Vera Matarese

Replicability is usually considered to be one of the cornerstones of science; however, the growing recognition of nonreplicable experiments and studies in scientific journals—a phenomenon that has been called ‘replicability crisis’—has spurred a debate on the meaning, function, and significance of replicability in science. Amid this discussion, it has become clear that replicability is not a monolithic concept; what is still controversial is exactly how the distinction between different kinds of replicability should be laid out terminologically and conceptually, and to what extent it bears on the more general debate on the centrality of replicability in science. This paper’s goals are to clarify the different uses of the terms related to replicability and, more importantly, to conceptually specify the kinds of replicability and their respective epistemic functions.

The pervasive employment of machine learning (ML) in experimental physics raises questions about its epistemic impact. While ML techniques are accelerating scientific progress at an unprecedented pace, the concern is that they may limit or even impede scientific understanding, and that, therefore, they should be regarded as mere instrumental tools. Drawing on a case study from accelerator physics where ML techniques successfully optimize beam intensity, this paper argues that ML-based experimental strategies can be epistemically salient with respect to understanding. In particular, they can provide ‘attributive understanding’, a genuine form of scientific understanding that is experiment-driven and centered on grasping robust modal relations among experimental variables. This conclusion not only challenges the view that ML techniques cannot provide scientific understanding, but also offers new insights into the epistemology of experimentation in general, urging a reconsideration of the role of ML in experimental physics.

Retrieval models are widespread in scientific research. This paper delves into the epistemic value of atmospheric retrieval models, which play a major scientific role in exoplanetary science. Despite being heuristic tools that offer no definitive outcomes and that are vulnerable to the problem of incompatible models, they are epistemically salient. Firstly, their hybrid nature confers them a stronger epistemic authority compared to purely theory-based or data-based models. Secondly, they can incorporate meta-empirical confirmation techniques, which can establish the viability of the models’ outcomes.

Quantum mechanics is arguably our most successful physical theory, yet the nature of the quantum state still constitutes an ongoing controversy. This paper proposes, articulates, and defends a metaphysical interpretation of the quantum state that is fictionalist in spirit since it regards quantum states as representing a fictional ontology. Such an ontology is therefore not physical, and yet it provides a reference for the language used in quantum mechanics and has explanatory power. In this sense, this view, akin to Allori’s recent account of wavefunctionalism, combines elements of the representationalist and anti-representationalist camps and aims to be the best of both worlds.

We propose that the epistemic functions of replication in science are best understood by relating them to kinds of experimental error/uncertainty. One kind of replication, which we call “direct replications,” principally serves to assess the reliability of an experiment through its precision: the presence and degree of random error/statistical uncertainty. The other kind of replication, which we call “conceptual replications,” principally serves to assess the validity of an experiment through its accuracy: the presence and degree of systematic errors/uncertainties. To illustrate the aptness of this general view, we examine the Hubble constant controversy in astronomy, showing how astronomers have responded to the concordances and discordances in their results by carrying out the different kinds of replication that we identify, with the aim of establishing a precise, accurate value for the Hubble constant. We contrast our view with Machery's “re-sampling” account of replication, which maintains that replications only assess reliability.

The replication crisis has spawned discussions on the meaning of replication. In fact, in order to determine whether an experiment fails to replicate, it is necessary to establish what replication is. This is, however, a difficult task, as it is possible to attribute different meanings to it. This paper offers a solution to this problem of ambiguity by engineering a concept of replication that, if compared to other proposals, stands out for being not only broadly applicable but also sufficiently specific. It features a minimal level of operationalism, which would otherwise limit its applicability, while it heavily relies on replication’s specific epistemic functions, which are inter-disciplinary. Another merit is its context sensitivity, which enables it to differentiate instances of replication from non-instances of replication in every scientific discipline according to the discipline’s own standards.

This is an open access book. This book, the first edited collection of its kind, explores the recent emergence of philosophical research in astrophysics. It assembles a variety of original essays from scholars who are currently shaping this field, and it combines insightful overviews of the current state of play with novel, significant contributions. It therefore provides an ideal source for understanding the current debates in philosophy of astrophysics, and it offers new ideas for future cutting-edge research. The selection of essays offered in this book addresses methodological and metaphysical questions that target a wide range of topics, including dark matter, black holes, astrophysical observations and modelling. The book serves as the first standard resource in philosophy of astrophysics for all scholars who work in the field and want to expand or deepen their knowledge, but it also provides an accessible guide for all those philosophers and scientists who are interested in getting a first, basic understanding of the main issues in philosophy of astrophysics.

The aim of this book is to provide a comprehensive guide to the metaphysics of Bohmian mechanics. Bohmian mechanics is a quantum theory that describes the motion of particles following trajectories that are determined by the quantum wave-function. The key question that the theory has to face relates to the ontological interpretation of the quantum wave-function. The main debate has mostly centered around two opposing views, wave-function realism on the one hand, and the nomological view on the other hand. The supporters of the former believe that the wave-function is a physical field living in a high-dimensional space; the supporters of the latter regard the wave-function as just an entity that appears in the laws of nature and lacks physical status. This monograph discusses both views open-mindedly, illuminating their tacit problems and providing new insight into how they can be overcome. Moreover, it discusses the structuralist view, which is often neglected and which can be regarded as a reconciliation of the two main opposing camps.

The purpose of this contribution is to examine the current state of the de Broglie-Bohm theory (dBB) in light of Bohm’s vision as he explicitly set it out in his book Quantum theory [In Bohm, D., Quantum theory, Courier corporation, (1961b)]. In particular, two programmes that differ in many crucial respects are currently being pursued. On the one hand, the Bohmian mechanics school, founded by Dürr Goldstein and Zanghì, considers the theory to be Galilean invariant, regards particles’ motion as determined by a nomological entity, the universal wave function, upholds the quantum equilibrium hypothesis and explains probabilities in terms of typicality. On the other hand, the Pilot-wave school advocated by Valentini considers the theory to be based on Aristotelian dynamics, regards the wave function as a physical field displaying a contingent nature, and explains quantum equilibrium as the result of a process of relaxation from quantum non-equilibrium. Looking at Bohm’s work [In Bohm, D., Quantum theory, Courier corporation, (1961b)], it is clear that his intention was to construct a theory that was empirically different from standard quantum mechanics, so that it would be testable and falsifiable. Only this way could he defend dBB from the criticism that accused the theory of being 'metaphysical'. These methodological concerns about the falsifiability of the theory constitute, in my opinion, a strong reason for regarding Valentini's programme as methodologically valuable, even if it might turn out to be wrong. Indeed, the programme of the Pilot-wave school aims to be falsifiable with respect to standard quantum mechanics and can in principle defend the empirical status of particle trajectories.

Astrophysicist Abraham Loeb suggests that the interstellar interloper 1I/2017 ‘Oumuamua, detected in our solar system in 2017, is alien space debris or even an alien operational probe. Does this conjecture have significant epistemic support, such that it can be justified as a viable hypothesis? In this paper, I propose that the meta-empirical confirmation approach, developed and defended by philosopher and physicist Dawid, provides an appropriate framework to answer this question. I defend this proposal by elucidating how meta-empirical confirmation applies to the ‘Oumuamua case and what specific meta-empirical arguments could support Loeb’s hypothesis. Even though Loeb would not himself endorse meta-empirical confirmation, because it is not traditional empiricism, this case shows that meta-empirical confirmation is not in fact a threat to empiricism.

Replicability is usually considered to be one of the cornerstones of science; however, the growing recognition of nonreplicable experiments and studies in scientific journals—a phenomenon that has been called ‘replicability crisis’—has spurred a debate on the meaning, function, and significance of replicability in science. Amid this discussion, it has become clear that replicability is not a monolithic concept; what is still controversial is exactly how the distinction between different kinds of replicability should be laid out terminologically and conceptually, and to what extent it bears on the more general debate on the centrality of replicability in science. This paper’s goals are to clarify the different uses of the terms related to replicability and, more importantly, to conceptually specify the kinds of replicability and their respective epistemic functions.

Humeanism started life as a metaphysical program that could turn out to be false if our best physical theories were to postulate ontological features at odds with Humean ones. However, even if this has arguably already happened, Humeanism is still considered one of the strongest and most appealing metaphysical theories for describing the physical world. What is even more surprising is that a radical Humean thesis—Super-Humeanism—which posits an extremely parsimonious ontology including nothing more than propertyless matter points and their distance relations, is said by its proponents to follow from an attentive reading of our best physical theories. Given its close relationship with physics, Super-Humeans argue that their doctrine conforms to Scientific Realism, offers the ontology that best explains physics’ empirical evidence, and is a naturalistic theory. This paper investigates the strategies that Super-Humeans have adopted to defend these three claims and, more generally, its alleged closeness to physics. I will show that, contrary to what advocates of Super-Humeanism claim, some of its commitments have inevitably created a gap between itself and physics that is difficult to overcome. While it is laudable that Super-Humeans have adopted various strategies to close this gap, no strategy has yet fully succeeded.

In this paper, I discuss whether the results of loop quantum gravity (LQG) constitute a fatal blow to Humeanism. There is at least a prima facie reason for believing so: while Humeanism regards spatiotemporal relations as fundamental, LQG describes the fundamental layer of our reality in terms of spin networks, which are not in spacetime. However, the question should be tackled more carefully. After explaining the importance of the debate on the tenability of Humeanism in light of LQG, and having presented the Humean doctrine, I review two cases which present serious threats to Humeanism, one concerning the fundamentality of vectorial quantities and the other concerning quantum entanglement. In particular, I recall the strategies that are usually employed in these two cases in order to save Humeanism: in the first case, the strategy consists in amending the characterization of the Humean mosaic; in the second case, it consists in adopting a realist or nomological interpretation of the wave function. These solutions will turn out to be helpful in my discussion of LQG where, after describing LQG, I show that Humeans might save their doctrine either by endorsing a realist interpretation of spin networks, or by giving them a nomological status and, at the same time, by revisiting the characterization of the Humean mosaic. However, I conclude that both solutions are wanting.

According to the doctrine of Super-Humeanism, the world’s mosaic consists only of permanent matter points and changing spatial relations, while all the other entities and features figuring in scientific theories are nomological parameters, whose role is merely to build the best law system. In this paper, I develop an argument against Super-Humeanism by pointing out that it is vulnerable to and does not have the resources to solve the well-known problem of immanent comparisons. Firstly, I show that it cannot endorse a fundamentalist solution à la Lewis, since its two pillars—a minimalist ontology and a best system account of lawhood—would generate, together, a tedious problem of internal coherence. Secondly, I consider anti-fundamentalist strategies, proposed within Humeanism, and find them inapplicable to the Super-Humean doctrine. The concern is that, since it is impossible to choose the best law system within Super-Humeanism, this doctrine may be charged with incoherence.

Quando, nel 1935, venne pubblicato il famoso articolo chiamato poi “EPR Paper” per le iniziali dei suoi autori - Einstein, Podolsky, Rosen -, la comunità scientifica dovette confrontarsi non solo con le manifeste provocazioni che il suo argomento voleva mostrare, ma anche con latenti problemi che sarebbero sbocciati più avanti in tutti i loro stridenti contrasti. L’incompletezza della meccanica quantistica, che l’“articolo EPR” si proponeva di dimostrare, poggiava infatti su un principio molto problematico, quello della località, che sarebbe esploso nell’esperimento prima concettuale di Bohm e poi sperimentale di Aspect. Ciò che questo articolo vuole delineare è lo sviluppo del problema della nonlocalità, dai suoi albori fino alla prova della sua effettiva esistenza nel mondo quantistico, dove, come ben ha dimostrato Bell, nulla possono fare le variabili nascoste per dissolvere la realtà nonlocale di alcuni fenomeni.