define a probability distribution renders arguments from naturalness internally contradictory, it is also explained why it is conceptually questionable to single out assumptions about dimensionless parameters from among a host of other (...) assumptions. Some other numerological coincidences and their problems are also discussed. (shrink)

In spite of successful tests, the standard cosmological model, the $$\varLambda$$ CDM model, possesses the most problematic concept: the initial singularity, also known as the big bang. In this paper—by adopting the Kantian difference between to think of an object and to cognize an object—it is proposed a degree of scientificity using fuzzy sets. Thus, the notion of initial singularity will not be conceived of as a scientific issue because it does not belong to the fuzzy set of what is (...) known. Indeed, the problematic concept of singularity is some sort of what Kant called the noumenon, but science, on the other hand, is constructed in the phenomenon. By applying the fuzzy degree of scientificity in cosmological models, one concludes that cosmologies with a contraction phase before the current expansion phase are potentially more scientific than the standard model. At the end of this article, it is shown that Kant’s first antinomy of pure reason indicates a limit to our cosmological models. (shrink)

Truth-makers are the dark matter of metaphysics. On the one hand, truth-makers seem obvious and necessary: if there are truths then there must be something that makes these truths true. On the other hand, it’s proven difficult to say exactly what these truth-makers are. Even defenders disagree about what sort of entity truth-makers are or whether all truths have truth-makers. Skeptics have questioned whether truth-makers are actually so obvious and necessary, or even whether they exist at all. Here I offer (...) an account of this unhappy state of affairs and a modest proposal. First, I argue that not only are there no good arguments for truth-makers but it’s unlikely that there ever will be. Second I point to how much can be done without resorting to truth-makers in the first place: they are not as essential as often assumed. Finally, I conclude that we needn’t jettison the concept of truth-makers entirely. Understood in a modest and pragmatic spirit we can hold on to truth-makers while recognizing their inherent limitations. (shrink)

In a recent article Merritt has claimed that current observational data provide “severe tests” falsifying the standard cosmological model. Based on Popper’s idea of conventionalism, he concludes that the introduction of some essential components of the standard cosmological model—including dark matter and dark energy—are a consequence of conventionalist stratagems. In this article, I provide more recent discoveries and discussions showing that the standard cosmological model is not built on any conventionalist stratagem.

While $$\Lambda $$ Λ CDM has emerged as the standard model of cosmology, a small group of physicists defends modified newtonian dynamics (MOND) as an alternative view on cosmology. Exponents of MOND have employed a broad, at times explicitly philosophical, conceptual perspective in arguing their case. This paper offers reasons why that MONDian defense has been ineffective. First, we argue that the defense is ineffective according to Popperian or Lakatosian views–ostensibly the preferred philosophical views on theory assessment of proponents of (...) MOND. Second, we argue that the defense of MOND can instead best be reconstructed as an instance of meta-empirical theory assessment. The formal employment of meta-empirical assessment by MONDians is unconvincing, however, because it lacks a sufficient epistemic foundation. Specifically, the MONDian No Alternatives Argument relies on falsifiability or explanation conditions that lack epistemic relevance, while the argument from Unexpected Explanatory Success fails since there is a known alternative to MOND. In the last part of the paper, we draw some lessons for applications of meta-empirical assessment more generally. (shrink)

This book examines the philosophical conception of abductive reasoning as developed by Charles S. Peirce, the founder of American pragmatism. It explores the historical and systematic connections of Peirce's original ideas and debates about their interpretations. Abduction is understood in a broad sense which covers the discovery and pursuit of hypotheses and inference to the best explanation. The analysis presents fresh insights into this notion of reasoning, which derives from effects to causes or from surprising observations to explanatory theories. The (...) author outlines some logical and AI approaches to abduction as well as studies various kinds of inverse problems in astronomy, physics, medicine, biology, and human sciences to provide examples of retroductions and abductions. The discussion covers also everyday examples with the implication of this notion in detective stories, one of Peirce’s own favorite themes. The author uses Bayesian probabilities to argue that explanatory abduction is a method of confirmation. He uses his own account of truth approximation to reformulate abduction as inference which leads to the truthlikeness of its conclusion. This allows a powerful abductive defense of scientific realism. This up-to-date survey and defense of the Peircean view of abduction may very well help researchers, students, and philosophers better understand the logic of truth-seeking. (shrink)

L’espace-vide est définit par Einstein comme substantiel et de densité d’énergie non nulle. Dans les premiers instants de l’univers, c’est cette substance espace-vide qui est apparue conjointement avec la grandeur temps, qui de ce fait doit présenter un lien de nature avec elle. Quel qu’est pu être le processus ayant conduit à la matérialisation des particules élémentaires, celles-ci ont été extraites de cette substance vide et procèdent donc d’une même nature. Ainsi la structure interne d’une particule composée de matière et (...) d’une charge électrique doit présenter une organisation prenant en compte cette origine unique. Il apparait ainsi logique de penser, en s’appuyant sur les travaux de Kaluza, que les charges électriques et la matière sont une seule et unique grandeur mais animée de dynamiques différentes dans des espaces différents à trois ou quatre dimensions spatiales. (shrink)

The concept of the universe is used in physical cosmology differently from the usual meaning of the term, naively considered as the entire reality. Traditionally, thinking about the whole led to logical contradictions. Taking as reference the Kantian antecedent, different contemporary philosophical notions of the universe are analysed in the first part of this paper, including realist and constructivist approaches, as well as a notion of the universe as a physical object. In the second part, the specific notion from the (...) standard physical cosmology is discussed. Although modelling the universe as a physical system provides a specific way to define some global properties, the universe as a whole remains empirically inaccessible. Hence, the discussion about the under-determined global properties depends ultimately on philosophical preferences. Under these circumstances, it is argued that the realist interpretation of such properties becomes problematic because it leads to unstable conclusions. Finally, it is argued that the notion of the universe as conceived in standard cosmology is not necessarily consistent with an approach that considers it to be a physical object. (shrink)

The Big Bang is the most accepted theory of how the Universe was born. However, this theory explains only the development of the Universe, not its origination. This paper develops two main ideas: a) that a strong philosophical approach encourages innovative thinking through the sharing of new scientific enlightenment, and b) the origination of “something” from “nothing” without violating the conservation laws. The second idea underlies our Universal Theory of Origination. The Universe has evolved on cosmological, physical, biological, psychological, and (...) intellectual levels. Our UTO explains how upper-level substances originate from lower-level substances. The origination of the physical level based on the origination of the biological level is described stepwise using a unitary law. We also provide a scope for understanding the origination of the biological, psychological, and intellectual levels. Our hypothesis is supported by a) well-known formal research and experiments, and b) an inference proof that nature behaves in a unitary way from one level to another. In the UTO, a fact can be displaced to another level by changing only the adjectives. A known aspect at one level can be interpreted on another level, giving rise to unknown truths. This work provides the basis of UTO, in turn resolving many open questions such as the origination of the physical world, space expansion, expansion acceleration, looking back in time, and the differences between galaxies. (shrink)

O artigo se insere em uma tradição existente de estudos de caso sobre a epistemologia de Imre Lakatos. Seu objetivo consiste em descrever uma reconstrução racional da cosmologia científica, cujo estatuto de cientificidade se consolida após a primeira metade do século XX, em uma combinação entre trabalhos teóricos e empíricos. Os critérios lakatosianos não nos permitem classificar a concepção de universo formulada por Albert Einstein como um programa de pesquisa. Podemos classificá-la, todavia, como uma tentativa de programa, que será recuperada (...) em boa medida pelas contribuições de Friedman, Lemaître e Hubble. Argumentamos, ao longo deste artigo, que a cosmologia do século XX pode ser descrita em termos da concepção do Programa de Pesquisa de Friedman-Lemaître, uma vez que identificamos em ambas as contribuições a presença de um mesmo núcleo de teses e axiomas fundamentais, que será preservado nos trabalhos posteriores, como o modelo do big bang e o modelo do estado estacionário. (shrink)